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

Abstract

Twelve new born Karadi lambs were docked within 3 days of their birth using rubber-rings, and left with their mothers till weaning (2.5 months). Another 12 weaned Karadi lambs obtained from local market were left intact. Following an adaptation period of a week, the docked and intact lambs with an average initial weight of 16.83±1.522 and 19.92± 0.748kg were randomly divided into three equal groups to be slaughtered at 20, 30 and 40kg. 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 0.261±0.014kg, 45.956±0.428%, 53.933±0.678%, 11.288±0.488cm2 and 2.023±0.76mm, respectively, and no significant difference exist between them except dressing percentage based on empty body weight. It appears that carcasses of intact lambs compared to docked lambs contained significantly higher lean (62.79 vs. 59.85%), lean: fat (5.319 vs. 4.142), lean: bone (2.772 vs. 2.489) and numerically lower fat (16.058 vs. 14.042%) and bone (23.172 vs. 24.096%). Also, it was noticed as slaughter weight increase, there is an increase in dressing percentage, rib eye area, fat thickness, fat content of their carcass with a lower proportion of lean and bone.

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

“…The allometric growth coefficient of leg weight is differ between treatments in relation to half carcass weight, while it was found that the b value in docked lambs is near to one (1.036), which means isogonic growth and grew at a similar rate to carcass weight, on the other hand, the b value in intact lambs was (0.845), indicating low impetus and early maturing cut and the growth rate was lower than that of carcass weight. Such difference could be attributed to more deposition of fat in the leg of docked lambs compared to intact lambs (20.18 vs. 12.99%) (8). This result for intact lambs are in accordance with Alvarez-Rodriguez, et al, (9) who indicated that the allometric growth of leg cuts in relation to half carcass weight was an early developed.…”

“…After an adaptation period of a week, the docked and intact lambs with an average initial weight of 16.83± and 19.92± kg respectively, were randomly divided into three equal groups to be slaughtered at 20, 30 and 40kg, and each group was housed in a separate pen and fed a pelleted diet containing 16% crude protein and 2769 Kcal energy and straw ad libitum. Full details of the experiment are described in our previous paper (8) Slaughtering of the animals When each lamb reached its desired slaughter weight (20, 30 and 40 kg), they were slaughtered after fasting for 12 hours, with unlimited access to water. The lambs were slaughtered at abattoir according to Islamic method, by severing the necks and major blood vessels.…”