Dietary Supplementation with Agave tequilana (Weber Var. Blue) Stem Powder Improves the Performance and Intestinal Integrity of Broiler Rabbits

SIMPLE SUMMARY: Natural products have been used as an alternative to the indiscriminate use of subtherapeutic antibiotics for improving the growth of animals. Although these synthetic products have been used in rabbits to a lesser extent than in other monogastrics, several natural products have been tested with positive responses in growth performance, immune activity, and antioxidant capacity. Agaves are plants with chemical compounds that have shown positive effects on performance and animal health. Specifically, the Agave tequilana stem has a high content of fructans and secondary metabolites, such as polyphenols and saponins, that are responsible for various biological activities. The dietary use of up to 1.5% of Agave tequilana stem powder in the diet of rabbits had a natural growth-promoting effect due to the improvement of their intestinal integrity (with an emphasis on the concentric layers, villi, and crypts), taken as indicator of intestinal health. Considering the results of this study and others carried out by this group of authors, this natural product (A. tequilana) could be utilized in rabbit farming, considering that the stem of the agave is currently not utilized for anything. ABSTRACT: This study evaluated the effect of Agave tequilana (Weber var. azul) stem powder on the growth performance and the intestinal integrity in rabbits. A total of 120 male rabbits [New Zealand × California] were weaned for 35 days and randomized into four dietary treatments, 15 replicates per treatment, and two rabbits per replicate. The treatments consisted of a basal diet (T0) and dietary supplementation with 0.5% (T1), 1.0% (T2) and 1.5% (T3) of Agave tequilana stem powder. The T3 treatment improved the body weight and average daily gain (p < 0.05) compared to the other groups, without affecting viability and feed conversion ratio (p > 0.05). Furthermore, the T3 treatment enhanced (p < 0.05) the thickness of the muscular and mucous layers, and the height, thickness, and number of villi in the duodenum (p < 0.05). However, this treatment (T3) significantly decreased (p < 0.05) values for the area and depth of the crypts in the duodenum and the villus/crypt ratio. Likewise, in the cecum, T3 treatment provoked a marked decrease (p < 0.05) in the depth and thickness of the crypts. The results indicate that the dietary use with 1.5% of A. tequilana stem powder had a natural growth-promoting effect and enhanced the histomorphometry of the concentric layers (muscle and mucosa), villi, and crypts as indicators of intestinal health in rabbits.