O objetivo com este trabalho foi determinar a exigência nutricional de lisina digestível para galinhas poedeiras leves em idade avançada. Foram utilizadas 288 galinhas poedeiras Hy Line W-36 com 60 semanas de idade, distribuídas em delineamento inteiramente casualizado, com seis níveis de lisina digestível (6,0; 6,6; 7,2; 7,8; 8,4 e 9,0g kg-1), oito repetições e seis aves por unidade experimental. Os níveis de lisina digestível na ração influenciaram de forma linear o consumo de lisina e a eficiência de utilização da lisina. Para a produção e massa de ovos, os platôs ocorreram a partir dos níveis de 6,57g kg-1 e de 7,10g kg-1 de lisina digestível, respectivamente. Houve efeito quadrático dos níveis de lisina sobre o peso de gema, com o nível estimado em 7,6g kg-1de lisina digestível. A exigência de lisina digestível de galinhas poedeiras leves no período de 60 a 76 semanas de idade é de 7,10g kg-1 de ração, correspondendo ao consumo diário de 690mg ave-1 de lisina digestível.

The objective of this research was to determine the nutritional requirement of digestible lysine for white laying hens in old age. Two hundred eighty-eight Hy Line W-36 laying hens at 60 weeks of age were distributed in a completely randomized design, with six levels of digestible lysine (6.0; 6.6; 7.2; 7.8; 8.4 and 9.0g kg-1) and eight replications with six birds per experimental unit. There was linear effect of lysine levels on lysine intake and efficiency of utilization of lysine. For the production and egg mass, the levels of digestible lysine in the diet from which the plateaus occurred were of 6.57g kg-1 and 7.10g kg-1, respectively. There was quadratic effect of lysine levels on yolk weight, with the estimated level of 7.6g kg-1 of digestible lysine. The digestible lysine requirement of white laying hens from 60 to 76 weeks of age is 7.10g kg-1 in diet, corresponding to daily intake of 690mg bird-1 of digestible lysine.

The experiment was conducted to determine the nutritional requirement of calcium and the best calcium:available phosphorus ratio for commercial layers at the post-laying peak. A total of 324 Hy-Line W-36 laying hens were utilized in the period from 42 to 58 weeks of age, distributed in a completely randomized design in a 3 × 3 factorial arrangement, composed of three levels of calcium (39, 42 and 45 g/kg) and three calcium:phosphorus ratios (12.12:1; 10.53:1; and 9.30:1), totaling nine treatments with six replications and six birds per experimental unit. There was no significant effect from the calcium levels × calcium:phosphorus ratio interaction for any of the variables studied. The calcium levels and the calcium:phosphorus ratios did not affect the variables performance or egg and bone quality. At the evaluation of the calcium:phosphorus balance, as the levels of calcium of the diet were raised, the intake of calcium and phosphorus and the contents of mineral matter and calcium in the excreta increased linearly, and the retention of calcium by birds decreased linearly. With the reduction of the calcium:phosphorus ratios of the diet, intake, retention and excretion of phosphorus by layers increased. Diets containing calcium at 39 g/kg and a calcium:phosphorus ratio of 12.12:1, corresponding to an increase in calcium of 3.51 g/bird/day and available phosphorus of 289 mg/bird/day, meet the requirements of calcium and available phosphorus of white egg layers in the period from 42 to 58 weeks of age.

Four experiments were conducted to study the requirements of available phosphorus (aP) for commercial male broilers of 1-10 day of age (exp.1), 11-21 days of age (exp. 2), 22-33 day of age (exp. 3) and 34-46 days of age (exp. 4), at a constant calcium:aP ratio. A complete randomized design was used in each experiment. The experimental diets were fed ad libitum to 8 replicate groups of ten broilers in each. The increments in the levels of aP ranged from 2.0 to 5.5 g/kg (exp. 1), 1.9 to 5.4 g/kg (exp. 2), 1.8 to 5.3 g/kg (exp. 3) and 1.7 to 5.2 g/kg (exp. 4), in 0.7 g/kg. The parameters evaluated were body weight gain, feed intake, feed conversion ratio and bone parameters. The level of aP in the diet influenced the performance of broilers of 1-10 and 11-21 days of age, but did not affect the performance of broilers at 22-33 and 34-46 days of age. Feed intake was not affected. The requirements of aP and Ca for male broilers from 1-10, 11-21, 22-33 and 34-46 days of age are 4.82 and 9.64 g/kg, 4.10 and 8.20 g/kg, 3.95 and 7.90 g/kg and 3.19 g.kg and 6.38 g/kg, respectively. The results indicate that low levels aP were required because the requirements of the mineral reduced as birds aged. Provided there is no excess of dietary levels of Ca, using a Ca:aP ratio of 2:1 may reduce the dietary levels of aP.

Two hundred and fifty-two Hy-Line W36 laying hens were allotted in a completely randomized design with 6 treatments, 7 replicates and 6 hens per experimental unit in order to determine the ideal ratio of isoleucine (Ile) in relation to lysine (Lys) to laying hens aged 42-58 weeks. Experimental diets contained digestible Ile at different levels, resulting in different Ile:Lys ratios (0.73:1; 0.78:1; 0.83:1; 0.88:1; 0.93:1 and 0.98:1). A basal diet was formulated to provide Isoleucine in levels below recommendations. This diet was supplemented with L-isoleucine to make up the 6 diets. Each diet was made isonitrogenous by varying the dietary contents of glutamic acid and isocaloric by adjusting the contents of cornstarch. All essential amino acids were provided proportionally to lysine. Egg production, egg weight, egg mass, feed conversion ratio, albumen, yolk and eggshell contents were recorded and compiled at every 28-day period. No differences were observed in the performance over a wide range of dietary isoleucine concentrations from 5.76 to 7.73 g/kg corresponding to 0.73:1 to 0.98:1 Ile:Lys ratios. The lowest Ile:Lys ratio (0.73:1) was sufficient to ensure satisfactory performance of birds, corresponding to the consumption of 534 mg of isoleucine and 731 mg of lysine/day.

O experimento foi realizado para avaliar o efeito da adição de fitase no aproveitamento dos ingredientes da ração para codornas. Foram utilizadas 200 codornas japonesas fêmeas com 251 dias de idade, peso médio de 187,2 ± 6,0 g e taxa de produção de ovos de 84,8%, distribuídas em delineamento inteiramente casualizado com quatro dietas experimentais e cinco repetições de dez aves por unidade experimental. As dietas experimentais consistiram de uma ração basal à base de milho e farelo de soja, formulada para atender às exigências nutricionais das codornas e às recomendações da matriz da fitase, suplementada com 0, 200, 400 ou 600 unidades de fitase (uf/kg). Utilizando-se o método de coleta total de excretas, foram determinados os valores de matéria seca ingerida, matéria seca excretada, energia metabolizável aparente (EMA), energia metabolizável aparente corrigida pela retenção de nitrogênio (EMAn) e os coeficientes de metabolizabilidade da energia corrigida ou não pelo balanço de nitrogênio. Foi calculada também a quantidade de fósforo, cálcio e nitrogênio retido por ave/dia. De maneira geral, houve melhora no aproveitamento da energia das rações com a suplementação de fitase. Os níveis de 195 e 186 uf/kg resultaram em maior aproveitamento da EMA e EMAn. Não houve diferença na retenção de fósforo e cálcio. O nível de 600 (uf/kg) promove menor excreção de nitrogênio, porém o de 368 uF/kg é suficiente para máxima retenção de nitrogênio pelas codornas.

This experiment was conducted to evaluate the effect of phytase addition on the use of feeding ingredients for laying quails. It was used 200 female Japanese quails at 251 days of age at an average weight of 187.2 ± 6.0 g and egg production rate of 84.8%. The quails were distributed in a complete random design with four experimental diets and five repetitions of ten birds per experimental unity. The experimental diets were consisted of corn and soybean meal based feedings formulated in order to meet the nutritional requirements of the quails and to the recomendations of phytase matrix supplemented with 0, 200, 400 or 600 phytase units (PU/kg). By using the method of total excreta collection, it was determined the values of ingested dry matter, excreted dry matter, apparent metabolizable energy (AME), apparent metabolizable energy corrected by nitrogen retention (AMEn), and the coefficients of energy metabolizability corrected or not by nitrogen balance. It was also calculated the quantities of phosphorus, calcium, and nitrogen retained by bird/day. In general, there was an improvement on the use of energy from feeding with phytase supplementation. Levels of 195 and 186 PU/kg resulted in a better use of AME and AMEn. There was no difference on retention of phosphorus and calcium. Level of 600 (PU/kg) promotes the lowest nitrogen excretion, however, 368 PU/kg is enough for a maximal retention of nitrogen by the quails.

Objetivou-se determinar os níveis de aminoácidos sulfurosos digestíveis para se estabelecer a relação ideal metionina+cistina:lisina em rações para poedeiras leves no período de 24 a 40 semanas de idade. Utilizaram-se 216 aves Hy-Line W36 em delineamento de blocos casualizados com seis níveis, cada um com seis repetições de seis aves por unidade experimental. Os níveis de aminoácidos sulfurosos digestíveis foram obtidos a partir de uma dieta basal com baixo nível de metionina+cistina digestível (0,65%) e suplementada com 0,00; 0,05; 0,10; 0,15; 0,20 e 0,25% de DL-metionina 99,2%, de forma a apresentar relações metionina + cistina:lisina de 84, 91, 97, 104, 110 e 117%. O período experimental teve duração de 16 semanas e foi subdividido em quatro subperíodos de coleta dos ovos, cada um com 28 dias de duração. Os níveis de metionina+cistina digestível influenciaram a produção de ovos e a eficiência de utilização de lisina por produção total de ovos, atingindo um platô em 0,811 e em 0,772% de metionina+cistina digestível, respectivamente. O nível de metionina+cistina digestível considerado exigência para poedeiras leves no período de 24 a 40 semanas de idade é de 0,772%, que corresponde a consumo de 682 mg/ave/dia de metionina+cistina digestível e a relação metionina+cistina:lisina de 100%.

The objective of this work was to determine digestible sulfurous amino acids levels to establish the ideal methionine+cystine:lysine relationships in meals of light-weight laying hens in the period from 24 to 40 weeks of age. It was used 216 Hy-Line W36 birds distributed in a randomized block design with 6 levels each one with 6 repetitions and 6 birds per experimental unit. The digestible sulfurous amino acids levels were obtained from a basal diet with low levels of digestible metionin+cistine (0.65%) supplemented with 0.00; 0.05; 0.10; 0.15; 0.20 and 0.25% of DL-methionine (99.2%) to provide a relationship methionine+cystine:lysine of 84, 91, 97, 104, 110 and 117%. The experimental period lasted 16 weeks and it was subdivided in 4 subperiods of collection of the eggs, each one corresponding to 28 days. Levels of digestible methionine+cistine affected egg production and lysine utilization efficiency per total egg production, reaching a plateau in 0.811 and 0.772% of digestible methionine+cistine, respectively. The digestible methionine+cystine level considered as a requirement for light-weight laying hens in the period from 24 to 40 weeks of age is of 0.772%, corresponding to digestible methionine+cystine consumption of 682 mg/hen/day, and the relationship methionine+cystine:lysine of 100%.