Print version ISSN 0103-8478
CATTELAN, Jonatan et al. Trim fat and external components of the body of steers and cull cows from different genetic groups. Cienc. Rural [online]. 2010, vol.40, n.12, pp. 2541-2548. ISSN 0103-8478. http://dx.doi.org/10.1590/S0103-84782010001200017.
The objective of this research was to evaluate the trim fat and external components of the body of two categories, steers and cull cows, from two genetic groups: 5/8 Charolais (Ch) 3/8 Nellore (Ne) and 5/8Ne 3/8Ch. The average age of animals at the end of the experimental period was of 23 and 68 months, for steers and cull cows, respectively. The animals were maintained at feedlot finished until they reached the finishing degree for slaughter. The experimental diet had a roughage concentrate ratio of 40:60 (dry matter basis), containing 14.2% of crude protein and 2,869kcal of digestible energy kg-1 dry matter. The experimental design was complete randomized in a 2x2 (two categories and two genetic groups) factorial scheme. The slaughter weight (PAB) (509.67 versus 414.50kg) and the empty body weight (PCVZ) (433.01 versus 355.27kg, respectively) were higher for cows in relation to steers. When the components were expreseds in absolutes values and adjusted for PCVZ and PAB, cull cows showed higher inguinal fat, renal fat and internal total fat weights. When the components weights were adjusted for PAB e PCVZ, the steers showed higher head, foots, tail broom and total external components. The 5/8Ch 3/8Ne animals showed higher head absolute weight and ruminal fat in relation to PCVZ, while the 5/8Ne 3/8Ch showed higher rawhide weight in relation to PAB and PCVZ, and in relation to PAB higher total extern components weight. The carcass dressing percentage and non integrants body parts of carcass didn't show any correlation.
Keywords : carcass dressing percentage; crossbreeding; empty body weight; rawhide.