Proteína bruta em dietas para codornas europeias (Coturnix coturnix).

Abstract

The objective of this study was to evaluate different crude protein (CP) levels on productive performance, carcass yield, noble cuts and edible viscera and the chemical composition of European quail carcasses (Coturnix coturnix), as well as economic analisys and nutrient metabolizability of experiments diets. A total of 250 mixed quails were used in a 35-days experiment. A completely randomized design with five treatments of CP levels (21.0, 22.0, 23.0, 24.0 and 25.0%) were used, with five replicates of 10 birds each. At 14 and 35 days of age, feed intake, weight gain, feed conversion, energy intake and protein intake were evaluated. At 35 days, we evaluated: live weight, absolute weight and carcass yield and noble cuts (chest and legs) and edible viscera (heart, liver and gizzard). The chemical composition of the carcass (DM, moisture, CP, EE and mineral matter) was determined from carcasses from slaughter. The metabolizable trial occurred from the 19th to the 27th day of age of the quails. Were evaluated: metabolizability coefficients of dry mater (DM), crude protein (CP), etheral extract (EE) and gross energy; nitrogen intake (NI), N excretion (NE), N retention (NR) and N metabolism coefficient (NMC). From one to 14 days of age there was an increasing linear effect (P<0.05) for weight gain. From 15 to 35 days, the weight gain presented a linear decreasing effect (P<0.05) and the feed conversion increased linear effect (P<0.05) with the increase of crude protein. The diet with 21.0% CP was bioeconomically superior to those with higher CP levels. The absolute weight and leg yield presented quadratic response (P<0.05) with the addition of crude protein. A decreasing linear effect (P<0.05) was observed for absolute weight and liver yield. The reduction of the CP content improved linearly (P<0.05) the metabolizability of DM and CP. The EE metabolizability coefficient increased linearly (P<0.05) with increasing CP levels. The NI and NE increased linearly with the increase in CP content. The NMC improved linearly (P<0.05) with the reduction of CP levels. Rations with 21.0% crude protein for European quails from one to 35 days of age are recommended.