Nutritive value of cereals in feeds for common carp

Abstract

Four isonitrogenous (gross protein content 32%) and isoenergetic (gross energy content 4 080 kcal/kg) diets were prepared by extrusion to investigate the effects of different cereal grains (barley – diet A, wheat – diet B, triticale – diet C, rye – diet D) as carbohydrate compounds of extruded feeds for carp. The physical and chemical properties of the feeds were established. A 60-day growth test was performed in experimental ponds of 40 m² area. Each diet was fed to three groups of fish (initial average weight 200 ± 10 g). The following rearing effectiveness indices were used in the final evaluation of the growth test: weight gain (WG, %), specific growth rate (SGR, %/d), food conversion ratio (FCR), protein efficiency ratio (PER) and protein retention (PR, %). Conclusions were based on statistical analysis using the Statistica 5.0 package. The results obtained in the growth test did not show any differences in the evaluated feeds regarding their usefulness in the nutrition of carp (there were no statistically significant differences in the values of fish rearing parameters, P ≤ 0.05). The recorded growth parameters of carp were as follows: WG: 308.48–324.0%; SGR: 2.81–2.92%/d; the feed conversion coefficients were: FCR: 1.43–1.50; PER: 1.75–1.83; PR: 29.54–31.72%.