Feno de pornunça (Manihot sp.) na alimentação de caprinos

Abstract

The effect of substitution of tifton hay for pork (0, 33, 66 and 100%) on the diet of goats, on consumption, nutrient digestibility, ingestive behavior, performance and blood parameters was evaluated. Characteristics of the carcass and the quality of the meat. A total of 40 uncastrated male goats without defined racial pattern were used, with initial body weight of 17.55 ± 0.62 kg, distributed in a completely randomized design. Food consumption was quantified by the difference between the amount of food offered and the feed conversion and feed conversion ratio by the ratio between feed intake and weight gain of the animals. To calculate dry matter and nutrient digestibility, the total collection of feces was collected through collection bags. The ingestive behavior was performed through the recording of the daily times spent with food consumption, rumination and idleness. Blood samples were collected over time (0, 15, 33 and 51 days) by jugular venipuncture to determine plasma glucose and serum levels of cholesterol, triglycerides, urea, creatinine, total protein, albumin, globulin, alanine aminotransferase ( ALT), aspartate aminotransferase (AST), gammaglutamyltransferase (GGT) and alkaline phosphatase (FALCA). After slaughter, the carcasses were weighed to obtain the warm carcass weight and then cooled in a cold room at 4 ° C for a period of 24 hours, and then the cold carcass weight and loss on cooling were determined. Afterwards, evaluation of the conformation and measurements of the carcass lengths was carried out. After the measurements, the carcasses were divided into two half-carcasses, which were weighed and then analyzed the yields of the commercial cuts (leg, palette, loin, ribs, serrote and neck). The left perennis were dissected to estimate the tissue yield, muscle: fat and muscle ratio: bone, and muslin index. For the qualitative analysis of the meat, the left loin (Longissimus lumborum) of each animal was used to determine the losses in cooking, shear force, staining, water retention capacity and pH. Data were submitted to analysis of variance and regression. Consumption of dry matter (DM), organic matter (OM), crude protein (CP) was not affected by substitution. Consumption of neutral detergent insoluble fiber (FDNcp) decreased linearly while that of non-fibrous carbohydrates (CNF) increased. The intake of hydrocyanic acid (HCN) was increasing. The digestibility of the nutrients reduced linearly, but did not influence the ingestive behavior and the performance of the animals. The porcine level did not alter the protein, energetic and enzymatic profile of the animals. The treatments influenced in an increasing linear form (P <0.05) the warm and cold carcass yield. Leg length and small intestine showed a linear decreasing behavior (P <0.05). The luminosity increased linearly (P <0.05) and shear force showed quadratic behavior (P <0.05). The yield of buchada and panelada also presented quadratic behavior with the inclusion of tifton hay. The results obtained with the consumption and the digestibility did not affect the performance and ingestive behavior of the animals. There was no influence of the substitution of tifton hay on porcine hay on carcass characteristics, weight and yield of commercial cuts, morphometric measurements, tissue composition, or on the physico-chemical quality characteristics of the meat. In view of the results, it can be concluded that pork hay can replace tifton hay by up to 100% in the diet of goats in confinement.