RESUMO -Objetivou-se avaliar as equações para predição das exigências protéicas de matrizes pesadas em crescimento, desenvolvidas em estudos anteriores na Faculdade de Ciências Agrárias e Veterinárias da UNESP, Jaboticabal, tendo como padrão de comparação as recomendações estabelecidas pelo manual de criação da linhagem. Foram utilizadas 288 matrizes pesadas da linhagem Hubbard Hy-Yield, com cinco semanas de idade, em delineamento inteiramente casualizado, com dois tratamentos e seis repetições, sendo 24 aves por unidade experimental até 14 semanas e, de 15 a 20 semanas de idade, 20 aves por unidade experimental. Um tratamento foi representado pelas recomendações protéicas para a linhagem (testemunha) e o outro pelas seguintes equações de predição das exigências de proteína: de 5 a 8 semanas -PB (g/ave/dia) = 2,02.P 0,75 + 0,350.G, 9 a 14 semanas -PB = 2,02.P 0,75 + 0,406.G e de 15 a 20 semanas -PB = 2,02.P 0,75 + 0,463.G, em que P é o peso corporal (kg) e G, o ganho de peso diário (g). Os resultados indicaram que as equações de predição para proteína, apesar de não comprometerem o peso ou a uniformidade corporal em relação ao tratamento testemunha, determinaram menor porcentagem de peito e maior de gordura abdominal e maior teor de gordura na carcaça, sendo atribuído à menor ingestão de proteína proporcionada pelas equações de predição e, conseqüentemente, deficiência em relação a alguns aminoácidos que não foram suplementados. Palavras-chave: desempenho de matrizes pesadas em crescimento, método fatorial Evaluation of the Prediction Equations of the Protein Requirements for BroilerBreeder Pullets ABSTRACT -The objective of this research was to evaluate the prediction equations of the protein requirements for broiler breeder pullets, that was previously determined at Faculdade de Ciências Agrárias e Veterinárias -UNESP -Jaboticabal. The equations were compared with standard recommendation for the used strain. Two hundred and eighty eight broiler breeder pullets for Hubbard Hy-Yield strain at 5 weeks old were assigned to a randomized design with two treatments and six replication of 24 pullets until 14 weeks and 20 pullets from 14 to 20 weeks old. One treatment was represented by the protein standard recommendation for the strain (control) and another by the following prediction equations: from 5 to 8 weeks -CP (g/bird/day)= 2.02. W .75 + .350.G, from 9 to 14 weeks -CP = 2.02. W .75 + 0,406.G and from 15 to 20 weeks old -CP = 2.02. W .75 + 0.463.G, where P is body weight (kg) and G is daily weight gain (g). The prediction equations for protein, in spite not affect the body weight and uniformity, but they promoted smaller breast percentage, higher abdominal fat percentage and fat in carcass. This result is attributed to the low protein intake determined by the prediction equations, and consequently deficiency in some amino acids that were not possible to add to the diets.
An experiment was conduced to evaluate the inclusion of sunflower meal (SBM) in commercial layer diets formulated on total or digestible amino acids basis. One hundred forty-four 41-week-old Lohmann LSL layers were distributed in a completely randomized experimental design in a 2 x 4 factorial arrangement with three replications of six birds each. Treatments consisted of a combination of four SBM inclusion levels SBM(0%, 4%, 8%, and 12%) and feed formulation according two amino acid recommendations (total or digestible). The experimental period was divided into five periods of fourteen days. Performance parameters (egg production, feed intake, feed conversion, egg mass) were evaluated for each period. In the last two days of each period, three eggs per replication were collected to evaluate egg quality (Haugh units, specific gravity, egg weight, eggshell thickness, and eggshell percentage). Hens fed on total amino acid recommendation presented the highest values for egg weight. Diets formulated on digestible amino acids basis showed an improvement in eggshell percentage and egg specific gravity. SBM addition in commercial layer diets did not influence performance; however, increasing SBM dietary levels SBM improved eggshell quality
KeywordsRice hulls, cottonseed hulls, soybean hulls, crude protein, egg production. ABSTRACTThis study aimed at evaluating diets containing different fiber sources and two crude protein levels on the performance, egg quality, and nitrogen metabolism of commercial layers. In total, 392 48-wk-old Isa Brown layers were distributed according to a completely randomized experimental design in a 3x2+1 (control) factorial arrangement, resulting in seven treatments with seven replicates of eight birds each. Treatments consisted of three fiber feedstuffs (cottonseed hulls, soybean hulls, and rice hulls) and two dietary crude protein levels (12% and 16%). Cottonseed hulls associated with the high crude protein level (16%) resulted in the worst feed conversion ratio per dozen eggs. Diets with 16% crude protein resulted in the highest feed intake, egg production, egg weight, egg mass values, and improved feed conversion ratio (kg eggs/kg feed). The dietary inclusion of soybean hulls determined low yolk pigmentation, and of rice hulls, low egg specific gravity. The 16% crude protein diet with rice hulls promoted the best feed conversion ratio. Hens fed the reference diet presented higher egg mass and better feed conversion ratio per kg eggs and per dozen eggs. Hens fed the diets with low crude protein level (12%) had reduced nitrogen excretion, but presented worse egg production.
This experiment was carried out to evaluate the effects of the inclusion of different levels of phytase on broiler performance, bone densitometry, and phosphorus and nitrogen excretion. Nine hundred and sixty one-day old broilers, 50% males and 50% females, were distributed in a completely randomized experimental design into five treatments and six replicates 32 birds each. The treatments consisted of a control diet and four diets with the addition 25, 50, 75, and 100 g/ ton of phytase (250, 500, 750 and 1000 FTU of phytase/kg fed). Diets were formulated to contain equal nutritional levels, and considered the phytase product nutritional levels. In general, the addition of phytase resulted in a linear decrease in broiler performance. However, the performance results obtained with the level of 250 FTU phytase/kg feed were not different from the control treatment. The best bone density results were observed in the control treatment, with no phytase. The results of this experiment indicate that the nutritional matrix of the phytase product needs to be reviewed when added in levels higher 250 FTU/kg to broiler diets. INTRODUCTIONAiming at lowering production costs, many current research studies have focused on improving the efficiency of feedstuff utilization and to reduce the impact of animal production on the environment (Payne et al., 2005).Phosphorus is one of the most expensive nutrient of poultry and swine feeds, second only to energy and protein (Borges, 1997). It is nutritionally essential, as shown by its several roles in the body, and it is particularly important during growth. However, two thirds of the phosphorus contained in cereal grains and oil seeds are in the form of phytate, which can bind to other nutrients, rendering them unavailable for poultry and pigs, thereby, requiring dietary inorganic phosphorus supplementation (Denbow et al., 1995).The production of industrial phytase is based on microorganisms, using DNA recombination techniques. This enzyme increases phosphorus (P) availability in plant feed ingredients, where P is usually present as phytate. The dietary supplementation of phytase allows poultry and pigs to more efficiently absorb phosphorus, reducing the amount of inorganic phosphorus supplementation, and promoting better weight gain, feed conversion ratio, feed intake, and bone mineralization, as well as reducing mortality (Qian et al., 1996).Along with calcium, phosphorus has an essential role in bone formation. In the animal, phosphorus comprises about 1% of live weight, and it is carefully considered when feeds and supplements are formulated. About 80% of phosphorus in the animal body is deposited 26in bones and teeth. Therefore, the inclusion of phytase in broiler diets may enhance their bone development. The objectives of the present study were to evaluate the effects of the inclusion of different levels of phytase on broiler performance, bone densitometry, and phosphorus and nitrogen excretion in the litter during the starter (1 to 21 days), grower (22 to 42 days), and t...
O objetivo deste experimento foi determinar o efeito de diferentes níveis de sódio para poedeiras nos períodos de repouso e segundo ciclo de postura. Foram utilizadas 216 poedeiras da linhagem Hy line W-36, pós-muda forçada, com 60 semanas de idade. O delineamento utilizado foi o inteiramente casualizado em arranjo fatorial 3 x 3 (três níveis de sódio no período de repouso x três níveis de sódio no período de postura), totalizando nove tratamentos com três repetições de oito aves cada. Foram avaliadas, em quatro ciclos de 28 dias, as seguintes variáveis: produção e peso dos ovos, consumo de ração, conversão alimentar, massa de ovos, qualidade do albúmen, percentagem de casca, gravidade específica e espessura das cascas. Não foram encontrados efeitos significativos dos níveis de sódio sobre as variáveis estudadas, entretanto, para a espessura de casca, o menor resultado foi obtido com o nível de 0,15% de sódio. Os níveis de sódio de 0,15% no período de repouso e de 0,25% no período de postura foram suficientes para atender às exigências nutricionais de poedeiras no segundo ciclo de postura.
An experiment was carried out to evaluate the effect of replacing corn with pearl millet in commercial layer diets, formulated according to the minimal requirements for total and digestible amino acids. Two hundred and forty Lohmann LSL laying hens with 25 weeks of age were distributed in a completely randomized experimental design according to a 2 x 5 factorial arrangement with 3 replicates of 8 birds. Feed was formulated on two amino acid basis (total or digestible) according to Rostagno et al. (2000) and there were five pearl millet inclusion levels (0%, 25%, 50%, 75%, and 100%). Performance and egg quality were evaluated during five periods of 21 days.At the end of each period, feed intake, egg production, egg weight and feed conversion were evaluated. In the last three days of each period, the following egg quality parameters were evaluated: Haugh Unit, yolk pigmentation index, egg specific weight, shell percentage and shell thickness. Digestible amino acid requirements resulted in decreased feed intake (p<0.01) and increased production costs per mass of eggs (kg) or per dozen eggs (p<0.01) compared to total amino acid requirements. There was a linear reduction in feed intake, egg production, egg weight and yolk pigmentation index with increasing inclusion levels of pearl millet. Therefore, increasing levels of replacement of corn by pearl millet affected bird performance negatively. Besides, production costs were higher with increasing pearl millet levels
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