Desempenho, componentes do corpo vazio e perfil de ácidos graxos da carne de bezerros holandês abatidos com diferentes pesos em dois sistemas de terminação

Abstract

This study was conducted at the Federal Technological University of Paraná, Campus Two neighbors, in order to evaluate two different finishing systems and slaughter weights through the performance, empty body components and fatty acids in the meat of calves to Dutch production meat. We used 43 male animals, not castrated Holstein breed, with initial weight of 57 kg and 58 days old. Of these animals, 23 were confined getting a diet consisting of corn silage as forage and commercial concentrate with corn meal and soybean meal, in relation 40:60. The remaining 20 animals, were completed in cultivated pasture, varying according to the time of year: ryegrass (Lolium multiflorum) in the first period, and the two subsequent millet (Pennisetum americanum) supplementation with the same concentrated confinement to 1% of body weight. In each system, the animals were randomly assigned to four different weights, pre-stipulated: 140; 180; 220 and 260 kg body weight. The feedlot finished possible reduction of slaughter age compared to pasture, which also met the nutritional requirements. For evaluation of the pasture consumption was used as an external marker chromium oxide. The calculation of nutrient intake was based on the diet DM, so the dry matter intake was (5.65 against 4.33 kg and 4.36 against 3.32% of body weight), NDT (3.70 against 2.58 kg and 2.88 and 2.01% of body weight) and FDA (0.98 against 0.66 kg and 0.76 against 0.51% of body weight), and the average daily gain (0.949 and 0.694 kg-1), all variables higher (P <0.05) in animals in feedlot in relation to the pasture. The consumption of CP, NDF and CA showed no significant difference. The Holstein calves have potential for the production of meat, expressing the best performance when finished in feedlot. The EBW showed linear growth with increasing slaughter weight, and the yield of hot and cold carcass was not affected in relation EBW / PAB. The growth of external components of substrate was proportional to the increased weight, grew rapidly in the early stages and accompanying weight gain. In relative units just head and feet. The absolute weight of the heart, kidney, lung, liver, spleen, gall bladder, trachea, reproductive tract, TGI and content amounted TGI (P <0.05) linearly. In relative units, individual behavior of some internal organs reversed, with decreases due to increased weight, only the liver, esophagus, TGI and the set of internal components increased linearly. The EBW was not influenced by food, chips and leather were significant (P <0.05) in absolute weights and the leather and the head relative weights. The differences presented by the liver, trachea, spleen and contents of TGI, were sufficient to alter the absolute and relative weights of the internal components (P <0.05) observed in animals on pasture, mainly due to the high protein present in pastures. For the analysis of fatty acids, the diet used in the termination systems did not change the saturated fatty acids. The C16 unsaturated acids: 1n7 (palmitoleic acid) had higher content of confinement 1.02 against 0.75 g / g lipid in the pasture, and on the content of linolenic acid-y (C18: 3n6) higher feedlot 0.07 against 0.04 g / g lipid in grassland eoe acid 5.8, II, 14,17-eicosapentaenoic (EPA) (C20: 5n3), which varied in a manner contrary with higher values in the pasture 0.45 against 0, 17 g / g lipid in confinement. In total the set of saturated fatty acids, unsaturated, polyunsaturated did not vary as to the termination system used and with the omega 6 alone. Only omega 3 have the highest levels of alpha-linolenic (ω3). Thus reduced the ω-6 ratio / ω-3, demonstrating the increased participation of ω-3 in the pastures and reducing the ω-6 in the flesh of animals in pastures. For different weights of slaughter, the SFA and UFA decreased due to increased weight of the animals. To 260 kg greatest participation of CLA and the best ω-6 ratio / ω-3. Featuring the highest quality of meat from animals raised on pasture and the best slaughter weight is from 194 kg for the production of calves.