Review On Effect Of Feeding Dairy Cow With Protected Fat And Protein On Milk Yield And Its Composition

Author : Ethan Garrett Carder
Publisher :
ISBN 13 :
Total Pages : 109 pages
Book Rating : 4.:/5 (97 download)

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Download or read book The Effects of Increased Metabolizable Protein in Fresh Dairy Cattle Throughout Peak Lactation written by Ethan Garrett Carder and published by . This book was released on 2016 with total page 109 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first few weeks after parturition in dairy cattle is a time marked by low, but increasing, feed intake and sharply increasing milk production. Because of low intake, nutrient density of the diet may need to be higher during this period to support increasing milk yields. We hypothesized that feeding higher levels of metabolizable protein (MP) and feeding supplemental rumen protected methionine and lysine would increase milk yield and protein concentration. The experiment consisted of 2 phases. Fifty-six Holstein cows (21 primiparous and 35 multiparous), starting at 3 DIM, were used in a randomized-block design with three diets (phase 1). At approximately 23 DIM, cows were moved into a free stall barn and fed the control diet (phase 2) to observe potential carry-over effects on production. Estimated DMI used in formulation was 17 kg/d. The treatments were control (16.5% CP, 10.9% RDP, 5.6% RUP, formulated for 25.1 kg/d MP allowable milk based on NRC model), high protein (HP; 18.5% CP,11.6% RDP, 6.9% RUP, 29.9 MP allowable milk), and amino acid treatment (MPAA; 17.5% CP, 10.5% RDP, 7.0% RUP 29.7 MP allowable milk). The MPAA diet included a proprietary spray-dried blood meal product (Perdue Agribusiness, Salisbury, MD) that provided 174 g/d and 62 g/d of dietary rumen-protected lysine and methionine, respectively, per the NRC model. The MP diet provided an estimated 156 g/d lysine and 45 g/d methionine, and the control diet provided 149 g/d lysine and 41 g/d methionine. Milk production and DMI were measured daily and milk was sampled for components on day 8, 15, and 20 during phase 1 and on day 30 during phase 2. Statistical model included parity, treatment, and week fixed effects, random effect of block, and cow as the experimental unit. In phase 1, treatment and treatment by parity interaction did not affect milk yield (33.6, 34.5, and 33.1 kg for Control, HP, and MPAA, respectively), DMI (17.8, 17.8, 18.5 kg/d for Control, HP, and MPAA, respectively), or milk protein yield (1.11 kg/d). Milk protein concentration was higher (3.30% vs 3.17% and 3.17%) for MPAA treatment as compared to the HP and control, respectively. Energy corrected milk (ECM) was higher (39.0 and 38.5 vs 35.2 kg) for MPAA and HP than for the control, respectively. MUN was higher (14.3 vs 12.7 and 11.5 mg/dl) for the Control compared to HP and MPAA. Plasma concentrations of Met were increased in HP and MPAA compared to the control, with MPAA being the highest. Plasma concentrations of 3-methylhistidine was decreased in HP and MPAA compared to the control. Production responses, for phases 1 and 2 combined, did not differ in HP and MPAA compared to the control. Overall, supplementing rumen-protected lysine and methionine with extra HP can increase ECM yield, milk protein concentration, and milk fat concentration and yield during the first 3 weeks of lactation.