抄録
Feeding rumen bypass polyunsaturated fatty acids (PUFA) affects the reproduction of Japanese Black cows, though its influence on superovulatory response in donor cows and conception in recipient cattle has not been well studied. Here we investigated the effects of PUFA to Japanese Black cows on blood biochemistry, the numbers of ova and embryos or transferable embryos, and pregnancy rate following embryo transfer (ET) to recipient Holstein heifers. PUFA (40% linoleic acid) was fed at 300 g/day in the experimental group since the last estrus day until day of artificial insemination for superovulatory treatment. Blood was collected on the first day of follicle-stimulating hormone administration. Total cholesterol level was significantly higher in the 15 to 19 days feeding group (117.4 mg/dl) than in the control group (95.0 mg/dl). The numbers of ova and embryos or transferable embryos were significantly higher in the 15 to 19 days feeding group than in the control group. The numbers of transferable embryos in the 15 to 19 days feeding group was significantly higher than in the 10 to 14 days feeding group. The pregnancy rate at Day 60 was significantly higher in the experimental group (66.7 and 57.1%) than in the control group (51.1 and 44.0%) after transfer of fresh and frozen-thawed embryos, respectively. In conclusion, the numbers of ova and embryos or transferable embryos after superovulatory treatment increased and pregnancy rate after ET was higher in Japanese Black cows fed PUFA than in the control group.
