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.

This study aimed to evaluate the effects of phytase superdosing in the diet of Japanese quails subjected to different thermal conditions on productive performance, egg characteristics, intestinal morphometry, and physiological parameters. The experiment was conducted in a completely randomized design in a 5 × 3 factorial arrangement, consisting of five phytase levels (0, 500, 1000, 1500, and 3000 FTU/kg) and three temperatures (24, 30, and 36°C), with six replicates of eight birds each. The performance variables evaluated included feed intake, egg production, egg weight, egg mass, feed conversion per egg mass, and feed conversion per dozen eggs. Egg quality was assessed by yolk color, shell thickness, specific gravity, Haugh units, and proportions of yolk, albumen, and shell. Spleen, liver, heart, and abdominal fat weights were also measured, along with duodenum and jejunum morphometry. Data were subjected to analysis of variance, Tukey's test, and regression analysis. Birds kept at 36°C showed lower feed intake compared with those maintained at 24 and 30°C (P < 0.001), with no significant effect of phytase on performance. Supplementation with 1500 FTU increased eggshell thickness at 36°C (P < 0.001). A temperature × phytase interaction was observed for liver weight (p = 0.010), whereas heart weight was higher at 24°C compared with 36°C (P = 0.005). The effects of phytase on duodenal morphometry were temperature-dependent, with the greatest absorptive area observed with 3000 FTU at 30°C (P < 0.001). The temperature of 24°C resulted in the best morphological parameters and the lowest hepatic glycogen index. It is concluded that although quails tolerate temperatures of 36°C, the best productive responses occur at 30°C. Therefore, the use of 1000 to 1500 FTU is recommended, as these levels provided benefits to intestinal morphometry and egg quality.

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.

The evaluation of blood biochemical parameters is an important tool for monitoring the physiological, nutritional, and health status of commercial birds. However, species-specific reference values for laying hens and Japanese quails are still scarce or variable in the literature. The aim of this study was to establish reference values for serum biochemical parameters in these two species. Laying hens (Gallus gallus domesticus) and Japanese quails (Coturnix coturnix japonica) were kept under standardized rearing conditions and fed a balanced diet according to their nutritional requirements. Blood samples were collected by jugular vein puncture, centrifuged to obtain serum, and analyzed using an automated biochemical analyzer. The following parameters were determined: glucose, triglycerides, cholesterol, uric acid, urea, creatinine, aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyltransferase (GGT), alkaline phosphatase, total proteins, albumin, calcium, and phosphorus. For each variable, measures of central tendency, dispersion, and range were calculated. The results revealed differences between species, with quails showing higher mean levels of glucose and cholesterol, while hens presented higher serum calcium values. It can be concluded that the values established in this study provide a reference basis for clinical, diagnostic, and zootechnical applications, as well as supporting future research in physiology and nutrition of laying birds.

Nutritional requirements of Japanese and European quails vary with genetic background, production phase, and production purpose, emphasizing the need to match nutrient supply with physiological demands. Multi-phase programs with balanced digestible amino acid profiles may improve nutrient utilization and productive efficiency. This study evaluated different nutritional programs for Japanese and European quails based on the recommendations of NRC (1994), Silva and Costa (2009), Rostagno et al. (2011, 2017, 2024), and commercial guidelines. A total of 1,800 quails were distributed into three experiments involving growing Japanese quails, laying Japanese quails, and growing European meat-type quails. In each experiment, six nutritional programs were evaluated, with 10 replicates of 10 birds per treatment. Performance, egg quality, feed efficiency, and carcass traits were evaluated according to the experimental phase and type of quail. Data were subjected to analysis of variance, and means were compared using Tukey's test at a 5% probability level (P < 0.05). In growing Japanese quails, the Rostagno et al. (2024) program resulted in the lowest feed intake (12.90 g/quail/day) and feed conversion ratio (3.37 g/g), representing reductions of 15.0% and 6.9%, respectively, compared with the highest values among treatments. In laying Japanese quails, the Rostagno et al. (2024) program resulted in the highest egg production (89.88%) and egg mass (9.51 g/quail/day), as well as the highest specific gravity (1.070 g/cm³) and eggshell percentage (8.90%). In European quails, the multi-phase program based on Rostagno et al. (2024) resulted in lower feed intake (17.3 g/quail/day), better feed conversion (2.6 g/g), and greater carcass yield (75.2%) than the NRC (1994) program. Overall, the Rostagno et al. (2024) program provided the most consistent improvements in feed efficiency across growing quails and enhanced productive performance and selected egg quality traits in laying Japanese quails. These findings highlight the importance of updating nutritional programs according to physiological stage, genetic potential, and productive purpose.