ABSTRACT 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). 18 onedayold one old chambers boxes 1 chicksbox box chicks/box design filmed from 0800 08 00 08:0 0900 09 09:0 h 1700 17 17:0 1800 18:0 h, , 7 3 water resting determined cold, (7 plot subsubdivided sub However Also usual. . usual) 080 0 08: 090 09: 170 17: 18: (

ABSTRACT. The objective is to evaluate the effects of the inclusion of yerba mate in the diet on the yield and quality of chicken meat stored frozen for 120 days after slaughter. The birds were distributed in a completely randomized design, with four treatments, and eight replications with 25 birds each. The treatments consisted of providing a basal diet with 1, 2, 4, and 6 g kg-1 of ground dehydrated Yerba mate. At slaughter, temperature, pH, and carcass yield were measured. 120 days after meat freezing, measurements of pH, colorimetry, cooking weight loss (CWL), shear force, and water retention capacity were estimated. The parameters evaluated after slaughter showed regression effects on breast and drumstick temperature. Breast temperature showed a decreasing linear effect (R2=0.61). For the variable thigh temperature, there was a negative quadratic effect (R2=0.66). The quality characteristics of breast and drumstick evaluated 120 days after freezing showed an increasing linear effect of drumstick CWL (R2=0.38). Yerba mate can be included in up to 6 g kg-1 in chicken feed without changing pH, color, and meat tenderness after 120 days of freezing, maintaining carcass and cut yields. ABSTRACT 12 design 2 each 1 4 kg1 kg kg- pH measured colorimetry CWL, , (CWL) force estimated R2=0.61. R2061 R R2=0.61 . R2 0 61 (R2=0.61) R2=0.66. R2066 R2=0.66 66 (R2=0.66) R2=0.38. R2038 R2=0.38 38 (R2=0.38) color yields (CWL R206 R2=0.6 (R2=0.61 (R2=0.66 R203 R2=0.3 3 (R2=0.38 R20 R2=0. (R2=0.6 (R2=0.3 R2=0 (R2=0. R2= (R2=0 (R2= (R2 (R

ABSTRACT The purpose of this study was to determine if in ovo feeding with 25(OH)D3 could influence the incubation parameters of bone mineral composition, mineral density, and bone breaking strength in post-hatch broilers. Fertile eggs from Cobb® broiler breeders were either non-injected or injected with 0, 1.2, 2.4, or 3.6 μg of 25(OH)D3/100 μL olive oil at eight days of incubation. The data were subjected to variance analysis using the General Linear Model procedure (GLM) of SAS®. There was a contrast-1 effect (non-injected eggs vs. injected eggs) for tibial bone mineral density and egg mass loss, with higher bone mineral density in non-injected eggs (0.836 mmAl) compared with injected eggs (0.790 mmAl) and lower egg mass loss in non-injected eggs (11.25%) compared with injected eggs (12.10%). Tibial and femur bone mineral density responded quadratically, and injections of 0.47 and 0.68 μg of 25(OH)D3 increased tibia and femur bone mineral density, respectively. Egg mass loss responded quadratically, and 25(OH)D3 injections of 2.21 μg reduced egg mass loss (11.60%). In ovo feeding of 25(OH)D3 can compromise bone mineral density of post-hatch chicken.

RESUMO: Este estudo analisou a eficácia do uso de diferentes níveis de um produto à base de cipermetrina a 6% e citronela a 2%, na produção de frangos de corte e no controle do cascudinho (Alphitobius diaperinus). Um total de 648 pintos de um dia de idade (Cobb®) foram distribuídos em três câmaras com os tratamentos (sem aplicação do produto comercial - controle, e duas concentrações do produto comercial - 2,00 e 3,33g/m2) em oito repetições com 27 aves cada. O produto comercial a base de cipermetrina foi aplicado nas câmaras com um atomizador. A população de cascudinho foi amostrada semanalmente (1, 7, 14, 21, 28, 35 e 42 dias do experimento) usando armadilhas, em três pontos (frente, meio e fundo) de cada parcela. Foram avaliados o desempenho, rendimentos de carcaça e cortes. Aos 21, 28, 35 e 42 dias do experimento, o número de adultos e larvas de cascudinho foi menor nos grupos de tratamento envolvendo 2,00 e 3,33g/m2 do produto quando comparado ao grupo controle. No primeiro e no 14º dia do estudo, o número de cascudinhos adultos foi menor no grupo tratado com 3,33g/m2 do produto em comparação ao grupo controle, embora os resultados não tenham diferido estatisticamente daqueles obtidos com 2,00g/m2 do produto. A conversão alimentar de 1 a 21 dias de idade foi significativa, com os melhores resultados para essa variável quando aplicado 3,33g do produto por metro quadrado e no tratamento controle. Em conclusão, a aplicação do produto comercial em ambas as concentrações (2,00 e 3,33g/m2) foi eficaz no combate a adultos e larvas de Alphitobius diaperinus e, não influenciou o desempenho.

ABSTRACT: This study analysed the effectiveness of using different levels of a product based on 6% cypermethrin and 2% citronella on broiler production and control the lesser mealworm (Alphitobius diaperinus). A total of 648 one-day-old chicks (Cobb®) which were allocated to one of three treatments (no application of the commercial product - control, and two concentrations of the product 2.00 and 3.33g/m2) in eight replicates with 27 birds each. The commercial product, which was based on cypermethrin was applied in the chambers with an atomizer. The lesser mealworm population was sampled weekly (1, 7, 14, 21, 28, 35 and 42 days of the experiment) using traps, at three points (front, middle and back) inside the pen. The performance, carcass and cut yields were evaluated. At 21, 28, 35 and 42 days of the experiment, the number of lesser mealworm adults and larvae was lower in the treatment groups involving 2.00 and 3.33g/m2 of the product than in the control group. On the first and 14th days of the study, the number of lesser mealworms adults was lower in the group treated with 3.33g/m2 of the product compared to the control group, although the results did not differ statistically from those obtained with 2.00g/m2 of the product. In conclusion, the application of the commercial product at both concentrations (2.00 and 3.33g/m2) was effective in combating Alphitobius diaperinus adults and larvae, and the performance was not influenced by treatments.

RESUMO: Condições de manejo pré-abate inadequadas podem comprometer o bem-estar e a produtividade animal. O objetivo deste estudo foi avaliar os índices de bem-estar animal (BEA) durante o manejo pré-abate e quantificar as lesões em carcaça de bovinos submetidos às diferentes densidades de carregamento. Para isto, foram utilizados 270 bovinos Nelore, aos 30 meses de idade, provenientes de três fazendas. Cada fazenda apresentou diferente densidade de carregamento: maior densidade (500kg/m2), densidade intermediária (450kg/m2) e menor densidade (420kg/m2). Foram realizados três carregamentos de cada fazenda, compostos por 30 animais cada. Para análise do BEA e quantificação de lesões nas carcaças bovinas foram considerados 10 animais de cada carregamento. Os índices de BEA foram classificados segundo o critério das cinco liberdades (fisiológica, ambiental, sanitária, comportamental e psicológica). Após o abate, as carcaças foram inspecionadas na linha de rotina e avaliadas quanto à presença de lesões. Foram encontradas diferenças significativas (P<0,001) para todas as variáveis estudadas em função do BEA e das lesões. O melhor índice de bem-estar e o menor peso médio de lesão foi encontrado na densidade de carregamento de 450kg/m2. O maior peso da carcaça foi encontrado na densidade de carregamento de 500kg/m2. Em 100% dos animais nas densidades de carregamento de 500 e 420kg/m2 foram encontradas lesões. Pode-se concluir que a densidade de carregamento de bovino de 450kg/m2 obteve os melhores índices de bem-estar e menor ocorrência de lesões. Este estudo confirma a importância do manejo pré-abate adequado na garantia do bem-estar aos bovinos e, consequentemente, na maior rentabilidade ao produtor e ao frigorífico.

ABSTRACT: Inadequate pre-slaughter handling conditions can compromise animal welfare and productivity. This study aimed to evaluate the animal welfare (AW) indexes during pre-slaughter handling and quantify the carcass lesions of beef cattle submitted to different loading densities. A total of 270 Nellore cattle, at 30 months of age, from three farms were used in the study. Each farm presented a different loading density: higher density (500kg/m2), intermediate density (450kg/m2), and lower density (420kg/m2). Three shipments of cattle from each farm with 30 animals each were used in the AW analysis. Ten animals from each shipment were considered for quantification of carcass bruises. The AW indexes were classified according to the five-freedom criterion (physiological, environmental, sanitary, behavioral, and psychological). After slaughter, the carcasses were inspected in the routine line and evaluated for the presence of lesions. Statistically significant differences (p<0.001) were found for all variables studied as a function of AW and bruises. The best AW index and the lowest mean weight of lesions were found at the loading density of 450kg/m2. The highest carcass weight was observed at the loading density of 500kg/m2. Lesions were found in 100% of the animals at the loading densities of 500 and 420kg/m2. In conclusion, the best AW indexes and the smallest occurrence of bruises were verified at the loading density of 450kg/m2. This study confirmed the importance of adequate pre-slaughter handling to ensure cattle welfare and, consequently, greater profitability for producers and slaughterhouses.

ABSTRACT We aimed to evaluate the performance, nutrient digestibility, and intestinal histomorphometry of broilers fed diet supplemented with chondroitin sulfate and glucosamine sulfate. The experiment was carried out with 320 male broiler chicks distributed in a completely randomized design in a 2×2 factorial scheme (0 and 0.1% chondroitin sulfate and 0 and 0.3% glucosamine sulfate), with eight replications of 10 birds. Performance was evaluated at 7 and 21 days of age, nutrient digestibility of the diet was performed from 18 to 21 days of age, and small intestine histomorphometry was evaluated at 21 days of age. Broilers fed diet supplemented with 0.3% glucosamine sulfate showed high final weight and weight gain. A significant interaction was observed between sulfates for digestibility coefficients of nitrogen, mineral matter, and calcium. The use of 0.1% chondroitin sulfate without glucosamine sulfate resulted in a reduced digestibility of nitrogen but increased digestibility of total minerals and calcium. Diets without chondroitin sulfate with 0.3% glucosamine sulfate increased the digestibility coefficients of mineral matter and calcium. A significant interaction was found for jejunum villus height, which was higher in broilers fed diet supplemented with 0.3% glucosamine sulfate, regardless of the inclusion of chondroitin sulfate. Thus, supplementation with glucosamine sulfate in broiler diets contributes to high weight gain and villus height. Sulfates used in isolation promote high digestibility of minerals.

ABSTRACT This study aimed to identify the influence of climate pattern and rearing conditions on broiler carcass condemnations observed during processing. We evaluated the registered data of 2015 from the federal inspection files in all broiler slaughterhouses located in the state of Mato Grosso do Sul, Midwestern Brazil. The percentages of condemnations by airsacculitis, cellulitis, dermatosis, ascites syndrome, total carcass condemnations, and average broiler weight at 42 days were analyzed. Data were associated with housing systems and season of the year in which each flock was reared. Two-way ANOVA was applied to the data in a completely randomized design 4×3 (four seasons and three houses) and compared by Tukey's test. The results indicated that the housing system did not affect the studied condemnations, and seasons of the year did not change condemnation by airsacculitis; however, the other pathologies leading to carcass condemnations were affected by season. Condemnations by cellulite were higher during summer than in winter. For dermatosis, the maximum index appears during summer and the lowest during winter and spring. The ascites syndrome presented the smallest index in summer and winter, and the minimum value was found in spring. The average bird weight was higher in autumn than in winter and spring. Type of broiler rearing did not affect the carcass condemnation index. Summer was the most detrimental period regarding the condemnation rates for the pathologies studied, mainly cellulitis and dermatosis, while the highest average weight of birds was found during autumn and spring.

RESUMO A erva mate ( Ilex paraguariensis) possui em compostos orgânicos com propriedades de modificar a composição química de carne de frangos de corte, desta maneira este estudo avaliou a influência da erva mate sobre a composição química e o perfil lipídico de carne de peito, coxas e sobrecoxas de frangos de corte. Foram utilizados 500 pintainhos de corte distribuídos em um delineamento inteiramente casualizado com inclusões de erva mate nas dietas (0.1; 0.2; 0.4, e 0.6%) com quatro repetições de 25 aves em cada tratamento, criados de 1 a 42 dias de idade para posterior abate e análises da composição de cortes cárneos. A adição de erva mate não afetou a composição química e o perfil lipídico dos peitos de frangos, porém a composição da carne de sobrecoxas foi afetada. Foi observado efeito da adição da erva mate em ácidos graxos saturados, insaturados, monoinsaturados e poli-insaturados na carne de sobrecoxas de frango, destacando-se a redução nas concentrações de ácidos graxos saturados e o aumento das concentrações dos ácidos poli-insaturados, em especial Linolênicoe Eicosapentaenoico, demonstrando assim o potencial da erva mate em alterar o perfil lipídico da carne de aves.

SUMMARY Yerba mate ( Ilex paraguariensis) has in its composition organic compounds wich can modify chemical composition of broiler meat. This study aimed to evaluate the influence of yerba mate in chemical composition and lipid profile of broiler breast and thigh meat. The trial was conducted using 500 broiler chicks distributed in a completely randomized design with four treatments (0.1; 0.2; 0.4, and 0.6%) and five replicates with 25 chicks each. The chicken were raised form 1 to 42 days old and slaughtered for analysis of breast and thigh meat. The addition of mate did not affect the chemical composition and the lipid profile of the chicken breast, however, the composition of the meat of thigh meat was affected. It was observed effect of the addition of the yerba mate to saturated, unsaturated, monounsaturated and polyunsaturated fatty acids in the chicken meat. Stands out the reduction in saturated fatty acid concentrations and the increase in the concentrations of polyunsaturated fatty acids, especially Linolenic and Eicosapentaenoic, thus demonstrating the potential of mate grass in altering the lipid profile of poultry meat.

ABSTRACT The large majority of broiler houses use two types of systems: dark-house system - DHP, and tunnel with curtain system - ATC. The objective of the present study was to evaluate the association and the prevalence of locomotion issues in the broiler commercial farming systems (DHP and ATC). For assessing the thermal environment and the litter quality, a completely random design was adopted using two factors (broiler houses, DHP and ATC) with 12 repetitions. To study the surface temperature of the broiler breast, and the locomotion ability (gait score) a completely randomized design was adopted in a double factorial scheme 2 × 2 (two houses typology vs. sex) with 24 repetitions. To verify whether the type of house and the sex were associated to broiler locomotion problems due to the lack in walking ability, and the presence of medular compression (spondylolisthesis) the logistic regression was applied to the analysis: odds ratio and relative risk. The chance of the poultry to present inability of walking was 3.80 times higher in the male population. The risk factor associated with the lack of walking ability of the poultry was correlated to the tunnel house with curtains, presenting a relative risk 1.58 times higher when compared to the dark-house with walls. There was not the relative risk of medular compression (spondylolisthesis) neither was found an association between the poultry’ sex and the type of house. The reduction in the male broiler locomotion ability might be associated with the rearing in the housing tunnel with curtains.

ABSTRACT 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.

ABSTRACT The objective of this study was to evaluate the effect of chamomile extract on Japanese quail on their performance, animal behavior, tonic immobility, body injuries, and surface temperature. The trial was conducted using 108 quail distributed in a completely randomized experimental design, with three treatments (0, 2.5, and 5.0 g chamomile/kg of feed), six replicates, and six birds per treatment, evaluated in six measures repeated in time (14, 28, 42, 56, 70, and 84 days of trial). The inclusion of chamomile presented a quadratic effect on sitting behavior, estimating the inclusion of 1.8 g chamomile/kg to maximize this behavior. There was a decreasing linear effect for aggressive pecking, that is, the higher the inclusion of chamomile in the diet, the lower the expression of this behavior. The inclusion of 1.8-5.0 g chamomile/kg in a Japanese quail diet reduces the behavior of aggressive pecking, in addition to keeping the birds seated longer. These results are innovative because they show in the literature for the first time that chamomile supplemented in Japanese quail diets has the capacity to modulate the behavior of the quail, leading to an improvement in the welfare of quail raised in cages.

RESUMO. Objetivou-se avaliar a ação da enzima fitase em rações formuladas com variação na proteína bruta sobre o desempenho e a qualidade de ovos de poedeiras comerciais. Foram alojadas 336 poedeiras comerciais, em esquema fatorial 3 x 2, com sete repetições e oito aves em cada gaiola. Os tratamentos constituíram de três níveis de proteína bruta (17, 15 e 13%) e dois níveis da enzima fitase (0 e 500 FTU kg-1 ração), distribuídos em delineamento inteiramente casualizado. Durante cinco períodos, de 28 dias cada, foram avaliados o consumo de ração, a produção de ovos, a conversão alimentar por dúzia e por quilograma, o peso e a massa de ovos, a gravidade específica, a espessura de casca e a unidade Haugh. Constatou-se piora no desempenho das poedeiras comerciais alimentadas com 13% de proteína bruta na ração, independente da adição da fitase. Porém, em 15% de proteína bruta, a inclusão da fitase não afetou a conversão alimentar e o peso dos ovos das aves. A inclusão da fitase proporciona resultados de qualidade de ovos e desempenho iguais para os níveis de 17 e 15% de proteína bruta na ração. Não se recomenda o nível de 13% de proteína bruta, com ou sem fitase, na ração de poedeiras semipesadas.

ABSTRACT. The aim of this study was to evaluate the action of the phytase enzyme in diets formulated with variations in the crude protein content on performance and egg quality of commercial layers. A total of 336 commercial layers were housed at eight birds per cage in a 3 × 2 factorial arrangement with seven replicates. Treatments consisted of four crude-protein levels (17, 15, and 13%) and two enzyme levels (0 and 500 FTU kg-1 diet), distributed in a completely randomized design. Feed intake, egg production, feed conversion per dozen eggs and per kilogram, egg weight and mass, specific gravity, eggshell thickness, and Haugh unit were measured over five 28-day periods. The performance of commercial layers fed the diet containing 13% crude protein worsened, irrespective of phytase addition. However, at 15% crude protein, phytase inclusion did not affect feed conversion or egg weight. Inclusion of phytase leads to equal egg-quality and performance results at the dietary crude protein levels of 17 and 15%. The crude protein content of 13%, with or without phytase, is not recommended for the diet of brown-egg layers.

ABSTRACT 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 d−1 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 kg−1) when compared to NC (0.88 and 1:02 106 mL kg−1), DFM (0.80 and 1:40 106 mL kg−1) and DFM + E (0.88 1:25 and 106 mL kg−1). 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.

O presente estudo teve por objetivo avaliar o efeito da utilização de níveis crescentes do gluconato de sódio sobre o desempenho, o rendimento de carcaça e de partes e a morfometria da mucosa intestinal de frangos de corte de 22 a 42 dias de idade. Foram utilizados 1200 frangos de corte da linhagem Cobb, distribuídos em um delineamento inteiramente casualizado, envolvendo cinco tratamentos (0,00; 0,10; 0,20; 0,30 e 0,40% de gluconato de sódio) com oito repetições de 30 aves cada parcela. As variáveis foram submetidas à análise de variância e em caso de significância estatística foram realizadas análises de regressão pelos modelos polinomial e quadrático. A inclusão do gluconato de sódio não afetou o desempenho e o rendimento de carcaça e de partes. Entretanto, exerceu efeito benéfico sobre a morfometria da mucosa intestinal do duodeno e do jejuno.

The objective of this experiment was to evaluate the effect of the sodium gluconate addition on performance (feed intake, body weight, weight gain, feed conversion, livability and productive efficiency), carcass characteristics (carcass, breast, thigh and drumstick, wing and back yield), and morphometry of duodenum, jejunal and ileum of broilers from 22 to 42 days of age. A total of 1,200 Cobb male broilers were distributed in a completely randomized design with five treatments (0.00, 0.10, 0.20, 0.30 and 0.40% sodium gluconate), and eight replications of 30 broilers each. The inclusion of sodium gluconate did not affect the broiler performance and carcass characteristics. However, the morphometry of duodenum and jejunal mucosa showed beneficial effects.

Cento e oitenta poedeiras comerciais Isa Brown, com 60 semanas de idade, foram distribuídas em delineamento inteiramente ao acaso, em esquema fatorial 2 õ 2, com dois níveis de fitase (0 e 500 ftu/kg de ração) e dois de farelo de girassol (4 e 8%), totalizando cinco dietas, avaliadas com seis repetições de seis aves. As dietas foram formuladas a partir de uma ração controle, à base de milho e farelo de soja, isenta de fitase e farelo de girassol, valorizando na formulação das dietas a matriz nutricional da fitase. O período experimental foi dividido em quatro ciclos de 28 dias cada. A matriz nutricional preconizada para fitase permitiu o atendimento pleno das exigências das aves, mesmo quando as dietas foram formuladas com níveis nutricionais reduzidos, isso quando desconsiderados os nutrientes presentes na matriz nutricional da enzima, de acordo com recomendação da empresa produtora. A adição de fitase na dieta reduz a excreção de fósforo pelas aves e melhora os parâmetros econômicos. A inclusão de farelo de girassol no nível de 8% prejudica a produção de ovos, mas não afeta os demais parâmetros de desempenho e qualidade dos ovos.

One hundred and eighty Isa Brown laying hens at 60 weeks of age were arranged in a completely randomized design in a 2 õ 2 factorial scheme, with two levels of phytase (0 and 500 ftu/kg ration) and two levels of sunflower meal (4 and 8%) totalizing five diets, evaluated with six replicates with six birds. Diets were formulated from a control ration based on corn and soybean meal free from phytase and sunflower meal, valuing the nutritional phytase matrix in diets formulation. The experimental period was divided in four 28-day cycles. The nutritional matrix suggested for phytase completely met the requirement by hens, even when diets were formulated with reduced nutritional levels when the nutrients present in the enzyme nutritional matrix were not considered accordingly to recommendations by the manufacturer. Addition of phytase in the diet reduces excretion of phosphorus by the birds and it improves the economical parameters. Inclusion of sunflower meal at 8% level negatively affects egg production, but it does not affect the other performance parameters and egg quality.