DESEMPENHO DE CORDEIROS SANTA INÊS TERMINADOS EM CONFINAMENTO COM ADIÇÃO DE NARASINA

Abstract

Sheep farming plays a very important socioeconomic role in many regions. Confinement is a very useful tool in finishing lambs in a short period. Narasin is an Ionophore additive synthesized by Streptomyces aureofaciens bacteria with great potential for use in small ruminants. The objective was to evaluate the performance of Santa Inês lambs finished in feedlot with the addition of Narasina. The experiment was carried out in the confinement shed of the Sheep and Goat Laboratory of the IF Goiano Campus Rio Verde - GO. 16 Santa Inês lambs, 8 males and 8 females, aged between 03 and 05 months, confined in individual stalls were used. The diets had a roughage:concentrate ratio of 30:70, with roughage Tiffton Hay 85 (30%); the concentrate the Soybean bran (19%), the whole corn grain (80%) and Mineral mixture (1%) and Narasin. The experimental design was completely randomized with four treatments: T1= Control, without inclusion of Narasin; T2=6.5 ppm; T3= 13 ppm and T4= 19.5 ppm of Narasin/kg of DM, containing four replicates. Dry matter (DM) consumption was estimated at 4% of live weight and leftovers were weighed daily so that it remained between 5% and 10%. The experimental period was 55 days, after the adaptation period of 07 days. Lambs were weighed at the beginning and end of the period after being submitted to a 16-hour solid fast. At the end, data on weight gain, consumption of Dry Matter and Natural Matter, feed conversion and feed efficiency were obtained. For the statistical analysis, the software R (2011) was used and the means were compared by the Tukey test at 5% probability. None of the characteristics studied were affected by the addition or not of the Ionophore. The addition of Narasin at levels 6.5 ppm, 13 ppm or 19.5 ppm did not change the performance of Santa Inês lambs finished in feedlot.