Effect of supplemental pig milk replacer on litter performance: seasonal variation in response

The objective of this study was to determine the effect of supplemental milk replacer on sow and litter performance. The study was conducted in 12 farrowing groups (171 litters) over a 3.5-yr period (October 1990 to April 1994). Commercial milk replacer was prepared fresh daily (150 g/L) and offered with ad libitum access in the farrowing crates within 24 h of parturition and was continued through weaning (d 21). Average pig weight (control, 5.5 kg/pig; supplemented, 6.4 kg/pig; P < .001) and total litter weight (control, 52.2 kg/litter; supplemented, 60.9 kg/litter; P < .001) at weaning were greater for litters receiving supplemental milk replacer. There was no effect (P > .2) of supplemental milk replacer on feed intake, backfat thickness, or body weight loss in the sow. Consumption of milk replacer varied greatly among litters. A portion of this variation in intake was accounted for by differences in ambient temperature among farrowing groups. Average milk replacer intakes (liters per pig) from birth to d 21 were 2.5 L/pig (.375 kg dry matter) and 9.9 L/pig (1.49 kg dry matter) for pigs born during the cool and warm seasons, respectively (P < .001). The weaning weight advantage conferred by milk replacer was most evident during the warmer months. Sow feed intakes averaged 5.8 and 3.9 kg/d over the same periods (P < .001). These results demonstrate the advantage of milk replacer on weaning weight and indicate that the greatest benefit from the supplement is during the warmer months when sow feed intake and subsequent milk production are lower.