A NOTE ON FERTILIZATION AND EMBRYO PRODUCTION IN SUPEROVULATED CATTLE WITH VARIOUS LEVELS OF SUBCUTANEOUS FAT TISSUE

One hundred and five Holstein cattle, with a mean body weight of 668 kg, were superovulated using a total dose of 18 mg FSH. Five animals did not have corpora lutea (CL). No ova or embryos were recovered from 12 of the 100 animals which had CL. A total of 810 ova/embryos were collected from the remaining 88 animals and 432 of these were of transferable quality. The mean (range) measurements for subcutaneous fat deposition in samples taken at slaughter from the back, rump and ventral abdominal wall were 14 mm (3 to 34), 7 mm (0·7 to 33) and 7 mm (0·8 to 32), respectively. The number of transferable embryos and fertilized ova decreased as fat levels increased, but the differences between the groups were not significant (P > 0·05). There was a positive relationship between the number of CL and (a) the number of fertilized ova, and (b) the number of transferable embryos (r = 0·53, P < 0·001 and r = 0·48, P < 0·001). The correlation between the number of fertilized embryos and the number of transferable embryos was r = 0·91, P < 0·001. © 1990, British Society of Animal Science. All rights reserved.