The 2003 agricultural statistics from the U.S. Department of Agriculture indicate that litter size per sow has increased over the past decade. As litter size increases, the sow must increase milk production so that the baby pigs can maintain a healthy growth rate. To produce milk, the sow must use a combination of nutrients derived from her diet and from the fat and protein stores in her body. As the demand for milk production increases, the sow mobilizes more of her body stores, which often results in a loss of body condition. If this loss of body condition is significant, her performance during this or subsequent lactations – the time when she produces milk – and her return to estrus – the breeding period – could be delayed. This in turn delays her rebreeding and subsequent birthing. The penalty for loss of performance during lactation or delayed estrus is decreased pig growth, potentially increased sow and pig mortality, and decreased litters produced per year. All of these penalties ultimately result in a loss of income to the producer.

A possible way, and perhaps the only way, to overcome the loss of body condition is to increase feed intake of the sow during lactation. This increase in feed intake would minimize the loss of body condition because the sow would use less of her body stores to maintain milk production. Currently, no available information demonstrates an increased feed intake to parallel the increase in litter size in sows. The purpose of our research was to investigate a highly digestible carbohydrate and protein ingredient called Nutri-Pal, which is manufactured by International Ingredients Corp., to determine if dietary supplementation with this product would increase feed intake of the sow and subsequently affect sow or litter performance.

This experiment was conducted with 96 sows fed a typical corn-and-soybean meal diet with or without 5 percent Nutri-Pal. The diets were fed from day 110 of gestation – 4 days before giving birth, or farrowing – until the pigs were weaned at approximately 21 days of age. From day 110 to farrowing, the sows were fed approximately 6.6 pounds of feed per day. After farrowing, the sows were not offered feed for the first 24 hours, but beginning one day after farrowing, the sows were offered feed three times a day until the piglets were weaned. Within 2 days of farrowing, some baby pigs were transferred to foster mothers to give litters of approximately 10 pigs per sow, and all sows weaned at least 8 pigs.

The sows fed the 5 percent Nutri-Pal diet weighed more at weaning than those fed the diet without Nutri-Pal (Table 1). Similarly, the sows fed Nutri-Pal lost less weight per day than those fed the diet without Nutri-Pal from day 110 of gestation to weaning. Feeding Nutri-Pal did not affect daily feed intake. The heavier weaning weight of the sows fed Nutri-Pal combined with slight increases in daily feed intake are typical responses to an increase in the energy level of the diet. This increase in energy would allow the sow to conserve body stores of fat and protein during lactation when the demand for milk production is greatest. The sows fed Nutri-Pal also had reduced days to estrus (4.67 vs. 5.06) compared with those fed the diet without Nutri-Pal, which means more timely breeding and more pigs produced per sow per year.

Sow weaning weight and feed intake were increased and days to estrus were decreased in sows fed Nutri-Pal. Thus, our data combined with more recently published data, suggest that highly digestible protein and carbohydrate sources, such as Nutri-Pal, will improve sow productivity.