The Effect of Weaning Weight on Growth to Slaughter for Growing Pigs

Introduction The early growth of young piglets up to weaning in commercial practice varies widely and depends on many factors such as the sow’s lactation yield, health status, genetics and the successful deployment of supplementary creep feeds. The achievement of good early pre-weaning growth however may be crucial to the whole growth curve through to slaughter and therefore the purpose of this study was to evaluate the relationships between weaning weight and growth performance through to slaughter at 90 kg. Materials and methods 256 piglets at SCA’s Green Hill Farm unit were weighed individually at weaning at 25 days of age and then at 32, 50, 100 and 140 days age. The relationships between early growth and weaning weights and the long-term performance to slaughterable weight were analysed by regression and correlation analysis. In addition 5000 piglets from the same unit were analysed similarly but between weaning and day 25 post weaning.

Results The relationship between overall growth rate to slaughter and the weight at 50 days of age given by the equation GR OVER = 0.432 + 0.0155 Wt50 (p=0; R2=30.2%). The relationship between overall growth rate and weight at 100 days of age is given by the equation GR OVER = 0.277 + 0.00737 Wt100 (p=0; R2=40.9%). The relationship between growth rate overall and the immediate post weaning weight is given by GR OVER = 0.493 + 0.0216 Wt32 (p=0; R2=21.9%). The relationship between growth rate in the first 7 days post weaning and growth performance all the way to slaughter is given by the equation GR OVER = 0.0623 + 0.344 ADG 1 (p=0; R2=25%; r2=0.502).

Conclusions Clearly there are very significant relationships between weaning, post weaning gain and performance to slaughter weights. This substantiates evidence from both Australia and North America where similar observations have been made. The economic benefits from achieving high weaning weights via high quality creep nutrition arises not only because of the immediate benefits in terms of growth and health status but also the accrued advantages demonstrated here. This will improve the profitability of the growing finishing pig by a significant margin.

Date published: 2003-05-05

M. Sprent, M.A. Varley
and M.A. Cole

SCA Nutrition Ltd,
Dalton, Thirsk, North
Yorkshire, YO7 3HE