Effect of diet and genotype on carcass characteristics of feedlot hair sheep

Abstract

-It was evaluated qualitative characteristics of confined hair sheep submitted to diets with two energy levels.Eighteen lambs from each genotype were used: Morada Nova, Santa Inez and Dorpper × Santa Inez crossbreds. The rations with the lowest and the highest energy level were made up with 2.5 and 2.94 Mcal EM/kg DM, respectively. It was evaluated conformation and finishing carcass, in addition to leg tissue composition. The score for conformation was significantly higher for animals kept in diet with the highest energy level and for Dorpper × Santa Inês crossbreds. Animals from Santa Inez and from Dorpper × Santa Inez breeds showed score for meat color close to red class, while Morada Nova genotype was close to slightly dark red. The muscle:bone ratio for Dorpper × Santa Inez crossbred and Morada Nova animals was higher than for Santa Inez animals. The muscle:fat ratio was higher in animals kept with the lowest energy concentration diet. The rib eye area of Dorpper × Santa Inez crossbred animals was similar to Morada Nova animals and higher than Santa Inez group. Carcass compactness index and subcutaneous fat thickness and maximum cover fat thickness on the surface of the 12 th rib were higher for animals submitted to the diet with the highest energy level. Leg fat was the only tissue influenced by diet calory density, while bone tissue was affected by the genotypes, since Santa Inez breed showed the highest percentage in this tissue. The genotype and level of energy in the diet affect carcass conformation. Diets with higher energy density improve carcass compactness index and subcutaneous fat thickness.

Physical, chemical and sensorial parameters for lambs of different groups, slaughtered at different weights

“…The lamb meat texture results found in this study agree with those for Costa et al (2010) where finer textured meat came from younger animals. This may indicate superiority of the meat texture of the animals under study.…”

“…Therefore, this study has implications for several meat animal species. Costa et al (2010) found no significant differences in marbling between Morada Nova (1.50), Santa Inês (1.33) or Dorper × Santa Inês (1.29) lambs slaughtered at approximately 17 kg. The values in the presente study (2.28) were also higher than those found by de Mendonça et al (2007) in Texel lambs (1.67), possibly due to factors such as feeding type, age, genetic group and slaughter weight.…”

The effect of combinations of dried or ensiled corn and sorghum on the performance of feedlot lambs

“…The carcasses of ¾ Dorper × ¼ Santa Inês lambs measured 14.02 cm 2 , those of ½ Dorper × ½ Santa Inês lambs, 14,28 cm 2 , higher than the 12.43 cm2 observed for Santa Inês carcasses. A similar result was observed by Costa et al (2010), who observed greater loin eye area for Dorper × Santa Inês lambs compared with Santa Inês. There was a difference (P <0.05) for mean subcutaneous fat thickness (SFT AVE ).…”

Farklı Yemlerle Beslenen Tibet Koyunlarında Büyüme Performansı ve Et Kalitesi

“…The average daily gain of sheep was not influenced by the type of forage offered (Table 2), and it was around 150 g/d for both diets. This value was similar to those reported by Costa et al [21] and Lima et al [22] for the same genotype consuming diets, because barley and oat both belonged to C3 photosynthetic pathway plants [23] , and both forages presented a similar anatomical arrangement. Replacement with an alternative food did not affect the weight gain of the sheep evaluated by Atti and Mahouachi [24] .…”