TAILIEUCHUNG - Báo cáo sinh học: " Genetic parameters for litter size in sheep: natural versus hormone-induced oestrus"

Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí sinh học thế giới đề tài: Genetic parameters for litter size in sheep: natural versus hormone-induced oestrus | Genet. Sel. Evol. 36 2004 543-562 INRA EDP Sciences 2004 DOI gse 2004016 543 Original article Genetic parameters for litter size in sheep natural versus hormone-induced oestrus Steven JANSSENSa Walter VANDEPlTTEa Loys BoDlNb a . Leuven Centre for Animal Genetics and Selection Department Animal Production Kasteelpark Arenberg 30 3001 Leuven Belgium b Station d amélioration génétique des animaux Institut national de recherche agronomique BP 27 31326 Castanet-Tolosan France Received 7 January 2004 accepted 27 April 2004 Abstract - The litter size in Suffolk and Texel-sheep was analysed using REML and Bayesian methods. Litters born after hormonal induced oestrus and after natural oestrus were treated as different traits in order to estimate the genetic correlation between the traits. Explanatory variables were the age of the ewe at lambing period of lambing a year flock-effect a permanent environmental effect associated with the ewe and the additive genetic effect. The heritabil-ity estimates for litter size ranged from to using REML in bi-variate linear models. Transformation of the estimates to the underlying scale resulted in heritability estimates from to . Posterior means of the heritability of litter size in the Bayesian approach with bivariate threshold models varied from to . REML estimates of the genetic correlations between the two types of litter size ranged from to in the Suffolk and from to in the Texel. The posterior means of the genetic correlation Bayesian analysis were and for the Suffolk and and for the Texel in the sire and animal model respectively. A bivariate threshold model seems appropriate for the genetic evaluation of prolificacy in the breeds concerned. sheep litter size oestrus induction heritability genetic correlation 1. INTRODUCTION Litter size LS is economically the most important trait in lamb meat production 20 but it also has an important indirect effect on

• Báo cáo khoa học
• Báo cáo sinh học hay
• cách trình bày báo cáo
• báo cáo sinh học
• công trình nghiên cứu sinh học
• tài liệu về sinh học