Growth performance and intestinal replacement time of 13C in newly weaned piglets supplemented with nucleotides or glutamic acid

Abstract

Dietary supplementation of nucleotides (NU) and glutamic acid (GA) have been suggested for post-weaned pigs because of their potential role as performance enhancers. During this phase, both additives may become essential for newly weaned piglets acting mainly for energy generation and forming molecular basis that are important for intestinal renewal. Two experiments were conducted to evaluate the effects of dietary NU and GA on growth performance and intestinal replacement time of 13C in weaned piglets. In both experiments pigs were assigned to treatments in a 2 × 2 factorial arrangement, based on two levels of NU (0 and 0.1%) and two levels of GA (0 and 1%). The energy source of the maternal diet was based on corn (rich in 13C) whereas piglets’ post-weaning diets were based on rice (poor in 13C). In the first experiment, 84 piglets were weaned at 21 days of age and growth performance was monitored during three experimental phases (0–15d, 16–27d and 28–35d). In the second experiment, in order to assess the intestinal replacement time of 13C in weaned piglets, the differences between the natural 13C abundance in maternal diet and piglets post-weaning diets were used. At day 0 (weaning), three piglets were slaughtered and used as an initial 13C ratio for duodenum and jejunum. At days 3, 6, 9, 14, 21, 34 and 49, three more piglets by treatment were slaughtered. Exponential regression analysis from each treatment was used to determine the incorporation of 13C in small intestine tissues between supplemented and control groups (without NU and GA) to determine the 13C replacement time. In the first study, dietary NU improved G:F (p < 0.05) from day 28–35, whereas dietary GA improved G:F (p < 0.05) from day 0–15, day 28–35 and for the overall experimental period (day 0–35). In the second study, NU supplementation and the interaction of NU × GA improved the replacement time of 13C in the duodenum mucosa (21.12 ± 2.14 days and 21.85 ± 2.13 days, respectively) compared to control (24.95 days). The use of dietary NU and GA during the post-weaning period improves performance but only NU accelerates the replacement time of 13C on duodenal mucosa during the post-weaning period in pigs.