Effect of crossbreeding with exotic breeds on meat quality of Awassi lambs

The influence of genotype on fattening performance and meat quality was studied in male lambs of five genotypes (n = 10): CA (F1 Charollais-Awassi), ACA (B1 Awassi-Charollais-Awassi), RA (F1 Romanov-Awassi), ARA (B1 Awassi-Romanov-Awassi) and A (Awassi). Lambs were weaned at 70 days of age and offered a diet containing 16% CP and 2.78 Mcal metabolizable energy/kg for 170 days. At the end of the fattening period, all lambs were slaughtered and Musculus semitendinosus and Musculus longissimus were excised from the right and left sides of the carcass for objective meat quality assessment. Birth weights were similar while weaning weights differed among genotypes being greater for the CA. The final and fasted live weights were found to be significantly affected by genotype; the CA genotype was heavier than A and ARA while the ACA genotype was heavier than A. Hot and cold carcass weights and dressing% differed significantly with CA genotype having greater values than A, while the remaining genotypes had intermediate values. Meat quality parameters for M. semitendinosus were different among genotypes with Awassi having higher cooking loss%, and hue angle values but lower redness values than the remaining genotypes. Yellowness values were higher for A and ARA genotype than CA and RA genotypes while ACA genotype was intermediate. Expressed juice% was the lowest for A and ARA genotypes. Lightness values for M. semitendinosus were greater for ARA and A genotypes, with no differences between A and ACA genotypes. However, M. longissimus had only greater lightness values for A and ARA with no significant differences between ARA, ACA and RA genotypes. Meat quality parameters for M. semitendinosus were affected by aging duration being significantly higher for pH, yellowness and hue angle, and lower for redness at 24 h compared to 7 days of aging. No differences were observed in all meat quality parameters for M. longissimus except in pH and cooking loss% being lower at 7 days of aging. Variation between muscles within each genotype was observed in cooking loss%, shear force values, lightness and redness. Results of this study indicate that the F1 crossbreeding of Awassi with either Charollais or Romanov yielded higher production in the resulting genotype while B1 progeny was intermediate without any adverse effects on meat quality. Additionally, aging for 7 days lowered pH and increased redness in both muscles.