Determination of nitrogen content in manure from quails raised under thermoneutral conditions and heat stress

Raising quail for meat production has great potential in Brazil, creating a need for studies of the needs of this species in tropical climates with regard to the micro-environment required for bird comfort and the environmental impacts of the waste produced. It is important to know the nutrient composition of quail manure, such as nitrogen (N) concentration, so that it can be used appropriately, e.g. the use of manure as a fertiliser requires a knowledge of the specific nutrients required to meet crop needs without exceeding acceptable levels in the soil. Hence, the aim of this study was to characterise and analyse the total N concentration in excreta collected from quails (Coturnix coturnix coturnix) raised in climate chambers under thermal comfort conditions and heat stress from the age of 1 day to 5 weeks. The study was conducted in two phases: in phase 1, two groups of 180 quails were raised from 1 to 21 days of age at environmental temperatures of 36, 33 and 30°C for weeks 1, 2 and 3 of age, respectively to thermal comfort conditions, and in phase 2, 180 quails were raised from 1 to 21 days of age at environmental temperatures of 42, 39 and 36°C to heat stress. In the second phase, two groups of 60 quails were raised from the age of 22 to 35 days at an environmental temperature of 26°C to thermal comfort and 33°C to heat stress. Feed was offered to the birds ad libidum and the composition was determined according to the growing phase (starter/growing ration: 1 to 21 days; growth/finisher ration: 22 to 23 days), according to the nutritional requirements and feed composition recommended by Silva and Costa (2009) and Rostagno et. al (2011). The total N content in excreta for the two phases was analysed using the Kjeldahl method, with the addition of salicylic acid. Results indicated that there was an increase in the N content of excreta that was directly proportional to age.