Allometric Growth of Non-Carcass Components, Carcass Cuts and Hind Limb Tissues in Kivircik Lambs Finished Under...

Obtaining information about the growth rates of animals' organs and tissues can help understand their meat production potential and determine the ideal slaughter weight (SW).

This study aimed to determine the effects of production system and SW on the allometric growth of the non-carcass components, carcass cuts, and hind limb tissues of Kivircik lambs.

A total of 54 single-born male lambs were randomly allocated into production systems (concentrate- and pasture-based) and SW groups: 25-26 kg (LOW), 30-31 kg (MEDIUM), and 35-36 kg (HIGH). The data for weights of non-carcass components, carcass cuts and hind limb tissues were analysed using General Linear Model (GLM). The allometric growth of non-carcass components, carcass cuts and hind limb tissues was estimated using the nonlinear allometric equation (Y = aX^b).

The mean of carcass components increased linearly with SW (p < 0.05). Similar omental-mesenteric fat, kidney knob and channel fat (KKCF), back fat thickness, subcutaneous fat, intermuscular fat and total fat levels were observed in the different SW groups in a pasture-based system (p > 0.05). Carcass cuts and hind limb fat tissues show late development (b > 1) in the concentrated system. Development of subcutaneous fat and total fat was late maturing (b > 1) in the pasture-based system. Allometric growth of KKCF, subcutaneous fat and total fat was rapid.

If more carcass weight is desired from Kivircik lambs in the concentrated production system, they should be slaughtered at higher weights than the HIGH group. Continuing to fatten pasture-based lambs after 30-31 kg may result in fatty carcasses.