Torta de girassol na alimentação de cordeiras confinadas

Abstract

The effect of sunflower cake (SC) on the feeding of lambs over: intake, digestibility, nitrogen balance, blood parameters, performance and carcass and meat characteristics were evaluated. The treatments were of 0, 15, 30 and 45% of SC in the dry matter (DM) of the diet, with these being isoprotein and isoenergetic. In the digestibility trial, eight crossbred lambs (½ Santa Inês x ½ Dorper) with initial weight of 25.56 ± 2.51 kg were used, with total collection of feces and urine. We adopted the two 4 x 4 Latin square design, with four 20 day periods. At the end of the periods, feces, urine and blood were collected. The blood was collected before feeding and 2, 4, 6 and 8 hours after feeding for analyzing doses of cholesterol, triglycerides, urea and aspartate aminotransferase (AST). In the performance trial, we adopted the completely randomized design, in which 36 crossbred lambs (½ Santa Inês x ½ Dorper), with initial weight of 21.52 ± 1.63 kg received the diets. At 43.6 ± 0.88 kg of live weight, we measured the rib-eye area (REA) and the subcutaneous fat thickness (SFT) by ultrasonography. The animals were slaughtered and the non-carcass components and the warm carcasses were weighed. After cooling, we obtained the weights of the carcasses and the cuts, in addition to the REA and SFT measurements. Samples of the L. thoracis et lumborum were analyzed regarding the physical-chemical characteristics. There was no effect of the use of SC over DM, crude protein (CP) and metabolizable energy intake, with increase in the intake of neutral detergent fiber (NDF), ethereal extract (EE) and reduction of non-fibrous carbohydrates (NFC). The digestibility of the DM, NDF and NFC decreased linearly with the use of SC in the diet, not altering the digestibility of CP and EE. No variation of the nitrogen balance was observed. The blood concentrations of cholesterol, triglycerides and of AST increased linearly with the use of the co-product in the diet, without variations on weight gain, feed conversion and time of confinement. A linear reduction of carcass yield and empty body weight, with elevation in the content of the gastrointestinal tract and SFT was observed, in function of the use of the co-product in the diet. With the use of SC in the diet, the luminosity (L*) and the contents of EE increased linearly, with the linear reduction of moisture. The use of up to 45% of SC in the DM of the diet of confined lambs does not affect dry matter intake and animal performance, however, it reduces carcass yield and increases fat deposition on the carcass and meat.