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Abstracts of Papers Presented at the Northeastern Section of the American Dairy Science Association Annual Meeting
A B S T R A C T S OF P A P E R S P R E S E N T E D AT T H E N O R T H E A S T E R N S E C T I O N OF T H E A M E R I C A N D A I R Y S C I E N C E ASSOCIATION ANNUAL MEETING of rancid flavor. H. A. Willey* and A. I4. Duthie, University of Vermont, Burlington. Six milk samples were prepared by different treatments with comparable acid degree values. Organoleptic analysis showed two distinct offflavors, one characterized as sickening, the other unclean. The five treatments used to induce lipolysis on nonspontaneous milk acquired from the creamery bulk tank were: mixing raw and homogenized milks, churning, foaming in a tall chromatographic column, agitation with a Waring Blendor, and temperature fluctuation. A sixth sample was taken from a cow that secreted milk which ]ipolyzed spontaneously. Three milk flavor judges independently analyzed the lipolyzed samples with comparable acid degree values. The samples were coded by a technician and presented to the judges at 10 C. Acid values were performed by the Modified Thomas Method after samples were scored for flavor. Preliminary results from several trials clearly indicate two distinct flavors. The following treatments constantly give a sickening type rancid flavor: mixing raw and homogenized milks, churning, agitation in a Waring Blendor, and temperature fluctuation. Foaming and spontaneous ]ipolyzing milk give ABSTRACTS OF P A P E R S P R E S E N T E D an unclean type of rancid flavor. Quantitative extraction of skimmilk lipids by New fat test for skimmilk. A. It. Duthie, ~ four methods. P. H. Foulkes* and A. H. P. H. Foulkes, and H. V. Atherton, University Duthie, University of Vermont, Burlington. of Vermont, Burlington. Lipids from skimmilk were extracted by the Skimmilk samples from the University following methods: the Mojonnier, Babcock, Creamery were tested for fat by four simple American Association, and a procedure recently laboratory procedures and the Mojonnier methdeveloped at the University of Vermont. The od. The results from eight trials showed the lipids recovered by each method were separated following mean values : Babcock, 0.01% ; Wilinto neutral lipid and phospholipid fractions damn modification of the Babcock (use of a using a modified BorgstrSm column. Each frac- quaternary ammonium compound), 0.01% ; tion was analyzed both qualitatively and quan- American Association (modified Babcock using titatively using weights, thin-layer chromatog- n-butanol), 0.02%; Gerber, 0.11%; and Moraphy, phosphorus and cholesterol analyses, and jonnier, 0.07%. These values show poor agreea photodensitometer. ment with the Mojonnier method. The means of six trials in per cent of total The need for a simple, reliable test to deterlipids extracted were as follows: Mojonnier, mine fat in skimmilk was self evident. Such a 0.1440%; Babcock, 0.0410%; American As- procedure was developed at the University of sociation, 0.0996%; Vermont, 0.1010%. Our Vermont (Vermont method). Patton's aqueous results show that the Mojonnier method ex- reagent of n-butylamine and n-butanol is used tracted the greatest amount of milk lipids from to release the fat along with Babcock equipment skimmilk and the Babcock the least. Both the and glassware and the TeSa water bath. American Association and the Vermont methods Six methods were tested on skimmilk samare almost identical in the amount of lipids recovered, which is greater than the Babcock ples purchased from four locM dealers and but less than the Mojonnier. Of the four meth- the University Creamery. The Gerber and Verods, phospholipids were identified only in the mont methods showed closer agreement with the Mojonnier. Ten trials on university skimmilk lipid extracted by the Mojonnier method. resulted in the following mean values: BabEvidence for existence of more than one type cock, 0.03%; Wildasin modification, 0.04%; American Association, 0.05% ; Vermont, 0.12% ; *Denotes author who presented paper. 277
The 1968 meeting of the Northeastern Section of the American Dairy Science Association was held at the University of Vermont in Burlington, August 18-20, 1968. The North Atlantic Section of the American Society of Animal Science met concurrently. Sixty contributed papers were presented in seven joint meeting sessions. A symposium on education and opportunities in animal and dairy science included papers by R. B. Patzer, Dean of Students, University of Vermont; R. E. Geyer, Executive Secretary, National Academy of Sciences; R. E. Morton, Director, Personnel Administration, Ralston Purina Company, and W. S. Leses, Agency for International Development, Ethiopia. Officers elected for the coming year were: President, D. H. Kleyn; Vice President, R. F. Davis; Secretary-Treasurer, J. M. Elliot. The next meeting will be held concurrently with a meeting of the North Atlantic Section of the American Society of Animal Science at the University of Delaware in Newark early in August, 1969. Over 200 individuals in attendance enjoyed a most successful and rewarding scientific meeting.
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Gerber, 0.15% and Mojonnier, 0.13%. Results on skimmilk obtained from local dealers were similar. Calibration techniques for protein estimation by the acid Orange 12 dye binding method. S. N. Gaunt ~ and D. J. ttankinson, University of Massachusetts, Amherst. I n dye binding methods for protein estimation, instrument calibration is required for predicting protein levels from light transmission or optical density readings. Three methods have been used: a) dye binding capacity, the milligrams of absorbed dye is divided by an established dye-binding value for the dye to obtain the milligrams protein in the sample; b) a series of samples from nonfat dry milk representative of the range of protein to be encountered with Kjeldahl analyses. Values are regressed on the spectrophotometric readings after dye binding to obtain an equation predicting per cent protein; and c) same as Method b except that milk samples randomly selected from typical test samples are used instead of skimmilk. Method e is the most reliable. F i f t y to 100 comparisons on each batch of dye diluted for use are necessary to obtain a reliable predicting equation. Standard errors for eight 13-gallon batches of dye were: ±.089, -----.136, ±.115, ---+.096, ±.117, ±.124, ±.112, and ± . 1 0 1 % protein, respectively; whereas, when values for all eight batches were pooled the standard error was ± . 1 3 7 % protein indicating that variations may occur from batch to batch even when care is used in standardizing the solution of dye. Factors affecting salting and cooling of Mozzarella cheese. A. S. Leake* and K. M. Nilson, University of Vermont, Burlington. Loaves of Mozzarella cheese were cooled in 4.6 C and --6.0 C salt-brine solution at 90% saturation. A t 4.6 C the cheese cooled from 51.8 to 16.2 C after 3 hr and to 15.6 C in 1.5 hr at --6.0 C. Salt-brine temperatures affected the moisture loss, but had little effect on the salt penetration of the cheese. A t --6.0, 0.7, 6.8, 12.8, and 21.1 C the moisture loss of 2.5 lb loaves was 1.20, 1.35, 2.15, 3.05, and 4.27% after 12 hr and 1.30, 1.40, 2.70, 3.12, and 5.5% after 20 hr, respectively. There was no significant difference in salt penetration at various brining temperatures. The salt penetration was gradual from 4 to 20 hr of brining, with 50% of the salt attained the first 4 hr. The salt content of 5-1b loaves of cheese ranged from 3.40 to 5.5%, 0.25 to 1.30%, and 0.4 to 0.8% in the outer onefourth inch, second one-fourth inch, and third one-fourth inch, respectively, after 4 to 20 hr of salting. A f t e r the second stretching in an Artofex machine and removal of all water, 1.6% salt was added directly to the cheese. A f t e r normal J. DAIRY SCIENCE "~OL. 52, NO.
ripening no defects in melting or stretching were found. Fortification of part-skimmilk for the mannfacture of Mozzarella cheese. A. S. Leake ~ and K. 1YI.Nilson, University of Vermont, Burlington. Effeet of adding :i, 2, and 4% nonfat dry milk solids and 0.25, 0.65, and 1.3% cream (40%) to 2% milk on the subsequent yield and quality of Mozzarella cheese was studied. Mozzarella cheese was manufactured by the regular method with a variation in cooking temperature from 43.5 to 41.2 C. Loss of fat and solids not f a t in the whey was 0.23 and 6.34% for the control, 0.21 and 7.02% for the sample with 1% added solids, 0.23 and 7.70% for the 2% added solids, and 0.245 and 8.56% for the 4% added solids. Losses in the mixing-molding water were 0.245, 0.26, 0.24, and 0.335% fat and 0.22, 0.29, 0.395, and 0.435% SNF, respectively. The finished cheese after salting contained 17.1, 16.5, 16.2, and 16.3% f a t and 49.7, 49.6, 49.4, and 49.1% total solids, respectively. Yields on a dry weight basis were 5.11% for the control, 5.54% for 1% added solids, 6.14% for 2% added solids and 7.19% for 4% added solids. Cheese manufactured from the higher solids milk required 7-10 days longer ripening for maximum flavor development and melting qualities. Preliminary comparison of summer annual grasses and alfalfa fed as green-chopped forage to dairy heifers. C. E. Church, W. P. Apgar, °~ and C. S. Brown. University of Maine, Orono.
I n Trial 1 of two feeding trials, alfalfa cut at approximately one-tenth bloom was compared with P i p e r Sudangrass and Sweet Sioux harvested while still in a vegetative stage. In Trial 2, aftermath alfalfa and P i p e r Sudangrass were compared. Average dry matter intakes for heifers in Trial 1 expressed as percentages of body weight did not vary significantly among alfalfa (1.8%), P i p e r (1.7%), and Sweet Sioux (1.6%). Earlier maturity resulted in higher intakes of Trial 2 alfalfa (2.3%) and P i p e r (2.2%). I n Trial 1, average net energy digestibility of Sweet Sioux (59.3%) was significantly greater (P ~ .05) than that of alfalfa (54.5%) while P i p e r was intermediate (56.5%). Average energy digestibility for alfalfa (60.0%) and P i p e r (62.4%) were similar in Trial 2. Nutritive value indices did no vary significantly in either Trial 1 or Trial 2. The summer annual grasses were essentally equal, but not superior to alfalfa based on an over-all nutritive comparison in this study. Ratios of solids-not-fat and protein to fat in the milk of three breeds. R. E. Mather, ~ Prabhu Lal, and E. T. Oleskie, New Jersey Agricultural Experiment Station, Sussex.
ASSOCIATION A F F A I R S
One possible method of increasing the solidsnot-fat (SNF) or protein (P) in milk in relation to fat (F) is to select on the basis of their ratios to fat. The mean S N F / F and P / F ratios for Guernseys (1,537 lactations 270-305 days), Holsteins (1,246), and Jerseys (1,332) and their within-herd standard deviations were 1.874 (0.141) and 0.751 (0.068; 2.224 (0.181) and 0.808 (0.077) ; and 1.799 (0.148) and 0.734 (0.057). After adjusting for age (cubic), year (6), season (2), year × season, and pregnancy ( > 1 6 0 days) by nested analysis of multiple regression to get adjusted components of variance and covariance, repeatabilities for S N F / F were 0.76 ± 0.02, 0.75 ± 0.02, 0.76 ± 0.018, and for the three breeds pooled 0.75 ± 0.01. For P / F the repeatabilities were 0.53 ± 0.03, 0.55 ± 0.03, 0.59 ± 0.03, and 0.53 ± 0.02. Heritability estimates were for S N F / F 0.59 ± 0.14, 0.95 ± 0.17, 0.69 ± 0.15, and 0.80 ± 0.09; for P / F they were 0.39 ± 0.12, 1.04 ± 0.15, 0.41 -+- 0.12, and 0.64 ~ 0.08. Genetic correlations (based on adjusted sire components) of milk with S N F / F were 0.38, 0.15, 0.64, and 0.26, and for milk with P / F were 0.26, 0.12, 0.21, and 0.15. Heritability of solids-not-fat and protein percentages adjusted for fat percentage in three breeds. R. E. Mather, ~ Prabhu La], and E. T. Oleskie, New Jersey Agricultural Experiment Station, Sussex. Lactation data (270-305 days) on solids-notfat (SNF) and protein percentages on Guernseys (5 herds, 191 sires, 817 cows, 1,537 records), Holsteins (9, 234, 670, 1,246), and Jerseys (5, 124, 727, 1,332), and pooled over the three breeds within herd, were adjusted for age (cubic), year (6), season (2), year × season, pregnancy ( > 160 days), and fat percentage by a nested analysis of multiple regression to get adjusted components of variance and covariance. Within-herd repeatabilities for adjusted SNF for the three breeds and pooled data were 0.55 ± 0.03, 0.74 ± 0.02, 0.49 ± 0.03, and 0.60 ± 0.02. For adjusted protein repeatabilities were 0.41 ± 0.03, 0.54 ± 0.03, 0.52 +-- 0.03, and 0 . 4 4 ± 0.02. Estimated heritabilities for adjusted SNF were 0.84 ± 0.13, 0.62 ± 0.17, 0.58 ± 0.13, and 0.73 ± 0.08. For adjusted protein heritabilities were 0.42 ± 0.11, 0.72-+0.15, 0.50 ± 0.13, and 0.44 ± 0.07. Thus it should be possible to select for higher SNF or protein percentage without modifying the fat percentage. Genetic correlations of adjusted SNF with similarly adjusted milk were --.91, --.21, 0.34, and --.13, and of protein with milk were --.37, --.17, --.25, and --.10. Genetic correlations between adjusted SNF and adjusted protein were 0.70, 0.81, 0.46, and 0.64. Blood protein changes during the lactation cycle of Holstein cows. J. W. Smith and E. M. Kesler, ~ The Pennsylvania State University, University Park. Holstein cows, aged 3-9 years, with known
27~
lactation potential were used. In Trial 1, 12 cows calved between February and May; in Trial 2, 10 with Fall parturitions. Blood samples were drawn 1-2 weeks before parturition, one day postpartum, weekly for the next six weeks, at longer intervals during the remainder of lactation, and at 1 and 4 weeks after beginning of the dry period. In Trial 1, blood hemoglobin values were highest at Day I postpartum (13.71 ± 1.16 g/100 ml) and during the dry period (13.26 ± 0.98). Significantly lower (P < 0.01) values were noted during Weeks 1-6 of lactation, with a low value of 11.31 ± 1.06 g/100 ml observed at 5 weeks. Trends in hematocrit were similar. Serum albumin levels remained relatively sable throughout, with values ranging from 2.08 to 3.40 g / 100 ml serum, a-Globulin levels were lowest prepartmn (1.01 ± 0.17 g) and rose to a high of 1 . 4 0 ± 0 . 1 3 g at Week 22 ( P < 0 . 0 1 ) . flglobulin was low prepartum (0.82 ± 0.10 g) and highest at Week 30 (1.00 --+ 0.08 g) (P < 0.05). T-Globulin was low prepartum and peaked at Week 3 (2.74 ± 0.36 and 3.56 ± 0.90 g, respectively) (P < 0.05). Values observed in Trial 2 were similar to those in Trial 1, except that T-globulin levels were significantly lower throughout. Effect of nitrogen fertilization and physiological maturity of timothy grass at the time of cutting on silage fermentation. H. Fenner ~ and W. G. Colby, University of Massachusetts, Amherst. A two-year old stand of timothy fertilized with Nitrogen at rates of 35, 70, 105, and 175 kg/hectare, was cut at the early head, full bloom and soft-dough seed stage, chopped and ensiled in quart size mason jars. After five months, the silages were analyzed for fermentation products. Nitrogen-fertilization raised the ash, crude protein, true protein and nonprotein nitrogen content of the forage and lowered the dry matter and nitrogen-free extract. Delayed cutting raised the average dry matter, nonprotein nitrogen and crude fiber content and lowered the ash, crude and true protein. Silages showed the following changes in constituents: High nitrogen fertilization increased the average pH, the concentrations of total volatile bases, total volatile fatty acids, propionic, iso-butyric, n-butyric, isovaleric, n-va]eric and n-caproic acids and lowered the lactic acid and alcohol content. The concentration of acetic acid changed irregularly. Delayed cutting of the forage lowered the pH, the proportions of total volatile bases, total volatile fatty acids, propionie~ iso-butyric, n-butyric, iso-valeric, n-valeric, and n-eaproic acids and raised that of lactic acid. Alcohol and acetic acid contents changed irregularly. Apparent dry matter losses, due to fermentation, rose with increased nitrogen-fertiliza,)'. DAIRY SCIEI~C~ ~/-OI~. 52, NO. 2
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tion, but were reduced when the forage was cut at a more mature stage. Mason jars served as useful miniature silos for estimating changes in forage constituents during storage as silage. Effect of recutting and plant maturity on kernel passage and feeding value of corn silage. G. R. Buck, W. G. Merrill, C. E. Coppoek,* and S. T. Slack, Cornell University, Ithaca, New York. I n each of two trials, sixteen first-calf ]~olstein cows were assigned to a Latin-square design for four, five-week feeding periods to compare the intake and milk production response when fed corn si]ages involving various plant maturities (as reflected by plant dry matter percentage) and fineness of chopping. Trial I, 22, 30, and 34% dry matter recur 5.1 em, and 46% dry matter recut 5.1 cm; and Trial I I , 33 and 33% dry matter recut 2.6 cm and 5.1 cm, 40 and 38% dry matter recur 2.6 Cl~.
With silages of higher dry matter content, less silage (as fed basis) was consumed, but more dry matter was consumed per 100 g of body weight. Recutting had no significant effect on silage dry matter intake. All silage treatments within trials supported milk production equally well. Steers were used to determine the digestibility of each silage and whole kernel passage was determined. Plant maturity had no significant effect on total digestible nutrients or digestible energy of the dry matter of the silages. Recutting the plant before ensiling significantly reduced the amount of kernel dry matter in the feces but recutting had no significant effect on the total digestible nutrients or digestible energy values of the silages. Observations on the efficiency of forage preservation in vacuum and stack silos. W. S. Gaunya,* W. A. Cowan, J. H. Whitaker, and J. J. Kolega, University of Connecticut, Storrs. Nine silos of varying capacity were utilized in this study to evaluate efficiency of forage preservation. Type of silo, amount of silage, kind and dry matter content of forage, days in storage, days of feeding and per cent of dry matter recovered were for Silo 1, vacuum stack; 41.7 tons; direct-cut hay-crop; 18.6%; 173 days; 19 days; 81.0% by weight, 80.1% by buried bags. Silo 2, vacuum stack; 26.5 tons; wilted hay-crop; 32.0%; 166 days; 5 days; 82.4% by weight, 92.2% by buried bags. Silo 3, vacuum stack; 8.2 tons; haylage; 64.6%; 76 days; 17 days; 79.3% by wt, 98.7% by buried bags. Silo 4, bunker; 38.1 tons; directcut hay-crop; 14.7%; 61 days; 13 days, 69.3%. Silo 5, vacuum; 39.6 tons; 14.4%; 73 days; 14 days ; 80.8%. Silo 6, vacuum 15.7 tons ; hay]age ; 56.6%; 33 days; 22 days; 82.2%. Silo 7, vacuum; 161.8 tons; corn forage; 29.8%; 32 days; 107 days; 88.0%. Silo 8, stack; 26.7 tons; corn forage; 31.7%; 115 days; 18 days; J. DAIRY SCI~IqCE X~O.L. 52, NO. 2
66.4%. Silo 9, stack; 16.2 tons; corn forage; 35.2%; 16 days; 12 days; 88.5%. Efficacy of forage evaluation systems for dairy cattle feeding programs. R. F. Welton* and E. Donefer, Macdonald College, MeGill University, Province of Quebec, Canada. A total of 269 hay samples was analyzed for protein and cellulose content, with nutritive value indices predicted using the HCl-pepsin dry matter disappearance procedure. A subsample of 40 hays was randomly selected for acid detergent fiber, lignin, and soluble cell contents, and assigned quality codes (estimated net energy) based on Cornell tables. Protein and nutritive indices for all samples were distributed in two distinct populations, based on first and second cutting. Highly significant (P < .01) simple correlation coefficients between nutritive indices and protein, cellulose, fiber, and soluble cell contents were 0.79, --.62, --.83, and 0.95, respectively. Although nutritive indices and Cornell Codes had similar means, the nutritive indices were distributed over a wider range. Approximately 38% of the 40 selected samples showed sufficient variation in their nutritive indices to justify laboratory evaluation procedures. Accuracy of feeding recommendations would not be changed if the remainder of the samples were rated by either a tabular estimated net energy value or a nutritive indice laboratory analysis. Milk production capacity of Maine concentrates used in dairy cattle rations. H. A. Leonard,* B. R. Poulton, and P. S. Young, University of Maine, Orono. Concentrate rations comprised of Maine oats, barley, potato pulp and beet pulp were formulated with and without urea and compared with a control concentrate ration consisting of cereal grains, byproduct feeds and plant proteins norreally used in the feed industry. Minerals, vitamins and salt were balanced in each ration. Second cutting hay and wilted hay crop silage were fed ad libitum; 1 kg of concentrate was fed for each 2 kg of FCM. I n single reversal feeding trials conducted for four consecutive years using 35 balanced pairs of cows it was found that concentrate rations comprised of Maine-produced concentrates with urea as a protein source can support milk production in excess of 26.8 kg of F C M per cow per day. There were no statistical differences between the level of milk production on the rations comprised of Maine ingredients versus the control ration. Heat increments of steam-volatile fatty acids infused separately and in a mixture into fasting cows. Preliminary report. J. B. Holter,* N. F. Colovos, and C. W. Heald, University of New Hampshire, Durham. Heat increments for equicaiorie amounts of acetic, propionic and butyric acids and a 52
ASSOCIATION
acetic:31 propionic:17 butyric molar mixture of acids were determined in mature, fasted dairy cows. Acids were infused continuously into the tureen at a rate of 32 kcal p e r kg body weight °'~ daily. A number of rmnen fluid and blood traits were measured daily during each of the 10 experiments. No acidosis was noted as indicated by the CO:-combining capacity of whole venous blood. Mean heat increments were as follows: acetic acid, 40; propionic acid, 18; butyric acid, 18; and acid mixture, 32 kcal per 100 keal metabolizable energy. Factors affecting diurnal rumination patterns. J. G. Welch, K. S. Gibson, and A. M. Smith, University of Vermont, Burlington. Diurnal variations in rumination patterns in dairy cattle and sheep were investigated in eight trials utilizing 132 individual, 24 hour, jaw motion recordings. F o u r lactating Holstein cows (Production average 30.0 k g / d a y ) and eight sheep, fed to allow for the major feed ingestion to occur during the day, ruminated more during the night. This has been interpreted by others to indicate that feed ingestion inhibits rumination. Observations were recorded showing normal rumination occurring during long periods of hay ingestion and immediately following hay or grain ingestion. F o u r trials were conducted to attempt to reverse the normal nighttime peak in rumination activity. Feeding four sheep their entire roughage allowance at 5 p ~ failed to inhibit the peak rumination during the midnight to 6 A~ period although it did decrease the rumination from 6 PM to midnight. Feeding the total roughage allowance at 8 P~ did not produce a complete reversal in the 24-hr rumination patterns when compared to those produced by feeding the forage at 8 A~ in one three-day trial with four sheep and one six-day trim with four heifers. A similar 12-day reversal trial with four sheep produced a reversal in rumination pattern during only the first two days folIowing the changes in feeding schedule. In vitro effects of pH and concentration upon L(+)-lactate-U-~'C transfer by bovine rumen epithelium. G. M. Jones,* E. M. Kesler, and R. J. Flipse, The Pennsylvania State University, University Park. The metabolism and absorption of L ( + ) lactate-U-~C by rumen epithelium from Itolstein-Angus cattle was investigated using respiration and diffusion techniques. The simple effects of mucosM buffer p H (4.8, 6.15, 6.9, 7.4) and lactate concentration (25, 75, 135 raM) were studied in a factorial experiment. Yariation in oxygen uptake, lactate utilization, and amount of label appearing in tissue protein was attributed to buffer pH. Oxygen uptake and C02 production were affected by substrate
AFFAIRS
281
concentration. Lactate was converted to Maninc (24.7%) at p H 7.5, fl-hydroxybutyrate (4.8%) at p H 6.8, and glutamate (2.6%) at p H 5.85. Lactate absorption was not influenced by p i t or concentration, ttowever, the interaction of these variables accounted for most of the variation (P < .05). Absorption rates were greater at p H 6.1 or lower and at highest substrate concentrations. I n a corollary study, lactate utilization by rumen and intestinM tissue was compared. Oxygen uptake and lactate utilization were greater for intestinal incubations. However, absorption was greater across rumen mucosa than intestine (10.1 vs. 3.0, respectively). The mechanism of L ( + ) - l a c t a t e absorption across rumen epithelium apparently differs from that in intestine. The metabolic route of lactate utilization by tureen mucosa was directed more by mucosal p H than by substrate concentration. Lability in fasting heat production of dairy cattle. Nicholas F. Colovos, University of New Hampshire, Durham. The basal metabolism or fasting heat production of eight steers was measured with an open-circuit indirect calorimeter. The experimental animals were one pair of idengeal twins each of Holsteins, Guernseys, and Jerseys. The other two Holsteins were urn'elated. The results of forty-eight monthly 24-hr experiments show much less variation between breeds and animals than results published some thirty years ago, suggesting much less lability of basal metabolism in cattle. Effect of trichloromethiazide and dexamethasone on control of udder edema and milk production in lactating dairy cows. H. E. Carlsen,* J. M. Keith, and J. E. Croshaw, Delaware Valley College of Science and Agriculture, Doylestown, Pennsylvania. Twenty-one cows in four herds were used in this study. Fourteen animMs were treated as recommended by Schering with one bolus (200 mg trichloromethiazide and 5 mg dexamethasone) at calving and one-half bolus at 24 and 48 hr postpartum. Seven treated animals comprised a control group. Edema was rated on a scale from 0 to 5, with 0 being no detectable edema and 5 being edema which extended into tissue surrounding the udder. The mean edema score for the control group at calving was 3.9 and declined to 3.7 and 3.6 at Days 3 and 5, respectively. The treated group had a mean edema score of 2.1 and declined to 1.0 and 0.4 at Days 3 and 5, respectively. The increase in milk production from the third to the tenth day after calving was determined. The control group of cows increased 8.6 kg of milk, whereas, the increase for those treated was 10.7 kg.
J . DAIRY SCIENCE VOL. 52, NO. 2
The 1968 meeting of the Northeastern Section of the American Dairy Science Association was held at the University of Vermont in Burlington, August 18-20, 1968. The North Atlantic Section of the American Society of Animal Science met concurrently. Sixty contributed papers were presented in seven joint meeting sessions. A symposium on education and opportunities in animal and dairy science included papers by R. B. Patzer, Dean of Students, University of Vermont; R. E. Geyer, Executive Secretary, National Academy of Sciences; R. E. Morton, Director, Personnel Administration, Ralston Purina Company, and W. S. Leses, Agency for International Development, Ethiopia. Officers elected for the coming year were: President, D. H. Kleyn; Vice President, R. F. Davis; Secretary-Treasurer, J. M. Elliot. The next meeting will be held concurrently with a meeting of the North Atlantic Section of the American Society of Animal Science at the University of Delaware in Newark early in August, 1969. Over 200 individuals in attendance enjoyed a most successful and rewarding scientific meeting.
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Gerber, 0.15% and Mojonnier, 0.13%. Results on skimmilk obtained from local dealers were similar. Calibration techniques for protein estimation by the acid Orange 12 dye binding method. S. N. Gaunt ~ and D. J. ttankinson, University of Massachusetts, Amherst. I n dye binding methods for protein estimation, instrument calibration is required for predicting protein levels from light transmission or optical density readings. Three methods have been used: a) dye binding capacity, the milligrams of absorbed dye is divided by an established dye-binding value for the dye to obtain the milligrams protein in the sample; b) a series of samples from nonfat dry milk representative of the range of protein to be encountered with Kjeldahl analyses. Values are regressed on the spectrophotometric readings after dye binding to obtain an equation predicting per cent protein; and c) same as Method b except that milk samples randomly selected from typical test samples are used instead of skimmilk. Method e is the most reliable. F i f t y to 100 comparisons on each batch of dye diluted for use are necessary to obtain a reliable predicting equation. Standard errors for eight 13-gallon batches of dye were: ±.089, -----.136, ±.115, ---+.096, ±.117, ±.124, ±.112, and ± . 1 0 1 % protein, respectively; whereas, when values for all eight batches were pooled the standard error was ± . 1 3 7 % protein indicating that variations may occur from batch to batch even when care is used in standardizing the solution of dye. Factors affecting salting and cooling of Mozzarella cheese. A. S. Leake* and K. M. Nilson, University of Vermont, Burlington. Loaves of Mozzarella cheese were cooled in 4.6 C and --6.0 C salt-brine solution at 90% saturation. A t 4.6 C the cheese cooled from 51.8 to 16.2 C after 3 hr and to 15.6 C in 1.5 hr at --6.0 C. Salt-brine temperatures affected the moisture loss, but had little effect on the salt penetration of the cheese. A t --6.0, 0.7, 6.8, 12.8, and 21.1 C the moisture loss of 2.5 lb loaves was 1.20, 1.35, 2.15, 3.05, and 4.27% after 12 hr and 1.30, 1.40, 2.70, 3.12, and 5.5% after 20 hr, respectively. There was no significant difference in salt penetration at various brining temperatures. The salt penetration was gradual from 4 to 20 hr of brining, with 50% of the salt attained the first 4 hr. The salt content of 5-1b loaves of cheese ranged from 3.40 to 5.5%, 0.25 to 1.30%, and 0.4 to 0.8% in the outer onefourth inch, second one-fourth inch, and third one-fourth inch, respectively, after 4 to 20 hr of salting. A f t e r the second stretching in an Artofex machine and removal of all water, 1.6% salt was added directly to the cheese. A f t e r normal J. DAIRY SCIENCE "~OL. 52, NO.
ripening no defects in melting or stretching were found. Fortification of part-skimmilk for the mannfacture of Mozzarella cheese. A. S. Leake ~ and K. 1YI.Nilson, University of Vermont, Burlington. Effeet of adding :i, 2, and 4% nonfat dry milk solids and 0.25, 0.65, and 1.3% cream (40%) to 2% milk on the subsequent yield and quality of Mozzarella cheese was studied. Mozzarella cheese was manufactured by the regular method with a variation in cooking temperature from 43.5 to 41.2 C. Loss of fat and solids not f a t in the whey was 0.23 and 6.34% for the control, 0.21 and 7.02% for the sample with 1% added solids, 0.23 and 7.70% for the 2% added solids, and 0.245 and 8.56% for the 4% added solids. Losses in the mixing-molding water were 0.245, 0.26, 0.24, and 0.335% fat and 0.22, 0.29, 0.395, and 0.435% SNF, respectively. The finished cheese after salting contained 17.1, 16.5, 16.2, and 16.3% f a t and 49.7, 49.6, 49.4, and 49.1% total solids, respectively. Yields on a dry weight basis were 5.11% for the control, 5.54% for 1% added solids, 6.14% for 2% added solids and 7.19% for 4% added solids. Cheese manufactured from the higher solids milk required 7-10 days longer ripening for maximum flavor development and melting qualities. Preliminary comparison of summer annual grasses and alfalfa fed as green-chopped forage to dairy heifers. C. E. Church, W. P. Apgar, °~ and C. S. Brown. University of Maine, Orono.
I n Trial 1 of two feeding trials, alfalfa cut at approximately one-tenth bloom was compared with P i p e r Sudangrass and Sweet Sioux harvested while still in a vegetative stage. In Trial 2, aftermath alfalfa and P i p e r Sudangrass were compared. Average dry matter intakes for heifers in Trial 1 expressed as percentages of body weight did not vary significantly among alfalfa (1.8%), P i p e r (1.7%), and Sweet Sioux (1.6%). Earlier maturity resulted in higher intakes of Trial 2 alfalfa (2.3%) and P i p e r (2.2%). I n Trial 1, average net energy digestibility of Sweet Sioux (59.3%) was significantly greater (P ~ .05) than that of alfalfa (54.5%) while P i p e r was intermediate (56.5%). Average energy digestibility for alfalfa (60.0%) and P i p e r (62.4%) were similar in Trial 2. Nutritive value indices did no vary significantly in either Trial 1 or Trial 2. The summer annual grasses were essentally equal, but not superior to alfalfa based on an over-all nutritive comparison in this study. Ratios of solids-not-fat and protein to fat in the milk of three breeds. R. E. Mather, ~ Prabhu Lal, and E. T. Oleskie, New Jersey Agricultural Experiment Station, Sussex.
ASSOCIATION A F F A I R S
One possible method of increasing the solidsnot-fat (SNF) or protein (P) in milk in relation to fat (F) is to select on the basis of their ratios to fat. The mean S N F / F and P / F ratios for Guernseys (1,537 lactations 270-305 days), Holsteins (1,246), and Jerseys (1,332) and their within-herd standard deviations were 1.874 (0.141) and 0.751 (0.068; 2.224 (0.181) and 0.808 (0.077) ; and 1.799 (0.148) and 0.734 (0.057). After adjusting for age (cubic), year (6), season (2), year × season, and pregnancy ( > 1 6 0 days) by nested analysis of multiple regression to get adjusted components of variance and covariance, repeatabilities for S N F / F were 0.76 ± 0.02, 0.75 ± 0.02, 0.76 ± 0.018, and for the three breeds pooled 0.75 ± 0.01. For P / F the repeatabilities were 0.53 ± 0.03, 0.55 ± 0.03, 0.59 ± 0.03, and 0.53 ± 0.02. Heritability estimates were for S N F / F 0.59 ± 0.14, 0.95 ± 0.17, 0.69 ± 0.15, and 0.80 ± 0.09; for P / F they were 0.39 ± 0.12, 1.04 ± 0.15, 0.41 -+- 0.12, and 0.64 ~ 0.08. Genetic correlations (based on adjusted sire components) of milk with S N F / F were 0.38, 0.15, 0.64, and 0.26, and for milk with P / F were 0.26, 0.12, 0.21, and 0.15. Heritability of solids-not-fat and protein percentages adjusted for fat percentage in three breeds. R. E. Mather, ~ Prabhu La], and E. T. Oleskie, New Jersey Agricultural Experiment Station, Sussex. Lactation data (270-305 days) on solids-notfat (SNF) and protein percentages on Guernseys (5 herds, 191 sires, 817 cows, 1,537 records), Holsteins (9, 234, 670, 1,246), and Jerseys (5, 124, 727, 1,332), and pooled over the three breeds within herd, were adjusted for age (cubic), year (6), season (2), year × season, pregnancy ( > 160 days), and fat percentage by a nested analysis of multiple regression to get adjusted components of variance and covariance. Within-herd repeatabilities for adjusted SNF for the three breeds and pooled data were 0.55 ± 0.03, 0.74 ± 0.02, 0.49 ± 0.03, and 0.60 ± 0.02. For adjusted protein repeatabilities were 0.41 ± 0.03, 0.54 ± 0.03, 0.52 +-- 0.03, and 0 . 4 4 ± 0.02. Estimated heritabilities for adjusted SNF were 0.84 ± 0.13, 0.62 ± 0.17, 0.58 ± 0.13, and 0.73 ± 0.08. For adjusted protein heritabilities were 0.42 ± 0.11, 0.72-+0.15, 0.50 ± 0.13, and 0.44 ± 0.07. Thus it should be possible to select for higher SNF or protein percentage without modifying the fat percentage. Genetic correlations of adjusted SNF with similarly adjusted milk were --.91, --.21, 0.34, and --.13, and of protein with milk were --.37, --.17, --.25, and --.10. Genetic correlations between adjusted SNF and adjusted protein were 0.70, 0.81, 0.46, and 0.64. Blood protein changes during the lactation cycle of Holstein cows. J. W. Smith and E. M. Kesler, ~ The Pennsylvania State University, University Park. Holstein cows, aged 3-9 years, with known
27~
lactation potential were used. In Trial 1, 12 cows calved between February and May; in Trial 2, 10 with Fall parturitions. Blood samples were drawn 1-2 weeks before parturition, one day postpartum, weekly for the next six weeks, at longer intervals during the remainder of lactation, and at 1 and 4 weeks after beginning of the dry period. In Trial 1, blood hemoglobin values were highest at Day I postpartum (13.71 ± 1.16 g/100 ml) and during the dry period (13.26 ± 0.98). Significantly lower (P < 0.01) values were noted during Weeks 1-6 of lactation, with a low value of 11.31 ± 1.06 g/100 ml observed at 5 weeks. Trends in hematocrit were similar. Serum albumin levels remained relatively sable throughout, with values ranging from 2.08 to 3.40 g / 100 ml serum, a-Globulin levels were lowest prepartmn (1.01 ± 0.17 g) and rose to a high of 1 . 4 0 ± 0 . 1 3 g at Week 22 ( P < 0 . 0 1 ) . flglobulin was low prepartum (0.82 ± 0.10 g) and highest at Week 30 (1.00 --+ 0.08 g) (P < 0.05). T-Globulin was low prepartum and peaked at Week 3 (2.74 ± 0.36 and 3.56 ± 0.90 g, respectively) (P < 0.05). Values observed in Trial 2 were similar to those in Trial 1, except that T-globulin levels were significantly lower throughout. Effect of nitrogen fertilization and physiological maturity of timothy grass at the time of cutting on silage fermentation. H. Fenner ~ and W. G. Colby, University of Massachusetts, Amherst. A two-year old stand of timothy fertilized with Nitrogen at rates of 35, 70, 105, and 175 kg/hectare, was cut at the early head, full bloom and soft-dough seed stage, chopped and ensiled in quart size mason jars. After five months, the silages were analyzed for fermentation products. Nitrogen-fertilization raised the ash, crude protein, true protein and nonprotein nitrogen content of the forage and lowered the dry matter and nitrogen-free extract. Delayed cutting raised the average dry matter, nonprotein nitrogen and crude fiber content and lowered the ash, crude and true protein. Silages showed the following changes in constituents: High nitrogen fertilization increased the average pH, the concentrations of total volatile bases, total volatile fatty acids, propionic, iso-butyric, n-butyric, isovaleric, n-va]eric and n-caproic acids and lowered the lactic acid and alcohol content. The concentration of acetic acid changed irregularly. Delayed cutting of the forage lowered the pH, the proportions of total volatile bases, total volatile fatty acids, propionie~ iso-butyric, n-butyric, iso-valeric, n-valeric, and n-eaproic acids and raised that of lactic acid. Alcohol and acetic acid contents changed irregularly. Apparent dry matter losses, due to fermentation, rose with increased nitrogen-fertiliza,)'. DAIRY SCIEI~C~ ~/-OI~. 52, NO. 2
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tion, but were reduced when the forage was cut at a more mature stage. Mason jars served as useful miniature silos for estimating changes in forage constituents during storage as silage. Effect of recutting and plant maturity on kernel passage and feeding value of corn silage. G. R. Buck, W. G. Merrill, C. E. Coppoek,* and S. T. Slack, Cornell University, Ithaca, New York. I n each of two trials, sixteen first-calf ]~olstein cows were assigned to a Latin-square design for four, five-week feeding periods to compare the intake and milk production response when fed corn si]ages involving various plant maturities (as reflected by plant dry matter percentage) and fineness of chopping. Trial I, 22, 30, and 34% dry matter recur 5.1 em, and 46% dry matter recut 5.1 cm; and Trial I I , 33 and 33% dry matter recut 2.6 cm and 5.1 cm, 40 and 38% dry matter recur 2.6 Cl~.
With silages of higher dry matter content, less silage (as fed basis) was consumed, but more dry matter was consumed per 100 g of body weight. Recutting had no significant effect on silage dry matter intake. All silage treatments within trials supported milk production equally well. Steers were used to determine the digestibility of each silage and whole kernel passage was determined. Plant maturity had no significant effect on total digestible nutrients or digestible energy of the dry matter of the silages. Recutting the plant before ensiling significantly reduced the amount of kernel dry matter in the feces but recutting had no significant effect on the total digestible nutrients or digestible energy values of the silages. Observations on the efficiency of forage preservation in vacuum and stack silos. W. S. Gaunya,* W. A. Cowan, J. H. Whitaker, and J. J. Kolega, University of Connecticut, Storrs. Nine silos of varying capacity were utilized in this study to evaluate efficiency of forage preservation. Type of silo, amount of silage, kind and dry matter content of forage, days in storage, days of feeding and per cent of dry matter recovered were for Silo 1, vacuum stack; 41.7 tons; direct-cut hay-crop; 18.6%; 173 days; 19 days; 81.0% by weight, 80.1% by buried bags. Silo 2, vacuum stack; 26.5 tons; wilted hay-crop; 32.0%; 166 days; 5 days; 82.4% by weight, 92.2% by buried bags. Silo 3, vacuum stack; 8.2 tons; haylage; 64.6%; 76 days; 17 days; 79.3% by wt, 98.7% by buried bags. Silo 4, bunker; 38.1 tons; directcut hay-crop; 14.7%; 61 days; 13 days, 69.3%. Silo 5, vacuum; 39.6 tons; 14.4%; 73 days; 14 days ; 80.8%. Silo 6, vacuum 15.7 tons ; hay]age ; 56.6%; 33 days; 22 days; 82.2%. Silo 7, vacuum; 161.8 tons; corn forage; 29.8%; 32 days; 107 days; 88.0%. Silo 8, stack; 26.7 tons; corn forage; 31.7%; 115 days; 18 days; J. DAIRY SCI~IqCE X~O.L. 52, NO. 2
66.4%. Silo 9, stack; 16.2 tons; corn forage; 35.2%; 16 days; 12 days; 88.5%. Efficacy of forage evaluation systems for dairy cattle feeding programs. R. F. Welton* and E. Donefer, Macdonald College, MeGill University, Province of Quebec, Canada. A total of 269 hay samples was analyzed for protein and cellulose content, with nutritive value indices predicted using the HCl-pepsin dry matter disappearance procedure. A subsample of 40 hays was randomly selected for acid detergent fiber, lignin, and soluble cell contents, and assigned quality codes (estimated net energy) based on Cornell tables. Protein and nutritive indices for all samples were distributed in two distinct populations, based on first and second cutting. Highly significant (P < .01) simple correlation coefficients between nutritive indices and protein, cellulose, fiber, and soluble cell contents were 0.79, --.62, --.83, and 0.95, respectively. Although nutritive indices and Cornell Codes had similar means, the nutritive indices were distributed over a wider range. Approximately 38% of the 40 selected samples showed sufficient variation in their nutritive indices to justify laboratory evaluation procedures. Accuracy of feeding recommendations would not be changed if the remainder of the samples were rated by either a tabular estimated net energy value or a nutritive indice laboratory analysis. Milk production capacity of Maine concentrates used in dairy cattle rations. H. A. Leonard,* B. R. Poulton, and P. S. Young, University of Maine, Orono. Concentrate rations comprised of Maine oats, barley, potato pulp and beet pulp were formulated with and without urea and compared with a control concentrate ration consisting of cereal grains, byproduct feeds and plant proteins norreally used in the feed industry. Minerals, vitamins and salt were balanced in each ration. Second cutting hay and wilted hay crop silage were fed ad libitum; 1 kg of concentrate was fed for each 2 kg of FCM. I n single reversal feeding trials conducted for four consecutive years using 35 balanced pairs of cows it was found that concentrate rations comprised of Maine-produced concentrates with urea as a protein source can support milk production in excess of 26.8 kg of F C M per cow per day. There were no statistical differences between the level of milk production on the rations comprised of Maine ingredients versus the control ration. Heat increments of steam-volatile fatty acids infused separately and in a mixture into fasting cows. Preliminary report. J. B. Holter,* N. F. Colovos, and C. W. Heald, University of New Hampshire, Durham. Heat increments for equicaiorie amounts of acetic, propionic and butyric acids and a 52
ASSOCIATION
acetic:31 propionic:17 butyric molar mixture of acids were determined in mature, fasted dairy cows. Acids were infused continuously into the tureen at a rate of 32 kcal p e r kg body weight °'~ daily. A number of rmnen fluid and blood traits were measured daily during each of the 10 experiments. No acidosis was noted as indicated by the CO:-combining capacity of whole venous blood. Mean heat increments were as follows: acetic acid, 40; propionic acid, 18; butyric acid, 18; and acid mixture, 32 kcal per 100 keal metabolizable energy. Factors affecting diurnal rumination patterns. J. G. Welch, K. S. Gibson, and A. M. Smith, University of Vermont, Burlington. Diurnal variations in rumination patterns in dairy cattle and sheep were investigated in eight trials utilizing 132 individual, 24 hour, jaw motion recordings. F o u r lactating Holstein cows (Production average 30.0 k g / d a y ) and eight sheep, fed to allow for the major feed ingestion to occur during the day, ruminated more during the night. This has been interpreted by others to indicate that feed ingestion inhibits rumination. Observations were recorded showing normal rumination occurring during long periods of hay ingestion and immediately following hay or grain ingestion. F o u r trials were conducted to attempt to reverse the normal nighttime peak in rumination activity. Feeding four sheep their entire roughage allowance at 5 p ~ failed to inhibit the peak rumination during the midnight to 6 A~ period although it did decrease the rumination from 6 PM to midnight. Feeding the total roughage allowance at 8 P~ did not produce a complete reversal in the 24-hr rumination patterns when compared to those produced by feeding the forage at 8 A~ in one three-day trial with four sheep and one six-day trim with four heifers. A similar 12-day reversal trial with four sheep produced a reversal in rumination pattern during only the first two days folIowing the changes in feeding schedule. In vitro effects of pH and concentration upon L(+)-lactate-U-~'C transfer by bovine rumen epithelium. G. M. Jones,* E. M. Kesler, and R. J. Flipse, The Pennsylvania State University, University Park. The metabolism and absorption of L ( + ) lactate-U-~C by rumen epithelium from Itolstein-Angus cattle was investigated using respiration and diffusion techniques. The simple effects of mucosM buffer p H (4.8, 6.15, 6.9, 7.4) and lactate concentration (25, 75, 135 raM) were studied in a factorial experiment. Yariation in oxygen uptake, lactate utilization, and amount of label appearing in tissue protein was attributed to buffer pH. Oxygen uptake and C02 production were affected by substrate
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concentration. Lactate was converted to Maninc (24.7%) at p H 7.5, fl-hydroxybutyrate (4.8%) at p H 6.8, and glutamate (2.6%) at p H 5.85. Lactate absorption was not influenced by p i t or concentration, ttowever, the interaction of these variables accounted for most of the variation (P < .05). Absorption rates were greater at p H 6.1 or lower and at highest substrate concentrations. I n a corollary study, lactate utilization by rumen and intestinM tissue was compared. Oxygen uptake and lactate utilization were greater for intestinal incubations. However, absorption was greater across rumen mucosa than intestine (10.1 vs. 3.0, respectively). The mechanism of L ( + ) - l a c t a t e absorption across rumen epithelium apparently differs from that in intestine. The metabolic route of lactate utilization by tureen mucosa was directed more by mucosal p H than by substrate concentration. Lability in fasting heat production of dairy cattle. Nicholas F. Colovos, University of New Hampshire, Durham. The basal metabolism or fasting heat production of eight steers was measured with an open-circuit indirect calorimeter. The experimental animals were one pair of idengeal twins each of Holsteins, Guernseys, and Jerseys. The other two Holsteins were urn'elated. The results of forty-eight monthly 24-hr experiments show much less variation between breeds and animals than results published some thirty years ago, suggesting much less lability of basal metabolism in cattle. Effect of trichloromethiazide and dexamethasone on control of udder edema and milk production in lactating dairy cows. H. E. Carlsen,* J. M. Keith, and J. E. Croshaw, Delaware Valley College of Science and Agriculture, Doylestown, Pennsylvania. Twenty-one cows in four herds were used in this study. Fourteen animMs were treated as recommended by Schering with one bolus (200 mg trichloromethiazide and 5 mg dexamethasone) at calving and one-half bolus at 24 and 48 hr postpartum. Seven treated animals comprised a control group. Edema was rated on a scale from 0 to 5, with 0 being no detectable edema and 5 being edema which extended into tissue surrounding the udder. The mean edema score for the control group at calving was 3.9 and declined to 3.7 and 3.6 at Days 3 and 5, respectively. The treated group had a mean edema score of 2.1 and declined to 1.0 and 0.4 at Days 3 and 5, respectively. The increase in milk production from the third to the tenth day after calving was determined. The control group of cows increased 8.6 kg of milk, whereas, the increase for those treated was 10.7 kg.
J . DAIRY SCIENCE VOL. 52, NO. 2