Split feeding para codornas japonesa (Coturnix japonica): uma abordagem integrada entre fisiologiae produção

Abstract

Quail farming has become established as an important poultry activity in Brazil, particularly with the rearing of Japanese quails (Coturnix japonica), due to their high productive efficiency and good adaptation to different environmental conditions. However, factors such as air temperature and relative humidity directly influence bird performance and welfare. This study aimed to evaluate the effects of a split feeding diet on physiological variables, productive performance, and internal and external egg quality of Japanese quails (Coturnix japonica). The experiment was conducted at the Poultry Teaching Module of the Department of Animal Science, Center for Agricultural Sciences, Federal University of Paraíba, Campus II, in the municipality of Areia, PB, from August to September 2025, and was approved by the Ethics Committee on the Use of Animals of the Federal University of Paraíba (CEUA/UFPB). Environmental variables included black globe temperature, relative humidity, air temperature, and the black globe temperature and humidity index. Cloacal temperature and surface temperature of the birds were collected. Physiological measurements were taken twice a week at three different times (09:00, 13:00, and 18:00). A total of 192 Japanese quails aged 38 weeks were used, distributed into 4 treatments, with 6 replicates and 8 birds per replicate, totaling 48 experimental units. The experimental design was completely randomized in a 4 × 4 factorial arrangement (four distinct experimental diets and four production phases). The treatments were arranged as follows: T1 – Control diet supplied twice a day; T2 – Morning diet containing 10% more crude protein (CP), 5% more metabolizable energy (ME), and 40% less calcium compared to the control, and afternoon diet containing 10% less CP, 5% less ME, and 40% more Ca compared to the control; T3 – Morning diet containing 20% more CP, 10% more ME, and 50% less Ca compared to the control, and afternoon diet containing 20% less CP, 10% less ME, and 50% more Ca compared to the control; T4 – Morning diet containing 30% more CP, 15% more ME, and 60% less Ca compared to the control, and afternoon diet containing 30% less CP, 15% less ME, and 60% more Ca compared to the control. For egg quality, the following variables were analyzed: shell strength, shell thickness, shell percentage, albumen percentage, yolk percentage, Haugh unit, specific gravity, and yolk color. The results indicated that the birds were subjected to cold stress at certain times of the day, based on the BGHI (69.83) at 07:00, requiring the use of physiological mechanisms for thermoregulation, such as increased feed intake. It was observed that even under stress conditions, among all treatments, moderate split feeding resulted in the best outcomes for egg weight, egg mass, feed conversion per dozen and per egg mass, and improved yolk color. Therefore, it is concluded that moderate split feeding promoted better nutrient optimization, resulting in satisfactory productive parameters.