Ivanor Nunes do Prado. These animals, with an average age of 19 months at the beginning of the experiment, were finished in a feedlot system during days, and were fed with diets containing three levels of concentrate 0. The interaction between sexual groups and the concentrate level was not significant for any of the variables. Likewise, no effect of the concentrate level was detected on the same variable traits. The bulls demonstrated higher hot carcass weights The bulls produced higher yields of muscle in the three primary cuts, there by resulting in higher yields of edible portions of the carcass.
The bulls also produced higher weights of tenderloin, knuckle, topside, flat, eye round, rump, and rump cover. The finishing of young bulls in feedlot is to be recommended, since the animals produce carcasses with higher amounts of edible meat and higher yields of commercial cuts, thus allowing for a better price for the carcass.
Low concentrate level could be used due to the lower cost of production for farmers. In these countries, the cattle carcasses are dissected and manufactured in wholesaler markets, according to the international or local standards, and depending on whether the destination of the products is for domestic trade or international markets.
With globalization of the red meat industry, the standardization of the cuts and a service that facilitates the comparison and commercialization between the different markets it is necessary Shimada et al. The Brazilian cattle primary cuts are the forequarter with five ribs, the side, and the hindquarter. Economically, a higher dressing of the hindquarter in relation to the other cuts is desired, because on this cut, the best parts with a high commercial value were found Macedo et al.
In commercialized systems in Brazil, the carcass quarters are separated into approximately 20 commercial cuts with high variation in regional names.
A cattle carcass with high quality and high dressing demonstrates an adequate relation between the component parts, maximum muscle, minimum bone, and adequate fat to secure a product with minimal handling and maximum palatability Rotta et al. The industry and wholesalers desire, in the market, carcasses that allow for a more adequate utilization.
Another use of the carcass dressing is to express the ratio between the carcass and animal weight. According to Macedo et al. The feeding system and the diet composition can influence cattle carcass and meat characteristics Rotta et al. The physiological groups have a strong influence on growth, composition and distribution of carcass tissues Aricetti et al.
The physiological effect can be evidenced through the fattening process, as heifers reach the finishing phase before steers, who in turn reach the finishing phase before bulls Rotta et al.
The fat accumulation in the carcass of bulls is lower than steers Prado et al. The use of bulls promotes a higher slaughter age, and consequently, a higher hot and cold carcass weight, there by resulting in carcasses with higher rib-eye area Aricetti et al. In relation to the commercial cuts, bulls demonstrate a minor carcass proportion of hindquarters and a higher proportion of forequarters, leading to greater values in the carcass characteristics.
The practice of slaughter castrated animals is traditionally performed for economic reasons and customer acceptance Bretschneider, Several slaughterhouses require animal castrated, justifying that this procedure favors the uniformity and quality of the carcass, and thus favors conservation and different aspects of the meat Knight et al.
In general, the performance results indicate that bulls grow faster, use food more efficiently, and produce carcasses with higher commercial meat percentages and less fat Field, ; Prado et al. On the other hand, steers produce carcasses with more tender meat. Despite all of the knowledge on the effects of castration, the technique is still a subject of studies, because it maybe that the results are affected by other factors of the finishing system and feeding management.
The objective of this paper was evaluate the carcass physical characteristics and the primary cuts of bulls and steers that were finished in a feedlot system and fed with diets containing three concentrate levels. The animals were selected at random and castrated at days of age by standard surgical method, as described by Henricks The animals were castrated at 7 months of age with a standard scalpel instrument.
The animals were allocated into individual pens and kept in a feedlot system for days. The animals were fed twice a day 8: Concentrate quantity was adjusted every 28 days when the animals were weighed after a hour fasting period.
The concentrate and corn silage intake were recorded daily until day of the experimental period for 1. The water, concentrate and corn silage were distributed ad libitum in separately drinkers and feeders.