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Japanese quails (Coturnix coturnix japonica) are sensitive to zinc (Zn) deficiency, a mineral essential for growth, development, and bone health. This study evaluated the effects of different levels of Zn in the diet on zootechnical performance, organ and carcass weight, and tibial breakage resistance in quails from 1 to 42 days of age. A 5 × 2 factorial design was used, consisting of five Zn levels (30, 60, 90, 120, and 150 mg/kg) and two thermal environments (thermal comfort and heat stress), with five replicates of 10 birds per treatment. The results indicate an antagonistic relationship between high levels of Zn in the diet (150 mg/kg) and quail performance, where the addition of the highest Zn level impaired performance. On the other hand, supplementation with the available Zn from the basal diet (30 mg/kg) was sufficient to ensure satisfactory weight gain, better feed conversion, and appropriate carcass and liver weights of quails during the initial rearing phase. At 42 days, supplementation with 150 mg/kg of Zn provided greater resistance to tibial breakage, regardless of thermal conditions. These findings highlight the importance of adjusting Zn supplementation according to the needs of quails at different rearing stages. The study emphasizes the need for a balanced nutritional approach, considering both adequate Zn levels and the management of thermal stress. The combination of appropriate Zn levels in the diet and environmental management, especially concerning thermal stress, is crucial to optimizing productive performance, bone health, and the well-being of the birds. Furthermore, the nutritional Zn requirements for quails in the initial rearing phase may be lower than previously established, without compromising performance. Gradual Zn supplementation, according to the needs of the production stage and environmental conditions, is essential to ensure the health and productivity of the birds. [ABSTRACT FROM AUTHOR]

The present study aimed to evaluate the effects of different nutritional plans on meat quails subjected to heat stress. A total of 324 quails male European quails (Coturnix coturnix coturnix) were used, with an average initial weight of 121.48 g ± 3.1 g, distributed in a completely randomized design with nine treatments and six repetitions of six birds each. The diets were evaluated from 22 to 42 days of age, according to the following treatments: T1 - Control diet; T2 - Moderate crude protein (CP) reduction, without amino acid supplementation (AA); T3 - Moderate CP reduction with supplementation of methionine (Met) and cystine (Cys); T4 - Moderate CP reduction with Met, Cys, and lysine (Lys) supplementation; T5 - Moderate CP reduction with Met, Cys, Lys, and threonine (Thr) supplementation; T6 - Severe CP reduction, without AA supplementation; T7 - Severe CP reduction with Met and Cys supplementation; T8 - Severe CP reduction with Met, Cys, and Lys supplementation; T9 - Severe CP reduction with Met, Cys, Lys, and Thr supplementation. The room temperature was maintained at 30°C, with relative humidity at 76.42%, and a black globe humidity index (BGHI) of 82.19. No significant (p > 0.05) effect of protein reduction or amino acid supplementation was observed on live weight, feed intake, carcass weight, yield, breast, legs, heart, and gizzard. However, significant effects were observed on weight gain (p < 0.04), feed conversion (p < 0.05), liver weight (p < 0.001), and liver yield (p < 0.001). In hot environments, crude protein in the diet of meat quails can be reduced from 22 to 17.6%, with adequate methionine supplementation to achieve 0.800% digestible Met + Cys during the growth phase (22–42 days). These nutritional strategies may optimize performance, reduce costs, and provide environmental benefits by decreasing nitrogen excretion. Future research should investigate the interactions between diet, heat stress, and quail performance, focusing on different amino acid combinations and their impacts on bird health and productivity under varied thermal conditions. [ABSTRACT FROM AUTHOR]

Simple Summary: Heat stress in tropical regions significantly affects the production and quality of eggs in laying quails, which is worsened by phytate's antinutritional effects on calcium and phosphorus absorption. Phytase, an exogenous enzyme, can counteract these effects by breaking down phytate and improving mineral availability. This enzyme's use in Japanese quails optimizes calcium absorption and enhances their performance under heat stress. Phytase not only improves productivity but also protects the digestive and reproductive systems, promoting bird welfare and sustainability in poultry production. In tropical and subtropical climate regions, heat stress is one of the main causes of production losses in laying quails, aggravated by the antinutritional effects of the phytate in diet ingredients, which negatively affect the bioavailability of minerals, especially calcium and phosphorus. This situation results in a reduction in production and the quality of eggs from commercial laying quails. Several nutritional strategies are utilized to reduce the adverse effects of high temperatures and antinutritional factors such as phytate. Among these strategies, the use of exogenous enzymes, such as phytase, stands out as a viable alternative. Phytase breaks down phytate molecules, optimizing the absorption of essential minerals and improving productive performance and egg quality under unfavorable conditions. Specifically, it is recommended to use 1500 FTU of phytase, as it not only reduces the effects of thermal stress but also enhances eggshell thickness and calcium absorption. In this context, this bibliographic review sought to produce a document demonstrating the beneficial effects of the phytase enzyme on the hydrolysis of the phytate molecule, the availability of calcium for Japanese quails (Coturnix japonica), and its implications in thermal stress due to heat. [ABSTRACT FROM AUTHOR]

This study was carried out to compare the impact of choline supplementation (available from two sources synthetic and natural) on various dosages in broilers. The mode of choline supplementation, via diet and additional sources, synthetic and natural, and the data of performance, carcass quality, blood parameters, and hepatic steatosis were compared. A total of 1050 day-old male Cobb 500 broiler chicks were randomly assigned to 10 treatments, using a completely randomized design model in a factorial scheme, with 6 replicates per treatment and 25 birds per replicate. Choline was supplemented using three sources: synthetic choline chloride 60% (CC), and two sources of natural choline A (NCA), and B (NCB). The Control treatment did not receive any choline supplementation. The diets were supplemented with low, intermediate and high doses of choline sources (400g/t, 800g/t, and 1200g/t of CC; 100g/t, 200g/t, and 300g/t of both NCA and NCB). Data analysis was performed using a factorial model to investigate the effects of choline supplementation (CC, NCA, NCB) and doses on the measured variables. Overall, the results indicated that the the performance of NCA was better than CC & NCB, specifically the dose of 100g/t of NCA outperformed MAR at 100g/t & CC at 400g/t, leading to a significant increase in body weight gain (85.66g & 168.84g respectively), and a noteworthy (9- & 12-point respectively) improvement in feed conversion ratio. Furthermore, NCA contributed to a reduction in steatosis when contrasted with various NCB & CC doses, likely due to the presence of curcumins and catechins in the natural choline source. These findings demonstrated that NCA supplementation yielded superior results compared to CC and NCB across both performance and liver health aspects in broilers aged 1 to 42 days. In conclusion, NCA can be used to replace the CC 60% without compromise on the zootechnical performance in broilers. [ABSTRACT FROM AUTHOR]

O experimento objetivou estimar as exigências de lisina total e a relação lisina: proteína em codornas, na fase de produção. Foram utilizadas 320 codornas, resultado do cruzamento entre a codorna japonesa e a européia de 60 a 144 dias de idade, com peso vivo médio de 178+12 g, alimentadas com rações contendo 20 e 23% de proteína bruta (PB) e, 0,80; 0,95; 1,10; 1,25 e 1,40% de lisina. O delineamento experimental foi o inteiramente ao acaso em esquema fatorial 2x5 (dois níveis de PB x cinco níveis de lisina), que resultou em dez tratamentos, cada um com quatro repetições de oito aves. As codornas foram submetidas a um programa de luz de 17 horas de duração e alimentadas à vontade. As variáveis estudadas foram obtidas em quatro períodos de 21 dias. Houve efeito quadrático dos níveis de lisina sobre a produção de ovos, sendo a exigência e o consumo, respectivamente, de 1,07% e 287 mg de lisina/dia com 20%PB e de 1,15% e 321 mg de lisina/dia com 23%PB. O nível de 23%PB aumentou o consumo de ração, produção, peso e massa de ovos e também melhorou a conversão alimentar por massa e dúzia de ovos. As relações lisina: PB não foram alteradas, sendo de 5,3 e 5,0%, respectivamente, com 20 e 23% de PB na ração. Os resultados do presente estudo sugerem aumento quantitativo da exigência de lisina de codornas na fase de produção, mas não da relação lisina: PB, à medida que a concentração de PB na ração é elevada.

Foram realizados dois experimentos para determinar o nível ideal de proteína bruta para frangos de corte Ross de ambos os sexos, nas fases inicial (1 a 21) e crescimento (22 a 42 dias de idade). Foram avaliados: o ganho de peso (GP), consumo de ração (CR), conversão alimentar (CA) e características de carcaça. Para cada fase, o delineamento experimental foi em blocos inteiramente casualisados. Na fase inicial, utilizou-se um fatorial 2x6, constituído de dois sexos e seis níveis de proteína bruta (20,00; 20,50; 21,00; 21,50; 22,00 e 22,50%), seis repetições e um total de 1440 aves. Na fase de crescimento, utilizou-se um fatorial 2x5, constituído de dois sexos e cinco níveis de proteína bruta (17,50; 18,00; 18,50; 19,00 e 19,50%), seis repetições e um total de 1200 aves. Os níveis de lisina total utilizados foram 1,27% e 1,16%, respectivamente para as fases inicial e de crescimento. Foram mantidas as relações lisina: metionina+cistina, treonina, triptofano e arginina, levando em consideração o perfil da proteína ideal. Com base nos resultados de desempenho, a exigência de proteína bruta estimada para machos, na fase de 1 a 21 dias foi de 22,42% PB, enquanto que para fêmeas, observou-se efeito linear para GP e CA. Na fase de crescimento, os machos responderam linearmente aos níveis de proteína para CR, CA, rendimento de peito e gordura abdominal, tendo estes resultados melhorados à medida que se aumentava o nível de proteína bruta da ração. Para as fêmeas, verificou-se efeito quadrático do nível dietético de proteína para GP e efeito linear para CA e gordura abdominal. Os níveis de proteína bruta estimados foram: na fase inicial 22,4 e 22,5% e na fase de crescimento 19,5 e 18,5% de PB, respectivamente, para machos e fêmeas.

The objective of this work was to evaluate the effect of protein reduction, with or without the supplementation of limiting amino acids, on the performance and carcass characteristics of meat quails from 22 to 42 days of age in a thermoneutral environment. A total of 324 European quails were randomly allocated into nine diets. The diets were formulated based on the recommended requirement (control) and were differentiated according to crude protein (CP) reduction levels into moderate reduction (10%) and severe reduction (20%). The diets were supplemented or not with limiting amino acids. The diets with severe and moderate protein reduction meeting the methionine + cystine, lysine and threonine requirements led to weight gain equivalent to that of the control quails. The diet with a moderate reduction in CP, with or without meeting the methionine + cystine requirement or meeting the methionine + cystine and lysine requirement, led to the greatest carcass yield and a greater leg weight and were similar to the control treatment. It is observed that supplementation with the crystalline sources of the amino acids is able to improve the performance of the quails, in addition, the attendance of methionine + cystine requirement important factor when the CP levels are reduced. In our studies, diets with 17.5% CP and supplemented with methionine + cystine, lysine and threonine meet the requirements of quails, thus generating a limiting amino acid requirement, so they are recommended for meat quails from 22 to 42 days old housed in thermoneutral environment. [ABSTRACT FROM AUTHOR]

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The goal of this study was to estimate the crude protein (CP) requirement for the maintenance, weight gain and egg production of free-range hens, and produce a predictive protein requirement equation. A linear regression equation of the nitrogen that was retained in the body relative to the production of eggs as a function of different nitrogen intake levels (ad libitum, 80%, 60% and 40% of the original ad libitum intake) provided the nitrogen requirement for maintenance. This relationship was determined at the x-axis intercept, and the efficiency of dietary nitrogen utilisation was expressed by the regression coefficient. The CP requirement for weight gain was estimated as a function of the nitrogen content in the carcass, and the dietary nitrogen utilisation efficiency was found after each week's slaughter. The CP requirement for egg production was determined by comparing egg protein concentrations with the efficiency of egg protein deposition. The requirements and efficiency of maintenance protein utilisation were 4.7 g CP/kg0.75.day and 56%, respectively. Because there were no changes in the live bodyweights and nitrogen contents of bird carcasses, the CP requirement and efficiency value for weight gain were not estimated. The protein requirement and utilisation efficiency for egg production were 0.18 g CP/g egg mass (EM) produced and 62%, respectively. From the requirements that were estimated in the present study, the following equation can be used to predict the protein requirements of free-range hens during the laying phase: CP = 4.7 W0.75 + 0.18 EM (g/bird.day). [ABSTRACT FROM AUTHOR]

Copyright of Revista Brasileira de Saúde e Produção Animal (RBSPA) is the property of Revista Brasileira de Saude e Producao Animal (RBSPA) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Caatinga is the property of Revista Caatinga and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Acta Scientiarum: Animal Sciences is the property of Universidade Estadual de Maringa and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study assessed the effect of both embryonic thermal manipulation and dietary threonine level on the response of broilers inoculated with Salmonella Enteritidis, considering bacterial counts in the cecal contents, intestinal morphology, mucin and heat shock protein 70 gene expression, body weight and weight gain. Thermal manipulation was used from 11 days of incubation until hatch, defining three treatments: standard (37.7°C), continuous high temperature (38.7°C) and continuous low temperature (36.7°C). After hatch, chicks were distributed according to a 3x2+1 factorial arrangement (three temperatures and two threonine levels and one sham-inoculated control). At two days of age, all chicks were inoculated with Salmonella Enteritidis, except for the sham-inoculated control group. There was no interaction between the factors on any analyses. High temperature during incubation was able to reduce colonization by Salmonella Enteritidis in the first days, reducing both Salmonella counts and the number of positive birds. It also increased mucin expression and decreased Hsp70 expression compared with other inoculated groups. High temperature during incubation and high threonine level act independently to reduce the negative effects associated to Salmonella Enteritidis infection on intestinal morphology and performance, with results similar to sham-inoculated birds. The findings open new perspectives for practical strategies towards the pre-harvest Salmonella control in the poultry industry.