Effect of slaughter weight on slaughtering and carcass characteristics in lambs from thin-tailed Kivircik and fat-tailed Kangal Akkaraman breeds

Allometric Growth of Non-Carcass Components, Carcass Cuts and Hind Limb Tissues in Kivircik Lambs Finished Under Concentrate- and Pasture-Based Systems

BACKGROUND

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).

OBJECTIVES

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.

METHODS

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 = aXb).

RESULTS

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.

CONCLUSION

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.

Carcass Characteristics and Meat Quality of Karacabey Merino lambs Reared under Triticale and Oat Pastures Compared with Stall-Fed Lambs

Fifty-eight Karacabey Merino lambs were used to study the effects of feeding system (triticale pasture, oat pasture, or stall-fed), birth type (single or multiple), gender (male or female), and birth year (2016 or 2017) on various carcass and meat quality characteristics. Stall lambs had higher conformation (CS) and fatness (FS) scores, and higher meat L* and h* values than the two pasture groups, possibly due to higher fat content, while oat pasture lambs had the most tender meat. Single-born lambs had higher CS, FS, and Longissimus thoracis muscle section area, while females had higher subcutaneous and non-carcass fat deposits than their counterparts. Both single-born lambs and 2016-born lambs had higher meat a* and C* values than their counterparts. In conclusion, a pasture-based feeding system is more suitable for Karacabey Merino lambs than a stall feeding system, if lean meat and/or meat products are preferred. However, it should not be ignored that stall-fed lambs showed a better fattening performance in terms of conformation and fatness, during the same period.

A Comprehensive Study of the Quality of Fat-Tailed Sheep Carcasses in Greece

Sheep farming in Greece is focused on milk production. Meat is considered a by-product and consists mainly light carcasses of undefined quality. The main challenge of the sector is to ensure sustainability, and hence efforts are towards efficient use of available resources, including undervalued carcasses of local fat-tailed sheep. The objective here was twofold: (i) to assess the carcass quality of fat-tailed sheep slaughtered at different live weights and (ii) to compare them with carcasses from thin-tailed sheep. In total, 146 fat-tailed and 97 thin-tailed dairy sheep were used. They belonged to five live-weight categories (LWC), representing 25%, 35%, 50%, 70% and 100% of mature body weight. Carcass length/weight/yield/pH and wither height were recorded. Muscle fiber minimum Feret’s diameter and meat color/tenderness/moisture/lipid and protein content were determined. Sex and LWC differences in fat-tailed sheep were assessed. Parametric and non-parametric tests were used to compare with thin-tailed sheep, considering the effects of LWC, sex and their interactions with sheep population (fat-tailed/thin-tailed). Most traits were significantly different (p < 0.05) between groups of fat-tailed sheep. Carcass yield of fat-tailed sheep was significantly higher compared to thin-tailed (p < 0.01). Interactions of sheep population with LWC or sex affected wither height, carcass pH, meat color and tenderness (p < 0.05). Fat-tailed sheep meat quality is equal or higher compared to thin-tailed. Finishing weights corresponding to 50 and 70% LWC may improve capitalization of fat-tailed carcasses.