Effect of lasalocid sodium and molasses on performance of fattening lambs and on rumen liquor and blood parameters.

Abstract

Two experiments were conducted to evaluate the effects of sugar beet molasses (0, 8 and 16%) with or without lasalocid sodium (33 ppm) on rumen liquor and blood parameters of sheep, and on fattening reared Karagouniko breed lambs. In Expt. 1 six adult Karagouniko fistulated wethers were fed six different pelleted diets. The results showed that lasalocid decreased (P less than 0.01) total VFAs concentration in the rumen (7.1%) by reducing (P less than 0.001) acetic, n-butyric and iso-valeric acids while increased (P less than 0.001) propionic acid concentrations. The same trends were observed in molar proportions of the individual VFAs. The total VFAs production was also depressed by 13.75% when molasses were used at the level of 16%. No interaction among the main treatments was observed with the exception of L X M with 16% molasses where the propionic acid concentration decreased, and those of butyric and iso-valeric acids increased. Lasalocid did not alter the mean values of rumen liquor pH and ammonia nitrogen concentration while molasses increased the later parameter. No significant differences on dietary protein degradability were observed among treatments. Lasalocid reduced the beta-HBA concentration by 13% in the blood while molasses increased it (P less than 0.001). Free fatty acids' concentration was decreased by the molasses inclusion to the diets, while lasalocid didn't alter blood glucose concentration. Finally, the number of protozoa in the rumen liquor was reduced by 49 and 70% at 0 and 5 hours post feeding respectively with the addition of lasalocid to the diets, regardless of the use of molasses. In Expt. 2 utilized 86 weaned male Karagouniko fattening lambs, with initial mean LW 13 kg, for 60 days. They were assigned to six groups and fed ad libitum with diets of the same composition as in Exp 1. Lasalocid increased the growth rate by 8.6%, reduced feed consumption by 4.8% (P less than 0.005) and improved feed conversion by 11.8%. Molasses also improved growth rate by 16-34% and increased feed consumption by 15-22%. The interaction of L X M to feed consumption was significant (P less than 0.001). None of the treatments had an effect on carcass characteristics. Finally lasalocid showed its positive action when it was used in combination with molasses in ruminants' diets.