Abstract
The commercial value of lamb carcasses is primarily determined by their weight and quality, with the latter commonly quantified according to muscle coverage and fat depth. The ability to predict these quality scores early in the season could be of substantial value to sheep producers, as this would enable tailored flock management strategies for different groups of animals. Existing methods of carcass quality prediction, however, require either expensive equipment or information immediately before slaughter, leaving them unsuitable as a decision support tool for small to medium-scale enterprises. Using seven-year high-resolution data from the North Wyke Farm Platform, a system-scale grazing trial in Devon, UK, this paper investigates the feasibility of using a lamb's early-life liveweight to predict the carcass quality realised when the animal reaches the target weight. The results of multinomial regression models showed that lambs which were heavier at weaning, at 13 weeks of age, were significantly more likely to have leaner and more muscular carcasses. An economic analysis confirmed that these animals produced significantly more valuable carcasses at slaughter, even after accounting for seasonal variation in lamb price that often favours early finishers. As the majority of heavier-weaned lambs leave the flock before lighter-weaned lambs, an increase in the average weaning weight could also lead to greater pasture availability for ewes in the latter stage of the current season, and thus an enhanced ewe condition and fertility for the next season. All information combined, therefore, a stronger focus on ewes' nutrition before and during lactation was identified as a key to increase system-wide profitability.
Highlights
The commercial value of lamb carcasses is primarily determined by carcass weight and carcass quality (Rius-Vilarrasa et al 2009)
In meat markets within the European Union, the latter is most commonly represented by premiums and penalties applied according to conformation score (CS) and fat class (FC), which are visually graded by trained assessors under the EUROP classification system to differentiate products by their genuine economic value (Johansen et al 2006)
While the exact scaling system varies from country to country, carcasses in the UK are graded on a 5-point scale (E/ U/R/O/P) for CS and on a 7-point scale (1/2/3L/3H/4L/4H/5) for FC, yielding 35 possible combinations of outcomes at quality assessment
Summary
The commercial value of lamb carcasses is primarily determined by carcass weight and carcass quality (Rius-Vilarrasa et al 2009). In meat markets within the European Union, the latter is most commonly represented by premiums and penalties applied according to conformation score (CS) and fat class (FC), which are visually graded by trained assessors under the EUROP classification system to differentiate products by their genuine economic value (Johansen et al 2006). CS characterises the desirability of carcass shape in terms of convex/ concave profiles, which are known to be associated with the proportion of muscle and fat in relation to bone, and the quantity of saleable. FC, on the other hand, quantifies the amount of subcutaneous fat on the carcass visible to the assessor and is used to select a destination market with the most compatible consumer preference as well as to ensure eating quality, as carcasses which are too lean are more likely to undergo cold-shortening. For CS, grade ‘E' corresponds to carcasses that are the most well-muscled and the most valuable, while for FC, grade ‘1’ corresponds to carcasses that are the leanest, but not necessarily the most valuable (as explained above)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
