Effect of replacing marine fish meal with catfish (Pangasius hypophthalmus) by-product protein hydrolyzate on the growth performance and diarrhoea incidence in weaned piglets.

The present study consists of two experiments. In experiment 1, a total of 120 weaned piglets (Yorkshire × Landrace) (7.3 ± 1.9 kg) were allocated to five treatments, and four replications (pens) with six piglets/pen. In experiment 2, 40 male pigs (23.0 ± 2.2 kg) were allocated to five treatments and eight replications (individual pens). In both experiments, the control diet contained fish meal (FM) as the sole protein supplement (CPH0), while the experimental diets consisted of four different diets in which crude protein (CP) from FM in CPH0 was replaced by the CP from catfish (Pangasius hypophthalmus) by-product protein hydrolyzate (CPH) at four different levels: 100 % (CPH100), 75 % (CPH75), 50 % (CPH50) and 25 % (CPH25). The results in experiment 1 showed that the highest average daily gain (ADG) over the 5-week period after weaning was recorded for piglets on CPH100 (307 g/day), and the lowest for piglets fed CPH0 (287 g/day) (P < 0.01). Feed conversion ratio (FCR) was lower in CPH100 (1.43 kg feed/kg gain) than in CPH0 (1.51 kg feed/kg gain) (P < 0.01). The piglets fed CPH100 were less affected by diarrhoea (6.55 %) than piglets fed the control diet CPH0 (17.3 %) after weaning, and faecal scores were also lower. In experiment 2, ADG was lowest in CPH0, and the cost/gain in pigs fed CPH100 was lowest in both weaning and growing pigs. In conclusion, it is possible to replace up to 100 % of the FM by CPH in diets for weaning and growing pigs, resulting in improved ADG and FCR, lower feed cost/gain as well as reduced diarrhoea incidence and improved faecal score.