Abstract

VAZQUEZ SORIA, Edith Tatiana; PARTIDA DE LA PENA, José Armando; RUBIO LOZANO, Ma. Salud  and  MENDEZ MEDINA, Danilo. Productive performance and carcass characteristics in lambs from crosses between Katahdin ewes and rams from four specialized meat breeds. Rev. mex. de cienc. pecuarias [online]. 2011, vol.2, n.3, pp.247-258. ISSN 2448-6698.

Productive performance and carcass characteristics were evaluated in lambs from crosses between Katahdin (K) ewes and Suffolk (S), Texel (T), Charollais (Ch) and Dorper (D) rams. Two hundred ewes were distributed randomly into four lots of 50 animals each, and laparoscopically inseminated with fresh semen from one of the four sire breeds. Lambs were weighed at birth, weaning and every 30 d until slaughter. All animals received a diet with 14% CP and 2.9 Mcal ME/kg DM. At 137±3 d of age, ten lambs were slaughtered from each treatment to measure carcass morphology, classification, grade, final pH, Longissimus dorsi area and muscle and fat color. Carcass blockiness index (weight (kg)/length (cm)) was calculated and left shoulder tissue composition determined by dissection. Data were analyzed using a completely randomized design. The KCh animals exhibited the highest slaughter weight (46.61±8.50), followed by the KD, KS and KT crosses. No differences (P>0.05) were present between KCh, KD and KS in the classification and conformation scores, carcass yield, rib-eye area and carcass blockiness index, but all these crosses exceeded (P<0.05) KT in these variables. Differences were found (P<0.05) in tissue composition between crosses, with the KD, KS and KT genotypes having more muscle (64.72±1.77 %) and less fat (13.83±2.80 %) on average than the KCh crosses (muscle= 61.07±2.60 %; fat= 18.10±3.30 %).

Keywords : Lamb; Crossbreeding; Daily gain weight; Carcass characteristics.

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