Resumo

This study evaluated the behavior of broiler chickens subjected to thermal stress during different periods of the day and age of birds. A total of 180 one-day-old male broiler chicks were allocated to three chambers. Each chamber contained five boxes, with 12 chicks/box. Birds were assigned to a completely randomized design. The birds were filmed, and the images recorded every minute during the two periods: morning (from 08:00 to 09:00 h) and afternoon (from 17:00 to 18:00 h), at 7, 14, and 35 d of age. The frequency of the behavioral category (water intake, feed intake, resting, exploration, and comfort) was determined. Data were subjected to variance analysis for mixed models with rearing temperatures (cold, usual, and hot) and age of birds (7, 14, and 35 d) as subdivided plot, and periods of the day (morning and afternoon) as sub-subdivided plot. Birds at cold and usual temperatures showed higher feed intake than those at hot temperature in the morning. Birds exposed to cold and usual temperatures explored the environment less frequently at 35 d when compared with 14 d. However, chickens at hot temperature showed decreased exploration according to the increase of age. Birds spent more time feeding during the morning, regardless of age and rearing temperature. Also, during this period of the day, chickens spent most of the time exploring the environment. The frequency of feed intake and exploration decreases with the increase of age. The similarity of behavior between chickens reared at cold and usual temperatures may be due to a change in the thermal comfort zone of the birds. It suggests that the real thermal comfort temperature is between the two temperature ranges studied (cold and usual).

Resumo

Trade liberalization during the last decades has increased among nations as a result of decreased tariffs. However, during the same period, market agents have created new protection measures to replace such mechanisms in an attempt to promote the domestic economic stability of countries, while expanding and ensuring the trade between nations. Considering that Brazil is the second largest broiler producer and chicken-meat exporter worldwide, the present study proposed to analyze the main barriers imposed on Brazilian chicken meat imports by the ten major importing countries. This is a documentary research with primary and secondary data, of a descriptive-exploratory nature, under a qualitative approach. Semi-structured questionnaires including open- and close-ended questions were sent using Survey Monkey software to the Brazilian Association of Animal Protein. The study revealed that technical requirements are those most often imposed by the importing countries, indicating their concern about the safety, quality, and origin of the imported good. Commercial requirements do not constitute a problem for the growth of Brazilian chicken meat exports; however, the requirements made by some countries preclude the exports.

Resumo

Different levels of glycosaminoglycans (chondroitin sulfate and glucosamine sulfate) and vitamin C were injected in ovo to determine whether additive use influences the incubation parameters and bone characteristics of posthatch chicks. Hatchability was not affected by addition of glycosaminoglycans and vitamin C in ovo. However, chicks that received 4 µg additive showed 2.86% reduction in total mortality when compared with chicks from non-injected eggs. Moreover, tibia area and femur bone mineral density increased in chicks from eggs injected with 2.16 and 6.00 µg of additive, respectively. In ovo feeding with glycosaminoglycans and vitamin C can benefit bone development in embryos and reduce total mortality during the incubation period.(AU)

Resumo

The effect of additives used in the feed of broilers on anaerobic bio-digestion of poultry litter was evaluated. Four diets were used: NC: negative control; DFM: NC + 500 ppm direct-fed microbials (DFM) containing Bacillus subtilis and Bacillus licheniformis; ENZ: diet formulated with an enzyme blend (20 ppm phytase, 200 ppm protease and 200 ppm xylanase); DFM+E: ENZ + DFM. Substrates for the anaerobic bio-digestion were prepared with litter from each treatment, containing 4 % total solids (TS). These were used in 16 continuous bio-digesters with a 2 kg d1 load, to determine the production and potential biogas production and composition during an 85-day period. Influent and effluent samples were collected for the amounts of TS and volatile solids (VS), fiber fraction (neutral detergent fiber [NDF], acid detergent fiber [ADF] and lignin), nutrients (N, P and K), and total and thermotolerant coliforms to be determined. For all treatments a reduction in the following effluents was observed as follows: TS (49, 48, 48 and 50 %) VS (70, 54, 55 and 62 %) NDF (91, 90, 95 and 96 %) ADF (89, 88, 93 and 94 %) and lignin (80, 76, 89 and 88 %). The efficiency of the treatment for coliforms in bio-digesters was higher than 90 % in the 85-day period in all treatment groups. There was a reduction in biogas and methane production when DFM (5500 and 4000 mL) and DFM + E (5800 and 4100 mL) were used, compared to treatments NC (6300 mL and 4400) and ENZ (6400 and 4500 mL). The potential production of reduced TS and VS was higher in ENZ (1:00 and 1.74 106 mL kg1) when compared to NC (0.88 and 1:02 106 mL kg1), DFM (0.80 and 1:40 106 mL kg1) and DFM + E (0.88 1:25 and 106 mL kg1). The additives did not affect the percentage of methane production, and all treatments showed values higher than 70 %. Adding enzymes to the diet of broilers influences the litter characteristics and, as a consequence, increases biogas production. The addition of DFM and DFM + E to broiler diets reduced biogas and methane production.

Resumo

T. Current experiment established different criteria to evaluate the requirements of digestible isoleucine for 22- and 42-day-old broilers by different regression models (quadratic, exponential and Linear Response Plateau) and, in the case of statistical significance, the comparison of means by Duncans test at 5% probability. A total of 1,920 Cobb 500 male broilers were used in an entirely randomized experimental design, with 6 treatments (6 digestible isoleucine levels: 0.6118; 0.6655; 0.7192; 0.7729; 0.8265 and 0.8802%) and 8 replications, with 40 broilers each. Data on performance and carcass characteristics were evaluated. Level 0.7192% of digestible isoleucine was considered standard. The digestible isoleucine level recommended for 22- and 42-day-old broilers is 0.7729%, corresponding to a digestible isoleucine:lysine ratio of 72%.

Um experimento foi realizado com o objetivo de estabelecer critérios de avaliação das exigências de isoleucina digestível para frangos de corte de 22 a 42 dias de idade utilizando-se diferentes modelos de regressão (quadrático, exponencial e de retas segmentadas ou Linear Response Plateau) e em caso de significância estatística, as médias foram comparadas pelo teste de Duncan a 5 % de probabilidade. Foram utilizados 1.920 frangos de corte machos com 22 dias de idade, em delineamento inteiramente ao acaso, com seis tratamentos (seis níveis de isoleucina digestível: 0,6118; 0,6655; 0,7192; 0,7729; 0,8265 e 0,8802%) e oito repetições de 40 aves. Utilizou-se como padrão o nível de 0,7192% de isoleucina digestível. O nível de isoleucina digestível recomendado para frangos de corte de 22 a 42 dias de idade é 0,7729%, correspondente à relação isoleucina:lisina digestível de 72%.

Resumo

Current experiment established different criteria to evaluate the requirements of digestible valine for broilers from 22 and 42 days of age, by different regression models (quadratic, exponential and Linear Response Plateau) and, in the case of statistical significance, the comparison of means by Duncantest at 5% probability. A total of 1,920 Cobb 500 male broilers were used and distributed in an entirely randomized experimental design, with 6 treatments (6 digestible valine levels: 0.7192, 0.7729, 0.8265, 0.8802, 0.9339 and 0.9876%) and 8 replications, with 40 broilers each. Data on performance and carcass characteristics were evaluated. The level of 0.8265% digestible valine was considered standard. The inclusion of 0.816, 0.848 and 0.903% of digestible valine levels, corresponding to digestible valine:lysine ratios of approximately 76.00%, 79.00% and 84.12%, provided best feed intake, weight gain and feed conversion ratio, respectively for broiler from 22 to 42 days of age.

Um experimento foi realizado com o objetivo de estabelecer critérios de avaliação das exigências de valina digestível para frangos de corte de 22 a 42 dias de idade utilizando-se diferentes modelos de regressão (quadrático, exponencial e de retas segmentadas ou Linear Response Plateau). Foram utilizados 1.920 frangos de corte machos com 22 dias de idade, distribuídos em delineamento inteiramente ao acaso, com seis tratamentos (6 níveis de valina digestível: 0,7192; 0,7729; 0,8265; 0,8802; 0,9339 e 0,9876) e oito repetições de 40 aves. Utilizou-se como padrão o nível de 0,8265% de valina digestível. A inclusão dos níveis 0,8160; 0,8484 e 0,9031% de valina digestível proporcionou os melhores resultados de consumo de ração, ganho de peso e conversão alimentar respectivamente.

Resumo

O presente estudo teve por objetivo avaliar o efeito do uso de diferentes níveis de lisina e de metionina + cistina digestíveis durante o período pós - muda, sobre a recuperação corporal, desempenho, qualidade de ovos e morfometria do aparelho reprodutor, fígado e pâncreas de poedeiras comerciais no segundo ciclo de produção. Foram utilizadas 432 poedeiras comerciais da linhagem Isa Brown, com 72 semanas de idade, distribuídas em 54 parcelas, em um delineamento inteiramente casualizado com seis tratamentos e nove repetições de oito aves cada. Durante o descanso foram utilizados seis rações cujos níveis de lisina e metionina + cistina digestíveis variaram: 0,48% de lisina digestível e 0,43% de metionina+cistina digestíveis; 0,48% de lisina digestível e 0,47% de metionina+cistina digestíveis; 0,48% de lisina digestível e 0,52% de metionina+cistina digestíveis; 0,56% de lisina digestível e 0,50% de metionina+cistina digestíveis; 0,56% de lisina digestível e 0,56% de metionina+cistina digestíveis; 0,56% de lisina digestível e 0,62% de metionina+cistina digestíveis.Os dados obtidos foram submetidos à análise de variância e em caso de efeito significativo, a comparação de médias foi realizada a 5% de probabilidade através do teste de Tukey. Os diferentes níveis de lisina e de metionina+cistina digestíveis das dietas de descanso, determinaram efeitos significativos sobre os parâmetros de desempenho das aves. Observou-se que, o nível de 0,56% de lisina e 0,56% de metionina + cistina digestíveis, proporcionou maior peso dos ovos durante o segundo ciclo de produção

This study was conducted to evaluate the effect of using different levels of lysine and methionine + cystine, about the body recovery, performance and egg quality of laying hens in the post molt. It was used four hundred and thirty two hens of Isa Brown strain, with 72 weeks of age, distributed in 54 cages in a completely randomized design with six treatments and nine replicates of eight birds each. During the rest period, were used six diets with different levels of digestible lysine and methionine + cystine. The values ranged from: 0.48% digestible lysine and 0,43% methionine + cystine; 0.48% digestible lysine and 0.47% methionine + cystine; 0.48% digestible lysine and 0.52% methionine + cystine; 0.56% digestible lysine and 0.50% methionine + cystine; 0.56% digestible lysine and 0, 56% methionine + cystine; 0.56% digestible lysine and 0.62% methionine + cystine. The data were subjected to analysis of variance and in case of significant effect, the comparison of means was performed at 5% probability by Tukey test. The different levels of lysine and methionine + cystine diets of rest have determined significant effects on the performance parameters of laying hens. It was observed that the level of 0.56% lysine and 0.56% methionine + cystine, resulted in greater weight of eggs during the second production cycle