1Jordan, E.R.,T.E. Chapman, D.W. Holtan, et al. Relationship of dietary crude protein to composition of uterine secretions and blood in high - producing dairy cows[J]. Dairy Sci. 1983,66:1854～1862
2Elord, C.C.,and W.R. Butler. Reduction of fertility and alteration of uterine pH in heifers fed excess ruminally degrsdable protein[J]. Anim.Sci. 1993,71:694～701
3W. R. Butler. Effect of protein nutrition on ovarian and uterine physiology in dairy cattle[J]. Dairy Sci. 1998,81:2533～2539
4Bruckental, I.,D. Dori, M. Kaim, et al. Effect of source and level of protein on milk yield and reproductive performance of high - producing primiparous and multiparous dairy cows[J]. Anim. Prod. 1989,48:319～329
5Anderson, G.W.,and B. Barton. Reproductive efficiency:potential nutrition management interactions. New England Feed Dealers Conf,Univ. Maine. Orono. 1987
6Ferguson, J.D., and W.V. Chalupa. Impact of protein nutrition on reproduction in dairy cows[J]. Dairy Sci. 1989, 72:746～766
7Canfield, R.W.,C.J. Sniffen, and W.R. Butler. Effects of excess degradable protein on postpartum reproduction and energy balance in dairy cattle[J]. Dairy Sci. 1990,73:2342～2349
8Carroll, D.J.,B.A. Barton, G.W. Anderson, et al. Influence of protein intake and feeding strategy on reproductive performance of dairy cows[J]. Dairy Sci. 1988, 71:3470～3481
9Howard H.J., E.P. Aalseth, G.D. Adams, et al. Influence of dietary protein on reproductive performance of dairy cows[J]. Dairy Sci. 1987, 70:1563～1571
