Carcass and lamb meat quality from improved Jezersko-Solčava flocks in Slovenia

Abstract

Forty lambs (progeny of two different genotype sires and Jezersko-Solcava ewes) were used to evaluate the effect of slaughter weight, genotype and sex on non-carcass components, carcass characteristics, carcass cuts and meat quality of Longissimus dorsi. Twenty-eight lambs were progeny by improved Jezersko-Solcava (JSR) sire (JSR lambs) and twelve were progeny by Texel (T) sire (JSRT lambs). After 10 days of age lambs were fed with commercial concentrate and hay ad libitum. Lambs remained indoors with their dams until weaning at 60 days of age. Lambs were divided into three groups according to genotype/sire and slaughter weight. JSR lambs were divided into JSR-light group (6 males and 6 females) and JSR-heavy group (6 males and 10 females). All Texel sired lambs representing the third group of JSRT lambs (6 males and 6 females). JSR-light group was slaughtered at the average 29.5 kg of live weight, JSR-heavy group and JSRT group were slaughtered at the adjusted 44 kg of live weight. Slaughter weight had effect on all non-carcass components presenting JSR-heavy the highest percentage. JSR-heavy carcasses had higher carcass fatness and were longer and wider in shoulder and hindleg. Slaughter weight affected carcass cuts, having the JSR-heavy lower percentage of shoulder and hindleg, but higher percentage of rib with flank. JSR-heavy carcasses had redder meat than JSR-light. When comparing JSRT and JSR-heavy lambs, JSRT had lower percentage of liver and lungs and higher percentage of head and pelt. JSRT carcasses had lower fatness, better conformation score and better dressing proportion than JSR- heavy. The composition of hindleg showed that JSRT carcasses had higher percentage of muscle and lower percentage of bone in hindleg than JSR-heavy carcasses. Meat quality differ only in b* value with more yellow meat in JSRT than JSR-heavy. Sex had effect on liver, heart and head with higher percentages in males. Males had lower dressing percentage, lower carcass fatness and higher percentages of neck, chuck and shoulder and had lighter meat. It was concluded that progeny by Texel sire had better carcass characteristics especially dressing percentage, carcass fatness and carcass conformation. Slaughtering JSR lambs at 44 kg of live weight have as a result longer and wider carcasses with slightly higher carcass fatness score, greater muscle and lower bone percentage in hindleg than JSR lambs slaughtered at 29.5 kg of live weight.