Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: 3/11/2002
Publication Date: 7/25/2002
Citation: Klindt, J. 2002. Influence of litter size and creep feeding on preweaning gain and influence of preweaning growth on growth to slaughter in barrows [abstract]. Journal of Animal Science. 80(Suppl. 1):199.
Technical Abstract: It has been advised that heavier weaning weights (Wnwt) are desired because pigs heavier at weaning attain market weights sooner. However, weaning ages have decreased and slaughter wts have increased, thus, Wnwt is a smaller proportion of the final wt. Herein, birth-to-weaning ADG (B-WADG) as a determinant of weight at a final age and yield of marketable pork was examined. Newborn pigs from 54 birth litters were crossfostered to create 47 assigned litters of 4 through 14 pigs/litter to create differences in B-WADG. Creep feed was offered from 5 d of age or for 2 d before weaning at 13 to 20 d. Data were obtained from 195 barrows slaughtered at an avg age of 170 d. Carcass dissection data were recorded. Analyses revealed a linear effect of assigned litter size (P < 0.01), linear effect of birth wt, kg (P < 0.01), and effect of birth dam (P < 0.01) on B-WADG, kg, and Wnwt, kg. B-WADG and Wnwt were not influenced (P > 0.71) by creep feeding treatment. The importance of birth wt (Brwt), B-WADG, Wnwt, and Brwt plus B-WADG in determination of measures of postweaning growth and yield of marketable pork (sum of trimmed picnic, butt, loin, and ham) were examined by regression analysis. The initial models included the linear and quadratic effects of the independent variables. In general, the R2s for the other models ranked as for wt at 170 d. The results indicate positive relationships between B-WADG and measures of post-weaning growth and carcass yield, suggesting management practices that increase B-WADG may be advantageous in pork production. However, these data do not allow evaluation of costs and benefits of management changes that would increase B-WADG, and thus, increase postweaning growth rate.