Effects of retained fetal membranes on milk yield and reproductive performance.

Effects of retained fetal membranes on subsequent productive and reproductive performance were measured in a single Florida Holstein dairy herd (n = 216 retained fetal membranes and 208 normal cases). Mean performance was peak daily milk yield, 31.9 kg; 305-d milk yield, 6317 kg; days to first service, 60; days open, 115; and services per conception, 2.3. Yield was unaffected by retained fetal membranes; however, retention resulted in an increase of 4 d to first service, 19 d open, and .2 services per conception. Detrimental effects of parturitions in hot weather (July through September) compared with cool (December through February) were peak daily milk yield, 5.5 kg; 305-d milk yield, 512 kg; days to first service, 3; days open 39; and services per conception, .9. Interactions could not be detected between diagnosis (retained or normal) and season for any response. Sex of calf effects could not be detected for any response. Continued research to reduce occurrence of retained fetal membranes or to obviate its effects should lead to improved reproductive performance.