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Interpretive Summaries, September 2014
Interpretive Summaries, SEPTEMBER 2014 Invited review: Effect, persistence, and virulence of coagulase-negative Staphylococcus species associated with ruminant udder health. By Vanderhaeghen et al., page 5275. The availability of (improved) molecular identification methods in veterinary microbiology has allowed for reliable and speciesspecific data on the overall effect on udder health and milk yield, capacity to persist, and virulence potential of the coagulase-negative staphylococci (CNS) species frequently associated with intramammary infections in ruminants. This review of the recent literature confirms that differences in these traits exist but that many questions remain open for further research, as studies greatly suffer from a lack of congruence. Because true progress might only be achieved if future studies are tailored to each other, proposals are made to advance on some critical aspects. http://dx.doi.org/10.3168/jds.2013-7775. Calcium release of concentrated milk by ultrafiltration and diafiltration. By Li and Corredig, page 5294. Concentration of milk by ultrafiltration (UF) and diafiltration (DF) affects the equilibrium between serum and colloidal calcium. The aim of this work was to observe differences in the solubilization of calcium during acidification in concentrated milk before or after heating milk at 80°C for 15 min. This is the first comprehensive study on the effect of concentration, distinguishing the effect of UF from DF, and it demonstrates that DF milk samples have a lower buffering capacity and that heat treatment can affect calcium solubilization at high volume fractions. http://dx.doi.org/10.3168/jds.2013-7567. Effects of ionic and nonionic surfactants on milk shell wettability during co-spray-drying of whole milk particles. By Lallbeeharry et al., page 5303. Dairy industries often coat spray-dried whole milk powders with lecithin, a food-grade surfactant, to enhance their wettability. This postdrying coating process is time and energy consuming. The present study demonstrated that mixing Tween 80 or lecithin with fresh whole milk before drying could improve the wettability of the resulting dried powder. The surface of surfactant-added milk was more wettable than that of normal milk from the start of shell formation. Milk particles with Tween 80 showed higher wettability than those with lecithin at the same loading, which was attributed to different interactions of each surfactant with fat and proteins in milk. http://dx.doi.org/10.3168/jds.2013-7772. Development and shelf-life determination of pasteurized, microfiltered, lactose hydrolyzed skimmed milk. By Antunes et al., page 5337. The
prevalence of lactose intolerance worldwide is very high. The aim of this work was the use of combination of microfiltration, pasteurization, and lactose hydrolysis to obtain skim milk with an extended shelf life. It was possible to obtain such a product with a shelf life of up to 50 d at 5°C, in terms of its microbiological stability and acidity. Microfiltration technology, in combination with pasteurization, can be used by the dairy industry to produce delactosed milk with an extended shelf life. http://dx.doi.org/10.3168/jds.2014-8020. Biopreservation of Fior di Latte cheese. By Angiolillo et al., page 5345. Two important topics of the dairy industry are shelf-life extension of fresh products and the use of biological and natural substances to preserve such products. Fior di Latte cheese has a very short shelf life and any treatment applied to extend its shelf life must help maintain its appearance and flavor characteristics, as these are perceived as quality indices by the consumer. Therefore, in this study, we developed a new biopreservation system consisting of an active sodium alginate coating containing Lactobacillus reuteri applied to Fior di Latte cheese. http://dx.doi.org/10.3168/jds.2014-8022. The role of sodium in the salty taste of permeate. By Frankowski et al., page 5356. This study determined the sensory and compositional properties of whey permeates and the role of sodium and other constituents on salty taste of permeate. Permeates had low salty taste, whereas reduced-lactose permeates had higher salty taste. For both permeate types, sodium was not the sole source of salty taste. Potassium and lactic and orotic acids also contributed to the salty taste of permeates. http://dx.doi.org/10.3168/jds.2014-8057. Short communication: Antiviral activity of subcritical water extract of Brassica juncea against influenza virus A/H1N1 in nonfat milk. By Lee et al., page 5383. Subcritical water extract (SWE) of Brassica juncea has been used in dairy products for use as antiviral food. At maximum nontoxic concentrations, SWE of B. juncea had higher antiviral activity against influenza virus A/H1N1 than n-hexane, ethanol, or hot water (80°C) extracts. Thus, the use of B. juncea SWE as a food supplement might aid in protection from influenza viral infection. http://dx.doi.org/10.3168/jds.2014-8016. Short communication: Dairy consumption among middle-aged and elderly adults in Switzerland. By Chollet et al., page 5387. In many countries, the consumption of dairy products is lower than recommended. The present study confirmed that
middle-aged and elderly Swiss (50–81 yr) are among those consuming less than the recommended intake of dairy products. Additionally, about a quarter of this population group is actually reducing consumption of dairy products for reasons that are not scientifically proven. Information campaigns specifically targeting the middle-aged and elderly are needed to increase awareness of the nutritional value of dairy products and their role in a healthy diet. http://dx.doi.org/10.3168/jds.2014-8193. Identifying the major bacteria causing intramammary infections in individual milk samples of sheep and goats using traditional bacteria culturing and real-time polymerase chain reaction. By Rovai et al., page 5393. One-hundred and eight lactating dairy ewes and 24 Murciano-Granadina dairy goats were used for identifying the main bacteria causing mastitis by traditional bacterial culturing (BAC) and real-time polymerase chain reaction (PCR). In addition, the effects of infection on milk yield and somatic cell count were determined. Prevalence of subclinical mastitis was 47% in sheep with an estimated milk loss of 16%; prevalence in goats was 42% with an estimated milk loss of 18%. According to BAC results, of the 30 samples with no bacterial finding, 29 were also found negative by the PCR. Of the 60 BAC-positive samples, 38 were identified as positive for coagulasenegative staphylococci species, with 36 isolates classified as Staphylococcus spp. or β-lactamase-positive Staphylococcus spp. by PCR. Eight more samples were identified as Staphylococcus aureus by BAC, of which 7 matched Staph. aureus and 1 as Staphylococcus spp. by PCR. Moreover, 5 isolates were identified as Streptococcus spp. by BAC, but failed to be confirmed as such by PCR. According to bacteriology results, 87% of the identified single bacteria species or cultures with no growth were identical, which agreed 98.9% with the PCR results. In conclusion, the PCR and BAC methods had similar accuracy for identifying udder-infecting bacteria in sheep and goats. http://dx.doi.org/10.3168/jds.2014-7988. Efficacy of ampicillin trihydrate or ceftiofur hydrochloride for treatment of metritis and subsequent fertility in dairy cows. By Lima et al., page 5401. Metritis affects 10 to 30% of dairy cows, leading to losses in production and reproduction and to increased risk of early removal from the herd. The pathogens isolated from the uterus of cows with metritis are normally susceptible in vitro to ampicillin and ceftiofur. The objective of this study was to evaluate the efficacy of ampicillin trihydrate for treatment of metritis in dairy cows compared with ceftiofur hydrochloride. Cows with puerperal metritis had reduced cure compared with those with metritis based on fetid uterine discharge. Ampicillin was an effective therapy
for metritis and led to similar or greater clinical cure compared with ceftiofur. http://dx.doi.org/10.3168/jds.2013-7569. Individual and combined effects of anovulation and cytological endometritis on reproductive performance of dairy cows. By Vieira-Neto et al., page 5415. Anovulation is associated with cytological endometritis (CTE); therefore, the negative association of either condition with reproductive performance could be confounded by the other. The objective was to evaluate the individual and combined effect of anovulation and CTE on reproductive performance of dairy cows. A total of 1,569 cows from 3 regions of the United States were analyzed. Both anovulation and CTE had a negative effect on time to pregnancy, and the negative effect was compounded if both conditions were present. In summary, both anovulation and CTE negatively affect reproductive performance; when combined, they have an additive negative effect. http://dx.doi.org/10.3168/jds.2013-7725. Treatments of clinical mastitis occurring in cows on 51 large dairy herds in Wisconsin. By Oliveira and Ruegg, page 5426. Treatments of clinical mastitis were recorded on 51 larger dairy farms in Wisconsin. Although 5 different intramammary compounds were used, 65% of treatments were performed using a third-generation cephalosporin. Farmers did not know the cause of most cases of mastitis, but milk samples collected from cases demonstrated that the majority of treatments were given for mild or moderate cases of clinical mastitis that were culture negative or caused by Escherichia coli. Even though no systemic therapies are approved for treatment of mastitis, about 23% of cows received systemic antimicrobials, and sulfonamides were administered on 8 farms. Increased use of diagnostic tests should be encouraged to allow farmers to make more-informed treatment decisions for clinical mastitis. http://dx.doi.org/10.3168/jds.2013-7756. Peroxisome proliferator-activated receptor γ1 and γ2 isoforms alter lipogenic gene networks in goat mammary epithelial cells to different extents. By Shi et al., page 5437. In nonruminants, 2 isoforms (γ1 and γ2) of the nuclear receptor peroxisome proliferator-activated receptor gamma (PPARG1 and PPARG2) are generated by alternative splicing. Their distribution in various goat tissues was analyzed, and key target genes were measured after overexpressing each isoform in goat mammary epithelial cells. Expression of PPARG2 was markedly greater in adipose than in mammary gland. In contrast, PPARG1 and its activation upregulated lipogenic gene networks in mammary cells to a greater extent than did PPARG2. Therefore, this isoform might be more important bio-
logically for regulating goat mammary cell lipogenesis during lactation. http://dx.doi.org/10.3168/jds.2013-7863. Age at calving in heifers and level of milk production during gestation in cows are associated with the birth size of Holstein calves. By Kamal et al., page 5448. Poor intrauterine growth resulting in small size at birth increases predisposition to metabolic diseases during later life. The objective of the present study was to determine factors that are associated with birth size of Holstein calves. In addition to the recognized factors (calf sex, season of calving, gestation length, parity, length of the dry period, and morphometrics of the dam), age at calving in heifers, and level of milk production during gestation in cows, were indicated as decisive determinants of calf birth size. The latter may provide a basis for developing managerial interventions to improve long-term health and productivity of offspring. http://dx.doi.org/10.3168/jds.2014-7898. Associations of udder health indicators with cow factors and with intramammary infection in dairy cows. By Nyman et al., page 5459. We investigated associations between cow factors (e.g., parity, breed), intramammary infection, and 4 udder health indicators in dairy cows. Udder health indicators are used to find cows with inflammation in one or more udder quarters that do not show signs of disease. Udder inflammation can be painful and cause milk losses and will have an economic impact for the farmer. Identifying cows with inflammation is important to prevent further spread of intramammary infections in the herd. We found several cow factors associated with the indicators; adjusting for these may improve the performance of the indicators. http://dx.doi.org/10.3168/jds.2013-7885. Thromboelastography in healthy dairy cows. By Sommerey et al., page 5474. Thromboelastography is a whole blood-based global coagulation assay. Coagulation of a blood sample is initiated and speed and strength of clot formation are monitored and assessed on a graph. Thromboelastography can be used to investigate coagulopathies caused by coagulation factor deficiencies and platelet disorders (thrombocytopenia and platelet dysfunction) as well as hypercoagulopathies. This study established reference intervals for thromboelastography for Holstein-Friesian dairy cows. Stability studies indicated that blood samples are stable for at least 48 h at room temperature. Thromboelastography is useful in situations with unexplained bleeding or delayed clotting after trauma, and in conditions known to cause disseminated intravascular coagulation or thromboembolic disease; therefore, this method could be helpful in cattle. http://dx.doi.org/10.3168/jds.2014-7909.
Cholesterol metabolism, transport, and hepatic regulation in dairy cows during transition and early lactation. By Kessler et al., page 5481. In order to assess interactions between the liver and mammary gland in cholesterol homeostasis, cholesterol metabolism, transport, and hepatic regulatory genes were studied in dairy cows during the transition and early lactation period at different regulatory and functional levels. Plasma lipids, enzyme activities, and hepatic messenger RNA abundance of key factors related to cholesterol metabolism were markedly affected by lactational stage, reflecting the varying demand for cholesterol and the associated regulatory mechanisms to achieve homeostasis. http://dx.doi.org/10.3168/jds.2014-7926. Study of progesterone and cortisol concentrations in the Italian Friesian’s claw. By Comin et al., page 5491. All even-toed ungulates (Artiodactyla) use their claws to walk. Unlike human nails, overloaded claws grow at a very fast rate. Steroid hormones play a critical role in the normal development of the claw horn and proper keratin formation. Claw quality is the product of horn characteristics, and high claw quality means lower susceptibility to claw disorders, resulting in less need for claw care and fewer economic losses. This study helps us to better understand the claw matrix and its interaction with the internal and external environment. http://dx.doi.org/10.3168/jds.2014-7943. Prediction of pregnancy viability in bovine in vitro-produced embryos and recipient plasma with Fourier transform infrared spectroscopy. By Muñoz et al., page 5497. We describe here a simple, fast, and inexpensive technique to predict the pregnancy potential of embryos and recipients before embryo transfer. The procedure, which is noninvasive for the embryo and minimally invasive for the recipient, can increase the economic benefit in the cattle breeding industry. http://dx.doi.org/10.3168/jds.2014-8067. The SLICK hair locus derived from Senepol cattle confers thermotolerance to intensively managed lactating Holstein cows. By Dikmen et al., page 5508. The SLICK haplotype in cattle confers animals with a short and sleek hair coat. Originally identified in Senepol cattle, the gene has been introduced into Holsteins. Holsteins with slick hair had superior thermoregulatory ability compared with nonslick animals and experienced a less drastic depression in milk yield during the summer. http://dx.doi.org/10.3168/jds.2014-8087. Prepartum stocking density: Effects on metabolic, health, reproductive, and productive re-
sponses. By Silva et al., page 5521. Prepartum stocking density has been associated with feeding behavior in peripartum cows. In the current experiment, nulli parous and parous animals were housed, separately, in pens with a headlock stocking density of 74.1 ± 0.4% or 94.5 ± 0.3% and corresponding stall stocking density of 80.8 ± 0.4% or 103.1 ± 0.4%, respectively. Prepartum stocking density did not affect metabolic, health, reproductive, or productive responses. These findings suggest that, in herds with weekly or twice-weekly movement of new cows to the prepartum pen, a 100% headlock stocking density target on the day of regrouping is not detrimental to performance. http://dx.doi.org/10.3168/jds.2014-8093. Effect of merging levels of locomotion scores for dairy cows on intra- and interrater reliability and agreement. By Schlageter-Tello et al., page 5533. Lameness is commonly detected by using locomotion scores. Reliability and agreement are not only important indicators of consistency and reproducibility but they are also related to the validity of locomotion scores. It was difficult for experienced raters to consistently score cows with slight impaired locomotion. Experienced raters obtained acceptable reliability and agreement values only when a 5-level scale was transformed into a 2-level scale with an important loss of resolution of locomotion score. http://dx.doi.org/10.3168/jds.2014-8129. Genetic merit for fertility traits in Holstein cows: V. Factors affecting circulating progesterone concentrations. By Moore et al., page 5543. Low circulating progesterone concentrations during the estrous cycle have been implicated as a major cause of poor fertility in lactating dairy cows. This study examined the factors associated with variation in circulating progesterone concentrations in cows with similar genetic merit for milk production but with good (Fert+) or poor (Fert−) genetic merit for fertility traits. Greater synthetic capacity of the corpus luteum is the primary reason that Fert+ cows had greater circulating progesterone concentrations during the estrous cycle compared with Fert− cows. http://dx.doi.org/10.3168/jds.2014-8133. Antibody response early after experimental infection with Mycobacterium avium subspecies paratuberculosis in dairy calves. By Mortier et al., page 5558. Serological testing for Mycobacterium avium ssp. paratuberculosis (MAP) infection in the early stages of Johne’s disease is not recommended because test sensitivity is too low. Fifty calves were inoculated orally at 2 wk or at 3, 6, 9, or 12 mo with a high or low dose of MAP. A dose-dependent antibody response was detected by ELISA in a larger proportion of calves than expected soon after inoculation. In conclusion, MAP
infection was detected earlier than expected using a commercially available ELISA; therefore, screening young stock in combination with adult cattle might be useful in the context of Johne’s disease control programs. http://dx.doi.org/10.3168/jds.2014-8139. Acute phase response elicited by experimental bovine diarrhea virus (BVDV) infection is associated with decreased vitamin D and E status of vitamin-replete preruminant calves. By Nonnecke et al., page 5566. The preruminant calf provides an excellent animal model for examining the effect of infection on immune response capacity and vitamin status of the neonate. In the present study, experimental infection of month-old, vitamin D- and E-replete calves with a high-virulence strain of bovine viral diarrhea virus (BVDV) elicited a marked elevation in body temperature and rapid reduction in the numbers of bloodborne immune cells. Blood levels of serum amyloid A and haptoglobin, both positive acute phase proteins, increased dramatically postinoculation. Concurrent with development of the clinical response was a rapid decrease in vitamin D status that was paralleled by an even more pronounced decrease in vitamin E status. Because both vitamins promote optimal immune function, their reduced availability during acute infection may contribute to the severity and duration of the infection. http://dx.doi.org/10.3168/jds.2014-8293. Short communication: Evaluation of an automated in-house hematology analyzer for bovine blood. By Roland et al., page 5580. The objective of this study was to evaluate the suitability of an automated hematology analyzer (V-Sight, A. Menarini Pharma GmbH, Vienna, Austria) for bovine blood. Accuracy was tested by comparison with a reference device using Bland-Altman analysis, Passing-Bablok regression, and correlation. Furthermore, intraassay precision, carryover, sensitivity, and specificity were calculated. The analyzer provided accurate and precise results for 2 out of 13 parameters: mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration. Proportional differences were detected for monocytes, granulocytes, hematocrit, and platelet counts. For all remaining analytes, significant proportional and systemic differences were discovered. Leukocyte results were especially impaired by high standard deviation and poor precision. With accurate and precise results for only 2 out of 13 parameters, the V-Sight cannot be recommended for analysis of bovine blood. http://dx.doi.org/10.3168/jds.2013-7736. Short communication: An in vitro assessment of the antibacterial activity of plant-derived oils. By Mullen et al., page 5587. Antibiotic use is not
allowed on organic dairy farms in the United States. Alternatives to antibiotics used by some organic producers include plant-derived essential oils, which may have antibacterial activity. The current in vitro study examined antibacterial activity of oils of Thymus vulgaris (thyme), Angelica dahuricae, Angelica sinensis, Gaultheria procumbens (wintergreen), and Glycyrrhiza uralensis (Chinese licorice) in milk against 3 common mastitis pathogens. Only thyme oil at concentrations ≥2% had consistent antibacterial activity against all 3 pathogens. Further testing in cows is recommended to evaluate thyme oil’s efficacy in vivo. http://dx.doi.org/10.3168/jds.2013-7806. Effects of rumen-protected γ-aminobutyric acid on performance and nutrient digestibility in heat-stressed dairy cows. By Cheng et al., page 5599. γ-Aminobutyric acid (GABA) is an inhibitory neurotransmitter in the central nervous system and has certain physiological functions, such as regulating body temperature and feed intake, as well as an antistress effect. The objective of this study was to investigate the effects of rumen-protected GABA on performance and nutrient digestibility in heat-stressed dairy cows. Rumen-protected GABA supplementation to dairy cows could alleviate heat stress, increase dry matter intake and milk yield, and improve milk composition. The optimal supplemental GABA level for heat-stressed dairy cows is 40 mg/kg of dry matter. http://dx.doi.org/10.3168/jds.2013-6797. Abomasal protein infusion in postpartum transition dairy cows: Effect on performance and mammary metabolism. By Larsen et al., page 5608. The effect of alleviating the postpartum protein deficiency on performance and mammary metabolism was investigated using abomasal casein infusion. The major response was a 7.2 ± 1.3 kg/d increase in milk production, on average, during the first 4 wk of lactation. Despite high utilization of additional protein for milk synthesis, more essential amino acids were available for other body functions. Thus, postpartum protein deficiency can have substantial negative effect on milk production. However, future investigations are needed to transfer the results into practical feeding strategies. http://dx.doi.org/10.3168/jds.2013-7247. Comparison of shortened and conventional dry period management strategies. By Cermakova et al., page 5623. The objective of this study was to compare 2 dry cow management strategies and evaluate the effect of a shortened dry period on feed intake, lactation performance, and metabolic status of dairy cows in early lactation. Shortening of the dry period to 35 d and feeding a late-lactation diet increased dry matter intake (DMI) prepartum; however, the dry period
strategy had no effect on postpartum DMI. The treatment did not affect milk production, postpartum concentrations of plasma metabolites, or basic parameters of rumen fluid. Considering DMI, milk production, and milk persistency, a traditional dry period management strategy appeared to be more favorable compared with a shortened dry period and feeding a late-lactation diet through the dry period. http://dx.doi.org/10.3168/jds.2013-7499. Comparison of enriched palmitic acid and calcium salts of palm fatty acids distillate fat supplements on milk production and metabolic profiles of high-producing dairy cows. By Rico et al., page 5637. The fatty acid profile of a fat supplement has implications for animal metabolism and milk production. A high palmitic acid (PA) fat supplement was compared with calcium salts of palm fatty acids in high-producing cows. The PA supplement increased milk and milk fat and protein yields but had no effect on the concentration of milk components. Secretion of palmitic acid in milk was increased by PA supplement, whereas biohydrogenation intermediates were decreased. Plasma insulin and nonesterified fatty acid concentrations did not differ. Palmitic acid supplements may modestly increase milk and milk fat yield while decreasing the risk of milk fat depression compared with calcium salts of palm fatty acids. http://dx.doi.org/10.3168/jds.2013-7723. A statistical filtering procedure to improve the accuracy of estimating population parameters in feed composition databases. By Yoder et al., page 5645. Large feed composition databases are generated by commercial testing laboratories but they are at times contaminated with samples that are improperly identified or that belong to more specific subpopulations of a larger population. Inclusion of these observations inflates estimates of variation within the population and can affect correlations among nutrients. Accurate composition data, including information on (co) variances, are needed for application of stochastic diet formulation. We developed a rapid statistical method to identify outliers. When the method was applied to a large database, more than 13% of the observations within classified feed populations were identified as outliers; when they were removed, variability decreased and correlations often changed. http://dx.doi.org/10.3168/jds.2013-7724. Effects of the heating process of soybean oil and seeds on fatty acid biohydrogenation in vitro. By Troegeler-Meynadier et al., page 5657. Addition of fat in dairy cow diets affects milk fat quality for human consumers. Effects of fat heating on ruminal biohydrogenation depend on duration and temperature. This paper provides new insights into effects of the heat-
ing process on ruminal biohydrogenation, which could be useful to optimize thermal treatment of oilseeds to improve milk fat quality. http://dx.doi.org/10.3168/jds.2013-7783. Dietary modulation of the expression of genes involved in short-chain fatty acid absorption in the rumen epithelium is related to short-chain fatty acid concentration and pH in the rumen of goats. By Yan et al., page 5668. Many studies have reported that feeding additional concentrate could enhance the short-chain fatty acid (SCFA) absorption capacity of rumen via increased messeneger (m) RNA expression of proteins that are involved in SCFA absorption. We investigated how mRNA expression of these genes is affected by diet. Dietary effects on rumen epithelial mRNA expression of genes involved in SCFA absorption are associated with ruminal SCFA and ruminal pH. http://dx.doi.org/10.3168/jds.2013-7807. Corn bran versus corn grain at 2 levels of forage: Intake, apparent digestibility, and production responses by lactating dairy cows. By Arndt et al., page 5676. Corn bran is the fibrous outer layer of corn grain present in small amounts in corn grain and corn silage and as a larger part of various co-products of corn processing. The energy value of corn bran is not well established but can be predicted from the analyzed chemical composition. This study measured the feeding value of relatively pure corn bran derived from dry-mill fractionation of corn grain. Substituting corn bran for corn grain decreased diet digestibility and milk yield and indicated that corn grain fiber digestibility predicted from chemical composition overestimates in vivo digestibility. http://dx.doi.org/10.3168/jds.2013-7815. Effects of reduced dietary protein and supplemental rumen-protected essential amino acids on the nitrogen efficiency of dairy cows. By Arriola Apelo et al., page 5688. Under current feeding practices, only 25% of N is captured in milk, with the remainder being excreted into the environment. Based on the National Research Council’s (2001) Nutrient Requirements of Dairy Cattle prediction, reducing dietary crude protein (CP) from 17 to 15% would lower milk protein yield by 29%; however, that reduction was not observed in this study. Furthermore, the marginal efficiency of the extra metabolizable protein (15 to 17%) was only 19%. Reducing dietary CP would significantly reduce N excretion to the environment. http://dx.doi.org/10.3168/jds.2013-7833. Addition of gut active carbohydrates to colostrum replacer does not improve passive transfer of immunoglobulin G in Holstein dairy calves.
By Villettaz Robichaud et al., page 5700. This study investigated the effects of the addition of gut active carbohydrates (GAC) to 1.5 doses (150 g of immunoglobulin G, IgG) of a commercial colostrum replacer on passive transfer of IgG in dairy calves. Treatment with GAC did not affect apparent efficiency of absorption of IgG (%), serum IgG concentrations (mg/mL), or serum total protein concentrations (g/dL) at 24 h of age. http://dx.doi.org/10.3168/jds.2013-7854. The effects of supplementation with a blend of cinnamaldehyde and eugenol on feed intake and milk production of dairy cows. By Wall et al., page 5709. Two experiments were conducted to study the effects of dietary addition of a plant extract product containing cinnamaldehyde and eugenol on the milk production performance of lactating dairy cows. When fed at moderate doses, the additive was associated with increased feed intake and milk production. In addition, we observed treatment by parity interactions that have not been described previously. http://dx.doi.org/10.3168/jds.2014-7896. Effect of flaxseed physical form on digestibility of lactation diets fed to Holstein steers. By Schroeder et al., page 5718. Four multi-cannulated Holstein steers were fed lactating cow diets in a 4 × 4 Latin square design to determine the effect of flaxseed processing method on ruminal fermentation and digestibility. Either rolling or grinding of flaxseed increases its nutrient availability and utilization when fed in lactating dairy cow diets. http://dx.doi.org/10.3168/jds.2014-7911. Effects on enteric methane production and bacterial and archaeal communities by the addition of cashew nut shell extract or glycerol—An in vitro evaluation. By Danielsson et al., page 5729. Methane (CH4) production from dairy cows is an issue for global warming and at the same time represents energy loss for the cow. The present in vitro study examined the effects of 2 feed additives × cashew nut shell extract (CNSE) and glycerol—on CH4 and volatile fatty acid concentrations and on microbial populations in rumen fluid. Reduced CH4 production was shown with CNSE but not with glycerol, suggesting that CNSE can be a promising inhibitor of CH4 formation in the rumen of dairy cows. http://dx.doi.org/10.3168/jds.2014-7929. Effect of reducing dietary forage in lower starch diets on performance, ruminal characteristics, and nutrient digestibility in lactating Holstein cows. By Farmer et al., page 5742. Providing sufficient dietary fiber from forages supports ruminal health and productivity. However, when forage quality or quantity is limited, lower forage diets may be fed. Additionally,
the price of corn grain has markedly increased, making lower starch diets more common. We found that reducing dietary forage content from 52 to 39% of dry matter while increasing wheat straw inclusion to maintain chewing and rumen function resulted in similar milk yield and composition, although feed intake increased. With our lower starch diets, the minimal forage content to maintain lactational performance was between 39 and 43%. http://dx.doi.org/10.3168/jds.2014-7963. Identification of lactic acid bacteria in the rumen and feces of dairy cows fed total mixed ration silage to assess the survival of silage bacteria in the gut. By Han et al., page 5754. We examined the lactic acid bacteria (LAB) communities in the gut content of dairy cows fed silage as the sole diet. The survival of silage LAB was evaluated by culture-independent microbial analysis using Lactobacillus-specific PCR amplification. Five of the 14 silage LAB species (Lactobacillus acetotolerans, Lactobacillus pontis, Lactobacillus casei, Lactobacillus suebicus, and Lactobacillus plantarum) survived and were detected in the feces. Elimination of silage LAB took place in the rumen rather than in the postruminal gut segments. Thus, several LAB species may have the potential to carry the probiotic function from silage to dairy cows. http://dx.doi.org/10.3168/jds.2014-7968. Effects of partial mixed rations and supplement amounts on milk production and composition, ruminal fermentation, bacterial communities, and ruminal acidosis. By Golder et al., page 5763. Feeding isoenergetic supplements in a partial mixed ration on a feed pad reduced the incidence of ruminal acidosis compared with feeding concentrates twice daily at milking, but did not improve milk production and composition in late-lactation cows. The incidence of ruminal acidosis increased linearly with increasing supplement amount. Distinct bacterial community compositions were found among cattle with different supplement feeding strategies and amounts. These communities were associated with altered ruminal fermentation measures. http://dx.doi.org/10.3168/jds.2014-8049. Chewing, rumen pool characteristics, and lactation performance by dairy cows fed 2 concentrations of a corn wet-milling coproduct with different forage sources. By Shepherd et al., page 5786. Fibrous corn milling coproducts provide highly digestible fiber with low starch and moderate protein concentration. We hypothesized that we could increase the coproduct from 20 to 30% while maintaining fiber digestibility and milk production if we substituted a portion of corn silage with alfalfa or grass hays. Grass hay increased particle size and pool size of ruminal contents and rumination but had slower ruminal diges-
tion of neutral detergent fiber than alfalfa hay. With increased inclusion of the co-product, producers should consider substituting a portion of corn silage with alfalfa or grass hays, depending on forage digestibility and the need for physically effective fiber. http://dx.doi.org/10.3168/jds.2014-8169. Genetic relationships of clinical mastitis, cystic ovaries, and lameness with milk yield and somatic cell score in first-lactation Canadian Holsteins. By Koeck et al., page 5806. Clinical mastitis, cystic ovaries, and lameness are among the 3 most frequently reported dairy cattle diseases. The aim of this study was to investigate the genetic relationships of these 3 diseases with test-day milk yield and somatic cell score using random regression models. Milk yield was unfavorably correlated with clinical mastitis and cystic ovaries, whereas a highly favorable association was found between somatic cell score and clinical mastitis. The unfavorable relationships with milk yield support the inclusion of direct health traits in genetic selection. http://dx.doi.org/10.3168/jds.2013-7785. Assigning unknown parent groups to reduce bias in genomic evaluations of final score in US Holsteins. By Tsuruta et al., page 5814. Unknown parent groups have been considered to minimize bias in genetic evaluations by adjusting differences among genetic groups. The bias in genomic evaluations of US Holstein bulls for final score could be amplified by poorly defined unknown parent groups, especially when genotyped young bulls have no daughters because of no contributions from phenotypic records to unknown parent groups for those young bulls. Redefining of unknown parent groups is a practical and rational approach to reduce bias in genomic evaluations for young bulls. http://dx.doi.org/10.3168/jds.2013-7821. Adding cows to the reference population makes a small dairy population competitive. By Thomasen et al., page 5822. The competitiveness of small dairy cattle populations is challenged by low reliabilities of genomic predictions. These are mainly due to limited numbers of proven sires in the reference population. Genotyping of cows for inclusion in the reference population increases reliabilities and thereby genetic gain. Inclusion also reduces the rate of inbreeding compared with breeding schemes with only progeny-tested bulls in the reference population. The increase in genetic gain is larger for a turbo scheme characterized by exclusive use of young bulls and hence achieving shorter generation intervals. Inclusion of cows in the reference population is a profitable and fast way to increase reliabilities of genomic predictions. It constitutes an attractive option for small dairy cattle populations. http://dx.doi.org/10.3168/jds.2014-7906.
A single-step genomic model with direct estimation of marker effects. By Liu et al., page 5833. Until now, a multi-step genomic model has been used in most countries for genomic evaluation of dairy cattle. We developed a single-step genomic model with direct estimation of marker effects. Our model evaluated genotyped and nongenotyped animals jointly and used all phenotypes and pedigrees. Our model can avoid bias in prediction caused by genomic preselection and provide accurate genomic predictions. The estimated marker effects can be used in frequent interim genomic evaluation, resulting in a reduction of costs in genomic selection. http://dx.doi.org/10.3168/jds.2014-7924. Genetic parameters across lactation for feed intake, fat- and protein-corrected milk, and liveweight in first-parity Holstein cattle. By Manzanilla Pech et al., page 5851. The objective of this study was to estimate genetic parameters for dry matter intake (DMI), fat- and protein-corrected milk (FPCM), and liveweight (LW) across the entire first lactation. Heritabilities and genetic correlations of DMI, FPCM, and LW changed across different stages of lactation, mainly differing during early and late lactation compared with mid lactation. Genetics of DMI appears to vary across lactation. The results are useful to understand the genetic relationship between DMI, FPCM, and LW on specific days across lactation, and should be taken into account when constructing a selection index. http://dx.doi.org/10.3168/jds.2014-8165. Mid-infrared spectrometry of milk as a predictor of energy intake and efficiency in lactating dairy cows. By McParland et al., page 5863. Residual feed intake, defined as the difference between the actual energy available and that demanded by the various energy sinks, is a potentially useful measure of feed efficiency in lactating dairy cows. The derivation of residual feed intake phenotypes for whole populations of cows is hampered, however, by a lack of individual cow feed intake records. Hence, easy-to-measure, low-cost predictors of either energy intake or residual feed intake are of interest. The present study shows that milk mid-infrared spectrometry can be a useful predictor of energy intake and efficiency in lactating dairy cows. http://dx.doi.org/10.3168/jds.2014-8214. Short communication: Genetic relationships between claw disorders, protein yield, and somatic cell score by days in milk. By Gernand and König, page 5872. Random regression models were applied to study daily genetic relationships between selected binary claw disorders with protein yield and somatic cell score. Genetic correlations with protein yield varied in the course of lactation for the same claw disorder
and were different for different claw disorders on identical test days. For example, obvious signs for genetic antagonisms were detected between protein yield and sole ulcer, whereas genetic correlations for interdigital hyperplasia and protein yield were mostly favorable. http://dx.doi.org/10.3168/jds.2013-7612. Short communication: Alteration of priors for random effects in Gaussian linear mixed models. By Vandenplas et al., page 5880. Some statistical analyses need to alter the default mean and (co) variance of the prior distribution of random effects of linear mixed models commonly used in animal breeding. However, most available software packages do not permit those alterations. Therefore, the aim of this study was to propose a method to alter both mean and (co)variance of prior distributions while using available software packages through the use of an extended data file and a user-supplied (co)variance matrix. http://dx.doi.org/10.3168/jds.2014-8155. Effects of ingesting fermented milk by using Lactococcus lactis H61 on skin health in young women: A randomized double-blind study. By Kimoto-Nira et al., page 5898. Healthy female volunteers (n = 23; age, 19–21 yr) received Lactococcus lactis H61-fermented milk (1010 cfu of strain H61/300 g per day) or conventional yogurt (1010 cfu of both Lactobacillus delbrueckii ssp. bulgaricus and Streptococcus thermophilus/d) for 4 wk, and various skin properties were measured. Sebum content in cheek increased significantly after intervention in the H61-fermented milk group but not in the conventional yogurt group. As skin lipids contribute to maintaining the skin barrier, H61-fermented milk would provide beneficial effects in skin for young women. http://dx.doi.org/10.3168/jds.2014-7980. Feeding strategies and manure management for cost-effective mitigation of greenhouse gas emissions from dairy farms in Wisconsin. By Dutreuil et al., page 5904. Dairy farmers are encouraged to decrease greenhouse gas emissions while remaining profitable. Survey data were used to characterize feeding and manure management strategies on conventional, grazing, and organic dairy farms followed by simulation of mitigation strategies. The incorporation of grazing in the conventional farms and the decrease in forageto-concentrate ratio in the grazing and organic farms were effective in reducing model-predicted greenhouse gas emissions while maintaining profitability. However, mitigation strategies should be implemented according to farm-specific characteristics. http://dx.doi.org/10.3168/jds.2014-8082. Effect of planting density on nutritional quality of green-chopped corn for silage. By Ferreira et
al., page 5918. Crop management practices may not be well established among dairy farmers when corn is destined for silage. Even though planting corn at high densities can diminish silage quality, dairy farmers frequently plant cornfields with high densities to obtain a greater yield of biomass. In this study, with abundant
precipitation, biomass yield increased when corn was planted at high densities. In addition, whole-plant nutritional quality was not affected by increasing corn plant density. http://dx.doi.org/10.3168/jds.2014-8094.
prevalence of lactose intolerance worldwide is very high. The aim of this work was the use of combination of microfiltration, pasteurization, and lactose hydrolysis to obtain skim milk with an extended shelf life. It was possible to obtain such a product with a shelf life of up to 50 d at 5°C, in terms of its microbiological stability and acidity. Microfiltration technology, in combination with pasteurization, can be used by the dairy industry to produce delactosed milk with an extended shelf life. http://dx.doi.org/10.3168/jds.2014-8020. Biopreservation of Fior di Latte cheese. By Angiolillo et al., page 5345. Two important topics of the dairy industry are shelf-life extension of fresh products and the use of biological and natural substances to preserve such products. Fior di Latte cheese has a very short shelf life and any treatment applied to extend its shelf life must help maintain its appearance and flavor characteristics, as these are perceived as quality indices by the consumer. Therefore, in this study, we developed a new biopreservation system consisting of an active sodium alginate coating containing Lactobacillus reuteri applied to Fior di Latte cheese. http://dx.doi.org/10.3168/jds.2014-8022. The role of sodium in the salty taste of permeate. By Frankowski et al., page 5356. This study determined the sensory and compositional properties of whey permeates and the role of sodium and other constituents on salty taste of permeate. Permeates had low salty taste, whereas reduced-lactose permeates had higher salty taste. For both permeate types, sodium was not the sole source of salty taste. Potassium and lactic and orotic acids also contributed to the salty taste of permeates. http://dx.doi.org/10.3168/jds.2014-8057. Short communication: Antiviral activity of subcritical water extract of Brassica juncea against influenza virus A/H1N1 in nonfat milk. By Lee et al., page 5383. Subcritical water extract (SWE) of Brassica juncea has been used in dairy products for use as antiviral food. At maximum nontoxic concentrations, SWE of B. juncea had higher antiviral activity against influenza virus A/H1N1 than n-hexane, ethanol, or hot water (80°C) extracts. Thus, the use of B. juncea SWE as a food supplement might aid in protection from influenza viral infection. http://dx.doi.org/10.3168/jds.2014-8016. Short communication: Dairy consumption among middle-aged and elderly adults in Switzerland. By Chollet et al., page 5387. In many countries, the consumption of dairy products is lower than recommended. The present study confirmed that
middle-aged and elderly Swiss (50–81 yr) are among those consuming less than the recommended intake of dairy products. Additionally, about a quarter of this population group is actually reducing consumption of dairy products for reasons that are not scientifically proven. Information campaigns specifically targeting the middle-aged and elderly are needed to increase awareness of the nutritional value of dairy products and their role in a healthy diet. http://dx.doi.org/10.3168/jds.2014-8193. Identifying the major bacteria causing intramammary infections in individual milk samples of sheep and goats using traditional bacteria culturing and real-time polymerase chain reaction. By Rovai et al., page 5393. One-hundred and eight lactating dairy ewes and 24 Murciano-Granadina dairy goats were used for identifying the main bacteria causing mastitis by traditional bacterial culturing (BAC) and real-time polymerase chain reaction (PCR). In addition, the effects of infection on milk yield and somatic cell count were determined. Prevalence of subclinical mastitis was 47% in sheep with an estimated milk loss of 16%; prevalence in goats was 42% with an estimated milk loss of 18%. According to BAC results, of the 30 samples with no bacterial finding, 29 were also found negative by the PCR. Of the 60 BAC-positive samples, 38 were identified as positive for coagulasenegative staphylococci species, with 36 isolates classified as Staphylococcus spp. or β-lactamase-positive Staphylococcus spp. by PCR. Eight more samples were identified as Staphylococcus aureus by BAC, of which 7 matched Staph. aureus and 1 as Staphylococcus spp. by PCR. Moreover, 5 isolates were identified as Streptococcus spp. by BAC, but failed to be confirmed as such by PCR. According to bacteriology results, 87% of the identified single bacteria species or cultures with no growth were identical, which agreed 98.9% with the PCR results. In conclusion, the PCR and BAC methods had similar accuracy for identifying udder-infecting bacteria in sheep and goats. http://dx.doi.org/10.3168/jds.2014-7988. Efficacy of ampicillin trihydrate or ceftiofur hydrochloride for treatment of metritis and subsequent fertility in dairy cows. By Lima et al., page 5401. Metritis affects 10 to 30% of dairy cows, leading to losses in production and reproduction and to increased risk of early removal from the herd. The pathogens isolated from the uterus of cows with metritis are normally susceptible in vitro to ampicillin and ceftiofur. The objective of this study was to evaluate the efficacy of ampicillin trihydrate for treatment of metritis in dairy cows compared with ceftiofur hydrochloride. Cows with puerperal metritis had reduced cure compared with those with metritis based on fetid uterine discharge. Ampicillin was an effective therapy
for metritis and led to similar or greater clinical cure compared with ceftiofur. http://dx.doi.org/10.3168/jds.2013-7569. Individual and combined effects of anovulation and cytological endometritis on reproductive performance of dairy cows. By Vieira-Neto et al., page 5415. Anovulation is associated with cytological endometritis (CTE); therefore, the negative association of either condition with reproductive performance could be confounded by the other. The objective was to evaluate the individual and combined effect of anovulation and CTE on reproductive performance of dairy cows. A total of 1,569 cows from 3 regions of the United States were analyzed. Both anovulation and CTE had a negative effect on time to pregnancy, and the negative effect was compounded if both conditions were present. In summary, both anovulation and CTE negatively affect reproductive performance; when combined, they have an additive negative effect. http://dx.doi.org/10.3168/jds.2013-7725. Treatments of clinical mastitis occurring in cows on 51 large dairy herds in Wisconsin. By Oliveira and Ruegg, page 5426. Treatments of clinical mastitis were recorded on 51 larger dairy farms in Wisconsin. Although 5 different intramammary compounds were used, 65% of treatments were performed using a third-generation cephalosporin. Farmers did not know the cause of most cases of mastitis, but milk samples collected from cases demonstrated that the majority of treatments were given for mild or moderate cases of clinical mastitis that were culture negative or caused by Escherichia coli. Even though no systemic therapies are approved for treatment of mastitis, about 23% of cows received systemic antimicrobials, and sulfonamides were administered on 8 farms. Increased use of diagnostic tests should be encouraged to allow farmers to make more-informed treatment decisions for clinical mastitis. http://dx.doi.org/10.3168/jds.2013-7756. Peroxisome proliferator-activated receptor γ1 and γ2 isoforms alter lipogenic gene networks in goat mammary epithelial cells to different extents. By Shi et al., page 5437. In nonruminants, 2 isoforms (γ1 and γ2) of the nuclear receptor peroxisome proliferator-activated receptor gamma (PPARG1 and PPARG2) are generated by alternative splicing. Their distribution in various goat tissues was analyzed, and key target genes were measured after overexpressing each isoform in goat mammary epithelial cells. Expression of PPARG2 was markedly greater in adipose than in mammary gland. In contrast, PPARG1 and its activation upregulated lipogenic gene networks in mammary cells to a greater extent than did PPARG2. Therefore, this isoform might be more important bio-
logically for regulating goat mammary cell lipogenesis during lactation. http://dx.doi.org/10.3168/jds.2013-7863. Age at calving in heifers and level of milk production during gestation in cows are associated with the birth size of Holstein calves. By Kamal et al., page 5448. Poor intrauterine growth resulting in small size at birth increases predisposition to metabolic diseases during later life. The objective of the present study was to determine factors that are associated with birth size of Holstein calves. In addition to the recognized factors (calf sex, season of calving, gestation length, parity, length of the dry period, and morphometrics of the dam), age at calving in heifers, and level of milk production during gestation in cows, were indicated as decisive determinants of calf birth size. The latter may provide a basis for developing managerial interventions to improve long-term health and productivity of offspring. http://dx.doi.org/10.3168/jds.2014-7898. Associations of udder health indicators with cow factors and with intramammary infection in dairy cows. By Nyman et al., page 5459. We investigated associations between cow factors (e.g., parity, breed), intramammary infection, and 4 udder health indicators in dairy cows. Udder health indicators are used to find cows with inflammation in one or more udder quarters that do not show signs of disease. Udder inflammation can be painful and cause milk losses and will have an economic impact for the farmer. Identifying cows with inflammation is important to prevent further spread of intramammary infections in the herd. We found several cow factors associated with the indicators; adjusting for these may improve the performance of the indicators. http://dx.doi.org/10.3168/jds.2013-7885. Thromboelastography in healthy dairy cows. By Sommerey et al., page 5474. Thromboelastography is a whole blood-based global coagulation assay. Coagulation of a blood sample is initiated and speed and strength of clot formation are monitored and assessed on a graph. Thromboelastography can be used to investigate coagulopathies caused by coagulation factor deficiencies and platelet disorders (thrombocytopenia and platelet dysfunction) as well as hypercoagulopathies. This study established reference intervals for thromboelastography for Holstein-Friesian dairy cows. Stability studies indicated that blood samples are stable for at least 48 h at room temperature. Thromboelastography is useful in situations with unexplained bleeding or delayed clotting after trauma, and in conditions known to cause disseminated intravascular coagulation or thromboembolic disease; therefore, this method could be helpful in cattle. http://dx.doi.org/10.3168/jds.2014-7909.
Cholesterol metabolism, transport, and hepatic regulation in dairy cows during transition and early lactation. By Kessler et al., page 5481. In order to assess interactions between the liver and mammary gland in cholesterol homeostasis, cholesterol metabolism, transport, and hepatic regulatory genes were studied in dairy cows during the transition and early lactation period at different regulatory and functional levels. Plasma lipids, enzyme activities, and hepatic messenger RNA abundance of key factors related to cholesterol metabolism were markedly affected by lactational stage, reflecting the varying demand for cholesterol and the associated regulatory mechanisms to achieve homeostasis. http://dx.doi.org/10.3168/jds.2014-7926. Study of progesterone and cortisol concentrations in the Italian Friesian’s claw. By Comin et al., page 5491. All even-toed ungulates (Artiodactyla) use their claws to walk. Unlike human nails, overloaded claws grow at a very fast rate. Steroid hormones play a critical role in the normal development of the claw horn and proper keratin formation. Claw quality is the product of horn characteristics, and high claw quality means lower susceptibility to claw disorders, resulting in less need for claw care and fewer economic losses. This study helps us to better understand the claw matrix and its interaction with the internal and external environment. http://dx.doi.org/10.3168/jds.2014-7943. Prediction of pregnancy viability in bovine in vitro-produced embryos and recipient plasma with Fourier transform infrared spectroscopy. By Muñoz et al., page 5497. We describe here a simple, fast, and inexpensive technique to predict the pregnancy potential of embryos and recipients before embryo transfer. The procedure, which is noninvasive for the embryo and minimally invasive for the recipient, can increase the economic benefit in the cattle breeding industry. http://dx.doi.org/10.3168/jds.2014-8067. The SLICK hair locus derived from Senepol cattle confers thermotolerance to intensively managed lactating Holstein cows. By Dikmen et al., page 5508. The SLICK haplotype in cattle confers animals with a short and sleek hair coat. Originally identified in Senepol cattle, the gene has been introduced into Holsteins. Holsteins with slick hair had superior thermoregulatory ability compared with nonslick animals and experienced a less drastic depression in milk yield during the summer. http://dx.doi.org/10.3168/jds.2014-8087. Prepartum stocking density: Effects on metabolic, health, reproductive, and productive re-
sponses. By Silva et al., page 5521. Prepartum stocking density has been associated with feeding behavior in peripartum cows. In the current experiment, nulli parous and parous animals were housed, separately, in pens with a headlock stocking density of 74.1 ± 0.4% or 94.5 ± 0.3% and corresponding stall stocking density of 80.8 ± 0.4% or 103.1 ± 0.4%, respectively. Prepartum stocking density did not affect metabolic, health, reproductive, or productive responses. These findings suggest that, in herds with weekly or twice-weekly movement of new cows to the prepartum pen, a 100% headlock stocking density target on the day of regrouping is not detrimental to performance. http://dx.doi.org/10.3168/jds.2014-8093. Effect of merging levels of locomotion scores for dairy cows on intra- and interrater reliability and agreement. By Schlageter-Tello et al., page 5533. Lameness is commonly detected by using locomotion scores. Reliability and agreement are not only important indicators of consistency and reproducibility but they are also related to the validity of locomotion scores. It was difficult for experienced raters to consistently score cows with slight impaired locomotion. Experienced raters obtained acceptable reliability and agreement values only when a 5-level scale was transformed into a 2-level scale with an important loss of resolution of locomotion score. http://dx.doi.org/10.3168/jds.2014-8129. Genetic merit for fertility traits in Holstein cows: V. Factors affecting circulating progesterone concentrations. By Moore et al., page 5543. Low circulating progesterone concentrations during the estrous cycle have been implicated as a major cause of poor fertility in lactating dairy cows. This study examined the factors associated with variation in circulating progesterone concentrations in cows with similar genetic merit for milk production but with good (Fert+) or poor (Fert−) genetic merit for fertility traits. Greater synthetic capacity of the corpus luteum is the primary reason that Fert+ cows had greater circulating progesterone concentrations during the estrous cycle compared with Fert− cows. http://dx.doi.org/10.3168/jds.2014-8133. Antibody response early after experimental infection with Mycobacterium avium subspecies paratuberculosis in dairy calves. By Mortier et al., page 5558. Serological testing for Mycobacterium avium ssp. paratuberculosis (MAP) infection in the early stages of Johne’s disease is not recommended because test sensitivity is too low. Fifty calves were inoculated orally at 2 wk or at 3, 6, 9, or 12 mo with a high or low dose of MAP. A dose-dependent antibody response was detected by ELISA in a larger proportion of calves than expected soon after inoculation. In conclusion, MAP
infection was detected earlier than expected using a commercially available ELISA; therefore, screening young stock in combination with adult cattle might be useful in the context of Johne’s disease control programs. http://dx.doi.org/10.3168/jds.2014-8139. Acute phase response elicited by experimental bovine diarrhea virus (BVDV) infection is associated with decreased vitamin D and E status of vitamin-replete preruminant calves. By Nonnecke et al., page 5566. The preruminant calf provides an excellent animal model for examining the effect of infection on immune response capacity and vitamin status of the neonate. In the present study, experimental infection of month-old, vitamin D- and E-replete calves with a high-virulence strain of bovine viral diarrhea virus (BVDV) elicited a marked elevation in body temperature and rapid reduction in the numbers of bloodborne immune cells. Blood levels of serum amyloid A and haptoglobin, both positive acute phase proteins, increased dramatically postinoculation. Concurrent with development of the clinical response was a rapid decrease in vitamin D status that was paralleled by an even more pronounced decrease in vitamin E status. Because both vitamins promote optimal immune function, their reduced availability during acute infection may contribute to the severity and duration of the infection. http://dx.doi.org/10.3168/jds.2014-8293. Short communication: Evaluation of an automated in-house hematology analyzer for bovine blood. By Roland et al., page 5580. The objective of this study was to evaluate the suitability of an automated hematology analyzer (V-Sight, A. Menarini Pharma GmbH, Vienna, Austria) for bovine blood. Accuracy was tested by comparison with a reference device using Bland-Altman analysis, Passing-Bablok regression, and correlation. Furthermore, intraassay precision, carryover, sensitivity, and specificity were calculated. The analyzer provided accurate and precise results for 2 out of 13 parameters: mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration. Proportional differences were detected for monocytes, granulocytes, hematocrit, and platelet counts. For all remaining analytes, significant proportional and systemic differences were discovered. Leukocyte results were especially impaired by high standard deviation and poor precision. With accurate and precise results for only 2 out of 13 parameters, the V-Sight cannot be recommended for analysis of bovine blood. http://dx.doi.org/10.3168/jds.2013-7736. Short communication: An in vitro assessment of the antibacterial activity of plant-derived oils. By Mullen et al., page 5587. Antibiotic use is not
allowed on organic dairy farms in the United States. Alternatives to antibiotics used by some organic producers include plant-derived essential oils, which may have antibacterial activity. The current in vitro study examined antibacterial activity of oils of Thymus vulgaris (thyme), Angelica dahuricae, Angelica sinensis, Gaultheria procumbens (wintergreen), and Glycyrrhiza uralensis (Chinese licorice) in milk against 3 common mastitis pathogens. Only thyme oil at concentrations ≥2% had consistent antibacterial activity against all 3 pathogens. Further testing in cows is recommended to evaluate thyme oil’s efficacy in vivo. http://dx.doi.org/10.3168/jds.2013-7806. Effects of rumen-protected γ-aminobutyric acid on performance and nutrient digestibility in heat-stressed dairy cows. By Cheng et al., page 5599. γ-Aminobutyric acid (GABA) is an inhibitory neurotransmitter in the central nervous system and has certain physiological functions, such as regulating body temperature and feed intake, as well as an antistress effect. The objective of this study was to investigate the effects of rumen-protected GABA on performance and nutrient digestibility in heat-stressed dairy cows. Rumen-protected GABA supplementation to dairy cows could alleviate heat stress, increase dry matter intake and milk yield, and improve milk composition. The optimal supplemental GABA level for heat-stressed dairy cows is 40 mg/kg of dry matter. http://dx.doi.org/10.3168/jds.2013-6797. Abomasal protein infusion in postpartum transition dairy cows: Effect on performance and mammary metabolism. By Larsen et al., page 5608. The effect of alleviating the postpartum protein deficiency on performance and mammary metabolism was investigated using abomasal casein infusion. The major response was a 7.2 ± 1.3 kg/d increase in milk production, on average, during the first 4 wk of lactation. Despite high utilization of additional protein for milk synthesis, more essential amino acids were available for other body functions. Thus, postpartum protein deficiency can have substantial negative effect on milk production. However, future investigations are needed to transfer the results into practical feeding strategies. http://dx.doi.org/10.3168/jds.2013-7247. Comparison of shortened and conventional dry period management strategies. By Cermakova et al., page 5623. The objective of this study was to compare 2 dry cow management strategies and evaluate the effect of a shortened dry period on feed intake, lactation performance, and metabolic status of dairy cows in early lactation. Shortening of the dry period to 35 d and feeding a late-lactation diet increased dry matter intake (DMI) prepartum; however, the dry period
strategy had no effect on postpartum DMI. The treatment did not affect milk production, postpartum concentrations of plasma metabolites, or basic parameters of rumen fluid. Considering DMI, milk production, and milk persistency, a traditional dry period management strategy appeared to be more favorable compared with a shortened dry period and feeding a late-lactation diet through the dry period. http://dx.doi.org/10.3168/jds.2013-7499. Comparison of enriched palmitic acid and calcium salts of palm fatty acids distillate fat supplements on milk production and metabolic profiles of high-producing dairy cows. By Rico et al., page 5637. The fatty acid profile of a fat supplement has implications for animal metabolism and milk production. A high palmitic acid (PA) fat supplement was compared with calcium salts of palm fatty acids in high-producing cows. The PA supplement increased milk and milk fat and protein yields but had no effect on the concentration of milk components. Secretion of palmitic acid in milk was increased by PA supplement, whereas biohydrogenation intermediates were decreased. Plasma insulin and nonesterified fatty acid concentrations did not differ. Palmitic acid supplements may modestly increase milk and milk fat yield while decreasing the risk of milk fat depression compared with calcium salts of palm fatty acids. http://dx.doi.org/10.3168/jds.2013-7723. A statistical filtering procedure to improve the accuracy of estimating population parameters in feed composition databases. By Yoder et al., page 5645. Large feed composition databases are generated by commercial testing laboratories but they are at times contaminated with samples that are improperly identified or that belong to more specific subpopulations of a larger population. Inclusion of these observations inflates estimates of variation within the population and can affect correlations among nutrients. Accurate composition data, including information on (co) variances, are needed for application of stochastic diet formulation. We developed a rapid statistical method to identify outliers. When the method was applied to a large database, more than 13% of the observations within classified feed populations were identified as outliers; when they were removed, variability decreased and correlations often changed. http://dx.doi.org/10.3168/jds.2013-7724. Effects of the heating process of soybean oil and seeds on fatty acid biohydrogenation in vitro. By Troegeler-Meynadier et al., page 5657. Addition of fat in dairy cow diets affects milk fat quality for human consumers. Effects of fat heating on ruminal biohydrogenation depend on duration and temperature. This paper provides new insights into effects of the heat-
ing process on ruminal biohydrogenation, which could be useful to optimize thermal treatment of oilseeds to improve milk fat quality. http://dx.doi.org/10.3168/jds.2013-7783. Dietary modulation of the expression of genes involved in short-chain fatty acid absorption in the rumen epithelium is related to short-chain fatty acid concentration and pH in the rumen of goats. By Yan et al., page 5668. Many studies have reported that feeding additional concentrate could enhance the short-chain fatty acid (SCFA) absorption capacity of rumen via increased messeneger (m) RNA expression of proteins that are involved in SCFA absorption. We investigated how mRNA expression of these genes is affected by diet. Dietary effects on rumen epithelial mRNA expression of genes involved in SCFA absorption are associated with ruminal SCFA and ruminal pH. http://dx.doi.org/10.3168/jds.2013-7807. Corn bran versus corn grain at 2 levels of forage: Intake, apparent digestibility, and production responses by lactating dairy cows. By Arndt et al., page 5676. Corn bran is the fibrous outer layer of corn grain present in small amounts in corn grain and corn silage and as a larger part of various co-products of corn processing. The energy value of corn bran is not well established but can be predicted from the analyzed chemical composition. This study measured the feeding value of relatively pure corn bran derived from dry-mill fractionation of corn grain. Substituting corn bran for corn grain decreased diet digestibility and milk yield and indicated that corn grain fiber digestibility predicted from chemical composition overestimates in vivo digestibility. http://dx.doi.org/10.3168/jds.2013-7815. Effects of reduced dietary protein and supplemental rumen-protected essential amino acids on the nitrogen efficiency of dairy cows. By Arriola Apelo et al., page 5688. Under current feeding practices, only 25% of N is captured in milk, with the remainder being excreted into the environment. Based on the National Research Council’s (2001) Nutrient Requirements of Dairy Cattle prediction, reducing dietary crude protein (CP) from 17 to 15% would lower milk protein yield by 29%; however, that reduction was not observed in this study. Furthermore, the marginal efficiency of the extra metabolizable protein (15 to 17%) was only 19%. Reducing dietary CP would significantly reduce N excretion to the environment. http://dx.doi.org/10.3168/jds.2013-7833. Addition of gut active carbohydrates to colostrum replacer does not improve passive transfer of immunoglobulin G in Holstein dairy calves.
By Villettaz Robichaud et al., page 5700. This study investigated the effects of the addition of gut active carbohydrates (GAC) to 1.5 doses (150 g of immunoglobulin G, IgG) of a commercial colostrum replacer on passive transfer of IgG in dairy calves. Treatment with GAC did not affect apparent efficiency of absorption of IgG (%), serum IgG concentrations (mg/mL), or serum total protein concentrations (g/dL) at 24 h of age. http://dx.doi.org/10.3168/jds.2013-7854. The effects of supplementation with a blend of cinnamaldehyde and eugenol on feed intake and milk production of dairy cows. By Wall et al., page 5709. Two experiments were conducted to study the effects of dietary addition of a plant extract product containing cinnamaldehyde and eugenol on the milk production performance of lactating dairy cows. When fed at moderate doses, the additive was associated with increased feed intake and milk production. In addition, we observed treatment by parity interactions that have not been described previously. http://dx.doi.org/10.3168/jds.2014-7896. Effect of flaxseed physical form on digestibility of lactation diets fed to Holstein steers. By Schroeder et al., page 5718. Four multi-cannulated Holstein steers were fed lactating cow diets in a 4 × 4 Latin square design to determine the effect of flaxseed processing method on ruminal fermentation and digestibility. Either rolling or grinding of flaxseed increases its nutrient availability and utilization when fed in lactating dairy cow diets. http://dx.doi.org/10.3168/jds.2014-7911. Effects on enteric methane production and bacterial and archaeal communities by the addition of cashew nut shell extract or glycerol—An in vitro evaluation. By Danielsson et al., page 5729. Methane (CH4) production from dairy cows is an issue for global warming and at the same time represents energy loss for the cow. The present in vitro study examined the effects of 2 feed additives × cashew nut shell extract (CNSE) and glycerol—on CH4 and volatile fatty acid concentrations and on microbial populations in rumen fluid. Reduced CH4 production was shown with CNSE but not with glycerol, suggesting that CNSE can be a promising inhibitor of CH4 formation in the rumen of dairy cows. http://dx.doi.org/10.3168/jds.2014-7929. Effect of reducing dietary forage in lower starch diets on performance, ruminal characteristics, and nutrient digestibility in lactating Holstein cows. By Farmer et al., page 5742. Providing sufficient dietary fiber from forages supports ruminal health and productivity. However, when forage quality or quantity is limited, lower forage diets may be fed. Additionally,
the price of corn grain has markedly increased, making lower starch diets more common. We found that reducing dietary forage content from 52 to 39% of dry matter while increasing wheat straw inclusion to maintain chewing and rumen function resulted in similar milk yield and composition, although feed intake increased. With our lower starch diets, the minimal forage content to maintain lactational performance was between 39 and 43%. http://dx.doi.org/10.3168/jds.2014-7963. Identification of lactic acid bacteria in the rumen and feces of dairy cows fed total mixed ration silage to assess the survival of silage bacteria in the gut. By Han et al., page 5754. We examined the lactic acid bacteria (LAB) communities in the gut content of dairy cows fed silage as the sole diet. The survival of silage LAB was evaluated by culture-independent microbial analysis using Lactobacillus-specific PCR amplification. Five of the 14 silage LAB species (Lactobacillus acetotolerans, Lactobacillus pontis, Lactobacillus casei, Lactobacillus suebicus, and Lactobacillus plantarum) survived and were detected in the feces. Elimination of silage LAB took place in the rumen rather than in the postruminal gut segments. Thus, several LAB species may have the potential to carry the probiotic function from silage to dairy cows. http://dx.doi.org/10.3168/jds.2014-7968. Effects of partial mixed rations and supplement amounts on milk production and composition, ruminal fermentation, bacterial communities, and ruminal acidosis. By Golder et al., page 5763. Feeding isoenergetic supplements in a partial mixed ration on a feed pad reduced the incidence of ruminal acidosis compared with feeding concentrates twice daily at milking, but did not improve milk production and composition in late-lactation cows. The incidence of ruminal acidosis increased linearly with increasing supplement amount. Distinct bacterial community compositions were found among cattle with different supplement feeding strategies and amounts. These communities were associated with altered ruminal fermentation measures. http://dx.doi.org/10.3168/jds.2014-8049. Chewing, rumen pool characteristics, and lactation performance by dairy cows fed 2 concentrations of a corn wet-milling coproduct with different forage sources. By Shepherd et al., page 5786. Fibrous corn milling coproducts provide highly digestible fiber with low starch and moderate protein concentration. We hypothesized that we could increase the coproduct from 20 to 30% while maintaining fiber digestibility and milk production if we substituted a portion of corn silage with alfalfa or grass hays. Grass hay increased particle size and pool size of ruminal contents and rumination but had slower ruminal diges-
tion of neutral detergent fiber than alfalfa hay. With increased inclusion of the co-product, producers should consider substituting a portion of corn silage with alfalfa or grass hays, depending on forage digestibility and the need for physically effective fiber. http://dx.doi.org/10.3168/jds.2014-8169. Genetic relationships of clinical mastitis, cystic ovaries, and lameness with milk yield and somatic cell score in first-lactation Canadian Holsteins. By Koeck et al., page 5806. Clinical mastitis, cystic ovaries, and lameness are among the 3 most frequently reported dairy cattle diseases. The aim of this study was to investigate the genetic relationships of these 3 diseases with test-day milk yield and somatic cell score using random regression models. Milk yield was unfavorably correlated with clinical mastitis and cystic ovaries, whereas a highly favorable association was found between somatic cell score and clinical mastitis. The unfavorable relationships with milk yield support the inclusion of direct health traits in genetic selection. http://dx.doi.org/10.3168/jds.2013-7785. Assigning unknown parent groups to reduce bias in genomic evaluations of final score in US Holsteins. By Tsuruta et al., page 5814. Unknown parent groups have been considered to minimize bias in genetic evaluations by adjusting differences among genetic groups. The bias in genomic evaluations of US Holstein bulls for final score could be amplified by poorly defined unknown parent groups, especially when genotyped young bulls have no daughters because of no contributions from phenotypic records to unknown parent groups for those young bulls. Redefining of unknown parent groups is a practical and rational approach to reduce bias in genomic evaluations for young bulls. http://dx.doi.org/10.3168/jds.2013-7821. Adding cows to the reference population makes a small dairy population competitive. By Thomasen et al., page 5822. The competitiveness of small dairy cattle populations is challenged by low reliabilities of genomic predictions. These are mainly due to limited numbers of proven sires in the reference population. Genotyping of cows for inclusion in the reference population increases reliabilities and thereby genetic gain. Inclusion also reduces the rate of inbreeding compared with breeding schemes with only progeny-tested bulls in the reference population. The increase in genetic gain is larger for a turbo scheme characterized by exclusive use of young bulls and hence achieving shorter generation intervals. Inclusion of cows in the reference population is a profitable and fast way to increase reliabilities of genomic predictions. It constitutes an attractive option for small dairy cattle populations. http://dx.doi.org/10.3168/jds.2014-7906.
A single-step genomic model with direct estimation of marker effects. By Liu et al., page 5833. Until now, a multi-step genomic model has been used in most countries for genomic evaluation of dairy cattle. We developed a single-step genomic model with direct estimation of marker effects. Our model evaluated genotyped and nongenotyped animals jointly and used all phenotypes and pedigrees. Our model can avoid bias in prediction caused by genomic preselection and provide accurate genomic predictions. The estimated marker effects can be used in frequent interim genomic evaluation, resulting in a reduction of costs in genomic selection. http://dx.doi.org/10.3168/jds.2014-7924. Genetic parameters across lactation for feed intake, fat- and protein-corrected milk, and liveweight in first-parity Holstein cattle. By Manzanilla Pech et al., page 5851. The objective of this study was to estimate genetic parameters for dry matter intake (DMI), fat- and protein-corrected milk (FPCM), and liveweight (LW) across the entire first lactation. Heritabilities and genetic correlations of DMI, FPCM, and LW changed across different stages of lactation, mainly differing during early and late lactation compared with mid lactation. Genetics of DMI appears to vary across lactation. The results are useful to understand the genetic relationship between DMI, FPCM, and LW on specific days across lactation, and should be taken into account when constructing a selection index. http://dx.doi.org/10.3168/jds.2014-8165. Mid-infrared spectrometry of milk as a predictor of energy intake and efficiency in lactating dairy cows. By McParland et al., page 5863. Residual feed intake, defined as the difference between the actual energy available and that demanded by the various energy sinks, is a potentially useful measure of feed efficiency in lactating dairy cows. The derivation of residual feed intake phenotypes for whole populations of cows is hampered, however, by a lack of individual cow feed intake records. Hence, easy-to-measure, low-cost predictors of either energy intake or residual feed intake are of interest. The present study shows that milk mid-infrared spectrometry can be a useful predictor of energy intake and efficiency in lactating dairy cows. http://dx.doi.org/10.3168/jds.2014-8214. Short communication: Genetic relationships between claw disorders, protein yield, and somatic cell score by days in milk. By Gernand and König, page 5872. Random regression models were applied to study daily genetic relationships between selected binary claw disorders with protein yield and somatic cell score. Genetic correlations with protein yield varied in the course of lactation for the same claw disorder
and were different for different claw disorders on identical test days. For example, obvious signs for genetic antagonisms were detected between protein yield and sole ulcer, whereas genetic correlations for interdigital hyperplasia and protein yield were mostly favorable. http://dx.doi.org/10.3168/jds.2013-7612. Short communication: Alteration of priors for random effects in Gaussian linear mixed models. By Vandenplas et al., page 5880. Some statistical analyses need to alter the default mean and (co) variance of the prior distribution of random effects of linear mixed models commonly used in animal breeding. However, most available software packages do not permit those alterations. Therefore, the aim of this study was to propose a method to alter both mean and (co)variance of prior distributions while using available software packages through the use of an extended data file and a user-supplied (co)variance matrix. http://dx.doi.org/10.3168/jds.2014-8155. Effects of ingesting fermented milk by using Lactococcus lactis H61 on skin health in young women: A randomized double-blind study. By Kimoto-Nira et al., page 5898. Healthy female volunteers (n = 23; age, 19–21 yr) received Lactococcus lactis H61-fermented milk (1010 cfu of strain H61/300 g per day) or conventional yogurt (1010 cfu of both Lactobacillus delbrueckii ssp. bulgaricus and Streptococcus thermophilus/d) for 4 wk, and various skin properties were measured. Sebum content in cheek increased significantly after intervention in the H61-fermented milk group but not in the conventional yogurt group. As skin lipids contribute to maintaining the skin barrier, H61-fermented milk would provide beneficial effects in skin for young women. http://dx.doi.org/10.3168/jds.2014-7980. Feeding strategies and manure management for cost-effective mitigation of greenhouse gas emissions from dairy farms in Wisconsin. By Dutreuil et al., page 5904. Dairy farmers are encouraged to decrease greenhouse gas emissions while remaining profitable. Survey data were used to characterize feeding and manure management strategies on conventional, grazing, and organic dairy farms followed by simulation of mitigation strategies. The incorporation of grazing in the conventional farms and the decrease in forageto-concentrate ratio in the grazing and organic farms were effective in reducing model-predicted greenhouse gas emissions while maintaining profitability. However, mitigation strategies should be implemented according to farm-specific characteristics. http://dx.doi.org/10.3168/jds.2014-8082. Effect of planting density on nutritional quality of green-chopped corn for silage. By Ferreira et
al., page 5918. Crop management practices may not be well established among dairy farmers when corn is destined for silage. Even though planting corn at high densities can diminish silage quality, dairy farmers frequently plant cornfields with high densities to obtain a greater yield of biomass. In this study, with abundant
precipitation, biomass yield increased when corn was planted at high densities. In addition, whole-plant nutritional quality was not affected by increasing corn plant density. http://dx.doi.org/10.3168/jds.2014-8094.