Evaluation of United States grain sorghum in lactation diets on sow and litter performance

A total of 568 sows (Line 1050, PIC Genetics, Hendersonville, TN) and their litters (PIC 337 × 1050) were used to evaluate the effects of United States grain sorghum compared to corn in lactation diets on sow and litter performance. Sows, in four separate farrowing groups (approximately 142 ± 1 sows per group), were moved into farrowing rooms and blocked by parity on d 112 ± 1 of gestation. Sows were assigned to one of three dietary treatments, consisting of diets with corn, grain sorghum, or a 50:50 blend of both serving as the grain source. The grain sorghum used was tannin-free and sourced from the Texas and Oklahoma panhandles. Diets were formulated to be balanced for amino acids, minerals, and net energy. Corn and sorghum were given the same net energy value (2,672 kcal/kg). Sows were fed a wheat-based gestation diet, then hand-fed 0.90 kg of their treatment diet twice a day, starting 3 to 5 d pre-farrow, and were given ad libitum access from farrow until weaning (approximately d 19 of lactation). Particle size of grain and complete feed were analyzed. Grain sorghum was slightly finer than corn, reducing dietary particle size as sorghum inclusion increased; however, all diets remained within a 30 μm range. Replacing corn with grain sorghum in the diet did not affect sow weight, backfat, or caliper score change from entry to weaning. Feeding sows grain sorghum did not affect sow average daily feed intake, litter feed efficiency, or wean-to-estrus interval. There were no differences in total born or born alive. However, there was a decrease (linear P < 0.001; quadratic, P = 0.003) in the percentage of stillborn pigs with increasing grain sorghum in the diet. Also, the percentage of mummies increased and then decreased (quadratic, P = 0.001) as grain sorghum inclusion increased compared to corn. There were no differences in litter size or litter weight after cross-fostering (d 1) or at weaning. Preweaning mortality tended to decrease then increase (quadratic, P = 0.080) with increasing grain sorghum compared to corn in the diet. As grain sorghum increased, preweaning removals increased (linear, P = 0.046); however, no differences were observed in total removals and mortality. In conclusion, grain sorghum grown and harvested in the United States can replace corn in lactation diets with little impact on sow or litter performance.