Desenvolvimento do trato gastrintestinal de aves de corte de genótipos de crescimento lento na fase inicial e digestibilidade de alimentos

• Autor(a) principal: Assis, Saullo Diogo de
• Data de Publicação: 2019
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tede/9703
• topic: Caipira; Exigência; Desempenho; Frango; Genética; Free range; Requirement; Performance; Broilers; Genetics; CIENCIAS AGRARIAS::ZOOTECNIA

Three experiments were carried out with the objective of evaluating the differences in performance, nutritional utilization of the ration and development of the digestive tract of four slow - growing broiler strains. The effects of the breeding system on the development of the digestive tract and determine the metabolizable energy values of the main feed of broiler chickens slow growing. In the experiment I were evaluated the zootechnical performance, the bioeconomic index and the metabolizability of the nutrients of the ration of different strains of slow - growth and early - growth broilers. A total of 544 day - old chicks, 136 of each genotypes were used: Label Rouge Pesadão, Isa Label Rouge Naked Neck, Carijó and CarijóNaked Neck, distributed randomly in eight replicates of 17 animals each. The studied variables were performance, bioeconomic index, nutrient metabolizable coefficients, apparent metabolizable energy (EMA) and apparent metabolizable energy corrected for nitrogen balance (AMEn). In experiment II, 600 slow - growing chickens (Label Rouge Naked Neck) were housed initially in a conventional masonry shed, raised up to 70 days old. At 35 days of age they were divided into two groups, one of which had access to free area and another one remained in the shed until the end of the experiment. The variables studied were live weight, digestive tract development and intestinal histomorphometry at different ages. For experiment III, six hundred broiler chicks of the Label Rouge Naked Neck line were used. The treatments consisted of seven foods and one reference diet. The methodology used was the total collection of excreta. The tested foods were: soybean meal, corn grain, rice bran, sorghum grain, 60% corn gluten, wheat bran and soybean oil. There were differences (P <0.05) for live weight, weight gain, feed intake and feed conversion among the four lines studied, at 7, 14, 21, 28and 63 days of age. The Carijó Neck strain showed the worst performance results from 1 to 63 days of age compared to the other lines studied. There was a difference (P <0.05) for the bioeconomic index (IBE). The Carijó, Label Rouge Neck and Label rouge lines had the highest IBE values. The metabolizable coefficients of the nutrients differed (P <0.05) between the lines at seven and 21 days of age. The highest value of the metabolizable coefficient of the protein and mineral matter of the diet was obtained by the Carijó line at seven and 21 days of age. There was a difference (P <0.05) between the lineages in live weight, allometry of digestive tract organs and intestinal histomorphometry at one, seven and 28 days of age. The breeding systems influenced (<0.05) the live weight and the allometry of the organs of the digestive system of broiler chickens of the Isa Label Neck Snack Line at 72 days of age. The semiconfined breeding system improved the performance and growth of the small intestine of the Isa Label Naked Neck line. The values of AMEn (kcal / kg) of foods based on natural matter were: soybean meal, 2215 kcal / kg; corn grain, 3568 kcal / kg; sorghum grain, 3212 kcal / kg; rice bran, 2365 kcal / kg; wheat bran, 2482 kcal / kg; soybean oil, 7902 kcal / kg and 60% corn gluten, 2860 kcal / kg. The slow growing strains present differences in performance, nutritional utilization, allometric digestion tract and energetic utilization of the ration when compared to each other.