Genetic parameters for carcass composition and performance data in crossbred lambs measured by Video Image Analysis

Area of Science:

• Animal Science
• Quantitative Genetics
• Meat Science

Background:

• Lamb carcass quality is crucial for the meat industry.
• Accurate estimation of carcass traits is essential for breeding programs.
• Video Image Analysis (VIA) offers a non-invasive method for assessing carcass composition.

Purpose of the Study:

• To estimate genetic parameters for lamb carcass quality traits using Video Image Analysis (VIA).
• To evaluate the potential of VIA in improving primal meat yield and carcass quality through selection.
• To assess the heritability and genetic correlations of performance and carcass traits measured by VIA.

Main Methods:

• Utilized data from 7074 crossbred lambs.
• Applied multivariate animal models and repeatability models for genetic parameter estimation.
• Estimated genetic parameters for average daily gain (ADG), scanning live weight (SW), ultrasonic muscle (UMD) and fat (UFD) depths, cold carcass weight (CCW), and VIA measurements of primal joints (LEG, CHUMP, LOIN, BREAST, SHOULDER).

Main Results:

• Direct heritability for VIA primal joint measurements was low to moderate (0.08-0.26).
• Repeatability estimates for VIA traits were high (>0.90).
• Moderate to high heritability (0.25-0.55) found for performance traits (ADG, SW, UMD, UFD) and CCW.
• Strong positive genetic correlations between VIA traits and ADG (0.75-0.93) and SW (0.60-0.97).
• Negative correlation between UFD and UMD, ADG, and CCW.

Conclusions:

• VIA is a repeatable trait with high heritability for primal joints.
• Selection based on performance and VIA traits can enhance primal meat yield without increasing carcass fatness.
• Incorporating VIA data into breeding programs can effectively improve lamb carcass quality.