Effect of dietary sunflower hulls on nutrient digestibility, ileal morphology, and volatile fatty acid concentration in broilers and pullets fed a broiler diet from 1 to 21 days of age

The effects of sunflower hulls (SFH) inclusion on performance, TTAR of nutrients, ileal mucosa morphology, and volatile fatty acid (VFA) concentration in the ceca were studied in birds from 1 to 21 d of age. There were 4 treatments organized as 2 × 2 factorial with 2 chicken lines (broilers vs. pullets) and 2 levels of SFH (0 vs. 3%). Each treatment was replicated 7 times (10 birds). The corn-soybean meal control diet contained 3,010 kcal AMEn/kg, 1.25% digestible Lys, and 8.7% NDF. In the experimental diet, SFH was included at the expense (wt:wt) of the control diet. Diets were offered in mash form. No interactions between main effects were detected for any trait. From 1 to 21 d of age, ADG was greater and FCR was better in broilers than in pullets (P < 0.001) but SFH inclusion did not affect bird performance. The TTAR of all nutrients was higher (P < 0.05) in broilers than in pullets. The inclusion of SFH improved AMEn of the diet (P < 0.05) at both ages and DM and N retention (P < 0.001) at 21 d. Broilers had larger villus and deeper crypt (P < 0.01) than pullets. Broilers tended to have higher (P = 0.077) cecal proportion of acetate than pullets but no effects were observed for the other VFA. SFH inclusion tended to increased villus height (P < 0.05) and cecal proportion of acetate and propionate (P < 0.01). In summary, broilers grew faster, were more efficient, had higher ileum absorptive capacity, TTAR of nutrients than pullets. The inclusion of 3% SFH in substitution (wt:wt) of the whole diet improved AMEn without showing any negative effect on growth performance of the bird