Óleo de palmiste na dieta de cordeiros em terminação

Abstract

The objective of this study was to evaluate the effects of the inclusion of palm kernel oil (PKO) on consumption, digestibility, ingestive behavior, nitrogen balance, blood metabolites and rumen fermentation parameters and productive performance in the lamb diet. Three experimental trials were conducted at the Experimental Farm of the School of Veterinary Medicine of the Federal University of Bahia, in São Gonçalo dos Campos - BA. The treatments consisted of the inclusion of palm kernel oil (PKO) in the diet, with PKOzero - level zero - without the inclusion of PKO; PKO1.3% - addition of 1.3% PKO; PKO2.6% - addition of 2.6% of PKO; PKO3.9% - addition of 3.9% of PKO; PKO5.2% - addition of 5.2% PKO, based on the dry matter of the total diet. The diets were formulated with a roughage ratio: 40:60 concentrate in the form of a complete mixture and the concentrate composed of corn bran, soybean meal, mineral salt and palm kernel oil according to each treatment. In the first experimental trial 40 non-castrated male lambs housed individually in stalls were used, distributed in a completely randomized design to assess the consumption of nutrients and blood metabolites. For the digestibility test, 25 non-castrated male Santa Inês lambs were used, distributed in a completely randomized design. The third experimental test was carried out using 5 male sheep, not castrated, fistulated and cannulated in the rumen, to evaluate ruminal fermentation parameters, distributed in a Latin square design. Samples of food, leftovers and feces were collected for chemical-chemical analysis to determine the consumption and digestibility of nutrients. There was a linear reduction in the consumption of dry matter (P<0.001), minerals (P<0.001), crude protein (P<0.001), neutral detergent fiber (P<0.001), non-fibrous carbohydrates (P<0.001), digestible nutrients total (P=0.021) and increased consumption of ether extract (P<0.001) as the inclusion of PKO increased in the diet. The digestibility coefficients of neutral detergent fiber (P=0.573) and non-fibrous carbohydrates (P=0.648) were not affected by the presence of PKO in the diet. The digestibility of dry matter (P=0.035), ether extract (P<0.001), crude protein (P<0.001) and total digestible nutrients (P<0.001) increased as the level of PKO in the diet increased. There was a reduction in consumption (P<0.001) and excretion of fecal nitrogen (P<0.001), as well as in the production of microbial protein (P<0.001) with the increased supply of PKO in the sheep diet. Serum cholesterol increased (P<0.001), while the serum concentration of the GGT enzyme decreased (P=0.048) when the level of PKO in the diet increased. The presence of PKO in the diet had no effect on total weight gain (P=0.058) and average daily gain (P=0.057), however, feed conversion improved (P=0.001) when the level of PKO in the diet increased. Palm kernel oil can be supplied in the sheep diet up to the level of 5.2% inclusion, with improved digestibility of nutrients. The presence of palm kernel oil in the diet improved feed conversion and reduced the nitrogen balance, with a decrease in the population of total protozoa in the rumen liquid.