Abstract
First-litter sows and their progeny were used to evaluate the interaction effects of three gestation crude protein levels (9, 13, or 17%) and two lactation protein levels (12 or 18%) on sow reproduction and litter performance. Diets were formulated to contain the desired protein level by altering the ratio of corn and soybean meal. Daily rations of 1.82 kg were individually fed during gestation and were offered ad libitum to the sows by 7 days postpartum. Litters were equalized to eight pigs each by 1 week of age and held constant to weaning (28 days). Sows fed the 9% protein diet gained less during gestation than those fed the 13 or 17% protein diets. Progeny parturition data were similar for the three gestation protein levels. Sows fed the 18% protein lactation diet and their litters performed similarly in regards to feed intake and progeny performance regardless of previous gestation protein level, while those sows fed the 12% protein lactation diet had decreasing lactation weight losses, but increasing feed intakes and litter gains as the level of gestation protein increased from 9 to 17%. There were significant gestation by lactation protein level sequence interactions on sow feed intakes and litter gains, suggesting a nutritional carry-over effect from gestation to lactation. Sows fed the 17% protein gestation diet had the greatest tissue buffer while those fed the 9% protein gestation diet had the least. These results further demonstrate that dams fed a 9% protein gestation diet perform similarly to those fed higher gestation diets, if the lactation dietary protein level is adequate to meet the lactation amino acid requirements.