Pattern of non-starch polysaccharide digestion along the gut of the pig:Contribution to available energy

We investigated the pattern of non-starch polysaccharide(NSP) digestion along the gut of pigs fed two different wheats, which were offered with or without xylanase supplementation. The two wheats used were pre-characterised before the experiment on the basis of low and normal feed intake of young pigs.Wheat type significantly influenced feed intake and growth rate in the first 7 days, however, by day 14 the only significant effect of wheat type was on growth rate. Xylanase supplementation increased the growth performance of pigs fed the poor quality wheat to a level similar to those fed the normal wheat. It also increased the daily gain of pigs fed the normal wheat. Wheat type had no significant effect on the digestibility of dry matter(DM), energy, free sugars or the different fractions of NSP in the duodenum,ileum or in the faeces. The duodenal gross energy digestibility values for the low and high performance diets were -27.4 and -47.5%, respectively, and xylanase supplementation significantly increased the digestibility of energy back to positive levels. Dry matter digestibility values followed a similar pattern. In the duodenum, xylanase increased(P < 0.05) the digestibility values of both soluble and insoluble NSP,whereas in the ileum, xylanase had a significant effect only on the digestibility of the soluble NSP fraction. Xylanase did not affect free sugar digestibility. The reduction in soluble NSP level coincided with a marked reduction in the amount of fucose, a prominent component of mucosal polysaccharides. This suggests that soluble NSP substantially increase endogenous losses. The absence of differences in the digestibility of the measured NSP between the two wheat samples suggests that the structures of the NSP, rather than just their amount and solubility, are important for the anti-nutritional properties of NSP in pig diets.

Black soldier fly larvae in broiler diets improve broiler performance and modulate the immune system

Non-conventional feed ingredients are receiving more interest in their ability to increase farming effi-ciency,sustainability and animal performance.The objective of this study was to determine the optimal rate of inclusion level of the full-fat black soldier fly larvae(BSFL)in broiler diets and to evaluate their impact on performance,nutrient digestibility,and the immune system(blood cells and intraepithelial lymphocytes).A total of 400 male day-old Ross 308 broilers were randomly assigned to 5 treatment groups with 8 replicates each.Five inclusion levels of full-fat BSFL were investigated across starter(0,2.5%,5%,7.5%and 10%),grower and finisher diets(0,5%,10%,15%and 20%).All diets were formulated based on digestible amino acid values according to the Aviagen(2016)recommendations.A polynomial regression at different degrees was performed to analyse broiler performance parameters(body weight,body weight gain,feed intake,and feed conversion ratio),nutrient digestibility,and blood cell count.Intraepithelial lymphocyte population data was analysed performing univariate linear regression.During the entire experimental period(from 2 to 42 d),BSFL inclusion levels decreased the feed conversion ratio by 10%in broilers that received 20%BSFL in their diets(P<0.05).Lymphocytes and white blood cell count decreased linearly by 47.7%and 35.9%,respectively,with up to 20%BSFL inclusion(P<0.001).A 4-fold decrease in CD3+T lymphocytes and a 9.7-fold decrease of CD3+CD8+intestinal cytotoxic T lymphocytes occurred in broilers fed 20%BSFL compared to the control group.These findings suggest that the inclusion of BSFL can improve broiler performance and potentially reduce immune response energy expenditure in birds fed 20%BSFL for 42 d.