Effects of guava pomace combined with gut modulators on growth performance, cecal histomorphology and gene expression in rabbits

Abstract Sustainable intensification of rabbit production necessitates the exploration of non-conventional feed resources to mitigate the rising costs and limited availability of conventional ingredients. The present study evaluated the effects of dietary inclusion of dried guava pomace (DGP), alone or combined with a prebiotic source of mannan-oligosaccharides and β-glucan or an organic acid blend, on growth performance, selected hemato-biochemical parameters, cecal histomorphology and some growth and immune-related gene expression in healthy New Zealand White growing, 28-day old, male rabbits. Compared with the control diet, the DGP-based diet presented significant improvements in final weight, final weight gain, feed intake, and feed conversion ratio as well as performance index ( P < 0.01). Furthermore, fortification of diets with an organic acid blend plus DGP improved selected hematological indices, with no signs of liver or kidney impairment. Examination of cecal histomorphology showed increased villus height and preserved mucosal integrity in rabbits fed DGP-based diets. Gene expression analysis revealed increased muscle insulin-like growth factor-1 (IGF-1) in supplemented groups, whereas expression of inflammatory markers (TNF-α and IL-1β) showed tissue-specific response. Cecal inflammatory gene expression was not significantly affected. These findings indicate that DGP can be used in rabbit diets, alone or with functional additives, as a promising strategy for supporting rabbit health and productivity. Further study is needed to evaluate optimal inclusion levels, characterize bioactive components, assess long-term physiological effects, gut microbiota outcomes, and assess economic viability under commercial production conditions.