Litherland N.B.,University of Minnesota |
Da Silva D.N.L.,University of Minnesota |
LaBerge R.J.,University of Minnesota |
Schefers J.,University of Minnesota |
Kertz A.,ANDHIL LLC
Journal of Dairy Science | Year: 2014
Eighty-one Holstein and Holstein-cross dairy calves fed calf milk replacer (CMR) were used to determine response to increasing amounts of supplemental fat during mild cold stress. Calves (n=27) were randomly assigned to 1 of 3 treatments: (1) low fat [LF; 28% crude protein:15% fat milk replacer (28:15 MR)]; (2) medium fat [MF; 28:15 MR+113g/d of commercial fat supplement (FS)]; (3) high fat (HF; 28:15 MR+227g/d of FS). The MF and HF calves received FS from d 2 to 21, and all calves were fed LF from d 22 to 49. The CMR was fed at 1.4% of birth body weight (BBW) from d 1 to 10, at 1.8% of BBW from d 11 to 42, and at 0.9% of BBW from d 43 to 49. Calves were weaned on d 49 and remained in hutches until d 56. The CMR was reconstituted to 13% solids. Calves were fed a commercial starter grain (19.2% crude protein on a dry matter basis) ad libitum and offered warm water after CMR feeding. Calves were fed CMR twice daily at 0630 and 1730h in hutches bedded with straw. Starter intake, CMR intake, and ambient temperature were measured daily, and body weight (BW), hip height, and body length were measured weekly. Data were analyzed using PROC MIXED in SAS (SAS Institute Inc., Cary, NC) as a randomized design with linear and quadratic contrasts. Calf BBW averaged 42.0±1.0kg, total serum protein averaged 5.8±0.1mg/dL, and birth ambient temperature averaged 5.0±1.1°C. Feeding FS increased metabolizable energy intake (MEI) over maintenance but decreased efficiency of conversion of BW gain:MEI. Starter intake by LF calves was greatest until the beginning of weaning, after which starter intake was similar among treatments. Because of higher starter intake, total MEI was similar among treatments. Feed efficiency through d 49 was greater for calves fed MF and HF. Average daily gain during fat supplementation was greater for MF and HF than for LF. Lack of increase in BW gain and feed efficiency between MF and HF treatments indicated that HF did not result in advantages over MF. Supplementing fat to preweaned calves fed CMR increased BW gain and decreased starter intake through d 21 which had carryover effects on starter intake on d 49 and reduced hip height and tended to reduced withers height and body length by d 56. The addition of supplemental fat to LF, during mild cold stress, may result in a suboptimal ratio of crude protein to metabolizable energy in the CMR. © 2014 American Dairy Science Association.
Stamey J.A.,Urbana University |
Stamey J.A.,Virginia Polytechnic Institute and State University |
Janovick N.A.,Urbana University |
Kertz A.F.,ANDHIL LLC |
Drackley J.K.,Urbana University
Journal of Dairy Science | Year: 2012
Our objectives were to determine the effect of starter crude protein (CP) content on growth of Holstein calves from birth to 10 wk of age in an enhanced early nutrition program, and to compare the enhanced program to a conventional milk replacer program. Calves (64 female, 25 male) were assigned to 3 treatments in a randomized block design: 1) conventional milk replacer (20% CP, 20% fat) plus conventional starter [19.6% CP, dry matter (DM) basis], 2) enhanced milk replacer (28.5% CP, 15% fat) plus conventional starter, and 3) enhanced milk replacer plus high-CP starter (25.5% CP, DM basis). Calves began treatments (n = 29, 31, and 29 for treatments 1 to 3) at 3 d of age. Conventional milk replacer (12.5% solids) was fed at 1.25% of birth body weight (BW) as DM daily in 2 feedings from wk 1 to 5 and at 0.625% of birth BW once daily during wk 6. Enhanced milk replacer (15% solids) was fed at 1.5% of BW as DM during wk 1 and 2% of BW as DM during wk 2 to 5, divided into 2 daily feedings. During wk 6, enhanced milk replacer was fed at 1% of BW as DM once daily. Calves were weaned at d 42. Starter was available for ad libitum intake starting on d 3. Starter intake was greater for calves fed conventional milk replacer. For calves fed enhanced milk replacer, starter intake tended to be greater for calves fed enhanced starter. During the weaning period, enhanced starter promoted greater starter DM intake than the conventional starter. Over the 10-wk study, the average daily gain of BW (0.64, 0.74, and 0.80. kg/d) was greater for calves fed enhanced milk replacer with either starter and, for calves fed enhanced milk replacer, tended to be greater for calves fed high-CP starter. Rates of change in withers height, body length, and heart girth were greater for calves fed enhanced milk replacer but did not differ between starter CP concentrations. The postweaning BW for enhanced milk replacer treatments was greater for calves receiving the enhanced starter at wk 8 (73.7, 81.3, and 85.8. kg) and wk 10 (88.0, 94.9, and 99.9. kg). Starter CP content did not affect height, length, or heart girth within enhanced milk replacer treatments. Regression analysis showed that gain of BW during the first week postweaning (wk 7) increased with greater 3-d mean starter intake in the week before weaning. Starter with 25.5% CP (DM basis) provided modest benefits in starter intake (particularly around weaning) and growth for dairy calves in an enhanced early nutrition program compared with a conventional starter (19.6% CP). © 2012 American Dairy Science Association.
Loften J.R.,Milk Specialties Global |
Linn J.G.,Milk Specialties Global |
Drackley J.K.,Urbana University |
Jenkins T.C.,Clemson University |
And 2 more authors.
Journal of Dairy Science | Year: 2014
Energy is the most limiting nutritional component in diets for high-producing dairy cows. Palmitic (C16:0) and stearic (C18:0) acids have unique and specific functions in lactating dairy cows beyond a ubiquitous energy source. This review delineates their metabolism and usage in lactating dairy cows from diet to milk production. Palmitic acid is the fatty acid (FA) found in the greatest quantity in milk fat. Dietary sources of C16:0 generally increase milk fat yield and are used as an energy source for milk production and replenishing body weight loss during periods of negative energy balance. Stearic acid is the most abundant FA available to the dairy cow and is used to a greater extent for milk production and energy balance than C16:0. However, C18:0 is also intimately involved in milk fat production. Quantifying the transfer of each FA from diet into milk fat is complicated by de novo synthesis of C16:0 and desaturation of C18:0 to oleic acid in the mammary gland. In addition, incorporation of both FA into milk fat appears to be limited by the cow's requirement to maintain fluidity of milk, which requires a balance between saturated and unsaturated FA. Oleic acid is the second most abundant FA in milk fat and likely the main unsaturated FA involved in regulating fluidity of milk. Because the mammary gland can desaturate C18:0 to oleic acid, C18:0 appears to have a more prominent role in milk production than C16:0. To understand metabolism and utilization of these FA in lactating dairy cows, we reviewed production and milk fat synthesis studies. Additional and longer lactation studies on feeding both FA to lactating dairy cows are required to better delineate their roles in optimizing milk production and milk FA composition and yield. © 2014 American Dairy Science Association.
Bernard J.K.,University of Georgia |
Castro J.J.,University of Georgia |
Kertz A.F.,ANDHIL LLC
Professional Animal Scientist | Year: 2012
A 10-wk lactation trial was conducted using 45 late lactation cows (199.7 ± 66.3 DIM and 32.0 ± 5.2 kg milk/d) to determine the effect of feeding supplemental fatty acids that were mostly (85%) saturated (SAT) or more (50%) unsaturated (UNS) on performance and select metabolic measures. The first 2 wk of the trial served as a standardization period, and all cows were then fed the control diet, which contained only whole cottonseed as a supplement. At the end of wk 2, cows were blocked by parity and randomly assigned to 1 of 3 treatments within each block for 8 wk. The 3 treatment diets were the control, the equivalent of 0.40 kg/d of SAT, and the equivalent of 0.46 kg/d of UNS. Dry matter intake, milk yield, milk fat percent, and milk protein percent were similar among treatments and averaged 23.8 kg/d, 32.5 kg/d, 3.47%, and 3.23%, respectively. Body weight gain and change in BCS were similar throughout the trial. Concentrations of total cholesterol, high-density lipoproteins, and low-density lipoproteins in the blood were higher for cows fed diets supplemented with UNS compared with control or SAT. Triglyceride and BUN concentrations were similar among treatments. Concentrations of nonesterified fatty acids were greater for UNS, whereas insulin concentrations were greater for SAT than either control or UNS. No differences in internal body temperature were observed among treatments, but there was an interaction of treatment and time during wk 4. Cows fed UNS had greater body temperatures from 0500 through 0530 h and from 0930 through 1030 h compared with control and SAT. These results indicate that supplemental SAT or UNS did not affect intake or performance of late lactation cows; however, feeding UNS did increase cholesterol and NEFA concentrations along with reduced insulin. © 2012 American Registry of Professional Animal Scientists.