Hydroxy-selenomethionine enhances the productivity and egg quality of 50- to 70-week-old semi-heavy laying hens under heat stress.

Oxidative stress significantly compromises the production efficiency of laying hens. It has been reported in literature that selenium (Se) in poultry diets has a positive effect on mitigating these effects. This study has been carried out to evaluate the effects of Se supplementation in feeds, from either an inorganic or a hydroxy-selenomethionine (OH-SeMet) source, on the performance and physiological traits of 50- to 70-wk-old Dekalb Brown laying hens under heat stress, and on their egg quality after different storage durations. The treatments consisted in supplementing 0.3 ppm of Se as sodium selenite (SS; 45%-0.7g/ton) or OH-SeMet (2%-15g/ton) in twelve 16-bird replicates. Supplementation with OH-SeMet resulted in a better performance of the laying hens than with SS: -5% feed conversion ratio and +3.6% of egg mass. A reduction in egg quality was observed with prolonged egg storage, which was mitigated with the use of OH-SeMet in laying hen diets. The use of OH-SeMet increased the antioxidant capacity of the birds, which showed higher glutathione peroxidase levels in the blood, kidneys, liver, and intestinal mucosa, in addition to a higher Se content in the eggs and a greater bone resistance. Thus, supplementing feeds with 0.3 ppm of OH-SeMet to 50- to 70-wk-old semi-heavy laying hens enhances their antioxidant capacity and leads to a higher egg quality and productivity than SS supplementation.

Protein and energy for maintenance and gain of European quail fed different energy sources and housed at two temperatures

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 of three diets formulated with the replacement of CS, corresponding to 15% of the metabolizable energy in the diet, with ISP and SO, two controlled temperatures (26 and 35 °C), and three levels of feed supply (ad libitum, and 70 and 40% of ad libitum intake), with four replicates of six birds. Protein and energy requirements for weight gain were determined from 160 European quail, slaughtered every five days at 10, 15, 20, 25, and 30 days of age. Birds were housed in four groups of 40 birds in a room with thermoneutral temperature (26 °C). The energy sources of the feed and temperatures studied affected protein and energy requirements for maintenance and gain of European quail. Replacing CS energy by 15% of dietary energy with SO results in lower protein and energy maintenance requirements for European quail at both temperatures. The protein and energy weight gain requirements of quail fed SO as an energy source is higher than CS and ISP.(AU)

Order of amino acid inclusion in the diet of DeKalb White laying hens / Ordem de inclusão de aminoácidos na dieta de poedeiras DeKalb White

Three hundred and twenty-four DeKalb White laying hens aged 42 weeks were distributed in a completely randomised design with nine treatments and six replicates of six birds in each treatment. The experiment lasted 112 days. Diets were: T1 = 16.02% crude protein - CP [Met + Lys + Thr + Trp + Val]; T2 = 14.02% CP [Met + Lys + Thr + Trp + Ile + Val]; T3 = 14.02% CP [no amino acid supplementation]; T4 = 14.02% CP [Met + Lys + Thr + Trp]; T5 = 14.02% CP [Met + Lys + Thr]; T6 = 14.02% CP [Met]; T7 = 14.02% CP [Lys]; T8 = 14.02% CP [Thr]; T9 = 14.02% CP [Trp]. Regarding the quality of the eggs, the percentage of yolk and albumen, shell thickness and Haugh unit were not affected by the different diets. The percentage of shell, specific gravity and albumen height showed significant differences. We found that supplementation of only one amino acid in the diet (T7, T8 or T9), with the exception of methionine (T6), worsened performance relative to the control. Supplementation of three amino acids (methionine, lysine and threonine; T5) or four amino acids (methionine, lysine, threonine and tryptophan; T4) worsened egg production and conversion per mass and per dozen eggs; however, feed intake and egg weight and mass were similar to the control treatment. When all amino acids (methionine, lysine, threonine, tryptophan, isoleucine and valine; T2) were supplemented performance was similar to...

Trezentos e vinte e quatro galinhas poedeiras DeKalb White com idades de 42 semanas foram distribuídas em um delineamento experimental inteiramente casualizado, com nove tratamentos e seis repetições de seis aves em cada tratamento. O experimento teve duração de 112 dias. As dietas foram: T1 = 16,02% - PB [Met + Lys + Thr + Trp + Val]; T2 = 14,02% PB [Met + Lys + Thr + Trp + Ile + Val]; T3 = 14,02% de PB [sem suplementação de aminoácidos]; T4 = 14,02% CP [Met + Lys + Thr + Trp]; T5 = 14,02% CP [Met + Lys + Thr]; T6 = 14,02% CP [Met]; T7 = 14,02% CP [Lys]; T8 = 14,02% CP [Thr]; T9 = 14,02% CP [Trp]. Em relação à qualidade dos ovos, a porcentagem de gema e albúmen, espessura de casca e a unidade Haugh não foram afetadas pelas dietas diferentes. A percentagem de casca, gravidade específica e altura do albúmen mostraram diferenças significativas. Verificou-se que a suplementação de apenas um aminoácido na dieta (T7; T8 ou T9), com a exceção de metionina (T6), piorou o desempenho das aves em relação a aves que consumiram a dieta controle. A suplementação de três aminoácidos (metionina, lisina e treonina; T5) ou quatro aminoácidos (metionina, lisina, treonina e triptofano; T4) agravou a produção de ovos e conversão por massa e por dúzia de ovos; no entanto, o consumo de ração e peso dos ovos e massa de ovos, o desempenho foi semelhante ao tratamento controle T1. Quando todos os...

Order of amino acid inclusion in the diet of DeKalb White laying hens / Ordem de inclusão de aminoácidos na dieta de poedeiras DeKalb White

Three hundred and twenty-four DeKalb White laying hens aged 42 weeks were distributed in a completely randomised design with nine treatments and six replicates of six birds in each treatment. The experiment lasted 112 days. Diets were: T1 = 16.02% crude protein - CP [Met + Lys + Thr + Trp + Val]; T2 = 14.02% CP [Met + Lys + Thr + Trp + Ile + Val]; T3 = 14.02% CP [no amino acid supplementation]; T4 = 14.02% CP [Met + Lys + Thr + Trp]; T5 = 14.02% CP [Met + Lys + Thr]; T6 = 14.02% CP [Met]; T7 = 14.02% CP [Lys]; T8 = 14.02% CP [Thr]; T9 = 14.02% CP [Trp]. Regarding the quality of the eggs, the percentage of yolk and albumen, shell thickness and Haugh unit were not affected by the different diets. The percentage of shell, specific gravity and albumen height showed significant differences. We found that supplementation of only one amino acid in the diet (T7, T8 or T9), with the exception of methionine (T6), worsened performance relative to the control. Supplementation of three amino acids (methionine, lysine and threonine; T5) or four amino acids (methionine, lysine, threonine and tryptophan; T4) worsened egg production and conversion per mass and per dozen eggs; however, feed intake and egg weight and mass were similar to the control treatment. When all amino acids (methionine, lysine, threonine, tryptophan, isoleucine and valine; T2) were supplemented performance was similar to...(AU)

Trezentos e vinte e quatro galinhas poedeiras DeKalb White com idades de 42 semanas foram distribuídas em um delineamento experimental inteiramente casualizado, com nove tratamentos e seis repetições de seis aves em cada tratamento. O experimento teve duração de 112 dias. As dietas foram: T1 = 16,02% - PB [Met + Lys + Thr + Trp + Val]; T2 = 14,02% PB [Met + Lys + Thr + Trp + Ile + Val]; T3 = 14,02% de PB [sem suplementação de aminoácidos]; T4 = 14,02% CP [Met + Lys + Thr + Trp]; T5 = 14,02% CP [Met + Lys + Thr]; T6 = 14,02% CP [Met]; T7 = 14,02% CP [Lys]; T8 = 14,02% CP [Thr]; T9 = 14,02% CP [Trp]. Em relação à qualidade dos ovos, a porcentagem de gema e albúmen, espessura de casca e a unidade Haugh não foram afetadas pelas dietas diferentes. A percentagem de casca, gravidade específica e altura do albúmen mostraram diferenças significativas. Verificou-se que a suplementação de apenas um aminoácido na dieta (T7; T8 ou T9), com a exceção de metionina (T6), piorou o desempenho das aves em relação a aves que consumiram a dieta controle. A suplementação de três aminoácidos (metionina, lisina e treonina; T5) ou quatro aminoácidos (metionina, lisina, treonina e triptofano; T4) agravou a produção de ovos e conversão por massa e por dúzia de ovos; no entanto, o consumo de ração e peso dos ovos e massa de ovos, o desempenho foi semelhante ao tratamento controle T1. Quando todos os...(AU)