Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: Genetic relationship between prepuberal plasma FSH levels and reproductive performance in Lacaune ewe lambs | Génét. Sil. Evol. 1988 20 4 489-498 Genetic relationship between prepuberal plasma FSH levels and reproductive performance in Lacaune ewe lambs L. BODIN B. BIBÉ . BLANC and G. RICORDEAU with the technical assistance of R. MOLLARET and . POIRIER Institut National de la Recherche Agronomique Station d Amelioration Génétique des Animaux Centre de Recherches de Toulouse Auzeville BP 27 31326 Castanet-Tolosan Cedex France Institut National de la Recherche Agronomique Station de Physiologic de la Reproduction Centre de Recherches de Tours 37380 Nouzilly France Summary In this study we have estimated the phenotypic and genetic relationships between prepuberal plasma FSH level FSH and logFSH of ewe lambs of the Lacaune meat breed and their reproductive performance at first mating fertility and prolificacy . Hormonal levels were assayed in a single blood sample collected at approximately 5 weeks of age mean . days from 829 ewe lambs born in July-September 1983 in 30 flocks from 33 Al sires. Mating took place over two periods in early breeding season at 11 months of age and in October-November at 15 months. Fertility analysis was conducted only on ewe lambs mated in June-July n 737 while prolificacy was analyzed for all pregnant ewe lambs n 732 . For plasma FSH and log plasma FSH the effects of birth type blood sampling date and time as well as age at blood sampling were not significant P . The flock and sire effects were highly significant P s and heritability was and for plasma FSH and log plasma FSH respectively. The phenotypic correlation between prolificacy and FSH levels was positive but non-significant the genetic correlation was for plasma FSH and for log plasma FSH. Prepuberal FSH levels of ewe lambs which remained barren after their first mating early in the breeding season were significantly higher than that of pregnant ones P 0 05 . Nevertheless the genetic correlation between fertility and logFSH was significantly
