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- Title
Supplemental rumen-protected choline and methionine for lactating dairy cows.
- Authors
Eastridge, M. L.; Engel, J.; Ribeiro, C. V. D. M.
- Abstract
In experiment one, 3 rumen protected choline (RPC) sources [Reashure® (REA), Balchem Encapsulates, New Hampton, NY; BPC, Robt Morgan, Inc., Paris, IL; and Pro-Choline™40 (PC), Probiotech, Inc., St-Eustache, QC, Canada] were incubated in situ using 2 rumen cannulated cows. Dacron bags containing the samples were suspended in the rumen and removed at 0, 2, 4, 6, 12, 24, and 48 h, with 2 samples per time point per cow. Rate of DM disappearance was lower for REA (0.015 /h) than for BPC (0.187 /h) and PC (0.215 /h). Rate of disappearance of choline also was lower for REA (0.003 /h) than for BPC (0.558 /h) and PC (0.254 /h). Although REA and BPC had similar DM residue after 48 h of incubation (31%), the choline remaining was only 2% for BPC but 85% for REA. In situ DM disappearance is inadequate for assessing choline protection, and REA provided greater choline protection compared to the other 2 sources. In experiment two, initially 56 lactating cows were fed one of 4 diets beginning at parturition: 1) control (duodenal flow of lysine:methionine (lys:met) 3.8, NRC 2001), 2) 0.26% RPC (REA; targeted at 60 g/d to provide 15 g/d of choline; lys:met 3.8; REA-L), 3) 0.52% RPC (REA, 120 g/d to provide 30 g/d of choline; lys:met 3.8; REA-H), or 4) 0.096% rumen protected methionine (Smartamine M™, Adisseo, Antony Cedex, France; lys:met 3.0; MET). Diets were fed as TMR for 13 weeks and consisted of 52% forage (76% corn silage and 24% alfalfa hay), 9% whole linted cottonseed, and 39% concentrates. Diets contained 16.8% CP, 39.2% NDF, and 20% forage NDF. Forty-eight of the cows (31 Holstein and 17 Jersey) completed the trial. The DMI (20.6 kg/d), milk yield (36.5 kg/d), milk fat (4.35%), and milk protein (3.14%) were not different among diets. The MUN was highest for REA-H (19.1 mg/dl) and intermediate for MET (18.1 mg/dl). Milk choline was higher for MET, but plasma choline and nonesterified fatty acids were similar among diets. Plasma glucose was higher for control and MET than for either level of REA. Milk choline was a better indicator of choline status than plasma choline, and MET resulted in higher milk choline concentration than the feeding of RPC.
- Subjects
METHIONINE; LYSINE; ALFALFA; U.S. Nuclear Regulatory Commission; FREE fatty acids; CHOLINE; MILKFAT; COWS; MILK proteins
- Publication
Journal of Animal Science, 2006, Vol 84, p77
- ISSN
0021-8812
- Publication type
Article