Valor nutritivo de dietas à base de tucumã (Astrocaryum aculeatum Meyer.) em substituição ao milho (Zea mays) na alimentação de vacas leiteiras

Abstract

The cost of traditional feed sources for supplementation has become a limiting factor for the profitability of production systems. Among the strategies adopted, the use of alternative sources such as agro-industrial residues has gained attention. Tucumã (Astrocaryum aculeatum Meyer) presents relevant nutritional properties and emerges as a promising option. This study aimed to evaluate the replacement of corn with increasing levels of tucumã peel residue (TPR) in the diet of dairy cows. Nutrient intake and digestibility were estimated, and blood samples were collected to assess the influence of this inclusion on biochemical parameters, as well as on milk production and feed cost. Results for intake and digestibility showed no significant linear or quadratic effects, except for the apparent digestibility coefficients of dry matter (ADCDM) and organic matter (ADCOM), which presented a decreasing linear effect (p<0.05). Regarding the biochemical profile, no significant effects were observed (p>0.05); cholesterol, urea, ALP, AST, and GGT remained within the reference values for the species. However, glucose, P, and Ca averages were below reference values at all levels of inclusion, while total protein was below reference at 20% and 30%. Milk yield and 3.5% fat-corrected milk yield showed no statistical differences (p>0.05), remaining stable compared to pre-inclusion values. Nevertheless, a significant reduction in feed cost was observed in diets containing 30% TPR. Therefore, the inclusion of tucumã peel residue is recommended at levels of up to 30% in the diet of dairy cows.