EVALUATION OF THE INFLUENCE OF MATERNAL AND PIGLET BREED DIFFERENCES ON BEHAVIOR AND PRODUCTION OF MEISHAN SYNTHETIC AND EUROPEAN WHITE BREEDS DURING LACTATION

Meishan synthetic sows and gilts have been shown to produce higher lit ter weights at weaning than White breed type sows and gilts. To invest igate the factors contributing to this, 64 multiparous sows were used in a 2 X 2 X 2 factorial experiment to assess the influence of materna l breed type (0.50 Meishan synthetic (M) or purebred European Landrace and Large White (W)), litter size (eight (L) or 12 (H) piglets) and b reed of piglet (0.25 Meishan hybrid (m) or white hybrid (w)) on sow an d litter production and behaviour over a 28-day lactation. All litters were formed by cross-fostering to standardized litter rearing size 24 h after farrowing. Sows were given food twice daily to appetite. When there were no treatment interactions, main effects ave presented. M s ows were lighter (M = 215, W = 241 (s.e. 3.61) kg, P < 0.001) and fatt er (M = 31.5, W = 21.7 (s.e. 0.72) mm, P < 0.001) at farrowing than W and had higher maternal weight loss (M = 14.7, W = 5.9 (s.e. 0.85) kg, P < 0.001) and higher back fat loss (L = 5.6, W = 2.0 (s.e. 0.28) mm, P < 0.001) in lactation. High lifter size resulted in higher maternal weight loss (L = 7.4, H = 13.2 (s.e. 0.85) kg, P < 0.001) and fat los s (L = 2.9, H = 4.7 (s.e. 0.28) mm, P < 0.001) than low litter size. L itter growth rate was higher for M than for W (M = 17.0, W = 14.5 (s.e . 0.42) kg/week, P < 0.001) and for high lifter size than for low litt er size (L = 14.3, H = 17.3 (s.e. 0.42 kg/week, P < 0.001). The m pigl ets had lower lifer growth rates than w piglets (m = 15.1, w = 16.5 (s .e. 0.42) kg/week, P < 0.001). There were no breed differences in the length of suckling periods but M had shorter suckling intervals than W (M = 38.1, W = 48.7 (s.e. 1.08) min, P < 0.001). It is concluded that the higher litter weights produced by M sows are due solely to matern al effects and not litter size or piglet genotype.