Nicotinic Acid Deficiency and Nicotinic Acid Requirement of Young Pigs on a Purified Diet

Abstract

The effect on young pigs of the lack of dietary nicotinic acid and the optimal nicotinic acid level for growing pigs were studied in a series of feeding experiments involving 152 animals from 38 litters for the deficiency study and 84 pigs from 17 litters for the study of optimal level. Emphasis was placed on the use of litter mates for all comparisons, on the importance of adjusting growth data to allow for differences in initial weights, and on the use of statistical methods, where applicable, in interpreting the significance of the results. Throughout the experiments the same high-protein ration consisting of purified ingredients including additions of purified accessory factors was employed. All animals not destined for use in subsequent studies were autopsied at the end of the experiment or on the occasion of their prior death. The mean effect of absence of nicotinic acid from an otherwise adequate diet consisted in a highly significant depression of growth, a conspicuous impairment of appetite with high incidence of diarrhea, high mortality, and a high incidence of necrotic lesions of colon and cecum. Occasional animals appeared to thrive with no nicotinic acid while other animals appeared to vary in their requirement. The level of nicotinic acid required for optimal mean growth in our experiments appeared to be between 0.6 and 1.0 mg. per kilogram live weight per day for growing pigs between the age of 3 and 9 weeks. Chemical studies failed to disclose a simple method for the diagnosis of nicotinic acid deficiency or to indicate the nature of the defect resulting therefrom.