Use of incremental levels of dehydrated olive cake in lamb diets as an alternative for grazing systems in the central dryland area in Chile: The effect on carcass traits of Suffolk Down lambs

Abstract

To evaluate increased levels of dehydrated olive cake (DOC) in lambs ration on main carcass traits, 40 Suffolk Down male lambs (75.8 ± 7.4 days of age, 24.5 ± 3.1 kg live weight) were randomly assigned to one of five treatment groups. Four experimental isoenergetic and isoproteic diets were used with different levels of DOC: 0, 16, 32 and 48%, and an un-weaned group were kept with their mothers on grazing. Lambs had 8 days of adaptation to the diets, which were gradually introduced along with good quality alfalfa hay. During 47 days of the experiment, the lambs were confined in individual pens (1.4 m 2 ) and subsequently slaughtered at 123 ± 7 days with an average live weight of 32.56 ± 2.62 kg. The live weight at slaughter (LWS), hot carcass weight, cold carcass weight, commercial yield (CY), real dressing percentage (RDP), body components weight (blood, hide, head, legs, full and empty digestive tract, and viscera), rib eye area (REA), back fat thickness (BFT), renal pelvic fat weight, and commercial cutting yield (CCY) were recorded. Additionally, the tissue composition and its ratios were calculated from the shoulder and leg. The carcass traits, CY, RDP, and REA decreased and BFT increased with increasing amounts of DOC in the diet (P≤0.05). No significant differences (P>0.05) in CCY, tissue composition and ratios among the tissues of the shoulder and leg joints were detected. The addition of DOC to the diet did not affect the quality of the lamb carcass. Se evaluo la inclusion de alperujo deshidratado de oliva (ADO) en la racion de corderos sobre las principales caracteristicas de la canal, utilizando 40 corderos Suffolk Down (75,8 ± 7,4 dias de edad, 24,5 ± 3,1 kg peso vivo). ADO se incluyo en cuatro dietas: Dieta control con 0% ADO (DC), DC con 16, 32 y 48% ADO, mas un grupo a pastoreo que se mantuvo con sus madres. Durante el ensayo (47 dias), los corderos se mantuvieron en corrales individuales (1,4 m 2 ). Los corderos fueron sacrificados a los 123 ± 7 dias, y peso vivo promedio de 32,56 ± 2,62 kg. Al sacrificio se registro: peso vivo, peso de la canal caliente, peso de la canal fria, rendimiento comercial (RC), rendimiento verdadero de la canal (RV), peso de los componentes del cuerpo (sangre, piel, cabeza, piernas, el tracto digestivo lleno y vacio, y visceras), area del ojo del lomo (AOL), espesor de grasa dorsal (EGD), peso de grasa peri-renal y rendimiento de corte comercial (RCC). Adicionalmente, en espaldilla (E) y pierna (P) se estudiaron los componentes del tejido (CT) y sus proporciones (PT). El incremento de ADO en la dieta causo una disminucion de RC, RV y AOL y un aumento de EGD (P 0,05) en RCC, ni en CT y PT de H y P. La adicion de ADO a dietas de corderos, en los niveles utilizados en este trabajo, no afecto la calidad de la canal de cordero.