- Email: [email protected]
CASE STUDY: Effect of Supplemental Live Yeast on Yield of Milk and Milk Components in High-Producing Multiparous Holstein Cows
The Professional Animal Scientist 26 (2010):443–449
©2010 American Registry of Professional Animal Scientists
C Supplemental S : Effect of Live Yeast ase
tudy
on Yield of Milk and Milk Components in High-Producing Multiparous Holstein Cows
M. B. de Ondarza,* C. J. Sniffen,† H. Graham,‡ and P. Wilcock‡1 *Paradox Nutrition LLC, West Chazy, NY 12992; †Fencrest LLC, Holderness, NH 03245; and ‡AB Vista, Marlborough, UK
ABSTRACT A well-managed, high-producing commercial dairy herd was used to test the effect of supplementing live yeast (4 g/d per cow) to lactating Holstein cow diets. When data from cows on study for >4 wk were analyzed separately, milk yield was greater (P < 0.05) for cows fed live yeast (41.2 vs. 42.4 kg/d for control vs. live yeast, respectively), indicating that an adaptation period for the rumen system may be necessary once live yeast is added to the diet. Cows fed live yeast for >4 wk produced more (P < 0.05) milk true protein (1.22 vs. 1.27 kg/d for control and live yeast, respectively). Overall milk yield during the complete 12-wk trial was not affected by live yeast supplementation. Live yeast supplementation had no effect (P > 0.10) on 3.5% FCM yield, milk fat percentage, yield of milk fat, or milk true protein percentage over the entire test period. Overall milk true protein yield tended (P = 0.11) to be higher with the addition of live yeast to the diet. Milk urea nitrogen (mg/dL) 1 Corresponding author: petewilcock@ abvista.us
and SCC were not affected (P > 0.10) by treatment. Cows supplemented with live yeast produced milk with a higher percentage of lactose and solids-not-fat (P < 0.05). Live yeast increased milk yield and milk true protein yield after 4 wk of supplementation. Key words: live yeast, milk component, milk yield
INTRODUCTION Much in vitro and in vivo research has been conducted with supplemental live yeast or yeast culture for dairy cattle. Supplemental yeast cultures provide organic acids, B vitamins, and amino acids that reportedly stimulate the rumen bacteria (Callaway and Martin, 1997). Unfortunately, intake and production responses to yeast supplements have been inconsistent, with some showing improvements [Wohlt et al., 1988 (live yeast); Dann et al., 2000 (yeast culture)] but others finding no responses [Putnam et al., 1997 (yeast culture); Soder and Holden, 1999 (live yeast)].
The effect of supplemental live yeast products should be considered separately from that of yeast culture products because their mode of action differs. Live yeasts may enhance the rumen environment by scavenging free oxygen, as evidenced by a lower redox potential in the rumen (ChaucheyrasDurand and Fonty, 2002). Others have also shown that live yeast can consume oxygen in vitro (Graham and McCracken, 2005). Marden et al. (2008) observed a lower redox potential and less lactate buildup in the rumen, as well as improved fiber digestion, with live yeast supplementation. Increases in rumen pH and decreases in rumen lactate concentration have been observed with supplemental live yeast (Guedes et al., 2007). Bach et al. (2007) increased average rumen pH and reduced the amount of time that rumen pH was under 5.6 and 6.0 with the addition of live yeast to the diet. Moallem et al. (2009) increased milk yield by 1.5 kg (4.1%) with supplemental live yeast. A meta-analysis concluded that supplemental live yeast (Saccharomyces cerevisiae) increased rumen pH
444 (+0.03) and rumen VFA concentration (+2.17 mM), tended to reduce rumen lactic acid concentrations (−0.9 mM), increased OM digestion (+0.8%), increased DMI (+0.44 g/ kg of BW), increased milk yield (+1.2 g/kg of BW), and tended to increase milk fat content (+0.05%; Desnoyers et al., 2009). According to the metaanalysis, the response to supplemental live yeast was affected by DMI, dietary concentrate level, and diet NDF. The objective of the current trial was to determine whether supplementing live yeast to high-producing lactating Holstein cows in a commercial herd would affect synthesis of milk components and milk yield.
MATERIALS AND METHODS Animals The study was 12 wk in length, and approximately 72% of the Holstein cows were on the study for the full 12 wk (Table 1). Treated and control cows were housed in separate pens with approximately 140 cows/pen. Cows were housed in a free-stall barn with ad libitum access to TMR and water, and were milked 3 times per day. Cows were managed in a manner typical of high-cow pen systems on US dairies in the Northeast. Despite the fact that animals were group-fed, cow was used as the experimental unit because bunk space was adequate and the TMR was not sorted. Throughout the study, cows were added to the study pens at approximately 21 DIM and removed from the study pens as milk yield declined, depending on total pen population pressure. Cows were omitted from the data set if they left the treatment pens at any time because of mastitis or other health issues. All procedures were in accordance with the guidelines presented in Guidelines for the Care and Use of Agricultural Animals in Agricultural Research and Teaching.
de Ondarza et al.
Table 1. Overview of characteristics of all cows by treatment during the 12-wk trial period Item Total cows Total observations Cows on study, % of total cows wk 1 wk 2 wk 3 wk 4 wk 5 wk 6 wk 7 wk 8 wk 9 wk 10 wk 11 wk 12 Lactation, no. of cows 1 2 3 4 5 6 7 Mean lactation number Mean DIM Mean previous ME305 milk,1 kg 1
Control 171 11,953 100 95.9 94.1 89.4 85.9 82.9 81.2 80.0 75.9 76.5 74.1 73.5 1 76 51 29 11 2 1 2.89 ± 1.02 143 ± 68 12,061 ± 1,860
Live yeast 170 11,961 100 97.1 97.1 94.1 91.2 86.5 81.2 76.5 74.1 71.8 71.8 71.8 0 81 52 31 5 0 1 2.79 ± 0.93 148 ± 73 12,355± 1,720
ME305 = 305-d mature-equivalent milk.
Experimental Treatments One-half the cows (n = 170) received live yeast (4 g/d per cow) and one-half did not (n = 171). Live yeast (S. cerevisiae) was supplied by AB Vista (Marlborough, UK). For 1 wk before feeding the live yeast, all cows received no yeast products in their diet. The basal ration consisted of corn silage, alfalfa and grass haylage, ground corn, whole cottonseed, soybean meal, wet brewers grains, and a commercial feed blend (Tables 2 and 3).
Measurements and Analytical Methods Daily pen DMI were monitored and recorded. The nutrient analyses of the diets consumed were calculated using CPM Dairy 3.08 (http://www.cpmdairy.net). Before beginning the study
and every 2 wk throughout the study, forages were sampled and analyzed via chemical analysis at Cumberland Valley Analytical Services (Hagerstown, MD). Samples were analyzed for DM [forages: 105°C for 3 h according to National Forage Testing Association (2002) recommendations; grains: method 930.15, AOAC, 2000], ash (method 942.05; AOAC, 2000, modified with a 0.5-g sample weight and 535°C furnace temperature), ether extract (method 920.39; AOAC, 1990, modified with anhydrous ether extraction, boiled 20 min, rinsed 20 min), CP (method 990.03; AOAC, 2000), soluble CP (Krishnamoorthy et al., 1982), ADF (method 973.18; AOAC, 2000, modified with Whatman 934-AH glass microfiber filters with a 1.5-μm particle retention used in place of a fritted glass crucible), NDF (Goering and Van Soest, 1970, modified without sodium sulfite and using
445
Live yeast effect on milk yield and components
Table 2. Nutrient analysis of control and live yeast diets Item
wk 1 to 2
wk 3 to 6
wk 7
wk 8 to 12
Weighted average
Ration DM, % (as-fed basis) CP, % of DM Soluble CP, % of CP RUP,1 % of CP Methionine,1 % of MP Lysine,1 % of MP NEl,1 Mcal/kg ADF, % of DM NDF, % of DM Forage NDF, % of DM Lignin, % of DM Nonfiber carbohydrate, % of DM Sugar, % of DM Starch, % of DM Soluble fiber,1 % of DM Ether extract, % of DM Long-chain fatty acids,1 % of DM Ash, % of DM Ca, % of DM P, % of DM Mg, % of DM K, % of DM S, % of DM Na, % of DM Cl, % of DM Fe, ppm Zn, ppm Cu, ppm Mn, ppm Se, ppm Co, ppm I, ppm Vitamin A, IU/kg Vitamin D, IU/kg Vitamin E, IU/kg
41.3 18.7 34.6 39.1 2.1 6.5 1.74 20.2 34.8 21.8 3.7 36.8 2.6 25.6 5.6 5.8 4.9 7.4 0.95 0.42 0.32 1.20 0.23 0.39 0.37 228.8 89.6 19.9 72.1 0.34 0.86 1.95 8,169 1,520 44
42.0 18.8 33.9 39.0 2.1 6.6 1.76 19.8 33.4 20.2 3.6 37.9 2.7 26.7 5.3 5.9 5.0 7.2 0.94 0.44 0.31 1.25 0.21 0.37 0.44 208.0 90.2 20.4 75.4 0.34 0.85 1.94 8,142 1,520 44
43.0 18.2 34.9 39.5 2.2 6.6 1.76 19.6 33.3 20.0 3.5 39.0 2.6 27.6 5.7 6.1 5.2 6.7 0.96 0.43 0.31 1.19 0.21 0.37 0.42 222.9 89.9 20.4 76.3 0.34 0.86 1.94 8,158 1,522 44
41.8 17.2 39.1 40.3 2.2 6.8 1.76 20.5 33.7 21.6 3.8 40.7 5.8 25.5 6.0 6.0 5.0 6.2 0.97 0.40 0.33 1.16 0.21 0.43 0.43 252.2 79.0 20.9 70.7 0.33 0.83 1.89 7,896 1,481 40
41.9 18.1 36.2 39.6 2.2 6.6 1.76 20.1 33.8 21.0 3.7 38.9 3.9 26.1 5.7 5.9 5.0 6.8 0.96 0.42 0.32 1.20 0.21 0.40 0.42 230.8 85.5 20.5 73.0 0.34 0.84 1.92 8,048 1,505 42
1
Predicted using CPM Dairy 3.08 (http://www.cpmdairy.net). MP = metabolizable protein.
Whatman 934-AH glass microfiber filters with a 1.5-μm particle retention used in place of a fritted glass crucible), lignin (Goering and Van Soest, 1970), starch (Holm et al., 1986), and sugar (Dubois et al., 1956). Nonfiber carbohydrate was calculated as the difference between 100 and the sum of CP (minus NDF-bound CP), NDF, ether extract, and ash. Analyses of Ca, P, Mg, K, Na, Fe, Zn, Cu, and Mn were conducted using a PerkinElmer 3300 XL inductively coupled plasma spectrometer (Perkin-Elmer, Shelton, CT) according to AOAC (2000) method 985.01. Sulfur was analyzed using a Leco S-144DR Sulfur
Combustion Analyzer (Leco, St. Joseph, MI). Chloride ion was extracted with 1% nitric acid and analyzed using a Corning 925 Chloride Analyzer (CIBA-Corning, Medfield, MA). Daily milk production of individual cows was recorded using the AFI2000 V1.28 system (S.A.E. Afikim, Kibbutz Afikim, Israel). Milk was sampled on wk 10, 11, and 12 of the study. Milk samples were preserved with Broad Spectrum Microtabs II (D&F Control Systems Inc., Dublin, CA), a preservative containing the active ingredient Bronopol, and sent to Vermont DHIA Laboratories (White River Junction, VT). Milk was analyzed for fat, true
protein, lactose, solids-not-fat (SNF), and milk urea N using an infrared analyzer (Bentley 2000, Bentley Instruments Inc., Chaska, MN). Milk was analyzed for SCC using flow cytometry (Bentley Somacount 500, Bentley Instruments Inc.).
Statistical Analysis Before the study was begun, cow groups were balanced based on parity, DIM, and production. Data were analyzed using JMP statistical software (SAS Institute Inc., Cary, NC) to determine whether milk yield and milk component percentages and
446
de Ondarza et al.
Table 3. Ingredient composition of control and live yeast diets (% of DM) Item Corn silage Haylage Wheat straw Ground corn, fine Sugar blend Wheat middlings Soybean meal (48% CP) Canola meal AminoPlus1 ProvAAI Preferred2 (animal protein) Whole cottonseed Wet brewers grains Urea Megalac3 Calcium carbonate Sodium bicarbonate Salt Magnesium oxide Trace mineral-vitamin mix Sel-Plex 6004 MTB-1005 Live yeast,6 treatment diet Live yeast,6 g/d 1
AminoPlus (Ag Processing, Inc., Omaha, NE).
2
ProvAAI Preferred (Venture Milling, Salisbury, MD).
3
Megalac (Arm & Hammer Animal Nutrition, Princeton, NJ).
4
Sel-Plex 600 (Alltech Corporation, Nicholasville, KY).
5
MTB-100 (Alltech Corporation).
6
ABVista Yeast (AB Vista Ltd., Marlborough, UK).
wk 1 to 2
wk 3 to 6
wk 7
wk 8 to 12
28.5 16.1 1.6 19.4 — 6.4 4.8 3.2 0.6 1.2 5.0 8.6 0.44 1.15 1.39 0.89 0.43 0.14 0.19 0.03 0.03 0.014 3.95
32.8 12.5 — 19.3 — 6.4 5.6 3.2 0.6 1.2 4.9 8.9 0.44 1.14 1.39 0.89 0.42 0.14 0.19 0.03 0.03 0.014 3.90
31.7 12.5 — 20.9 — 6.4 4.8 3.2 0.6 1.2 4.9 8.9 0.44 1.32 1.38 0.89 0.43 0.14 0.19 0.03 0.03 0.014 4.06
34.3 12.6 — 17.2 4.7 — — 10.9 0.6 1.2 5.0 9.0 0.41 1.33 1.29 0.83 0.40 0.13 0.18 0.03 0.03 0.013 3.76
Table 4. Production and component least squares means (±SE) of all cows by treatment during the 12-wk trial period Item Milk,1,2,3,4 kg/d 3.5% FCM,1,2 kg/d Fat, % Fat,1,2 kg/d True protein,1,2 % True protein,1,2 kg/d Milk urea N,1 mg/dL SCC,2 ×1,000 cells Lactose,2 % Solids-not-fat,2 %
Control
Live yeast
P-value
41.64 ± 0.40 44.55 ± 1.47 3.87 ± 0.18 1.62 ± 0.07 2.92 ± 0.05 1.21 ± 0.03 13.00 ± 0.45 279.03 ± 105.47 4.66 ± 0.05 5.53 ± 0.06
42.34 ± 0.39 44.60 ± 0.92 4.03 ± 0.13 1.60 ± 0.04 2.97 ± 0.03 1.27 ± 0.02 13.83 ± 0.33 147.11 ± 77.02 4.78 ± 0.03 5.68 ± 0.04
0.21 0.98 0.45 0.80 0.37 0.11 0.14 0.31 0.05 0.04
1
Covariate = previous 305-d mature-equivalent milk, kg (P < 0.05).
2
DIM category interactions with treatment were significant (P < 0.05).
3
Week of study interactions with treatment were significant (P < 0.05).
4
Effect of dietary sugar (% of DM) was significant (P < 0.05).
yields were affected by treatment. Milk yield, percentage of milk fat, kilograms of milk fat, percentage of protein, kilograms of protein, 3.5% FCM, percentage of milk lactose, percentage of milk SNF, milk urea N (mg/dL), and SCC were analyzed using the JMP restricted maximum likelihood model-fitting protocol, and subsequent multiple 2-sample comparisons were performed with Tukey’s honestly significant differences test. The model fit used DIM (by category), week on study (by category), and pen (treatment vs. control) as independent factors. Week on study refers to the number of weeks an individual cow had been receiving treatment, depending on entry date into the study pens during the 12-wk study. There were 3 categories for week on study: wk 1 to 2, wk 3 to 4, and wk 5 to 12. Previ-
447
Live yeast effect on milk yield and components
ous 305-d mature-equivalent milk (kg) was used as a covariate in the statistical models. Because of the increase in dietary sugar (% of DM) from wk 8 to 12 of the study, dietary sugar (% of DM) was included in the statistical models when significant. When a significant interaction existed, pair-wise comparisons between
the control and treatment within week of study category (wk 1 to 2, wk 3 to 4, and wk 5 to 12) and within DIM category (0 to 100 DIM, 101 to 200 DIM, and 201+ DIM) were subsequently recalculated using the contrast analysis in JMP, which uses Student’s t-test. Student’s t-test does not adjust for multiple comparisons
and is less conservative than Tukey’s honestly significant differences test. Because of the significant interaction between milk yield and week of study category, data from cows on study for more than 4 wk (wk 5 to 12) were also analyzed as a separate data set.
RESULTS AND DISCUSSION Animals and Experimental Diets
Table 5. Production and component least squares means (±SE) according to week on study and DIM by treatment when a significant interaction existed Item Milk,2,3,4,5 kg/d wk 1 to 2 wk 3 to 4 wk 5 to 12 0 to 100 DIM 101 to 200 DIM 201+ DIM 3.5% FCM,2,3 kg/d 0 to 100 DIM 101 to 200 DIM 201+ DIM Fat,2,3 kg/d 0 to 100 DIM 101 to 200 DIM 201+ DIM True protein,2,3 % 0 to 100 DIM 101 to 200 DIM 201+ DIM True protein,2,3 kg/d 0 to 100 DIM 101 to 200 DIM 201+ DIM SCC,3 ×1,000 cells 0 to 100 DIM 101 to 200 DIM 201+ DIM Lactose,3 % 0 to 100 DIM 101 to 200 DIM 201+ DIM Solids-not-fat,3 % 0 to 100 DIM 101 to 200 DIM 201+ DIM
Control
Live yeast
P-value1
41.56 ± 0.41 42.23 ± 0.41 41.13 ± 0.40 42.24 ± 0.41 42.15 ± 0.40 40.53 ± 0.45
41.92 ± 0.41 42.77 ± 0.41 42.34 ± 0.40 42.62 ± 0.41 42.86 ± 0.40 41.55 ± 0.44
0.53 0.35 0.03 0.51 0.21 0.11
47.33 ± 1.58 44.28 ± 1.53 42.05 ± 1.64
45.08 ± 1.15 46.37 ± 1.00 42.35 ± 1.14
0.25 0.25 0.88
1.73 ± 0.08 1.60 ± 0.07 1.54 ± 0.08
1.57 ± 0.05 1.68 ± 0.05 1.54 ± 0.05
0.09 0.31 0.96
2.82 ± 0.05 2.92 ± 0.05 3.03 ± 0.05
2.84 ± 0.04 2.95 ± 0.03 3.13 ± 0.04
0.76 0.58 0.15
1.25 ± 0.03 1.22 ± 0.03 1.17 ± 0.04
1.29 ± 0.03 1.30 ± 0.02 1.23 ± 0.03
0.27 0.06 0.20
143.6 ± 109.3 247.2 ± 119.9 446.3 ± 128.2
99.0 ± 83.4 103.0 ± 93.9 239.3 ± 102.5
0.75 0.34 0.21
4.72 ± 0.06 4.69 ± 0.05 4.57 ± 0.06
4.85 ± 0.04 4.80 ± 0.04 4.68 ± 0.04
0.05 0.10 0.12
5.60 ± 0.07 5.57 ± 0.07 5.42 ± 0.07
5.77 ± 0.05 5.70 ± 0.04 5.57 ± 0.05
0.04 0.08 0.09
Student’s t-test contrast analysis does not adjust for multiple comparisons. Significant differences indicate likely trends in the data.
1
2
Covariate = previous 305-d mature-equivalent milk, kg (P < 0.05).
3
DIM category interactions with treatment were significant (P < 0.05).
4
Week of study interactions with treatment were significant (P < 0.05).
5
Effect of dietary sugar (% of DM) was significant (P < 0.05).
The 2 groups of cows used for the study were very similar in lactation number (2.89 and 2.79 for the control and treatment) and DIM (143 and 148 for the control and treatment; Table 1). The diet was typical of highproduction diets fed in the Northeast region of the United States. Diet nutrient analyses and diet ingredient compositions were calculated from means of daily ingredients offered in the TMR (Tables 2 and 3). Because of changes in forage supply and quality, it was necessary to adjust the diet during the study. Four different diets were fed during the 12-wk study. Generally, the diet changes were small. However, during the last 4 wk of the study, a sugar source (25% glycerin, 50% whey, 25% molasses) was added to the diet, making total dietary sugars significantly higher during this period. Daily pen DMI were excellent throughout the study for both groups, with 25.0 ± 0.78 kg/d per cow consumed by control cows and 25.3 ± 0.93 kg/d per cow consumed by live yeast-supplemented cows.
Milk Yield and Milk Components Overall milk yield was excellent throughout the study, with means of 41.6 and 42.3 kg/d per cow for the control and live yeast-supplemented diets, respectively. Overall milk yield was not affected (P = 0.21) by live yeast supplementation (Table 4). However, according to the contrast analysis, cows fed live yeast for >4 wk produced more milk (P < 0.05) than those on the control diet (Table
448
de Ondarza et al.
Table 6. Production and component least squares means (±SE) of all cows on study for more than 4 wk Item Milk,1,2,3 kg/d 3.5% FCM,1,2 kg/d Fat, % Fat,1,2 kg/d True protein,1,2 % True protein,1,2 kg/d Milk urea nitrogen,1 mg/dL SCC,2 ×1,000 cells Lactose,2 % Solids-not-fat,2 %
Control
Live yeast
P-value
41.21 ± 0.41 44.67 ± 0.68 3.95 ± 0.07 1.65 ± 0.03 2.97 ± 0.02 1.22 ± 0.01 14.05 ± 0.19 169.4 ± 43.7 4.72 ± 0.02 5.60 ± 0.03
42.36 ± 0.41 44.95 ± 0.67 3.92 ± 0.07 1.64 ± 0.03 3.02 ± 0.02 1.27 ± 0.01 14.25 ± 0.17 198.6 ± 41.2 4.77 ± 0.02 5.67 ± 0.03
0.05 0.77 0.77 0.77 0.13 0.01 0.45 0.63 0.09 0.08
1
Covariate = previous 305-d mature-equivalent milk, kg (P < 0.05).
2
DIM category interactions with treatment were significant (P < 0.05).
3
Effect of dietary sugar (% of DM) was significant (P < 0.05).
5). When data from cows on study for >4 wk were analyzed separately, milk yield was higher (P = 0.05) for cows fed live yeast (41.2 vs. 42.4 kg/d for control vs. live yeast, respectively; Table 6). There is likely to be an adaptation period for the rumen system once yeast is added to the diet. Before this study was begun, it was assumed that the length of the adaptation period would be 2 wk, as others have suggested (Guedes et al., 2007; Marden et al., 2008). However, the significant milk production result from cows on study for >4 wk could indicate a longer adaptation period of the rumen microbial system. Live yeast supplementation had no effect on 3.5% FCM yield (P = 0.98; Table 4). Milk fat percentage was not affected (P = 0.45) by treatment but was numerically higher for cows supplemented with live yeast (3.87 and 4.03% for the control and live yeastsupplemented diets, respectively; Table 4). Yield of milk fat was not affected (P = 0.80) by treatment (1.62 vs. 1.60 kg/d for control and live yeast, respectively (Table 4). Based on Student’s t-test contrast analysis, early-lactation cows (0 to 100 DIM) tended (P = 0.09) to have higher fat yield on the control diet (1.73 vs. 1.57 kg/d; Table 5), but the reason for this is not known.
Milk true protein percentage was not affected (P = 0.37) by live yeast supplementation, with means of 2.92 and 2.97% for control and live yeast, respectively (Table 4). Milk true protein yield tended to be higher (P = 0.11) with the addition of live yeast to the diet (1.21 and 1.27 kg/d for control and live yeast, respectively; Table 4). This trend was more pronounced for cows at 101 to 200 DIM (Table 5). Cows fed live yeast for >4 wk produced more (P = 0.01) milk true protein (1.22 vs. 1.27 kg/d for control and live yeast, respectively; Table 6). Milk urea N (mg/dL) was not affected (P = 0.14) by treatment. However, cows supplemented with live yeast tended to produce milk with numerically higher milk urea N levels (13.00 vs. 13.83 mg/dL for control and live yeast, respectively; Table 4). Others have observed lower ruminal ammonia concentrations with supplemental live yeast (ChaucheyrasDurand and Fonty, 2001; Moallum et al., 2009). Somatic cell count was not affected (P = 0.31) by treatment (Table 4). Cows supplemented with live yeast produced milk with a greater (P = 0.05) percentage of lactose (4.66 vs. 4.78% for control vs. live yeast, respectively; Table 4), especially cows less than 100 DIM (Table 5). Solidsnot-fat percentage was greater (P
= 0.04) for cows supplemented with live yeast (5.53 vs. 5.68% for control and live yeast, respectively; Table 4), especially for those cows less than 100 DIM (Table 5). The response in milk and milk protein production from live yeast supplementation with a trend for increased milk urea N but without a response in milk fat percentage could indicate an improvement in microbial protein synthesis in the rumen, as seen by other researchers (Moya et al., 2007). In addition, the response in milk lactose may indicate an increase in availability of gluconeogenic precursors and improvements in ruminal propionate production. Additional evidence that this might be true is that SNF was improved by live yeast supplementation.
IMPLICATIONS The positive response in milk yield and milk true protein yield after 4 wk of live yeast supplementation indicates an improvement in rumen function and microbial protein synthesis. The increase in milk lactose and SNF with supplemental live yeast is interesting; however, the reason for this response is not clear. Future research with both in vitro continuous culture systems and high-producing cows should help predict responses to live yeast supplementation relative to adaptation time, production level, and dietary nutrient parameters.
LITERATURE CITED AOAC. 1990. Official Methods of Analysis. 15th ed. Vol. 1. Assoc Off. Anal. Chem., Arlington, VA. AOAC. 2000. Official Methods of Analysis. 17th ed. Vol. 1. Assoc. Off. Anal. Chem., Arlington, VA. Bach, A., C. Iglesias, and M. Devant. 2007. Daily rumen pH pattern of loose-housed dairy cattle as affected by feeding pattern and live yeast supplementation. Anim. Feed Sci. Technol. 136:146. Callaway, E. S., and S. A. Martin. 1997. Effects of a Saccharomyces cerevisiae culture on ruminal bacteria that utilize lactate and digest cellulose. J. Dairy Sci. 80:2035.
Live yeast effect on milk yield and components Chaucheyras-Durand, F., and G. Fonty. 2001. Establishment of cellulolytic bacteria and development of fermentative activities in the rumen of gnotobiotically-reared lambs receiving the microbial additive Saccharomyces cerevisiae CNCM I-1077. Reprod. Nutr. Dev. 41:57. Chaucheyras-Durand, F., and G. Fonty. 2002. Influence of a probiotic yeast (Saccharomyces cerevisiae CNCM I-1077) on microbial colonization and fermentations in the rumen of newborn lambs. Microb. Ecol. Health Dis. 14:30. Dann, H. M., J. R. Prockley, G. C. McCoy, M. F. Hutjens, and J. E. Garrett. 2000. Effects of yeast cultures (Saccharomyces cerevisiae) on prepartum intake and postpartum intake and milk production of Jersey cows. J. Dairy Sci. 83:123. Desnoyers, M., S. Giger-Reverdin, G. Bertin, C. Duvaux-Ponter, and D. Sauvant. 2009. Meta-analysis of the influence of Saccharomyces cerevisiae supplementation on ruminal parameters and milk production of ruminants. J. Dairy Sci. 92:1620.
Graham, H., and K. McCracken. 2005. Yeasts in animal feeds. p. 169 in Recent Advances in Animal Nutrition, 2005. P. C. Garnsworthy and J. Wiseman, ed. Nottingham University Press, Nottingham, UK. Guedes, C. M., D. Goncalves, M. A. M. Rodrigues, and A. Dias-da-Silva. 2007. Effects of a Saccharomyces cerevisiae yeast on ruminal fermentation and fibre degradation of maize silages in cows. Anim. Feed Sci. Technol. 145:27. Holm, J., I. Bjorck, A. Drews, and N.G. Asp. 1986. A rapid method for the analysis of starch. Starch/Die Starke 7:224. Krishnamoorthy, U., T. V. Muscato, C. J. Sniffen, and P. J. Van Soest. 1982. Nitrogen fractions of selected feedstuffs. J. Dairy Sci. 65:217. Marden, J. P., C. Julien, V. Monteils, E. Auclair, R. Moncoulon, and C. Bayourthe. 2008. How does live yeast differ from sodium bicarbonate to stabilize ruminal pH in highyielding dairy cows? J. Dairy Sci. 91:3528.
Dubois, M., K. A. Gilles, J. K. Hamilton, P. A. Rebers, and F. Smith. 1956. Colorimetric method for determination of sugars and related substances. Anal. Chem. 28:350.
Moallem, U., H. Lehrer, L. Livshitz, M. Zachut, and S. Yakoby. 2009. The effects of live yeast supplementation to dairy cows during the hot season on production, feed efficiency, and digestibility. J. Dairy Sci. 92:343.
Goering, H. K., and P. J. Van Soest. 1970. Forage Fiber Analysis. Agric. Handb. No. 379. US Dept. Agric., Agric. Res. Serv., Washington, DC.
Moya, D., S. Calsamiglia, A. Ferret, and M. C. Fuentes. 2007. Effects of yeast and type of starch on pH fluctuation, nutrient digestion, and microbial fermentation in a dual flow
449 continuous culture system. J. Dairy Sci. 90(Suppl. 1):337. (Abstr.) National Forage Testing Association. 2002. Method 2.2.2.5: Dry matter by oven drying for 3 hr at 105°C. Natl. Forage Testing Assoc., Omaha, NE. http://www.foragetesting.org/lab_procedure/sectionB/2.2/ part2.2.2.5.htm Accessed June 18, 2010. Putnam, D. E., C. G. Schwab, M. T. Socha, N. L. Whitehouse, N. A. Kierstead, and B. D. Garthwaite. 1997. Effect of yeast culture in the diets of early lactation dairy cows on ruminal fermentation and passage of nitrogen fractions and amino acids to the small intestine. J. Dairy Sci. 80:374. Soder, K. J., and L. A. Holden. 1999. Dry matter intake and milk yield and composition of cows fed yeast prepartum and postpartum. J. Dairy Sci. 82:605. Van Soest, P. J., J. B. Robertson, and B. A. Lewis. 1991. Methods for dietary fiber, neutral detergent fiber, and nonstarch polysaccharides in relation to animal nutrition. J. Dairy Sci. 74:3583. Wohlt, J. E., T. T. Corcione, and P. K. Zajac. 1998. Effect of yeast on feed intake and performance of cows fed diets based on corn silage during early lactation. J. Dairy Sci. 81:1345.
©2010 American Registry of Professional Animal Scientists
C Supplemental S : Effect of Live Yeast ase
tudy
on Yield of Milk and Milk Components in High-Producing Multiparous Holstein Cows
M. B. de Ondarza,* C. J. Sniffen,† H. Graham,‡ and P. Wilcock‡1 *Paradox Nutrition LLC, West Chazy, NY 12992; †Fencrest LLC, Holderness, NH 03245; and ‡AB Vista, Marlborough, UK
ABSTRACT A well-managed, high-producing commercial dairy herd was used to test the effect of supplementing live yeast (4 g/d per cow) to lactating Holstein cow diets. When data from cows on study for >4 wk were analyzed separately, milk yield was greater (P < 0.05) for cows fed live yeast (41.2 vs. 42.4 kg/d for control vs. live yeast, respectively), indicating that an adaptation period for the rumen system may be necessary once live yeast is added to the diet. Cows fed live yeast for >4 wk produced more (P < 0.05) milk true protein (1.22 vs. 1.27 kg/d for control and live yeast, respectively). Overall milk yield during the complete 12-wk trial was not affected by live yeast supplementation. Live yeast supplementation had no effect (P > 0.10) on 3.5% FCM yield, milk fat percentage, yield of milk fat, or milk true protein percentage over the entire test period. Overall milk true protein yield tended (P = 0.11) to be higher with the addition of live yeast to the diet. Milk urea nitrogen (mg/dL) 1 Corresponding author: petewilcock@ abvista.us
and SCC were not affected (P > 0.10) by treatment. Cows supplemented with live yeast produced milk with a higher percentage of lactose and solids-not-fat (P < 0.05). Live yeast increased milk yield and milk true protein yield after 4 wk of supplementation. Key words: live yeast, milk component, milk yield
INTRODUCTION Much in vitro and in vivo research has been conducted with supplemental live yeast or yeast culture for dairy cattle. Supplemental yeast cultures provide organic acids, B vitamins, and amino acids that reportedly stimulate the rumen bacteria (Callaway and Martin, 1997). Unfortunately, intake and production responses to yeast supplements have been inconsistent, with some showing improvements [Wohlt et al., 1988 (live yeast); Dann et al., 2000 (yeast culture)] but others finding no responses [Putnam et al., 1997 (yeast culture); Soder and Holden, 1999 (live yeast)].
The effect of supplemental live yeast products should be considered separately from that of yeast culture products because their mode of action differs. Live yeasts may enhance the rumen environment by scavenging free oxygen, as evidenced by a lower redox potential in the rumen (ChaucheyrasDurand and Fonty, 2002). Others have also shown that live yeast can consume oxygen in vitro (Graham and McCracken, 2005). Marden et al. (2008) observed a lower redox potential and less lactate buildup in the rumen, as well as improved fiber digestion, with live yeast supplementation. Increases in rumen pH and decreases in rumen lactate concentration have been observed with supplemental live yeast (Guedes et al., 2007). Bach et al. (2007) increased average rumen pH and reduced the amount of time that rumen pH was under 5.6 and 6.0 with the addition of live yeast to the diet. Moallem et al. (2009) increased milk yield by 1.5 kg (4.1%) with supplemental live yeast. A meta-analysis concluded that supplemental live yeast (Saccharomyces cerevisiae) increased rumen pH
444 (+0.03) and rumen VFA concentration (+2.17 mM), tended to reduce rumen lactic acid concentrations (−0.9 mM), increased OM digestion (+0.8%), increased DMI (+0.44 g/ kg of BW), increased milk yield (+1.2 g/kg of BW), and tended to increase milk fat content (+0.05%; Desnoyers et al., 2009). According to the metaanalysis, the response to supplemental live yeast was affected by DMI, dietary concentrate level, and diet NDF. The objective of the current trial was to determine whether supplementing live yeast to high-producing lactating Holstein cows in a commercial herd would affect synthesis of milk components and milk yield.
MATERIALS AND METHODS Animals The study was 12 wk in length, and approximately 72% of the Holstein cows were on the study for the full 12 wk (Table 1). Treated and control cows were housed in separate pens with approximately 140 cows/pen. Cows were housed in a free-stall barn with ad libitum access to TMR and water, and were milked 3 times per day. Cows were managed in a manner typical of high-cow pen systems on US dairies in the Northeast. Despite the fact that animals were group-fed, cow was used as the experimental unit because bunk space was adequate and the TMR was not sorted. Throughout the study, cows were added to the study pens at approximately 21 DIM and removed from the study pens as milk yield declined, depending on total pen population pressure. Cows were omitted from the data set if they left the treatment pens at any time because of mastitis or other health issues. All procedures were in accordance with the guidelines presented in Guidelines for the Care and Use of Agricultural Animals in Agricultural Research and Teaching.
de Ondarza et al.
Table 1. Overview of characteristics of all cows by treatment during the 12-wk trial period Item Total cows Total observations Cows on study, % of total cows wk 1 wk 2 wk 3 wk 4 wk 5 wk 6 wk 7 wk 8 wk 9 wk 10 wk 11 wk 12 Lactation, no. of cows 1 2 3 4 5 6 7 Mean lactation number Mean DIM Mean previous ME305 milk,1 kg 1
Control 171 11,953 100 95.9 94.1 89.4 85.9 82.9 81.2 80.0 75.9 76.5 74.1 73.5 1 76 51 29 11 2 1 2.89 ± 1.02 143 ± 68 12,061 ± 1,860
Live yeast 170 11,961 100 97.1 97.1 94.1 91.2 86.5 81.2 76.5 74.1 71.8 71.8 71.8 0 81 52 31 5 0 1 2.79 ± 0.93 148 ± 73 12,355± 1,720
ME305 = 305-d mature-equivalent milk.
Experimental Treatments One-half the cows (n = 170) received live yeast (4 g/d per cow) and one-half did not (n = 171). Live yeast (S. cerevisiae) was supplied by AB Vista (Marlborough, UK). For 1 wk before feeding the live yeast, all cows received no yeast products in their diet. The basal ration consisted of corn silage, alfalfa and grass haylage, ground corn, whole cottonseed, soybean meal, wet brewers grains, and a commercial feed blend (Tables 2 and 3).
Measurements and Analytical Methods Daily pen DMI were monitored and recorded. The nutrient analyses of the diets consumed were calculated using CPM Dairy 3.08 (http://www.cpmdairy.net). Before beginning the study
and every 2 wk throughout the study, forages were sampled and analyzed via chemical analysis at Cumberland Valley Analytical Services (Hagerstown, MD). Samples were analyzed for DM [forages: 105°C for 3 h according to National Forage Testing Association (2002) recommendations; grains: method 930.15, AOAC, 2000], ash (method 942.05; AOAC, 2000, modified with a 0.5-g sample weight and 535°C furnace temperature), ether extract (method 920.39; AOAC, 1990, modified with anhydrous ether extraction, boiled 20 min, rinsed 20 min), CP (method 990.03; AOAC, 2000), soluble CP (Krishnamoorthy et al., 1982), ADF (method 973.18; AOAC, 2000, modified with Whatman 934-AH glass microfiber filters with a 1.5-μm particle retention used in place of a fritted glass crucible), NDF (Goering and Van Soest, 1970, modified without sodium sulfite and using
445
Live yeast effect on milk yield and components
Table 2. Nutrient analysis of control and live yeast diets Item
wk 1 to 2
wk 3 to 6
wk 7
wk 8 to 12
Weighted average
Ration DM, % (as-fed basis) CP, % of DM Soluble CP, % of CP RUP,1 % of CP Methionine,1 % of MP Lysine,1 % of MP NEl,1 Mcal/kg ADF, % of DM NDF, % of DM Forage NDF, % of DM Lignin, % of DM Nonfiber carbohydrate, % of DM Sugar, % of DM Starch, % of DM Soluble fiber,1 % of DM Ether extract, % of DM Long-chain fatty acids,1 % of DM Ash, % of DM Ca, % of DM P, % of DM Mg, % of DM K, % of DM S, % of DM Na, % of DM Cl, % of DM Fe, ppm Zn, ppm Cu, ppm Mn, ppm Se, ppm Co, ppm I, ppm Vitamin A, IU/kg Vitamin D, IU/kg Vitamin E, IU/kg
41.3 18.7 34.6 39.1 2.1 6.5 1.74 20.2 34.8 21.8 3.7 36.8 2.6 25.6 5.6 5.8 4.9 7.4 0.95 0.42 0.32 1.20 0.23 0.39 0.37 228.8 89.6 19.9 72.1 0.34 0.86 1.95 8,169 1,520 44
42.0 18.8 33.9 39.0 2.1 6.6 1.76 19.8 33.4 20.2 3.6 37.9 2.7 26.7 5.3 5.9 5.0 7.2 0.94 0.44 0.31 1.25 0.21 0.37 0.44 208.0 90.2 20.4 75.4 0.34 0.85 1.94 8,142 1,520 44
43.0 18.2 34.9 39.5 2.2 6.6 1.76 19.6 33.3 20.0 3.5 39.0 2.6 27.6 5.7 6.1 5.2 6.7 0.96 0.43 0.31 1.19 0.21 0.37 0.42 222.9 89.9 20.4 76.3 0.34 0.86 1.94 8,158 1,522 44
41.8 17.2 39.1 40.3 2.2 6.8 1.76 20.5 33.7 21.6 3.8 40.7 5.8 25.5 6.0 6.0 5.0 6.2 0.97 0.40 0.33 1.16 0.21 0.43 0.43 252.2 79.0 20.9 70.7 0.33 0.83 1.89 7,896 1,481 40
41.9 18.1 36.2 39.6 2.2 6.6 1.76 20.1 33.8 21.0 3.7 38.9 3.9 26.1 5.7 5.9 5.0 6.8 0.96 0.42 0.32 1.20 0.21 0.40 0.42 230.8 85.5 20.5 73.0 0.34 0.84 1.92 8,048 1,505 42
1
Predicted using CPM Dairy 3.08 (http://www.cpmdairy.net). MP = metabolizable protein.
Whatman 934-AH glass microfiber filters with a 1.5-μm particle retention used in place of a fritted glass crucible), lignin (Goering and Van Soest, 1970), starch (Holm et al., 1986), and sugar (Dubois et al., 1956). Nonfiber carbohydrate was calculated as the difference between 100 and the sum of CP (minus NDF-bound CP), NDF, ether extract, and ash. Analyses of Ca, P, Mg, K, Na, Fe, Zn, Cu, and Mn were conducted using a PerkinElmer 3300 XL inductively coupled plasma spectrometer (Perkin-Elmer, Shelton, CT) according to AOAC (2000) method 985.01. Sulfur was analyzed using a Leco S-144DR Sulfur
Combustion Analyzer (Leco, St. Joseph, MI). Chloride ion was extracted with 1% nitric acid and analyzed using a Corning 925 Chloride Analyzer (CIBA-Corning, Medfield, MA). Daily milk production of individual cows was recorded using the AFI2000 V1.28 system (S.A.E. Afikim, Kibbutz Afikim, Israel). Milk was sampled on wk 10, 11, and 12 of the study. Milk samples were preserved with Broad Spectrum Microtabs II (D&F Control Systems Inc., Dublin, CA), a preservative containing the active ingredient Bronopol, and sent to Vermont DHIA Laboratories (White River Junction, VT). Milk was analyzed for fat, true
protein, lactose, solids-not-fat (SNF), and milk urea N using an infrared analyzer (Bentley 2000, Bentley Instruments Inc., Chaska, MN). Milk was analyzed for SCC using flow cytometry (Bentley Somacount 500, Bentley Instruments Inc.).
Statistical Analysis Before the study was begun, cow groups were balanced based on parity, DIM, and production. Data were analyzed using JMP statistical software (SAS Institute Inc., Cary, NC) to determine whether milk yield and milk component percentages and
446
de Ondarza et al.
Table 3. Ingredient composition of control and live yeast diets (% of DM) Item Corn silage Haylage Wheat straw Ground corn, fine Sugar blend Wheat middlings Soybean meal (48% CP) Canola meal AminoPlus1 ProvAAI Preferred2 (animal protein) Whole cottonseed Wet brewers grains Urea Megalac3 Calcium carbonate Sodium bicarbonate Salt Magnesium oxide Trace mineral-vitamin mix Sel-Plex 6004 MTB-1005 Live yeast,6 treatment diet Live yeast,6 g/d 1
AminoPlus (Ag Processing, Inc., Omaha, NE).
2
ProvAAI Preferred (Venture Milling, Salisbury, MD).
3
Megalac (Arm & Hammer Animal Nutrition, Princeton, NJ).
4
Sel-Plex 600 (Alltech Corporation, Nicholasville, KY).
5
MTB-100 (Alltech Corporation).
6
ABVista Yeast (AB Vista Ltd., Marlborough, UK).
wk 1 to 2
wk 3 to 6
wk 7
wk 8 to 12
28.5 16.1 1.6 19.4 — 6.4 4.8 3.2 0.6 1.2 5.0 8.6 0.44 1.15 1.39 0.89 0.43 0.14 0.19 0.03 0.03 0.014 3.95
32.8 12.5 — 19.3 — 6.4 5.6 3.2 0.6 1.2 4.9 8.9 0.44 1.14 1.39 0.89 0.42 0.14 0.19 0.03 0.03 0.014 3.90
31.7 12.5 — 20.9 — 6.4 4.8 3.2 0.6 1.2 4.9 8.9 0.44 1.32 1.38 0.89 0.43 0.14 0.19 0.03 0.03 0.014 4.06
34.3 12.6 — 17.2 4.7 — — 10.9 0.6 1.2 5.0 9.0 0.41 1.33 1.29 0.83 0.40 0.13 0.18 0.03 0.03 0.013 3.76
Table 4. Production and component least squares means (±SE) of all cows by treatment during the 12-wk trial period Item Milk,1,2,3,4 kg/d 3.5% FCM,1,2 kg/d Fat, % Fat,1,2 kg/d True protein,1,2 % True protein,1,2 kg/d Milk urea N,1 mg/dL SCC,2 ×1,000 cells Lactose,2 % Solids-not-fat,2 %
Control
Live yeast
P-value
41.64 ± 0.40 44.55 ± 1.47 3.87 ± 0.18 1.62 ± 0.07 2.92 ± 0.05 1.21 ± 0.03 13.00 ± 0.45 279.03 ± 105.47 4.66 ± 0.05 5.53 ± 0.06
42.34 ± 0.39 44.60 ± 0.92 4.03 ± 0.13 1.60 ± 0.04 2.97 ± 0.03 1.27 ± 0.02 13.83 ± 0.33 147.11 ± 77.02 4.78 ± 0.03 5.68 ± 0.04
0.21 0.98 0.45 0.80 0.37 0.11 0.14 0.31 0.05 0.04
1
Covariate = previous 305-d mature-equivalent milk, kg (P < 0.05).
2
DIM category interactions with treatment were significant (P < 0.05).
3
Week of study interactions with treatment were significant (P < 0.05).
4
Effect of dietary sugar (% of DM) was significant (P < 0.05).
yields were affected by treatment. Milk yield, percentage of milk fat, kilograms of milk fat, percentage of protein, kilograms of protein, 3.5% FCM, percentage of milk lactose, percentage of milk SNF, milk urea N (mg/dL), and SCC were analyzed using the JMP restricted maximum likelihood model-fitting protocol, and subsequent multiple 2-sample comparisons were performed with Tukey’s honestly significant differences test. The model fit used DIM (by category), week on study (by category), and pen (treatment vs. control) as independent factors. Week on study refers to the number of weeks an individual cow had been receiving treatment, depending on entry date into the study pens during the 12-wk study. There were 3 categories for week on study: wk 1 to 2, wk 3 to 4, and wk 5 to 12. Previ-
447
Live yeast effect on milk yield and components
ous 305-d mature-equivalent milk (kg) was used as a covariate in the statistical models. Because of the increase in dietary sugar (% of DM) from wk 8 to 12 of the study, dietary sugar (% of DM) was included in the statistical models when significant. When a significant interaction existed, pair-wise comparisons between
the control and treatment within week of study category (wk 1 to 2, wk 3 to 4, and wk 5 to 12) and within DIM category (0 to 100 DIM, 101 to 200 DIM, and 201+ DIM) were subsequently recalculated using the contrast analysis in JMP, which uses Student’s t-test. Student’s t-test does not adjust for multiple comparisons
and is less conservative than Tukey’s honestly significant differences test. Because of the significant interaction between milk yield and week of study category, data from cows on study for more than 4 wk (wk 5 to 12) were also analyzed as a separate data set.
RESULTS AND DISCUSSION Animals and Experimental Diets
Table 5. Production and component least squares means (±SE) according to week on study and DIM by treatment when a significant interaction existed Item Milk,2,3,4,5 kg/d wk 1 to 2 wk 3 to 4 wk 5 to 12 0 to 100 DIM 101 to 200 DIM 201+ DIM 3.5% FCM,2,3 kg/d 0 to 100 DIM 101 to 200 DIM 201+ DIM Fat,2,3 kg/d 0 to 100 DIM 101 to 200 DIM 201+ DIM True protein,2,3 % 0 to 100 DIM 101 to 200 DIM 201+ DIM True protein,2,3 kg/d 0 to 100 DIM 101 to 200 DIM 201+ DIM SCC,3 ×1,000 cells 0 to 100 DIM 101 to 200 DIM 201+ DIM Lactose,3 % 0 to 100 DIM 101 to 200 DIM 201+ DIM Solids-not-fat,3 % 0 to 100 DIM 101 to 200 DIM 201+ DIM
Control
Live yeast
P-value1
41.56 ± 0.41 42.23 ± 0.41 41.13 ± 0.40 42.24 ± 0.41 42.15 ± 0.40 40.53 ± 0.45
41.92 ± 0.41 42.77 ± 0.41 42.34 ± 0.40 42.62 ± 0.41 42.86 ± 0.40 41.55 ± 0.44
0.53 0.35 0.03 0.51 0.21 0.11
47.33 ± 1.58 44.28 ± 1.53 42.05 ± 1.64
45.08 ± 1.15 46.37 ± 1.00 42.35 ± 1.14
0.25 0.25 0.88
1.73 ± 0.08 1.60 ± 0.07 1.54 ± 0.08
1.57 ± 0.05 1.68 ± 0.05 1.54 ± 0.05
0.09 0.31 0.96
2.82 ± 0.05 2.92 ± 0.05 3.03 ± 0.05
2.84 ± 0.04 2.95 ± 0.03 3.13 ± 0.04
0.76 0.58 0.15
1.25 ± 0.03 1.22 ± 0.03 1.17 ± 0.04
1.29 ± 0.03 1.30 ± 0.02 1.23 ± 0.03
0.27 0.06 0.20
143.6 ± 109.3 247.2 ± 119.9 446.3 ± 128.2
99.0 ± 83.4 103.0 ± 93.9 239.3 ± 102.5
0.75 0.34 0.21
4.72 ± 0.06 4.69 ± 0.05 4.57 ± 0.06
4.85 ± 0.04 4.80 ± 0.04 4.68 ± 0.04
0.05 0.10 0.12
5.60 ± 0.07 5.57 ± 0.07 5.42 ± 0.07
5.77 ± 0.05 5.70 ± 0.04 5.57 ± 0.05
0.04 0.08 0.09
Student’s t-test contrast analysis does not adjust for multiple comparisons. Significant differences indicate likely trends in the data.
1
2
Covariate = previous 305-d mature-equivalent milk, kg (P < 0.05).
3
DIM category interactions with treatment were significant (P < 0.05).
4
Week of study interactions with treatment were significant (P < 0.05).
5
Effect of dietary sugar (% of DM) was significant (P < 0.05).
The 2 groups of cows used for the study were very similar in lactation number (2.89 and 2.79 for the control and treatment) and DIM (143 and 148 for the control and treatment; Table 1). The diet was typical of highproduction diets fed in the Northeast region of the United States. Diet nutrient analyses and diet ingredient compositions were calculated from means of daily ingredients offered in the TMR (Tables 2 and 3). Because of changes in forage supply and quality, it was necessary to adjust the diet during the study. Four different diets were fed during the 12-wk study. Generally, the diet changes were small. However, during the last 4 wk of the study, a sugar source (25% glycerin, 50% whey, 25% molasses) was added to the diet, making total dietary sugars significantly higher during this period. Daily pen DMI were excellent throughout the study for both groups, with 25.0 ± 0.78 kg/d per cow consumed by control cows and 25.3 ± 0.93 kg/d per cow consumed by live yeast-supplemented cows.
Milk Yield and Milk Components Overall milk yield was excellent throughout the study, with means of 41.6 and 42.3 kg/d per cow for the control and live yeast-supplemented diets, respectively. Overall milk yield was not affected (P = 0.21) by live yeast supplementation (Table 4). However, according to the contrast analysis, cows fed live yeast for >4 wk produced more milk (P < 0.05) than those on the control diet (Table
448
de Ondarza et al.
Table 6. Production and component least squares means (±SE) of all cows on study for more than 4 wk Item Milk,1,2,3 kg/d 3.5% FCM,1,2 kg/d Fat, % Fat,1,2 kg/d True protein,1,2 % True protein,1,2 kg/d Milk urea nitrogen,1 mg/dL SCC,2 ×1,000 cells Lactose,2 % Solids-not-fat,2 %
Control
Live yeast
P-value
41.21 ± 0.41 44.67 ± 0.68 3.95 ± 0.07 1.65 ± 0.03 2.97 ± 0.02 1.22 ± 0.01 14.05 ± 0.19 169.4 ± 43.7 4.72 ± 0.02 5.60 ± 0.03
42.36 ± 0.41 44.95 ± 0.67 3.92 ± 0.07 1.64 ± 0.03 3.02 ± 0.02 1.27 ± 0.01 14.25 ± 0.17 198.6 ± 41.2 4.77 ± 0.02 5.67 ± 0.03
0.05 0.77 0.77 0.77 0.13 0.01 0.45 0.63 0.09 0.08
1
Covariate = previous 305-d mature-equivalent milk, kg (P < 0.05).
2
DIM category interactions with treatment were significant (P < 0.05).
3
Effect of dietary sugar (% of DM) was significant (P < 0.05).
5). When data from cows on study for >4 wk were analyzed separately, milk yield was higher (P = 0.05) for cows fed live yeast (41.2 vs. 42.4 kg/d for control vs. live yeast, respectively; Table 6). There is likely to be an adaptation period for the rumen system once yeast is added to the diet. Before this study was begun, it was assumed that the length of the adaptation period would be 2 wk, as others have suggested (Guedes et al., 2007; Marden et al., 2008). However, the significant milk production result from cows on study for >4 wk could indicate a longer adaptation period of the rumen microbial system. Live yeast supplementation had no effect on 3.5% FCM yield (P = 0.98; Table 4). Milk fat percentage was not affected (P = 0.45) by treatment but was numerically higher for cows supplemented with live yeast (3.87 and 4.03% for the control and live yeastsupplemented diets, respectively; Table 4). Yield of milk fat was not affected (P = 0.80) by treatment (1.62 vs. 1.60 kg/d for control and live yeast, respectively (Table 4). Based on Student’s t-test contrast analysis, early-lactation cows (0 to 100 DIM) tended (P = 0.09) to have higher fat yield on the control diet (1.73 vs. 1.57 kg/d; Table 5), but the reason for this is not known.
Milk true protein percentage was not affected (P = 0.37) by live yeast supplementation, with means of 2.92 and 2.97% for control and live yeast, respectively (Table 4). Milk true protein yield tended to be higher (P = 0.11) with the addition of live yeast to the diet (1.21 and 1.27 kg/d for control and live yeast, respectively; Table 4). This trend was more pronounced for cows at 101 to 200 DIM (Table 5). Cows fed live yeast for >4 wk produced more (P = 0.01) milk true protein (1.22 vs. 1.27 kg/d for control and live yeast, respectively; Table 6). Milk urea N (mg/dL) was not affected (P = 0.14) by treatment. However, cows supplemented with live yeast tended to produce milk with numerically higher milk urea N levels (13.00 vs. 13.83 mg/dL for control and live yeast, respectively; Table 4). Others have observed lower ruminal ammonia concentrations with supplemental live yeast (ChaucheyrasDurand and Fonty, 2001; Moallum et al., 2009). Somatic cell count was not affected (P = 0.31) by treatment (Table 4). Cows supplemented with live yeast produced milk with a greater (P = 0.05) percentage of lactose (4.66 vs. 4.78% for control vs. live yeast, respectively; Table 4), especially cows less than 100 DIM (Table 5). Solidsnot-fat percentage was greater (P
= 0.04) for cows supplemented with live yeast (5.53 vs. 5.68% for control and live yeast, respectively; Table 4), especially for those cows less than 100 DIM (Table 5). The response in milk and milk protein production from live yeast supplementation with a trend for increased milk urea N but without a response in milk fat percentage could indicate an improvement in microbial protein synthesis in the rumen, as seen by other researchers (Moya et al., 2007). In addition, the response in milk lactose may indicate an increase in availability of gluconeogenic precursors and improvements in ruminal propionate production. Additional evidence that this might be true is that SNF was improved by live yeast supplementation.
IMPLICATIONS The positive response in milk yield and milk true protein yield after 4 wk of live yeast supplementation indicates an improvement in rumen function and microbial protein synthesis. The increase in milk lactose and SNF with supplemental live yeast is interesting; however, the reason for this response is not clear. Future research with both in vitro continuous culture systems and high-producing cows should help predict responses to live yeast supplementation relative to adaptation time, production level, and dietary nutrient parameters.
LITERATURE CITED AOAC. 1990. Official Methods of Analysis. 15th ed. Vol. 1. Assoc Off. Anal. Chem., Arlington, VA. AOAC. 2000. Official Methods of Analysis. 17th ed. Vol. 1. Assoc. Off. Anal. Chem., Arlington, VA. Bach, A., C. Iglesias, and M. Devant. 2007. Daily rumen pH pattern of loose-housed dairy cattle as affected by feeding pattern and live yeast supplementation. Anim. Feed Sci. Technol. 136:146. Callaway, E. S., and S. A. Martin. 1997. Effects of a Saccharomyces cerevisiae culture on ruminal bacteria that utilize lactate and digest cellulose. J. Dairy Sci. 80:2035.
Live yeast effect on milk yield and components Chaucheyras-Durand, F., and G. Fonty. 2001. Establishment of cellulolytic bacteria and development of fermentative activities in the rumen of gnotobiotically-reared lambs receiving the microbial additive Saccharomyces cerevisiae CNCM I-1077. Reprod. Nutr. Dev. 41:57. Chaucheyras-Durand, F., and G. Fonty. 2002. Influence of a probiotic yeast (Saccharomyces cerevisiae CNCM I-1077) on microbial colonization and fermentations in the rumen of newborn lambs. Microb. Ecol. Health Dis. 14:30. Dann, H. M., J. R. Prockley, G. C. McCoy, M. F. Hutjens, and J. E. Garrett. 2000. Effects of yeast cultures (Saccharomyces cerevisiae) on prepartum intake and postpartum intake and milk production of Jersey cows. J. Dairy Sci. 83:123. Desnoyers, M., S. Giger-Reverdin, G. Bertin, C. Duvaux-Ponter, and D. Sauvant. 2009. Meta-analysis of the influence of Saccharomyces cerevisiae supplementation on ruminal parameters and milk production of ruminants. J. Dairy Sci. 92:1620.
Graham, H., and K. McCracken. 2005. Yeasts in animal feeds. p. 169 in Recent Advances in Animal Nutrition, 2005. P. C. Garnsworthy and J. Wiseman, ed. Nottingham University Press, Nottingham, UK. Guedes, C. M., D. Goncalves, M. A. M. Rodrigues, and A. Dias-da-Silva. 2007. Effects of a Saccharomyces cerevisiae yeast on ruminal fermentation and fibre degradation of maize silages in cows. Anim. Feed Sci. Technol. 145:27. Holm, J., I. Bjorck, A. Drews, and N.G. Asp. 1986. A rapid method for the analysis of starch. Starch/Die Starke 7:224. Krishnamoorthy, U., T. V. Muscato, C. J. Sniffen, and P. J. Van Soest. 1982. Nitrogen fractions of selected feedstuffs. J. Dairy Sci. 65:217. Marden, J. P., C. Julien, V. Monteils, E. Auclair, R. Moncoulon, and C. Bayourthe. 2008. How does live yeast differ from sodium bicarbonate to stabilize ruminal pH in highyielding dairy cows? J. Dairy Sci. 91:3528.
Dubois, M., K. A. Gilles, J. K. Hamilton, P. A. Rebers, and F. Smith. 1956. Colorimetric method for determination of sugars and related substances. Anal. Chem. 28:350.
Moallem, U., H. Lehrer, L. Livshitz, M. Zachut, and S. Yakoby. 2009. The effects of live yeast supplementation to dairy cows during the hot season on production, feed efficiency, and digestibility. J. Dairy Sci. 92:343.
Goering, H. K., and P. J. Van Soest. 1970. Forage Fiber Analysis. Agric. Handb. No. 379. US Dept. Agric., Agric. Res. Serv., Washington, DC.
Moya, D., S. Calsamiglia, A. Ferret, and M. C. Fuentes. 2007. Effects of yeast and type of starch on pH fluctuation, nutrient digestion, and microbial fermentation in a dual flow
449 continuous culture system. J. Dairy Sci. 90(Suppl. 1):337. (Abstr.) National Forage Testing Association. 2002. Method 2.2.2.5: Dry matter by oven drying for 3 hr at 105°C. Natl. Forage Testing Assoc., Omaha, NE. http://www.foragetesting.org/lab_procedure/sectionB/2.2/ part2.2.2.5.htm Accessed June 18, 2010. Putnam, D. E., C. G. Schwab, M. T. Socha, N. L. Whitehouse, N. A. Kierstead, and B. D. Garthwaite. 1997. Effect of yeast culture in the diets of early lactation dairy cows on ruminal fermentation and passage of nitrogen fractions and amino acids to the small intestine. J. Dairy Sci. 80:374. Soder, K. J., and L. A. Holden. 1999. Dry matter intake and milk yield and composition of cows fed yeast prepartum and postpartum. J. Dairy Sci. 82:605. Van Soest, P. J., J. B. Robertson, and B. A. Lewis. 1991. Methods for dietary fiber, neutral detergent fiber, and nonstarch polysaccharides in relation to animal nutrition. J. Dairy Sci. 74:3583. Wohlt, J. E., T. T. Corcione, and P. K. Zajac. 1998. Effect of yeast on feed intake and performance of cows fed diets based on corn silage during early lactation. J. Dairy Sci. 81:1345.