Efecto del propionato de calcio en el peso vivo, consumo y canal de corderos alimentados con heno de alfalfa ( Medicago sativa )

Calcium propionate (PrCa) is a hepatic gluconeogenic precursor in ruminants, but its use as an energy source in food it is questioned for its hypophagic effects. The objective of this study was to evaluate the addition of PrCa to diets with alfalfa hay ( Medicago sativa ) and molasses, on live weight, food consumption and carcass characteristics of lambs. The experimental design was completely randomized; treatments were four diets with 0 (control), 30, 35 and 40 g of PrCa per kg of dry matter that were randomly assigned to 32 (eight repetitions per treatment) Ramboulliet lambs (initial average live weight 28.1  2.1 kg). Data was analyzed with a mixed model (treatment as fixed and lamb as random) and means were compared with least squares means. The PrCa added to the diet replaced alfalfa hay. Evaluation lasted 42 d. Live weight, food consumption and feed conversion were not different (p  0.05) between the treatments. The yield of the cold and hot carcass was higher in lambs fed with 35 g PrCa, compared to the three other treatments (p  0.05). Diets with PrCa increased the degree of conformation and the area of the Longissimus dorsi , and they decreased the degree of fatness, the back and perirenal fat, and the pH of the meat, compared to the control (p  0.05). Polynomial analysis indicated that the most desirables attributes were obtained in the carcass with 40 g of PrCa. Whilst 35 g of PrCa did not affect the consumption of dry matter nor the live weight of lambs, but their yield and carcass quality attributes improved.