Sustainable Farming: Nanofiber from the Pupunha Heart of Palm Sheath (<i>Bactris gasipaes</i>)-Enhanced Diets for Growing Rabbits and Their Health Impacts

The use of nanofibers in farm animal diets can enhance nutrient absorption, minimize environmental problems, and generate a sustainable source of income. In this study, we investigated the effects of the partial inclusion of nanofibers produced from the pupunha heart of the palm sheath (nanopupunha) in the diet of growing New Zealand White rabbits on zootechnical performance, organ morphometry, digestive content pH, intestinal histology, biochemical and immunological parameters, and cecum microbiota. Twenty-four male and female New Zealand White rabbits were distributed into the control group fed a basal diet with 14% crude fiber and treatment groups with the basal diet supplemented with 3.5% or 10.5% of nanopupunha, according to their initial weight. After euthanasia on day 42, we analyzed the pH of the stomach contents, jejunum, and cecum, and the relative weights of the digestive tract, liver, kidneys, and spleen. Duodenal and jejunal samples were collected for structural and ultrastructural analyses of the intestinal villi. Additionally, blood samples were collected to analyze blood glucose, cholesterol, triglycerides, and immunological analysis (IgG and IgM), and digesta samples from the cecum were collected to count enterobacteria and lactic acid bacteria. The inclusion of dietary nanopupunha did not affect the zootechnical performance of animals, but resulted in a linear decrease in the relative weight of the stomach and a linear increase in the relative weight of the spleen. No significant differences were observed in the pH of the digestive tract. Nanopupunha inclusion also resulted in a linear increase in the crypt depth of the duodenum, total mucosal thickness, and total cholesterol levels in growing rabbits. Including 10.5% of nanopupunha added to the diet showed the best results in terms of the intestinal health of the growing rabbits.