Quitosana como aditivo alimentar para bovinos

Abstract

This study aimed to develop and validate a method for extracting chitosan from Nile tilapia (Oreochromis niloticus) scales, based on their structural and bromatological characteristics and potential uses. It also aimed to evaluate the effect of chitosan obtained from fish scales on nutrient digestibility, fermentative parameters, and in vitro ruminal fermentation kinetics of different feedstuffs. An integrative review on the use of chitosan was conducted, synthesizing information on doses, effects on consumption, nutrient digestibility, ruminal parameters, volatile fatty acid profile, and methane production, seeking to critically evaluate data using chitosan and identify possible outdated themes for future research in the area. Chitosan from Nile tilapia (Oreochromis niloticus) scales was obtained through deacetylation and solubilization steps and characterized by infrared spectroscopy (FTIR). Subsequently, bromatological analyses and an in vitro ruminal degradability assay were performed. To evaluate the fermentative, digestibility, and kinetic parameters, a randomized block design was used, with a 4x3 factorial arrangement, divided into four treatments: control, monensin, crustacean chitosan, and fish chitosan; and three feedstuffs: ground corn, soybean meal, and cassava silage. Bromatological analysis, dry matter and crude protein digestibility, fermentative parameters, volatile fatty acid production, and ruminal fermentation kinetics were analyzed. Bromatological analysis revealed a higher dry matter content (95.49%) and absence of ash and residual proteins in chitosan extracted from scales, compared to chitosan obtained from crustaceans, demonstrating greater product purity. The degree of deacetylation was 76%, characterizing it as chitosan. The inclusion of chitosan altered ruminal kinetics and digestibility, reducing the in vitro dry matter digestibility (IVDMD) and vitro crude protein digestibility (IVCPD) of soybean meal and N-NH₃, but stimulating protein digestion and carbohydrate fermentation of cassava silage. The results indicate that tilapia scales constitute an alternative source for the production of high-quality chitosan, due to digestibility and fermentation patterns similar to crustacean chitosan. They can be used as a rumen modulating additive, particularly in association with diets that acidify the rumen environment, such as in high-grain feedlots, as they help control rumen pH.