Relação entre energia e proteína digestíveis para matrizes de tilápia do Nilo (Oreochromis niloticus)

• Autor(a) principal: Sousa, Sília Maria de Negreiros
• Data de Publicação: 2012
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações do UNIOESTE
• Texto Completo: http://tede.unioeste.br:8080/tede/handle/tede/1651
• topic: Fecundidade; Fêmeas; Nutrição; Peixe; Proles; Reprodutor; Fecundity; Females; Nutrition; Fish; Offspring; Broodstock; CIÊNCIAS AGRÁRIAS:RECURSOS PESQUEIROS E ENGENHARIA DE PESCA:AQUICULTURA:PISCICULTURA

The goal of this study was to evaluate the effects of different levels of digestible protein (DP) and energy (DE) over growth, breeding performance and offspring quality in females of Nile tilapia (Oreochromis niloticus). Nine food formulae were evaluated using a combination of three DP levels (28, 34 and 40%) and three DE levels (2,800, 3,400 and 4,000 kcal.kg-1) in three repetitions. Fish were kept in net cages along a naturally carved tank. Temperature was measured daily while pH and dissolved oxygen values were taken weekly. The breeding management was carried out in 260 days (September 2010 to April 2010) using a sex ratio of 3 females: 1 male with ten days of resting and four days of mating. Mean weight, standard length, weight gain, condition factor, specific growth rate, feed conversion and survival rate were evaluated in females each 14 days. As for breeding performance, the analyzed parameters were: mean egg weight, egg diameter, absolute fecundity, relative fecundity and mean larval weight at hatching. For that, eggs were collected from oral cavity after mating for subsequent artificial incubation. In January 2011, offspring samples were collected and raised up to 30 days of age to evaluate growth parameters during sex reversal stage. A broodstock sample was dissected to measure visceral-somatic, hepatosomatic and gonadosomatic indexes. Water quality remained adequate to maintain this fish species, but temperature was lower than that recommended for broodstock. The tested food formulae influenced female growth (p<0.05) throughout the experimental period, as well as the visceral-somatic index in the selected month (p<0.05). In relation to reproductive features, the treatments had no effects on egg production (p>0.05). Nonetheless, energy levels affected relative fecundity (p<0.05) and protein levels influenced both egg and larval weight (p<0.05). No differences in the growth of offspring derived from broodstock fed on distinct formulae were detected (p>0.05). Thus, food formulae containing 28% of DP and 2,800 kcal of DE.kg of food -1 are indicated to Nile tilapia once they assure a higher egg production per gram of female without affecting offspring performance