Effects of protein on the performance of dairy cows in early lactation
2001
Argete, E.C. | Revilleza, R.P. | Trung, L.T.
A ninety-day post partum feeding trial was conducted on twelve cows using corn silage based complete rations with three levels of crude protein (CP). Ration 1 - 9.84 percent, Ration 2 - 11.54 percent, and Ration 3 - 13.5 percent CP. Performance of the animals in all treatments did not significantly differ in terms of average daily milk production, 4 percent fat-corrected milk, total milk production, projected 305-day production, persistency of milk production and body weight changes. In all cases, however, animal in ration 2 gave the highest results. Protein intake did not significantly differ. Except for milk protein which was significantly higher in ration 3 (P.05) than in ration 1 and 2. All the other milk components (milk fat, total solids and ash) were not significantly different. Likewise, no significant differences were found in rumen pH, rumen ammonia, nitrogen (N), rumen urea-N, blood ammonia-N, and blood urea-N, the latter was found highly correlated with total protein intake. The number of animals impregnated were: ration 1-2, ration 2-2, and 3-3. Conception rate was found to be highest in ration 3 (75 percent) followed by ration 2 (60.75 percent) and then ration 1 (56.25 percent). Post partum estrus followed the same trend. Income above feed cost was found to be highest in ration 2 with P33.97 while rations 1 and 3 were P27.70 and P28.47, respectively.
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