Even though tilapia is of great economic interest, data on the nutritional requirements of amino acids during commercial breeding stages are scarce. So, the aim of this study was to analyse the performance and muscula...Even though tilapia is of great economic interest, data on the nutritional requirements of amino acids during commercial breeding stages are scarce. So, the aim of this study was to analyse the performance and muscular growth of Nile tilapia larvae (Oreochromis niloticus) fed diets containing increasing concentrations of phenylalanine. The experiment took place at the Laboratory of Aquaculture of the Grupo de Estudos de Manejo na Aquicultura (GEMAq) of the Universidade Estadual do Oeste do Paraná (Unioeste), Toledo, PR, Brazil, for 30 days. A total of 450 larvae, with mean initial length of 1.5 ± 0.14 cm and mean initial weight of 0.04 ± 0.004 g, were randomly distributed into 6 treatment groups with 5 repetitions (30 tanks). Each experimental unit consisted of a 30 L tank containing 15 larvae. Six diets were formulated with increasing concentrations of phenylalanine (1.09, 1.24, 1.39, 1.54, 1.69 and 1.84%) and offered four times a day until apparent satiation. By the end of the experimental period, the following productivity indexes were analysed: length, weight, survival, weight gain, uniformity, feed conversion, specific growth rate and protein efficiency ratio. Three fish from each tank were collected for muscular growth analysis and the frequency of small ( 0.05) was observed in the productive performance parameters between the treatment groups. Thus, it can be concluded that the levels of phenylalanine contained in the experimental diets did not influence the performance of Nile tilapia larvae. However, there was more hyperplasia when we put 1.39% of phenylalanine in the diet.展开更多
In one trial 360 gilthead bream fingerlings received two different feed mixtures containing two different levels of protein (diet A 400 and B 360 g?kg<sup>?1</sup>). The average initial live weight was abo...In one trial 360 gilthead bream fingerlings received two different feed mixtures containing two different levels of protein (diet A 400 and B 360 g?kg<sup>?1</sup>). The average initial live weight was about 2.2 ± 0.1 g fish<sup>?1</sup> in each replicate of all treatments. Sixty fish per tank were stocked randomly in 6 fiberglass tanks (1 m<sup>3</sup> each). Fish were fed with experimental diets at rate 8% of the body weight daily. The Amino Acids (AA) content was analyzed in the diets, whole fish and muscle at the end of the growth period (60 days). The results indicated that at the end of experiment gilthead bream fingerlings had reached an average live weight 18.5 and 16.2 g fish<sup>?1</sup> for fish fed diet A and B respectively. Also the increase of protein levels in the feed to 40% caused a significant increase in the content of Indispensable Amino Acid (IAA) and dispensable amino acid (as %v of whole fish and muscle of wet weight). Two methods were subsequently used to estimate the quantitative IAA requirements of gilthead bream fry based on the hypothesis that (a) the dietary requirement pattern of IAA reflected the tissue pattern and (b) the rate of daily deposition in the fish could be equated with the dietary requirement as percentage of 100 g<sup>?1</sup> diet. The quantitative IAA requirement (%) of gilthead bream (Sparus aurata) diets was as follow: Lysine 2.27, Methionine 1.09, Therionine 0.61, Leucine 2.4, Isoleucine 0.47, Histidine1.6, Arginine 1.39, Phenylalanine 1.43, Valine 1.22 and Tryptophane 0.42.展开更多
文摘Even though tilapia is of great economic interest, data on the nutritional requirements of amino acids during commercial breeding stages are scarce. So, the aim of this study was to analyse the performance and muscular growth of Nile tilapia larvae (Oreochromis niloticus) fed diets containing increasing concentrations of phenylalanine. The experiment took place at the Laboratory of Aquaculture of the Grupo de Estudos de Manejo na Aquicultura (GEMAq) of the Universidade Estadual do Oeste do Paraná (Unioeste), Toledo, PR, Brazil, for 30 days. A total of 450 larvae, with mean initial length of 1.5 ± 0.14 cm and mean initial weight of 0.04 ± 0.004 g, were randomly distributed into 6 treatment groups with 5 repetitions (30 tanks). Each experimental unit consisted of a 30 L tank containing 15 larvae. Six diets were formulated with increasing concentrations of phenylalanine (1.09, 1.24, 1.39, 1.54, 1.69 and 1.84%) and offered four times a day until apparent satiation. By the end of the experimental period, the following productivity indexes were analysed: length, weight, survival, weight gain, uniformity, feed conversion, specific growth rate and protein efficiency ratio. Three fish from each tank were collected for muscular growth analysis and the frequency of small ( 0.05) was observed in the productive performance parameters between the treatment groups. Thus, it can be concluded that the levels of phenylalanine contained in the experimental diets did not influence the performance of Nile tilapia larvae. However, there was more hyperplasia when we put 1.39% of phenylalanine in the diet.
文摘In one trial 360 gilthead bream fingerlings received two different feed mixtures containing two different levels of protein (diet A 400 and B 360 g?kg<sup>?1</sup>). The average initial live weight was about 2.2 ± 0.1 g fish<sup>?1</sup> in each replicate of all treatments. Sixty fish per tank were stocked randomly in 6 fiberglass tanks (1 m<sup>3</sup> each). Fish were fed with experimental diets at rate 8% of the body weight daily. The Amino Acids (AA) content was analyzed in the diets, whole fish and muscle at the end of the growth period (60 days). The results indicated that at the end of experiment gilthead bream fingerlings had reached an average live weight 18.5 and 16.2 g fish<sup>?1</sup> for fish fed diet A and B respectively. Also the increase of protein levels in the feed to 40% caused a significant increase in the content of Indispensable Amino Acid (IAA) and dispensable amino acid (as %v of whole fish and muscle of wet weight). Two methods were subsequently used to estimate the quantitative IAA requirements of gilthead bream fry based on the hypothesis that (a) the dietary requirement pattern of IAA reflected the tissue pattern and (b) the rate of daily deposition in the fish could be equated with the dietary requirement as percentage of 100 g<sup>?1</sup> diet. The quantitative IAA requirement (%) of gilthead bream (Sparus aurata) diets was as follow: Lysine 2.27, Methionine 1.09, Therionine 0.61, Leucine 2.4, Isoleucine 0.47, Histidine1.6, Arginine 1.39, Phenylalanine 1.43, Valine 1.22 and Tryptophane 0.42.
