Effect of different levels of fiber and protein on growth performance and fecal characteristics in weaning pigs

This experiment was conducted to evaluate the growth performance, fecal score, and fecal microbial shedding in weaning pigs fed diets with different levels of fiber and protein. A total of 96 weaning piglets ($7.41{\pm}0.71kg$) were used in a 5-week trial. Pigs were allotted to dietary treatments based on initial body weight in a $2{\times}2$ factorial design with the following factors: dietary fiber (100 and 200 g/kg, respectively, during days 0 to 14; 175 and 300 g/kg, respectively, during days 14 to 35) and dietary protein (170 or 200 g/kg). There were 6 replicates with 4 pigs per pen. On day 14, pigs fed high protein or high fiber diets had heavier body weight (p < 0.05). During days 0 to 14, pigs fed high protein or high fiber diets grew faster (p < 0.05). Additionally, during days 14 to 35, an interactive effect of fiber and protein was found (p < 0.05) on average daily gain. The different levels of protein and fiber in diet did not affect the pigs' fecal scores (p > 0.05). However, feces from the high fiber group showed lower concentration of Escherichia coli (p < 0.05). In conclusion, the results of the present study indicate that a high protein diet improves the growth of weaning pigs especially during the first two weeks. Moreover, the increments in fiber level, even in the high protein diet, favorably decreased the number of E. coli.