Effects of vitamin A supplementation on ovarian development of Astyanax lacustris (Teleostei: Characidae) during the non-breeding season.

Vitamin A (VA) is essential for fish reproduction, however, knowledge of VA requirement of broodstock fish is scarce. We investigated the physiological role of VA supplementation in the ovarian maturation of Astyanax lacustris throughout the non-breeding season. Adult females were distributed in five nutritional treatments, which differed by the amount of VA supplemented in a plant-based diet: T1 = 0, T2 = 1800, T3 = 3600, T4 = 7200, and T5 = 14,400 IU kg-1 of VA for 60 days after a period of 16 days feeding on a diet poor in VA to reduce body VA content. Plasma total lipids (TL), lipoproteins, and 17ß-estradiol (E2) levels were measured after 30 and 60 days. Somatic indexes and morphophysiological ovarian parameters were calculated and VA concentration was analyzed in the ovaries and liver after 60 days. VA supplementation did not increase the concentration of this nutrient in the liver and ovaries. E2 plasma level increased in animals fed on 3600 IU kg-1 of VA (T3) after 60 days and females from T5 group presented a higher RF after 60 days. Ovarian development increased after 60 days compared to that after 30 days, confirmed by the higher gonadosomatic index (all groups). The supplementation with the highest VA level increased RF and decreased plasma TL (after 30 days) and low-density lipoprotein (LDL) (after 60 days) concentrations, showing a potential to improve reproduction even during the non-breeding season; however, its nutritional requirements of VA could be higher.

Farelo de trigo e complexo enzimático na alimentação de frangas de reposição / Wheat bran and enzymatic complex in laying hens feed

Foram avaliados os efeitos da inclusão do farelo de trigo (FT) com e sem a suplementação da ração com um complexo enzimático (CE), composto de amilase, protease e celulase, sobre o desempenho de frangas semipesadas (15 semanas de idade) e seu efeito residual na produção de ovos. Foram utilizadas 288 frangas, distribuídas em delineamento inteiramente casualizado, em esquema fatorial 4X2, sendo quatro níveis de FT e dois níveis de um CE na ração: 0 (controle), 10, 20 e 30% X suplementação com 0 ou 50g de um CE/100 kg de ração, resultando em oito tratamentos, com seis repetições. Na fase de crescimento, o consumo de ração, o ganho de peso, a conversão alimentar e o peso vivo foram melhores para as aves que receberam as dietas isentas de FT. A adição do CE diminuiu o consumo de ração nas dietas com 0 e 30% de FT. Durante a fase de produção, o uso do CE na ração de recria sem FTaumentou o peso vivo das aves, mas reduziu no nível de 30% de FT. A produção de ovos diminuiu no nível de 20% de FT quando a dieta foi suplementada com o CE. As conversões alimentares no nível de 10% de FT foram semelhantes ao controle. Observou-se efeito quadrático do nível de FT sobre a conversão por massa de ovos, que foi melhor com 8,01%. Portanto, recomenda-se até 8,01%de inclusão do farelo de trigo na ração de poedeiras semipesadas de 15 a 19 semanas de idade.

This study was carried out with the aim of evaluating the effects of the inclusion of the wheat bran (WB) and the addition of an enzymatic complex (EC), amylase, protease and celullase contained, on the performance of semi-heavily pullets from 14 weeks of age and its residual effect on egg-production phase. 288 pullets were used, distributed in a completely randomized design in a factorial arrangment 4X2, being the following levels of WB in the ration: 0 (control), 10, 20 and 30% X 0 or 50g of a EC/100 kg of diet, resulting in eight treatments, with six replicates of six birds. The EC contained the enzymes amylase, protease and celullase. In the growth phase, FI, WG, FC and LW showed better for the birds that received the diets without FT. The addition of the EC decreased the consumption in the diets with 0 and 30% of WB. During the production phase, the use EC in the level 0% of WB increased LW of the birds, but it reduced in the level 30% of WB. The production of eggs fell in the level of 20% of WB when the diet was supllementing with EC. The feed conversion in the level of 10% of WB was similar to the control. Quadratic effect of the level of WBwas observed on the feed egg-mass conversion, that was better with 8,01%. Therefore, it is recommended up to 8.01% of inclusion of the wheat bran in the ration of semi-heavily pullets from 14 to 19 weeks of age.