CRESCIMENTO RELATIVO E COEFICIENTES ALOMÉTRICOS DE COMPONENTES DO CORPO DE LINHAGENS DE TILÁPIAS-DO-NILO (Oreochromis niloticus)

Este trabalho foi desenvolvido no setor de piscicultura da Universidade Federal de Lavras, MG, com o objetivo de estudar o crescimento relativo e coeficientes alométricos de componentes do corpo em relação ao peso corporal de tilápias-do-nilo. Amostraram-se, aleatoriamente, peixes pesando entre 150 e 790g durante todo o período de crescimento, sendo 93 da linhagem Chitralada e 78 da Supreme. Após jejum de 24 horas, foram insensibilizados por choque térmico, abatidos (por anóxia), pesados e dissecados para se obter o peso das partes componentes do corpo. Utilizou-se a equação alométrica de Huxley (1932), y = axb e a estatística t (á = 0,01) para testar a hipótese b=1 e classificar o crescimento das partes componentes do corpo em: isogônico (b=1), tardio (b>1) e precoce (b1 e

Productive performance in winter of juveniles of Prochilodus vimboides in earthen ponds under different stocking densities

El objetivo de este estudio fue determinar la densidad de curimba (Prochilodus vimboides) en invierno en estanques, teniendo en cuenta los parámetros de rendimiento del crecimiento y morfométricos. Utilizaron 900 alevines de Prochilodus vimboides con peso inicial de 24,91g ± 0,39, que se distribuyeron en 12 estanques de 100m³ con las densidades de 0,5; 0,75 y 1,0 peces/m², en cuatro repeticiones. Los peces fueron alimentados con ración comercial de proteína bruta del 28% durante el período de prueba. Los datos fueron sometidos a ANOVA y regresión lineal para estimar el mejor ajuste en el 5% de probabilidad. Parámetros productivos como la supervivencia, el peso promedio final, la ingesta total de alimento, conversión alimenticia, coeficiente de longitud estándar de variación (CVCP), coeficiente de variación del peso (CVP) y la tasa de crecimiento específico no se vieron afectados por la densidad así como los parámetros de calidad del agua. La evaluación de los resultados, se puede concluir que la densidad de curimba (Prochilodus vimboides) en invierno en estanques hasta 1 pez/m² es el que ofrece mayor productividad y no representa efectos negativos sobre el rendimiento de los peces.This study sought to evaluate the winter-time stocking density of juvenile curimba fish (Prochilodus vimboides) in earthen ponds, based on growth performance and morphometric parameters, using 900 juveniles of 24.91 + 0.39 g initial weight distributed among 12 nurseries of 100 m² surface area. The densities tested were 0.5, 0.75, and 1.0 fish/m³. The experimental design was completely randomized factorial with split plots and four replications. Four samplings of the fish were conducted, at the beginning and at 45, 90, and 130 d of culture, at each of which, and after a 24-h fast, 10% of the population in each pond was anesthetized and examined. Data recorded included weight, measurements of standard length and head length, and height and width of the body. At the end of the experiment, all the fish were harvested to estimate the production parameters. After first verifying that the data met the basic assumptions for variance analysis, the statistical analysis proceeded. The results indicated that stocking densities did not influence growth performance. Various models were tested for describing the growth of the species and the first-degree linear one gave the best fit, according to Akaike Criterion (AIC). Given these results under the present experimental conditions, it is concluded that the wintertime juvenile stocking density of curimba of 1.0 fish/m³ provided the highest productivity and caused no negative effects on animal performance

PARÁMETROS MORFOMÉTRICOS EN EL RENDIMIENTO DE LOS COMPONENTES CORPORALES DE TILAPIA DEL NILO (OREOCHROMIS NILOTICUS)

The aim of this experiment was to study the influence of the morphometric measurements on characteristics of weight and on body yields of Nile tilapia (Oreochromis niloticus), an experiment was conducted in the pisciculture sector of the Federal University of Lavras, MG. Fingerlings of the Supreme and the Chitralada strains, with an initial weight of 0.5 a 1.0 g, were stocked and reared separately in two ponds (40 m3). During fish growth, samples were taken in 78 individuals of the Supreme strain and 93 of the Chitralada. Measurements of height, width and perimeters on the regions of the fi rst ray of the dorsal and anal fins and on the anterior circumference of the caudal peduncle as well as the head and standard lengths were obtained. In addition, fish were weighted and dissected for obtaining the weights and yields of scales, fins, viscera, head, carcass, skin, fillet and residue. The correlation and grouping analysis of the data obtained revealed a low association degree between the morphometric measurements with the yelds of body components. There was a similarity between head and standard lengths and between height and perimeter of each region. The regression analysis was accomplished for body yelds as related with the morphometric relationship by backward method. The relation between the first-ray anal fin width and CP (LC2/CP) and between the first-ray dorsal f n and LC2 (AC1/LC2) were related to carcass (RCAR) and fillet (RFSP) yields, respectively. These yields were estimated as, RCAR = 43.2426 + 79.6399 LC2/CP (R2=0.096) and RFSP = 36.028 – 1.7415 AC1/LC2 (R2 = 0,014). The morphometric relationship was that better explained the yeld of body components had have the measurements LC2/CP and AC1/LC2, respectively, of the carcass and fillet yelds.Con el propósito de estudiar los efectos de los parámetros morfométricos en el rendimiento corporal de la tilapia del Nilo (Oreochromis niloticus), se realizó este trabajo en la Universidad Federal de Lavras-MG, Brasil. Fueron mantenidos 1000 juveniles de linajes Supreme y Chitralada, con peso inicial entre 0,5 y 1,0 g, en separado, en dos tanques de cemento (40 m3). Fueron retiradas muestras y las medidas del alto, ancho y perímetros de las regiones del primer radio de las aletas dorsal, anal y de la circunferencia anterior del pedúnculo caudal, así como el largo de la cabeza y longitud total, fueron obtenidas de 78 peces de linaje Supreme y 93 de Chitralada. Los peces fueron pesados y disecados para obtención de los rendimientos de escamas y aletas, vísceras, cabeza, canal, piel, filete y residuo. Fueron hechos los análisis de correlación, el agrupamiento de variables en el dendograma y la regresión múltiple de los datos por el método backward para el estudio de la variación en los rendimientos corporales. Los rendimientos de los componentes corporales, en general, están poco relacionados con las medidas morfométricas. Los rendimientos de la canal y fi lete fueron calculados por las ecuaciones de regresión: RCAR = 43,2426 + 79,6399 LC2/CP (R2=0,096) y RFSP = 36,028 – 1,7415 AC1/LC2 (R2 = 0,014). Los análisis de regresión indicaron que el ancho a nivel del primer radio de la aleta anal, con relación a largura padrón (LC2/CP) y la altura a nivel del primer radio de la aleta dorsal, con relación al ancho del primer rayo de la nadadera anal (AC1/LC2) contribuyeron para la variación, respectivamente, en los rendimientos de canal y filete

Rendimento do processamento de linhagens de tilápias (Oreochromis niloticus) em função do peso corporal Process yield of tilapias (Oreochromis niloticus) strains in function of body weight

Com o objetivo de avaliar os rendimentos do processamento de linhagens de tilápias em função dos pesos de abate, um experimento foi conduzido no setor de piscicultura da Universidade Federal de Lavras, M.G. - Brasil. Foram utilizados 93 peixes da linhagem Chitralada e 78 da Supreme, pesando entre 150 e 790 g. Os peixes foram cultivados em dois tanques de alvenaria de 40 m², sendo alimentados com ração comercial fornecida de acordo com a biomassa e a temperatura da água. A temperatura e o oxigênio da água foram tomados diariamente, no início do dia e no final da tarde, e o pH aferido semanalmente. Com o crescimento dos animais, amostras aleatórias foram tomadas. Nas amostragens, os peixes foram abatidos após terem passado por um jejum de 24 horas e insensibilização por choque térmico. Em seguida, foram pesados e dissecados. A análise de regressão indicou que em pesos mais elevados, a linhagem Chitralada apresenta maior porcentagem de cabeça e rendimento de pele. A linhagem Supreme apresentou maior peso de carcaça, filé e resíduos, sendo mais expressivos em pesos superiores a 500 g e menor valor à maturidade para a % de vísceras. Conclui-se que as duas linhagens possuem crescimento das partes componentes proporcional ao aumento do peso corporal, e este aumento não altera o rendimento desses constituintes. A linhagem Supreme apresentou maiores rendimentos de carcaça e filé do que a Chitralada, sendo a mais indicada para a produção e comercialização de filés mais pesados.<br>With the objective of evaluating the yield processing of tilapia strains in function of body weight, an experiment was carried out at the Fish Culture of the Animal Sciences Department, Federal University of Lavras, M.G. - Brazil. A total 93 fish of the Chitralada strain and 78 of the Supreme strain, weighting between 150 and 790 g were used. The fish were cultivated in two tanks of 40 m², fed with commercial ration supplied according to the biomass and water temperature. The water temperature and oxygen were evaluated every day, at the early morning and at the late afternoon, and the pH checked weekly. During the fish growth, random samples were taken. After 24 hours of fasting, the fish were insensibilized (thermal shock), slaughtered (anoxia), weighted and dissected. The regression analysis showed that in higher weight, the Chitralada strain presented higher head percentage and skin yield. The Supreme strain presented higher carcass, fillet and residue weights, being more expressive in body weights superior to 500 g and smaller limiting value for the percentage of viscera. It was concluded that the two strains have growth of body parts proportional to the increase of the body weight, and this increase does not modify the parts yield. The Supreme strain showed more carcass and fillet yield than Chitralada, and is should be indicated for production and commercialization of heavier fillet

Direct and indirect effects of measures and reasons morphometric on the body yield of Nile tilapia, Oreochromis niloticus - doi: 10.4025/actascianimsci.v35i4.19807

The study was carried out with the objective of verifying which measures and morphometric ratios are more directly related to the body yield of Nile tilapia, Oreochromis niloticus, in two weight classes. Data were analyzed from 257 specimens of tilapia divided into two weight classes: p1 = 400 to 599 g and p2 = 600 to 900 g. The morphometric measurements standard length (SL), head length (HL), body height (BH) and body width (BW), and the ratios of these measures (HL / SL, BH / SL, BW / SL, HL / BH, BW / BH, BW / HL) were evaluated. The following body yields were calculated: carcass (RCAR), fillet (RFILE) and head (RCAB). The data were initially submitted to the "stepwise" procedure to eliminate problems of multicollinearity among the morphometric variables, then the correlations between the dependent variables (body yield) and the independent variables (measured and morphometric relationships) were calculated. Later, these correlations were divided into direct and indirect effects through path analysis, and the direct and indirect contributions of each variable measured in percentage terms. The morphometric ratio BW/HL, for both weight classes, was the variable most highly correlated and with the highest direct effect on RFILE and RCAB, showing to be the most important morphometric variable studied for tilapia carcass trait determination.  

Efeito do peso de abate nos rendimentos do processamento da piracanjuba (Brycon orbignyanus, Valenciennes, 1849) Effect of body weight on processing yields of piracanjuba (Brycon orbignyanus Valenciennes, 1849)

Objetivou-se, com o presente trabalho, avaliar o efeito do peso de abate sobre os rendimentos do processamento do peixe teleósteo piracanjuba (Brycon orbignyanus, Valenciennes, 1849). Inicialmente, alevinos com peso médio de 12 g, oriundos da Estação Experimental da Usina Hidrelétrica de Itutinga, foram estocados e cultivados em um viveiro de terra na Estação de Piscicultura do Departamento de Zootecnia da Universidade Federal de Lavras. Ao final de 18 meses de cultivo, 121 peixes foram insensibilizados, abatidos, pesados e dissecados, para a determinação das porcentagens de cabeça (%CAB), nadadeiras (%NAD), vísceras (%VIS), pele com escamas (%PE), e resíduos da filetação (%RF) e dos rendimentos de carcaça (RCAR) e de filé sem pele (RFSP), em relação ao peso de abate. Para as análises de variância, os dados obtidos foram agrupados em 4 classes de peso (CP1=515 g a 629 g; CP2=630 g a 744 g; CP3=745 g a 859 g; e CP4=860 g a 975 g) e as equações de regressão estimadas em função do peso médio de cada classe. Não foi constatado (P>0,05) efeito de classe de peso sobre RCAR, %NAD e %PE. Por outro lado, observaram-se efeito linear do peso de abate sobre %CAB (PThe objective of this study was to evaluate the effect of body weight on processing yields of a teleost fish piracanjuba (Brycon orbignyanus, Valenciennes, 1849). Firstly, fingerlings were reared in ponds in the Fish Culture of the Animal Sciences Department, Federal University of Lavras, M.G. - Brazil, for 18 months. Then, 121 fishes were insensibilized, slaughtered, weighed and dissected, in order to determine the percentages of head (%CAB), fins (%NAD), visceras (%VIS), skin with scales (%PE), and fillet residues (%RF), and the carcass yield (RCAR) and fillet without skin yield (RFSP), in relation to body weight. For analyses of variances, data were distributed over four weight classes (CP1 = 515 to 629g; CP2 = 630 to 744g; CP3 = 745 to 859g; and CP4 = 860 to 975g) and the regression equations were estimated in function of mean weight of each class. There was no effect (P>0,05) of weight class on RCAR, %NAD and %PE. However, a linear effect of body weight on %CAB (P<0,01), %RF (P<0,01) and RFSP (P<0,09) and a quadratic effect on %VIS (P<0,05) were observed. The %CAB and %RF decreased while RFSP and %VIS increased, with the increase of body weight. Based on these results, it can be concluded that heavier piracanjubas provide larger RFSP, smaller %CAB and smaller %RF. The smaller %CAB on heavier fish did not increase RCAR, as expected probably because of the increase on %VIS