Effects of Sire Breed on the Subsequent Reproductive Performances of Landrace Sows

Y H Huang,S H Liu,S W Roan,Y P Lee,T S Yang

doi:10.5713/ajas.2003.489

Abstract

Reproductive traits of sows are determined chiefly by the genetic background of the dam herself. Whether the breed of the serviced boars also contributes is not yet clear. A total of 8,946 litters of Landrace (L) sows from 68 farms were examined. Of these, 876, 1,260, and 6,810 litters were produced from natural mating with L, Yorkshire (Y), and Duroc (D) breeds, respectively. The birth litter size (BLS), weaning litter size (WLS), live born piglets (LBP), and survival rate % (SR), of every litter were recorded. A general linear-model procedure was followed to estimate the effects of boars' breed (B), parity (P) and B×P interaction on the reproductive traits of the sows. Results show that BLS, WLS, and LBP were all significantly (p<0.001) affected by B and P. SR% was significantly influenced by B but not by P. L sows crossbred with Y or purebred with L produced litters with higher BLS, WLS, and LBP values than those bred with D. Pure L breeding yielded litters with lower SR% than did crossbreeding with D, while the difference between SR% due to LY and that due to LD crossbreeding was not significant. The interaction of B with P was significant with respect to BLS, WLS, and LBP (p<0.001), but not SR%. No significant B effect on reproductive traits was measured in sows at their first parity; but at latter parities, LL or LY produced litters with similarly high BLS, WLS and LBP, which values were all significantly greater than those of LD litters. The breed of boar evidently affected the subsequent reproductive performance of L sows and this effect may be further manipulated by the parity effect. Breed differences in semen quality and the success of fetus development with different interactions of the genetic background with the uterus function of the sow that may contribute to these effects are discussed. (Asian-Aust. J. Anim. Sci. 2003. Vol 16, No. 4 : 489-493)

Highlights

Reproductive traits of sows are determined by the genetic background of the dam herself
A general linear-model (GLM) procedure was used to estimate the effects of boar breed (B), parity (P) and B and P (B×P) on the reproductive traits of the sows, as follows: Yijklm=μ+Bi+Pj+(B×P)ij+εijk where Yijk represents any observation; Bi represents the effects of the breed of the sire; Pj represents the effects of the dam’s parity; B×Pij represents the joint effects of the sire’s breed and the dam’s parity; andεijk is the random residual effect
Numerous studies have shown the effect of breed on both growth and reproduction in pigs (Hill and Webb, 1982; A total of 8,946 liters were examined of which, 876 Pepper et al, 1984; Yen et al, 1987; Baas et al, 1992)

Summary

INTRODUCTION

Integrity, and the sire’s genetic background affects embryo mortality and fetal development The reproductive performance of sows is usually Dyck, 1976; Hill and Webb, 1982; Van der Lende et al, indicated by a number of traits including birth litter size 1994). This effect may persist even through the lactation (BLS), live born pigs (LBP), weaning litter size (WLS), and period (Strang, 1970), since well-developed piglets with survival rate (SR). These traits vary with the genetic higher birth weights tend to acquire more milk and background of the dam and environmental factors such as have a higher survival rate during nursing. The genetic background of the serviced boar should breed (B), sow’s parity (P), and their interaction (B×P) on contribute to the variation of the reproductive traits of the the reproductive traits of L sows

MATERIALS AND METHODS

RESULTS

DISCUSSION