Effects of chitosan supplementation on the growth performance, nutrient digestibility, and digestive enzyme activity in weaned pigs

Abstract

The present experiments were conducted to investigate the effects of dietary chitosan on growth performance, nutrient digestibility, and digestive enzyme activities in weaned pigs. A total of 180 weaned pigs (35 days of age, 11.56 ± 1.61 kg of body weight (BW)) were selected and assigned randomly to 5 treatments containing 0, 100, 500, 1000, and 2000 mg chitosan per kg feed, respectively. Each treatment involved six replicate pens and six pigs per pen. On days 14 and 28, all pigs were weighed and six from each treatment (one from each replicate pen) were killed, and the contents of the stomach, jejunum, and rectum were collected and used for determining nutrient digestibility and digestive enzyme activity. The results showed that supplementation of chitosan improved quadratically average daily gain (ADG) (P < 0.05). Moreover, dietary chitosan quadratically (P < 0.05) increased apparent digestibility of crude protein (CP) on days 14 and 28, and quadratically increased apparent digestibility of dry matter (DM) on day 14 and of Ca and P on day 28, whereas decreased (P < 0.05) apparent digestibility of ether extract in comparison with the control diet. In addition, dietary chitosan quadratically increased (P = 0.062) amylase activity of proximal jejunum and decreased (P < 0.05) lipase activity of distal jejunum compared with the control. These data indicated that diets supplemented with increasing levels of chitosan (0, 100, 500, 1000, and 2000 mg chitosan per kg) quadratically improved ADG of weaned pigs. The growth-promoting action was achieved probably by improved digestibility of major nutrients (DM, CP, Ca, and P) and increased amylase activity of jejunum.