Effects of feeding diets with zinc-l-selenomethionine on growth performance of broilers subjected to cyclic heat stress.

Limited information exists on the use of zinc-l-selenomethionine (Zn-L-SeMet) in broiler diets and its effects on the growth performance, body temperature, mortality rates, blood profile, and gene expression, especially when animals are reared under cyclic heat stress conditions. This study aimed to investigate the impact of Zn-L-SeMet in broiler diets from 1 to 42 days of age reared under cyclic heat stress and its effects on growth performance, cloacal temperatures, mortality rate, blood parameters, and insulin-like growth factor 1 (IGF-1) and growth hormone receptor (GHR) gene expression in the breast muscle. A total of 1000 male Cobb 500® broiler chicks were randomly assigned to five treatments: 0, 0.15, 0.23, 0.47, and 1.30 mg/kg of Zn-L-SeMet. Each treatment consisted of 10 replicates with 20 birds each. No statistically significant differences in growth performance were observed from 1 to 21 days of age (P > 0.05). However, from 1 to 42 days, feed intake (FI) and feed conversion ratio (FCR) decreased linearly (P < 0.05). Cloacal temperatures showed no significant effects (P > 0.05), while overall mortality rate exhibited a quadratic response (P < 0.05), with the optimal inclusion level predicted to reduce broiler mortality at 0.71 mg/kg. Triglyceride (TRG) levels increased with 0.97 mg/kg (P < 0.05), and gama-glutamil transferase (GGT) levels decreased with the inclusion of 1.19 mg/kg (P < 0.05). No significant effects on IGF-1 and GHR gene expression were found (P > 0.05). In conclusion, the inclusion of 1.30 mg/kg of Zn-L-SeMet in diets of heat-stressed broilers improved growth performance from 1 to 42 days of age. An inclusion of 0.71 mg/kg reduced mortality rate, while 0.97 mg and 1.19 mg increased and reduced TRG and GGT levels, respectively.

Performance and biometry of the gastrointestinal tract in growing Japanese quails fed bee pollen / Desempenho e biometria do trato gastrointestinal de codornas japonesas em crescimento alimentadas com pólen apícola

The aim of this study was to evaluate the effects of different levels of bee pollen in the diet of growing Japanese quails on productive performance, relative weight of the gastrointestinal organs and length of small and large intestines. A total of 650 one-day-old female Japanese quails were distributed in a completely randomized design with five treatments according to the dietary levels of bee pollen (0.0, 0.4, 0.8, 1.2, and 1.6%), five replicates, and 26 birds per experimental unit. At the end of the experimental period (35 days of age), the performance and relative weight of the gastrointestinal organs and length of small and large intestines were evaluated. The dietary inclusion of bee pollen did not influence (P > 0.05) performance, relative weight of proventriculus, gizzard, pancreas, liver, and large intestine, as well as the length of small and large intestines. However, a linear reduction (P < 0.05) was observed in the relative weight of small intestine as dietary bee pollen levels increased. The inclusion of bee pollen from 0.4 to 1.6% in the diet of growing Japanese quails did neither improve productive performance nor alter the biometry of digestive organs.(AU)

O objetivo deste estudo foi avaliar os efeitos de diferentes níveis de pólen apícola nas dietas de codornas japonesas em crescimento sobre o desempenho produtivo, peso relativo dos órgãos do trato gastrointestinal e comprimento do intestino delgado e grosso. Um total de 650 codornas japonesas, fêmeas, de um dia de idade, foram distribuídas em um delineamento inteiramente casualizado com cinco tratamentos de acordo com os níveis dietéticos do pólen apícola (0,0; 0,4; 0,8; 1,2 e 1,6%), cinco repetições e 26 aves por unidade experimental. Ao final do período experimental (35 dias de idade), o desempenho e o peso relativo dos órgãos do trato gastrointestinal e o comprimento do intestino delgado e grosso foram avaliados. A inclusão dietética de pólen de abelha não influenciou (P > 0,05) o desempenho, peso relativo do proventrículo, moela, pâncreas, fígado e intestino grosso, bem como o comprimento do intestino delgado e intestino grosso. Entretanto, uma redução linear (P < 0,05) foi observada no peso relativo do intestino delgado de acordo com o aumento dos níveis de pólen apícola. A inclusão dietética de 0,4 a 1,6% de pólen apícola para codornas japonesas em crescimento não melhorou o desempenho produtivo e não alterou a biometria dos órgãos digestivos.(AU)