Parámetros genéticos para características de crecimiento, canal, calidad y espinas intramusculares en cachama blanca (Piaractus brachypomus) / Genetic parameters for growth, carcass, quality and intramuscular spine traits in white blanca (Piaractus brachypomus)

RESUMEN Los temas de la acuicultura en los que se requiere innovación e investigación están orientados al mejoramiento y al conocimiento genético de especies nativas. En este sentido, el presente estudio se concentró en estimar heredabilidades, correlaciones genéticas y fenotípicas para características de crecimiento, canal, calidad y espinas intramusculares derechas (EIMD), en cachama blanca (Piaractus brachypomus). La progenie de 12 hembras y 24 machos por fertilización artificial de una hembra por dos machos, es decir, doce familias de hermanos medios, fueron analizados por medio del paquete estadístico SAS 9.4 (SAS®, 2014). Se asumió un modelo lineal general univariado, con inclusión de los efectos fijos, como factores de entorno, estanque y edad y factores genéticos, como efectos aleatorios. Las heredabilidades, en general, para las variables de crecimiento, mostraron valores de medios a altos; para las variables de la canal presentaron valores bajos a medios; para las variables de calidad fueron bajos y, de particular interés para la EIMD, la magnitud de la estima fue de 0,11 ± 0,15. Las correlaciones estuvieron, generalmente, cercanas a la unidad entre características de crecimiento. Estas fueron significativamente positivas para peso corporal, a 180 días de edad, con la mayoría de variables, a diferencia con las variables de calidad, la correlación para rendimiento en canal con EIMD de -0,99 fue encontrada significativamente negativa. Los resultados del estudio destacan el potencial para mejorar características de crecimiento, de canal y de calidad, a través de la explotación de la variación genética aditiva observada.

ABSTRACT The topics of aquaculture in which innovation and research are required are directed towards the improvement and genetic knowledge of native species. In this sense the present study concentrated on the estimation of heritabilities, genetic and phenotypic correlations for growth, carcass, quality and right intramuscular spines (RIMS) in white cachama (Piaractus brachypomus). The progeny of 12 females and 24 males by artificial fertilization of a female by two males, that is to say twelve half-sib families, were analyzed by means of the statistical package SAS 9.4 (SAS®, 2014), assumed an univariate general linear model with inclusion of Fixed effects such as environmental factors, pond and age as fixed effects and genetic factors as random effects. Heritabilities in general for growth variables showed medium to high values; for carcass variables, presented low to medium values; And for the quality variables were low; For the RIMS the magnitude of the estimate was 0,11 ± 0,15. The correlations were generally close to unity between growth characteristics. These were significantly positive for body weight at 180 days of age with most variables unlike quality variables; the correlation for channel performance with RIMS of -0.99 was found to be significantly negative. The results of the study highlight the potential to improve growth, carcass and quality traits through the exploitation of the additive genetic variation observed in this study.

Efeito do peso ao abate nos rendimentos dos processamentos do pacu (Piaractus mesopotamicus) / Effect of body weight on processing yields of Pacu (Piaractus mesopotamicus)

The objective was to evaluate the effect of slaughter weight on the processing efficiency of Pacu (Piaractus mesopotamicus).The fish were cultivated in a soil vivarium and fed commercial feed. After ten months of cultivation, 96 fish were deadened, slaughtered, weighed and dissected to determine the yield of clean body, fillet and percentage of entrails. The weight classes analyzed were: CI - 135 to 285g; CII - 310 to 385g; CIII - 400 to 585g; CIV - 600 to 1.285g. For the variance analysis the data was grouped in four weight classes, and the regression equations were estimated regarding mean weight in each class. No effect of the weight class (P>0,05) was observed on the yield of clean body (RTL). However, there was a linear effect (P<0,05) of the weight classes in slaughter over the fillet yield (RF) and percentage of entrails. Pacus slaughtered in more elevated weight classes had greater filled yield. Thus, the fish destined to the fillet process should preferably be slaughtered at higher weights. The fish cultivated with the objective of being commercialized as a carcass or whole with entrails removed may be slaughtered at lower weights.

Características morfométricas, rendimento e composição do filé de tilápia do Nilo, Oreochromis niloticus, da linhagem tailandesa, local e do cruzamento de ambas / Morphometrics, fillet yield and fillet composition in Nile tilapia, Oreochromis niloticus, strains thai chitralada, brazil local and their hybrid

As características morfométricas, rendimento e a composição do filé foram pesquisadas em tilápia do Nilo Oreochromis niloticus, das linhagens tailandesas chitralada (Tai), local (Local, Norte do Paraná, Brasil), e da proveniente do cruzamento de ambas (Hbr, macho tailandesa x fêmea local). Ao início do experimento os peixes (n:900) apresentavam peso de 0,39+-0,20 e 0,45+-0,15 g e ao final 650,67; 534,25 e 360,00 g para as variedades Tai, Local e Hbr, respectivamente. Foram estabelecidas quatro razões morfométricas, sendo a razão entre altura da cabeça/ comprimento da cabeça da variedade Tai foi maior (P<0,05) quando comparada às duas outras linhagens. A linhagem Hbr apresentou maior rendimento em filé (39,05) (P<0,05) quando comparada à Local (38,00) e Tai (36,51), que não diferiram entre si (P>0,05). A composição centesimal do filé da linhagem Local apresentou menor teor de lipídios (1,88) (P<0,05) quando comparada à Hbr (2,44) e Tai (2,96), que também diferiram entre si, com menor teor de lipídios para a Hbr (P<0,05). O teor em proteína bruta, cinzas e umidade do filé não apresentaram diferenças significativas (P>0,05) entre as variedades

Morphometrics, fillet yield and fillet composition differences were researched in Nile tilapia, Oreochromisniloticus, strain thai-chitralada (Tai), Brazil (Local) Northern Paraná and their hybrid (Hbr, male Thailandx Brazilians female ). The experiment was designed entirely randomly with three treatments (strains) andthree repetitions per treatment in hapa nets in ponds. The initial weights were 0.39 ± 0.20, 0.45 ± 0.22 and0.41 ± 0.15 g for the strains Tai, Bras and Hbr, respectively. At the end of the experiment, the weights were650.67, 534.25 and 360.00 g for the same previous sequence, with statistically significant differencesbetween groups (P<0.05). Four morphometric proportions were established to characterise each group. For the ratio (head height)/(head length), the Tai strain was largest (P<0.05) as compared to the two otherstrains. The other morphometric proportions were not different (P>0.05). The strain Hbr produced(P<0.05) greater fillet yield (39.05%) when compared to Local (38.00 %) and Tai (36.51 %), the latter twowere not different from each other (P>0.05). Considering fillet composition, Local strain had the leastcrude lipid content of (1.88 %), as compared to Hbr (2.44 %) and Tai (2.96 %) which were significantlydifferent (P<0.05). Crude protein, ash and moisture of the fillets were not different (P> 0.05)