ABSTRACT
The objective of this study was to evaluate the effects of different oil sources and alpha-lipoic acid levels on pacus performance, chemical composition of fillets and histological changes in the liver. Were used 480 pacu juveniles (3.35 ± 0.78 g), distributed in 24 experimental units (n = 20). Six treatments were delineated in a completely randomized design (CRD), in a 3x2 factorial scheme, with three sources of oil (soybean, sesame and linseed) and two levels of alpha-lipoic acid (0 and 0.1 %), with four replications. Data were analyzed statistically by analysis of variance (ANOVA) and Tukeys test (5%). Diets containing linseed oil as the only lipid source provided better indices of final body weight and individual weight gain in pacu juveniles. Crude protein content was higher in fish fillets that fed diets without alpha-lipoic acid. Livers histology was not affected by the experimental diets. In conclusion, linseed oil improved final body weight and individual weight gain on pacus, and alpha-lipoic acid did not affect the performance of the animals, however its absence promoted higher levels of crude protein in fish fillets.(AU)
O objetivo do estudo foi avaliar os efeitos de óleos vegetais e níveis de ácido alfa-lipoico sobre o desempenho de pacus, composição química de filés e alterações histológicas no fígado. Foram utilizados 480 juvenis de pacu (3,35 ± 0,78 g), distribuídos em 24 unidades experimentais (n = 20). Foram testados seis tratamentos em delineamento inteiramente casualizado (DIC), no esquema fatorial 3x2, sendo três fontes de óleo (soja, gergelim e linhaça) e dois níveis de ácido alfa-lipoico (0e 0,1%), com quatro repetições. Os dados obtidos foram analisados estatisticamente por análise de variância (ANOVA) e teste de Tukey (5%). As dietas contendo óleo de linhaça como única fonte lipídica proporcionaram melhores índices de peso médio e ganho de peso individual nos juvenis de pacu. O teor de proteína bruta foi maior nos filés dos peixes alimentados com as dietas sem ácido alfa-lipoico. Os fígados de juvenis de pacu não foram afetados pelas dietas experimentais. Conclui-se que o óleo de linhaça promoveu os melhores índices de peso médio e ganho de peso individual em pacus e o ácido alfa-lipoico não afetou o desempenho dos animais, mas a sua ausência promoveu maiores teores de proteína bruta nos filés dos pacus.(AU)
Subject(s)
Animals , Characidae/growth & development , Diet/veterinary , Plant Oils/administration & dosage , Thioctic Acid/administration & dosage , Weight Gain , Chemical Phenomena , Liver , Linseed Oil , Sesame OilABSTRACT
The objective of this study was to evaluate the effects of different oil sources and alpha-lipoic acid levels on pacus performance, chemical composition of fillets and histological changes in the liver. Were used 480 pacu juveniles (3.35 ± 0.78 g), distributed in 24 experimental units (n = 20). Six treatments were delineated in a completely randomized design (CRD), in a 3x2 factorial scheme, with three sources of oil (soybean, sesame and linseed) and two levels of alpha-lipoic acid (0 and 0.1 %), with four replications. Data were analyzed statistically by analysis of variance (ANOVA) and Tukeys test (5%). Diets containing linseed oil as the only lipid source provided better indices of final body weight and individual weight gain in pacu juveniles. Crude protein content was higher in fish fillets that fed diets without alpha-lipoic acid. Livers histology was not affected by the experimental diets. In conclusion, linseed oil improved final body weight and individual weight gain on pacus, and alpha-lipoic acid did not affect the performance of the animals, however its absence promoted higher levels of crude protein in fish fillets.
O objetivo do estudo foi avaliar os efeitos de óleos vegetais e níveis de ácido alfa-lipoico sobre o desempenho de pacus, composição química de filés e alterações histológicas no fígado. Foram utilizados 480 juvenis de pacu (3,35 ± 0,78 g), distribuídos em 24 unidades experimentais (n = 20). Foram testados seis tratamentos em delineamento inteiramente casualizado (DIC), no esquema fatorial 3x2, sendo três fontes de óleo (soja, gergelim e linhaça) e dois níveis de ácido alfa-lipoico (0e 0,1%), com quatro repetições. Os dados obtidos foram analisados estatisticamente por análise de variância (ANOVA) e teste de Tukey (5%). As dietas contendo óleo de linhaça como única fonte lipídica proporcionaram melhores índices de peso médio e ganho de peso individual nos juvenis de pacu. O teor de proteína bruta foi maior nos filés dos peixes alimentados com as dietas sem ácido alfa-lipoico. Os fígados de juvenis de pacu não foram afetados pelas dietas experimentais. Conclui-se que o óleo de linhaça promoveu os melhores índices de peso médio e ganho de peso individual em pacus e o ácido alfa-lipoico não afetou o desempenho dos animais, mas a sua ausência promoveu maiores teores de proteína bruta nos filés dos pacus.
Subject(s)
Animals , Weight Gain , Characidae/growth & development , Diet/veterinary , Thioctic Acid/administration & dosage , Plant Oils/administration & dosage , Chemical Phenomena , Liver , Sesame Oil , Linseed OilABSTRACT
Records from 106,212 Nellore animals, born between 1998 and 2006, were used to estimate (co)variance components and genetic parameters for birth weight (BW), average weight gains from birth to weaning (GBW), average weight gains from weaning to after yearling (GWAY), weaning hip height (WHH), postweaning hip height (PHH) and scrotal circumferences at 9 (SC9), 12 (SC12) and 15 (SC15) months of age. (Co)variance components were estimated by an animal model using multi-trait analysis. Heritability estimates for BW, GBW, GWAY, WHH, PHH, SC9, SC12 and SC15 were 0.31 ± 0.01; 0.25 ± 0.02; 0.30 ± 0.04; 0.51 ± 0.04; 0.54 ± 0.04; 0.39 ± 0.01; 0.41 ± 0.01 and 0.44 ± 0.02, respectively. Genetic correlations between growth traits ranged from 0.09 ± 0.01 to 0.88 ± 0.01, thereby implying that, at any age, selection to increase average weight gains will also increase stature. Genetic correlations between BW and average weight gains with scrotal circumferences were all positive and moderate (0.15 ± 0.03 to 0.38 ± 0.01). On the other hand, positive and low genetic associations were estimated between hip height and scrotal circumference at different ages (0.09 ± 0.01 to 0.17 ± 0.02). The results of this study pointed out that selection to larger scrotal circumferences in males will promote changes in average weight gains. In order to obtain Nellore cattle with the stature and size suitable for the production system, both weight gain and hip height should be included in a selection index.
ABSTRACT
Records from 106,212 Nellore animals, born between 1998 and 2006, were used to estimate (co)variance components and genetic parameters for birth weight (BW), average weight gains from birth to weaning (GBW), average weight gains from weaning to after yearling (GWAY), weaning hip height (WHH), postweaning hip height (PHH) and scrotal circumferences at 9 (SC9), 12 (SC12) and 15 (SC15) months of age. (Co)variance components were estimated by an animal model using multi-trait analysis. Heritability estimates for BW, GBW, GWAY, WHH, PHH, SC9, SC12 and SC15 were 0.31 ± 0.01; 0.25 ± 0.02; 0.30 ± 0.04; 0.51 ± 0.04; 0.54 ± 0.04; 0.39 ± 0.01; 0.41 ± 0.01 and 0.44 ± 0.02, respectively. Genetic correlations between growth traits ranged from 0.09 ± 0.01 to 0.88 ± 0.01, thereby implying that, at any age, selection to increase average weight gains will also increase stature. Genetic correlations between BW and average weight gains with scrotal circumferences were all positive and moderate (0.15 ± 0.03 to 0.38 ± 0.01). On the other hand, positive and low genetic associations were estimated between hip height and scrotal circumference at different ages (0.09 ± 0.01 to 0.17 ± 0.02). The results of this study pointed out that selection to larger scrotal circumferences in males will promote changes in average weight gains. In order to obtain Nellore cattle with the stature and size suitable for the production system, both weight gain and hip height should be included in a selection index.