Carcass composition and meat quality differences between pasture-reared ewe and ram lambs

Area of Science:

• Animal Science
• Meat Science
• Livestock Production

Background:

• Understanding sex-based differences in lamb carcass and meat quality is crucial for optimizing production and consumer satisfaction.
• Texel-cross lambs are a significant breed in sheep production, making their specific characteristics important to study.

Purpose of the Study:

• To compare carcass and meat quality traits between pasture-raised Texel-cross ewe and ram lambs.
• To identify significant differences that may impact lean meat yield predictions and consumer perception.

Main Methods:

• Carcass assessment involved linear dimensions and leg dissection (muscle, fat, bone).
• Meat quality was evaluated using Warner-Bratzler shear force, pH, and color measurements (a*, L*) on specific muscles (M. semimembranosus, M. longissimus).
• Statistical comparisons were made between ewe (n=269) and ram (n=275) lambs aged 5-8 months with an average carcass weight of 17.2kg.

Main Results:

• Ewe lambs exhibited higher dressing percentages, shorter carcasses, and heavier leg cuts.
• Ram lambs possessed more muscle and bone in their legs, but ewe lambs had a higher leg muscle-to-bone ratio and muscularity.
• Ram lambs had lower meat quality, indicated by higher shear force, higher ultimate pH, and lower redness and lightness values.

Conclusions:

• Significant differences in carcass composition and meat quality exist between Texel-cross ewe and ram lambs.
• Predicting lean meat yield based on carcass shape may overestimate yields in males and underestimate them in females.
• While differences are present, most meat quality variations between sexes were found to be small.