SUMMARY. This study evaluated the additive effects of a commercial feed supplementation blend (Ava Cid P)—consisting of humic substances, coated sodium butyrat

Despite the acknowledged advancements in the utilization of phytase dosing, limited research has been conducted on commercial laying hens. To assess the effectiveness of doses of exogenous phytase, a total of 320 laying hens aged between 44 and 64 weeks were utilized. These hens were divided into five treatments, which were then distributed using a completely randomized design with eight replicates, each containing eight birds. The treatments consisted of phytase supplementation levels of 0, 500, 1000, 1500, and 3000 FTU/kg. Quadratic regression equations were utilized to determine the maximum and minimum values for the levels of phytase supplementation. A significant difference was observed in the levels of phytase supplementation, where a quadratic model was fitted to various variables including egg weight (g), egg mass (g/bird/day), feed conversion per egg mass (g/g), yolk concentration (%), albumen concentration (%), shell thickness (μm), shell strength (kgf), specific gravity, and yolk color. Further, an increased supplementation improved the digestive tract of the hens, thereby providing a better villus–crypt ratio. Considering the advantageous effects of phytase dosing, it is recommended to supplement corn and soybean meal-based diets with 1500 FTU/kg of bacterial phytase for laying hens during the 44- to 64-week production period.

The objective of this study was to evaluate whether replacing corn starch (CS) energy with isolated soy protein (ISP) and soybean oil (SO) and the ambient temperature affect the protein and energy requirements for maintenance and gain of European quail. Thus, a total of 432 European quail from 10 to 30 days of age, distributed in a completely randomized design, were used to estimate the protein and energy requirements for maintenance through the comparative slaughter methodology. The treatments consisted [...] ABSTRACT The objective of this study was to evaluate whether replacing corn starch (CS) energy with isolated soy protein (ISP) and soybean oil (SO) and the ambient temperature affect the protein and energy requirements for maintenance and gain of European quail. Thus, a total of 432 European quail from 10 to 30 days of age, distributed in a completely randomized design, were used to estimate the protein and energy requirements for maintenance through the comparative slaughter methodology. The treatments consisted

O objetivo deste estudo foi avaliar o efeito da suplementação com diferentes fontes de metionina sobre o desempenho produtivo e a qualidade da carcaça de codornas europeias (Coturnix coturnix coturnix). Utilizou-se 525 codornas distribuídas em sete tratamentos, com diferentes fontes (DL-metionina, L-metionina e metionina hidroxianáloga - MHA-Ca) e níveis (50 e 100% do requerimento) de metionina, além de um grupo controle sem suplementação. O delineamento foi inteiramente casualizado, com cinco repetições por tratamento. O desempenho das aves foi avaliado com base no consumo de ração, ganho de peso, conversão alimentar, rendimento e qualidade da carcaça. Os resultados demonstraram que a suplementação com L-metionina resultou na melhor conversão alimentar, sugerindo maior biodisponibilidade e eficiência na absorção do aminoácido. A DL-metionina apresentou bom desempenho, sendo uma alternativa viável. A MHA-Ca, quando fornecida em 100% do requerimento, favoreceu o ganho de peso e o consumo de ração, embora tenha mostrado menor eficiência alimentar quando fornecida em 50% do requerimento. A escolha da fonte de metionina deve considerar não apenas o desempenho zootécnico, mas também fatores econômicos e de formulação da dieta. A L-metionina foi a fonte mais eficiente, enquanto a DL-metionina se mostrou uma opção intermediária viável. A MHA-Ca pode ser utilizada com sucesso, desde que formulada corretamente para atender às exigências nutricionais das aves. Estudos futuros podem explorar combinações dessas fontes para otimizar a eficiência alimentar e o custo-benefício das dietas.

Were used 724 quails, with initial weight of 105.05±1.40g to determine the model requirements for European quails 16-36 days old. Were used 384 quails for the maintenance requirement experiment and 240 for the gain requirement experiment and the remaining 100 quails composed the birds of the comparative slaughter. Maintenance requirement: the treatments consisted of four levels of feed offerings (100, 75, 50 and 25% of consumption ad libitum) with four pens and four quails per pen for each climatic environment (18, 24 and 28ºC), being 192 quails for each nutrient under study. Gain requirement: the requirements of the studied nutrients for gain were determined from 240 quails, created and fed ad libitum, being 120 quails for each nutrient studied, that is, 30 quails were slaughtered at 21, 26, 31 and 36 days of age. The quails of the reference slaughter comprise the same as the experiment for determining the maintenance requirement. In conclusion. The prediction equations for estimating the requirements were: 1) Pr (mg/quail/day) = (27.029 + 1.5943 × T) × kg0.75 + 12.24 × WG, in which Pr is the phosphorus requirement, kg0.75 is metabolic weight (kg), WG is weight gain (g/quail/day). 2) Ca (mg/quail/day) = (158.93 - 5.187 × T) × kg0.75 + 23.66 × WG, in which Ca is the calcium requirement, kg0.75 is metabolic weight (kg), WG is weight gain (g/quail/day), T is temperature.