ORIGINAL PAPER
Lactational responses to ruminally-protected methionine in cows fed a low-protein grass silage-based diet
 
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1
The Agricultural University of Cracow, Department of Human Nutrition, al. 29 Listopada 46, 31-425 Kraków, Poland
2
The Agricultural University of Cracow, Department of Animal Nutrition, al. 29 Listopada 46, 31-425 Kraków, Poland
3
Department of Animal Science, University of Cukurova, Adana, Turkey
Publication date: 2002-05-09
 
J. Anim. Feed Sci. 2002;11(2):189–203
 
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ABSTRACT
Twelve multiparous Polish Red-and-White cows, were assigned to two-factorial (2×2) arrangement of treatments, in a balanced changeover design, involving two levels of dietary protein (PDI: 100 vs 85% of the INRA requirement) and two levels of ruminally-protected DL-methionine (Smartamine™M: 0 vs 20 g/d). The cows were in wk 8-12 of lactation and were fed a mixed diet with grass silage and concentrates representing 50 and 50% of the dietary DM, respectively. The four combinations of treatments were: 100% PDI (0 g Met), 100% PDI (+20 g Met), 85% PDI (0 g Met) and 85% PDI (+20 g Met). The calculated intestinal concentrations of lysine and methionine (% PDI) were: 6.91 and 1.79, 6.88 and 2.27, 6.88 and 1.87, 6.84 and 2.42, respectively. Dry matter and net energy (UFL) intakes were similar across the treatments. Crude protein, PDIN and PDIE intakes were significantly (P<0.001) higher in cows fed the 100% PDI diets, as compared to those fed the 85% PDI diets. Milk and 4% FCM yields and the efficiency of milk production were not significantly different. Milk fat, lactose, and SNF contents did not respond to the treatments. Feeding the 100% PDI diets compared to the 85%) PDI ones increased significantly (P<0.05) milk protein yield (from 0.67 to 0.76 kg/d). Milk NPN and urea concentrations were significantly (P<0.001) decreased, and the relative concentration of milk protein N (% of total N) was significantly (P<0.05) increased in milk from cows fed the 85% PDI diets compared to the 100% PDI diets. No effects of methionine supplementation and no interactions between dietary protein intakes and supplemental methionine levels on the variables addressed in this study were detected. It is concluded that supplementing ruminally-protected methionine to grass silage-based diets did not result in any apparent changes in lactational responses, regardless of the protein status of these cows, thus indicating that methionine is not the first limiting amino acid in these diets.
 
CITATIONS (5):
1.
Meta-analysis of lactation performance in dairy cows receiving supplemental dietary methionine sources or postruminal infusion of methionine
G.I. Zanton, G.R. Bowman, M. Vázquez-Añón, L.M. Rode
Journal of Dairy Science
 
2.
Effect of rumen-protected methionine on feed intake, milk production, true milk protein concentration, and true milk protein yield, and the factors that influence these effects: A meta-analysis
R.A. Patton
Journal of Dairy Science
 
3.
Impacts of manipulating ration metabolizable lysine and methionine levels on the performance of lactating dairy cows: A systematic review of the literature
P.H. Robinson
Livestock Science
 
4.
Effects of Dietary Supplements of Folic Acid and Rumen-Protected Methionine on Lactational Performance and Folate Metabolism of Dairy Cows
C.L. Girard, H. Lapierre, J.J. Matte, G.E. Lobley
Journal of Dairy Science
 
5.
Predictions of ruminal outflow of essential amino acids in dairy cattle
A.J. Fleming, H. Lapierre, R.R. White, H. Tran, P.J. Kononoff, R. Martineau, W.P. Weiss, M.D. Hanigan
Journal of Dairy Science
 
ISSN:1230-1388