Avaliação do perfil sanguíneo, desempenho, protozoários ruminais e da qualidade da carne de cordeiros confinados suplementados com concentrado de urucum encapsulado

Abstract

Lamb feedlot is a strategy to meet domestic meat demand, but it can generate metabolic stress and impact animal homeostasis, especially in hot climates. Annatto, rich in carotenoids, has antioxidant properties that can contribute to animal health and meat quality. This study aimed to evaluate the effects of adding annatto concentrate encapsulated in sodium alginate on lamb metabolism, lipid oxidation, meat quality, performance, and ruminal protozoa. The experiment was conducted at UNOESTE with 32 ½ Suffolk lambs confined and divided into four groups: control (no addition of encapsulated annatto concentrate), Group 0.15%, Group 0.3%, and Group 0.45% of encapsulated annatto concentrate per kg of feed consumed. The animals were slaughtered when they reached 37,25 ± 2,47 kg of live weight. Feed intake and conversion data were calculated for performance, as well as the count and classification of protozoa present in the ruminal fluid. The animals were weighed before and after slaughter to control carcass yield. The Longissimus lumborum muscles were analyzed for color, including the ΔE index, as well as marbling, centesimal composition, shear force (SC), lipid oxidation (TBARS), and iron reduction potential (FRAP). Statistical analysis was performed in RStudio software, using the Shapiro-Wilk normality test and, as necessary, Tukey's test (5%) or analysis of variance. The results indicated that annatto supplementation influenced the intensity of the red color (p=0.0331), reducing the a* values in Group 0.15% and Group 0.3% (14.98 and 14.64). Lipid oxidation also varied between groups (p=0.0454), being lower in the 0.3% Group (0.252 mg MDA/kg) compared to the 0.45% Group (0.465 mg MDA/kg). However, there was no significant impact on productive performance, centesimal composition, pH, marbling, FC, or FRAP. Supplementation with encapsulated annatto positively modulated metabolic and meat quality parameters, reducing serum cholesterol and lipid oxidation (TBARS), in addition to intensifying the red color in a visually perceptible manner (ΔE). These effects occurred without compromising productive performance, nutritional composition, or technological characteristics of the meat, indicating the potential of annatto as a natural additive to improve the quality and commercial appeal of the product.