Relationships between feed efficiency and meat quality traits of Nellore bulls feedlot finished

Abstract

Brazilian producers and meatpacking industries have few mechanisms that allow them to identify efficient cattle in an integrated manner, which will produce superior carcasses and meat cuts to meet the most demanding markets and which pay better. This "efficiency × quality" paradigm occurs because there are limitations regarding the use of technology in these sectors, which may be a reflection of little basic and applied research being developed for this purpose. This project will integrate information from feedlot and laboratory analyzes to evaluate feed efficiency, carcass and meat quality traits of Zebu cattle. Non-castrated male Nellore cattle finished in commercial feedlots, the main biological type found on finishing farms, will be evaluated. Data on dry matter intake (DMI), gross feed efficiency (FE) and average daily gain (ADG) of Nellore bulls will be collected in a collective pen with capacity for 120 animals, equipped with static scales coupled to Intergado® electronic troughs. The performance test will take at least 70 days of data collection to evaluate growth characteristics and feed efficiency. Subsequently, in the meatpacking industry, the carcasses of these animals will be classified using the BeefScore (BS) platform, which collects several carcass traits and predicts the quality of the meat from the consumer's perspective (represented in a quality index [IQ] from 0 to 100 involving tenderness, flavor, juiciness and overall satisfaction). In total, 100 bovines will be evaluated, obtaining individual information on DMI, FE, ADG and carcass characteristics. Subsequently, samples will be collected from the sirloin steak (Longissimus thoracis muscle), being used in the laboratory for physical-chemical analysis (shear force, cooking losses, color, intramuscular fat, glycogen, among others). The differences between the FE traits (more efficient versus less efficient), carcass and meat quality (Category 2 [good for everyday] versus Category 3 [very good]), their interactions (efficiency × quality) will be analyzed by correlation analysis and a multivariate approach (PCA, PLS regression). The measurement of growth characteristics, FE, carcass and meat quality traits is still little explored in Brazilian studies, and may contribute to the generation of new technologies and improve the identification of characteristics of economic importance in beef cattle.