Feeding broilers with the addition of an Ilex paraguariensis coproduct affects zootechnical performance and meat quality responses.

Abstract

During the harvest of Ilex paraguariensis, approximately 2-5 tons per hectare of thick stems are left on the soil surface. The outer portion of these stems, referred to as the coproduct, constitutes 30% of the total residue mass. Although this coproduct has been partially characterized in terms of its phytochemical profile, its technological applications remain unexplored. The objective of this research is to evaluate whether broilers fed with feed incorporating I. paraguariensis harvest prunings will exhibit improved zootechnical performance as well as enhanced biochemical and impacts on meat quality. One-day-old Cobb 500 broilers (n = 300) were raised for 42 days in the broiler shed at the experimental farm in housed in 2.0 m² pens with a 10 cm layer of poultry litter and equipped with tubular feeders and nipple drinkers. They were arranged in a completely randomized design, comprising four treatments with five replicates of 15 birds each. The treatments consisted of the following diets: a basal diet (0%; the control), feed with 1% coproduct (1% treatment), feed with 2% coproduct (2% treatment), and feed with 3% coproduct (3% treatment). Broilers were assessed for zootechnical performance, intestinal morphometry, and serum biochemical properties. Additionally, meat quality was evaluated, including centesimal composition, chlorogenic acid content, antioxidant activity, metal concentration, and fatty acid profile. Chlorogenic acid was not detected in the meat of broiler chickens. The inclusion of the coproduct impacted both zootechnical performance and meat quality, with a linear effect proportional to the concentration of the additive used in the diet; that is, the worst performance was seen in chickens that consumed 3% of the co-product. It reduced feed consumption and weight gain, lowered cholesterol and triglyceride levels in broiler blood, but increased polyunsaturated fatty acids in the meat, one effect verified for the two largest inclusions (2 and 3% of the co-product). In the intestine, greater villus height and levels of reactive oxygen species were observed in the highest dose of the additive, a group of birds in which greater activity of the enzymes creatine kinase and pyruvate kinase was also observed. In general, none of the doses tested proved to be effective in enhancing productive performance; in addition, it did not increase the concentration of chlorogenic acid in the meat, which would be our hypothesis of having a nutraceutical food.