1. This study was conducted to evaluate the protective effect of natural sodium bentonite (NaB) in the prevention of toxic effects of aflatoxins. Five hundred and twenty-eight 1-d-old Ross male broiler chickens were housed in pens (22 chickens per pen) for 42 d. There were 3 inclusion rates of NaB (0, 2.5, and 5 g/kg) and 2 of aflatoxins (0 and 3 mg/kg food). Each treatment had 4 replicates of 22 chickens. 2. All chickens treated with aflatoxin and without bentonite were adversely affected. NaB treatment at 5.0 g/kg improved body weights at 42 d of age by 31.3%, increased food intake by 23.8% and improved productive efficiency by 40.1%. Weights of liver, heart, pancreas and crop and biochemical variables were not affected by dietary NaB. However, serum phosphorous concentration was reduced by 30% compared with chickens that received aflatoxin. 3. NaB caused no adverse effects on chickens that did not receive aflatoxin. 4. It is concluded that NaB at pH 7.9 partially neutralises the effects of aflatoxins on broiler chickens when included at 5.0 g/kg in the diet.

The effects of supplementing canthaxanthin on productive and reproductive aspects of broiler breeders were examined in this study. In total, 360 female pullets and 36 roosters were placed in an open-sided house with 12 pens, each pen with an area of 7.0 m(2) (3.5 × 2.0 m). At 42 wk of age, the breeder hens and roosters were distributed into 2 experimental groups with similar BW and uniformity. From 46 to 66 wk of age, one group received 6 mg/kg of canthaxanthin supplemented in the diet and the other group received the diet without the addition of canthaxanthin (control diet). Body weight was measured every 28 d, the laying rate was calculated weekly, and mortality was evaluated at the end of the study. Twenty-one weekly incubations were performed to evaluate fertility and incubation responses. To evaluate the antioxidant effect of canthaxanthin at different storage times and during the incubation process, eggs from each treatment were subject to thiobarbituric reactive substances analysis. Body weight, mortality, and laying rate were not affected by the inclusion of canthaxanthin in the breeder's diets. An increase in hatchability of total and fertile eggs (P ≤ 0.0001 and P ≤ 0.0003, respectively) in breeders fed canthaxanthin during the experimental period was observed. Canthaxanthin also improved breeder fertility and reduced embryo mortality. This can be attributed to reductions in embryo mortality in the first 48 h of incubation and in the last wk of incubation. No differences were observed in BW and quality of the chicks. A reduction of thiobarbituric reactive substances was observed in yolks from stored hatching eggs produced by breeders fed diets plus canthaxanthin. The same effect was observed in yolks of eggs stored for 4 d and incubated for 7 d. The supplementation of broiler breeder diets with canthaxanthin improved the hatchability rate, fertility, and reduced the presence of thiobarbituric reactive substances in eggs.

RESUMO -Verificou-se o efeito dos sistemas de climatização de aviários sobre a temperatura média corporal de frangos de corte (TMC). Utilizaram-se 610 fêmeas da linhagem Cobb distribuídas em delineamento de blocos ao acaso repetidos no tempo, considerando o dia como critério de bloqueamento, em esquema fatorial 2 × 5, composto de duas orientações solares (Norte-Sul, NS, e Leste-Oeste, LO) e cinco sistemas de climatização (ventilador e nebulização, VN; ventilador com nebulização e sombreamento, VNS; apenas ventilador, V; apenas sombreamento, S; e apenas nebulização, N), de modo que cada tratamento teve sete repetições (dias de coleta). Foram coletados dados meteorológicos para o cálculo de carga térmica de radiação (CTR) e monitoradas as temperaturas de superfície corporal e retal para cálculo da TMC. A associação de ventilação e nebulização melhora significativamente as condições ambientais dos aviários e as condições fisiológicas das aves. Com a utilização adequada de métodos de climatização, é possível a criação de frangos de corte em aviários com orientações solares diversas.Palavras-chave: ambiência, conforto térmico, frangos de corte, temperatura Broiler body surface temperature in function of different thermal control systems in broiler housingABSTRACT -The effect of different thermal control systems on broiler body temperature was evaluated in 610 female broiler chickens, Cobb breed, housed in 10 small scale of aviaries models (treatments). Climate data were collected inside the models and were used to calculate the Thermal Heat Load (THL). Bird surface and rectal temperature were recorded to calculate average body temperature (ABT). Data were always collected from 1:00 and 2:00 pm, the hour of maximum THL inside models. The treatments consisted of a factorial 2 × 5 (two orientations and five models of thermal control) and were analyzed as a randomized blocks design, where the days were blocking criteria. Environment and body temperature data were statically analyzed by Duncan test, with 5% of probability level. The use of forced ventilation associated to misting nozzles improved thermal behavior of the buildings resulting in better broilers physiological conditions. The adequate utilization of thermal control equipments allows to raise broiler chicks in houses with different solar orientation.Key Words: environment, temperature, thermal comfort, broiler chickens IntroduçãoAs aves mantêm a temperatura corporal constante quando a temperatura ambiente é termoneutra. Em condições de alta temperatura, os animais precisam de mecanismos físicos, como o resfriamento evaporativo e a redução do consumo de alimentos. Segundo Brown-Brandl et al. (1997), o aumento na temperatura corporal das aves é resultado de um desbalanceamento entre a perda de calor por meios evaporativos e sensíveis e a produção de calor. Quando a temperatura corporal das aves é comparada à temperatura corporal dos mamíferos, aquela, além de ser mais alta, é variável. A temperatura corporal de aves adultas oscila entre 41 e 42°C. A temperatura d...

No abstract

No abstract