Effects of dietary valine concentration on lactational performance of sowsnursing large litters

A cooperative study, using 231 primi- and multiparous crossbred sows from s ix experiment stations (IN, KS, MI, MN, ND, and OH), was conducted to deter mine the effects of elevating dietary valine concentration in corn-soybean meal diets on lactational performance of sows nursing large litters. Crossb red sows were fed diets' containing a minimum of .60% lysine during gestati on. Sows were allotted at farrowing to four dietary valine concentrations, .80, .95, 1.10, and 1.25%. Crystalline L-valine replaced cornstarch to main tain a constant ratio of corn:soybean meal across diets. Dietary lysine, pr ovided by corn, soybean meal, and .15% crystalline L-lysine . HCl, was .90% in all diets. Sows were allowed ad libitum access to feed. Sows were weigh ed within 24 h after farrowing, and all litters were adjusted to greater th an or equal to 10 pigs/litter by d 2 following farrowing. Average sow parit y, number of pigs on d 2, and lactation length for the four treatment's wer e, respectively, 2.3, 2.3, 2.3, 2.5; 10.9, 10.8, 10.8, 10.7; and 25.1, 24.5 , 25.2, 25.0 d. The ADFI during lactation was 5.87, 5.77, 5.87, and 5.74 kg (P > .50); hence, valine intakes were 41, 48, 55, and 61 g/d (linear, P > .01). Lysine intake ranged from 51.5 to 52.7 g/d (P > .50). Sow weight afte r farrowing averaged 198 kg (P > .60). Overall pig survival to weaning was high (>92%), and the number of pigs weaned (10.1, 10.3, 10.3, 10.3) did not differ(P > .30) among treatments. Litter weaning weights (73.6, 73.6, 74.5 , 72.6 kg), litter weight gains (55.1, 55.1, 56.0, 54.1 kg), sow weight cha nge during lactation (-4.9, -5.4, -4.8, -6.3 kg), and return-to-estrus inte rval(7.5, 6.4, 6.9, 8.2 d) were not affected (P > .30) by dietary valine; T here were no station x treatment interactions (P > .50). These results indi cate no benefit of elevated dietary valine for lactating sows nursing 2 10 pigs and consuming a corn-soybean meal diet containing .90% lysine and .80% valine.