A Comparative Studty on Growth, Carcass Traits and Body Composition of Awassi and Karadi Lambs Raised Under Two Levels of Feeding and Slaughtered at Different Weights: 1- Growth Performance and Carcass Traits

Abstract

Sixteen weaned (3.5-4 months) entire male lambs from each of Awassi and Karadi were weighed and randomly divided equally into two groups to receive concentrate (16% crude protein and 2769 kcal energy) either ad libitum or 3% of their body weights, and to be slaughtered at 36 or 44 kg. Results revealed that overall means of daily gain in weight, dressing percentage based on slaughter and empty body weight, rib eye area and fat thickness were 0.258±0.01 kg, 46.54± 0.49%, 54.35 ± 0.40%, 14.98 ±0.44 cm2 and 2.86 ± 0.12 mm, respectively. It seems that Awassi lambs significantly surpass Karadi lambs in dressing percentage based on slaughter weight and had thicker subcutaneous fat, only. Also, lambs fed ad lib excell significantly those lambs fed 3% in daily gain in weight, dressing percentage based on slaughter weight, and fat thickness. Lambs slaughtered at 44 kg had significantly higher dressing percentage, rib eye area and fat thickness.

The Impact of Docking Karadi Lambs on Growth Performance, Carcass Traits and Body Composition

“…It is generally agreed that daily live weight gain in lambs slaughtered at different weight decrease with increasing slaughter weight (2,44,50), mainly due to fat deposition. However, this result agree with the finding of Balci and Karkas (12) and Al-Sherwany and Alkass (10) who noticed an increase in average daily gain with the increasing slaughter weight of lambs. Fattening period for docked and undocked lambs being 49.67 and 37.83 days, respectively and the difference was not significant (Table 1).…”

“…It is of interest to note that no statistical analysis was carried out for this trait because of lambs are fed on a group basis. Moreover, the feed conversion ratio obtained in the current work is lower than those reported earlier for Karadi and Awassi lambs by Alkass and Kak, (9), Alkass and Hassan (6) and Al-Sherwany and Alkass (10). 2).…”

“…Growth performance: Growth performance as affected by docking and slaughtered at different weights are presented in Table (1). In the current investigation, daily gain in weight averaged 0.261±0.01 kg which is comparable to those obtained for the same breed by Alkass and Kak (9), Sefdin and Alkass (50), Alkass and Hassan (6) and Al-Sherwany and Alkass (10). Daily gain for docked and intact lambs averaged 0.265±0.021 kg and 0.256±0.021 kg, respectively and the difference between them lacked significance (P>0.05).…”

“…It is well known that bone is an early maturing carcass component so it grows at slower rate during post-natal life, and consequently decreasing with increasing body weight (31,34). Several investigators noted that as slaughter weight increased, there is mainly an increase in fat and a decrease in bone proportion of the carcass carcass (3,10,23,41,50). From the results given in Table ( 6), it appears that lambs slaughtered at 20kg had significantly (P<0.01) higher lean: fat ratio (6.926±0.575) as compared with lambs slaughtered at 30kg (4.232±0.467) and 40kg (3.034±0.317), while lean: bone ratio increased numerically by increasing slaughter weight from 20 to 30kg and 20 to 40kg, and the difference was not significant.…”

Allometric Growth Patterns of Body and Carcass Component in Docked and Intact Karadi Lambs

“…Carcass composition: The weights in kg of lean, fat and bone in the left side of the carcass increased linearly as the slaughter weight increased in the docked and intact lambs (Tables 1 , 2). This result were close to other workers (5,7,11,30), who reported that as the carcass weight increased, the weights of lean, fat and bone increased. The allometric growth coefficients of dissectible lean and bone weights in docked and intact Karadi lambs were negative heterogenic (b<1), indicating low impetus and early maturing tissue, and the growth of these two tissues are significantly (P<0.01) slower than carcass weight.…”