Revista Brasileira de Zootecnia
On-line version ISSN 1806-9290
MORENO, Greicy Mitzi Bezerra et al. Non-carcass components yield of lambs fed corn silage or sugar cane under two levels of concentrate. R. Bras. Zootec. [online]. 2011, vol.40, n.12, pp.2878-2885. ISSN 1806-9290. http://dx.doi.org/10.1590/S1516-35982011001200035.
The objective of this result was to evaluate the yields of non-carcass components of lambs finished in feedlot feeding on diets with corn silage or sugarcane under two levels of concentrate. Thirty-two non-castrated Ile de France lambs fed on corn silage or sugar cane with two roughage:concentrate ratios: 60:40 or 40:60. Lambs were confined until they reached 32 kg of body weight (BW), when they were slaughtered. After the bleeding, all non-carcass components (blood, skin, head, feet, rumen, reticulum, omasum, abomasum, small intestine, large intestine, spleen, liver, heart, lung with trachea, pancreas, kidneys with perirenal fat, omental and mesenteric fat) were separated and weighed, and their percentages were calculated in relation to the BW. The content of gastrointestinal tract was greater in lambs which fed on sugar cane (15.17%) and 60% of roughage (14.55%); while omental and kidney fats were greater in lambs that received corn silage, 0.53 and 0.63%, respectively. The roughage:concentrate ratio and type of forage affected the proportions of rumen, omasum and small intestine in relation to the total weight of gastrointestinal tract. The roughage:concentrate ratio and type of forage influence the content of the gastrointestinal tract of lambs, indirectly affecting the carcass yields. The type of food has greater influence on the proportions of the organs responsible for digestion and absorption of nutrients. The factors that influence the non-carcass components of lambs are varied and contradictory, requiring more research that might encourage their use and, consequently, add more value to the production systems of sheep meat.
Keywords : feedlot; nutrition; organs; sheep; viscera.