Đang chuẩn bị liên kết để tải về tài liệu:
báo cáo khoa học: "Components of prolificacy in hyperprolific Large White sows compared with the Meishan and Large White breeds"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: Components of prolificacy in hyperprolific Large White sows compared with the Meishan and Large White breeds | Génét. Sél. Evol. 1986 18 3 333-342 Components of prolificacy in hyperprolific Large White sows compared with the Meishan and Large White breeds G. BOLET 1 Fransoise MARTINAT BOTTE A. LOCATELLI J. GRUAND M. TERQUI Frangoise BERTHELOT INRA Station de Génétique quantitative et appliquée F 78530 Jouy-en-Josas INRA Station de Physiologic de la Reproduction F 37380 Monnaie INRA Station experimentale de Selection porcine F 86480 Rouillé Summary We identified the most prolific sows in French Large White herds and 17 hyperprolific sows HLW were bought whose average litter size on 3 farrowings was 16.5 piglets born alive i.e. a superiority of 5.3 piglets per litter over their contemporaries. In 1 to 3 subsequent pregnancies we compared ovulation and embryonic mortality rates of 10 HLW with those of 10 Large White LW and 7 Meishan MS sows. The ovulation rate of HLW was significantly higher than that of LW 5.3 and MS 5.7 . The ovulation rate of HLW daughters was higher by 2.1 corpora lutea compared to that of LW gilts at the 3rd oestrus after puberty which occurred at the same age in the 2 genotypes 228 days MS gilts were pubescent significantly earlier 88 days and had a significantly lower ovulation rate than both Large White groups. The embryonic mortality rate was high in HLW sows 41 p. 100 whereas that of MS sows was low 16 p. 100 compared to that of LW sows 26 p. 100 . Regression of embryonic mortality rate on ovulation rate was significantly positive 2.5 and embryonic mortality rate remained significantly higher in both Large White groups than in MS sows when corrected for ovulation rate. It is concluded that the improvement of embryonic survival in Large White sows should be a high priority to improve the efficiency of the hyperprolific line and that the Meishan breed which is prolific owing to a low embryonic mortality may be an appropriate experimental model. Key words Pig breeds prolificacy ovulation rate embryonic mortality. Resume Composantes de la proliịicité de