Many of the requirements are based on feeding a corn-soybean meal diet. In this publication, the nutrient recommendations have been increased beyond the NRC levels to add a margin of safety for each of the essential nutrients. In addition, with improved record keeping programs, there are data to suggest that feed intake in swine production systems may not be as great as previously estimated. Although a pig's requirement for a specific nutrient may be the same, if it is not eating the estimated amount, the nutrient density of the diet must be increased in order to meet its daily nutrient requirement. Our purpose is to reduce the risk of nutrient deficiencies that might occur because of differences in ingredient quality, genetics, health, environment, and performance on individual farms, and provide a margin of safety in a cost effective manner.
Several factors affect a pig's requirement for a specific nutrient.
Level of feeding, such as limit feeding versus ad libitum Environmental temperatures and housing conditions play an important role in determining the pig's nutrient needs for maintenance. Pigs housed in outside dirt lots are exposed to greater temperature changes than those housed in confinement facilities and may have greater maintenance needs. In addition, research has indicated that pigs of different sex, breeds, or genetic back-ground may have different capacities for production, thus different nutrient requirements. It is reasonable to expect that a sow weaning 27 pigs per year would have a higher requirement than one weaning only 15 pigs per year. Herd health status and the presence and level of feed additives or growth promotants will also alter nutrient utilization.