Dieta hiperlipídica com farinha de soja como fonte proteica: utilização na seleção de ratos propensos e resistentes à obesidade

OBJETIVO: Desenvolver uma dieta hiperlipídica de baixo custo, tendo farinha de soja como fonte proteica, que seja eficiente na seleção de ratos propensos e resistentes à obesidade e que permita alcançar fenótipo obeso nos animais propensos. Além desses requisitos, a dieta deve ser palatável e não rejeitada a curto prazo pelo animal. MÉTODOS: A dieta proposta foi obtida misturando-se leite condensado (15,5%), amendoim (18,5%), farinha de soja (20,0%), óleo de milho (6,0%), ração Bio Tec (30,0%) e bolacha wafer de chocolate (10,0%). A mistura foi peletizada e submetida à análise bromatológica. A dieta foi ofertada a ratos Wistar durante uma semana; posteriormente, os animais foram divididos em três grupos, de acordo com o ganho de peso. O terço superior foi considerado propenso à obesidade e o terço inferior, resistente à obesidade. Após 80 dias de oferta da dieta, os animais foram sacrificados e foram quantificados o peso corpóreo, consumo alimentar, gorduras retroperitoneal, periepididimal, de carcaça e gorduras totais. RESULTADOS: Verificou-se que a dieta apresentava 5,31kcal/g, com a seguinte composição: 22,3% de gordura, 22,2% de proteína, 15,9% de fibra, estimando-se 35,7% de carboidrato. Ratos propensos à obesidade, alimentados por 87 dias com a dieta hipercalórica, apresentaram peso corpóreo, gorduras retroperitoneal, periepididimal e totais significativamente maiores do que animais resistentes à obesidade (p<0,05). O consumo de alimentos também foi maior em animais propensos (p<0,05). Verificou-se também que a substituição da caseína pela farinha de soja, como componente proteico da ração, levou à diminuição de 96,0% no custo do estudo. CONCLUSÃO: A dieta formulada com farinha de soja apresentou custo reduzido e foi capaz de desenvolver o fenótipo obeso em ratos propensos, à semelhança do observado na literatura com outras dietas.OBJECTIVE: The objective was to develop a high-fat, low cost diet, using soybean meal as protein source. This diet should effectively discriminate between rats prone and resistant to obesity and allow the obese phenotype to be achieved in the animals that are prone to obesity. Furthermore, the diet must be palatable and not be rejected by the animal in the short run. METHODS: The chow was obtained by mixing the following ingredients: condensed milk (15.5%), peanuts (18.5%), soybean meal (20.0%), corn oil (6.0%), Bio Tec chow (30.0%) and chocolate wafer cookies (10.0%). In order to make it appropriate for rats, the mixture was pelleted and subjected to food analysis. The chow was offered to Wistar rats for a week. The animals were subsequently separated according to weight gained. The upper third group was considered prone to obesity and the lower third group was considered resistant to obesity. The animals were sacrificed 80 days later to determine body weight, food intake, retroperitoneal, periepididymal and carcass fats and total fats. RESULTS: Food analysis found that the chow had an energy density of 5.31 Kcal/g, 22.3% fat, 22.2% protein, 15.9% fiber and 35.7% carbohydrates. After being fed for 87 days with the high-fat diet, obesity-prone rats had higher body weight and retroperitoneal, periepididymal and total fats than obesity-resistant animals (p<0.05). Food intake was also higher among obesity-prone rats (p<0.05). The replacement of casein by soybean meal as protein source reduced the cost of the study by 96.0%. CONCLUSION: The substitution of casein by soybean meal in a high-fat diet allows cost reduction and the identification of obese-prone rats. Continuous use of this high-fat diet resulted in the development of the obese phenotype, as seen with other diets used in the literature

Effects of chromium yeast supplementation on productive and metabolic responses of laying hens fed diets containing different energy levels

This study evaluated the effects of chromium yeast (Cr yeast) and two apparent metabolizable energy (AME) levels on productive performance, egg quality, and lipid and carbohydrate metabolism in laying hens. A total of 192 Bovans White laying hens at 47 weeks of age were randomly assigned to eight dietary treatments (six replicates each) in a 4 × 2 factorial arrangement: four levels of supplemental Cr (0, 0.2, 0.4, and 0.8 ppm as Cr yeast) and two AME levels (2,780 and 2,900 kcal AME kg−1). No significant effect of Cr yeast supplementation on feed intake, egg weight, egg production, intact eggs, egg mass, feed conversion ratio, or egg quality was observed. Egg quality parameters and Cr content in the yolk were not affected by dietary treatments. Plasma glucose and lipid levels were not influenced by either Cr yeast or AME levels used in this study. However, Cr yeast supplementation improved yolk percentage and hepatic glycogen content. The inclusion of Cr yeast at 0.2 and 0.4 ppm induced the highest hepatic glycogen content with the energy levels 2,900 and 2,780 kcal AME kg−1, respectively. Laying hens fed 2,900 kcal AME kg−1 showed the highest abdominal fat. The results observed in the present study support the hypothesis that the lack of positive effects of Cr yeast supplementation on production performance and egg quality may be related to good management practices, as the birds were not subjected to stressful condition

Uso da somatotropina bovina recombinante - rbST como alternativa para a produção de leite de cabra na entressafra

O experimento desenvolveu-se no Setor de Caprinocultura da FMVZ - UNESP - Campus de Botucatu, com o objetivo de estudar a influência da somatotropina bovina recombinante (rbST - nome comercial: Boostin 250 mg) na produção de leite, nos constituintes do leite, peso e escore de condição corporal de cabras durante o ciclo lactacional. Foram usadas 21 cabras da raça Parda Alpina, com idade entre 1 &frac12; e 4 anos, distribuídas aleatoriamente entre três tratamentos de sete animais cada: controle (T1 - sem rbST); completo, safra e entressafra (T2 - rbST após 45 dias de lactação); e apenas entressafra (T3 - rbST após 154 dias de lactação). Os animais dos três tratamentos receberam a mesma alimentação, que diferiu apenas na quantidade de concentrado, ajustada de acordo com a produção de leite dos animais. Não se observou aumento na produção de leite dos animais tratados, mas a persistência da lactação foi maior nestes animais. Não se observou diferença entre animais controles e tratados quanto aos constituintes do leite (densidade, gordura, EST, lactose e proteína). O peso e o índice de condição corporal também não apresentaram diferença significativa entre animais tratados e controle.The experiment was conducted at the Goat Husbandry Sector of FMVZ - UNESP - Botucatu Campus, with the purpose of studying the influence of recombinant bovine somatotropin (rbST - commercial name: Boostin 250 mg) on the lactation curve, milk production, milk constituents, body weight and body score of goats during the lactation cycle. Twenty-one Alpine Brown goats between 1&frac12; and 4 years old were used, randomly allotted to three treatments with seven animals each: control (T1 - no rbST), complete (T2 - rbST after the milk production peak) and low production season (T3 - rbST during the low production season). All animals received the same diet, excepting the amount of concentrate, which was adjusted according to milk yield. No increase in milk yield was observed in the treated animals, but lactation persistency was greater in these goats. The body weight and the body score also did not show significant difference between treatment and control animals