Six hundred and forty one-day-old Cobb male broilers were used to evaluate ornithine decarboxylase (ODC) expression in the mucosa of the small intestine. Birds were submitted to early feed restriction from 7 to 14 days of age. The provided feed was supplemented with glutamine. A completely randomized design with a 2 x 2 factorial arrangement was used (with or without glutamine, with or without feed restriction). Restricted-fed birds were fed at 30% the amount of the ad libitum fed group from 7 to 14 days of age. Glutamine was added at the level of 1% in the diet supplied from 1 to 28 days of age. Protein concentration in the small intestine mucosa was determined, and ODC expression at 7, 14, 21, and 28 days of age was evaluated by dot blotting. ODC was present in the mucosa of broilers, and the presence of glutamine in the diet increased ODC activation. Glutamine prevented mucosa atrophy by stimulating protein synthesis, and was effective against the effects of feed restriction. Dot blotting can be used to quantify ODC expression in the intestinal mucosa of broilers.

An experiment was conducted to evaluate the effect of different digestible amino acid profiles on the performance of broilers in two phases: from 1 to 21 days and from 22 to 42 days of age. At the end of the experiment, carcass yield and cut percentages were evaluated. Nine hundred and sixty AgRoss birds were distributed in a randomized block design with four treatments (four digestible amino acid profiles): Rostagno et al. (2000), Baker & Han (1994b), Degussa (1997) and those recommended by AgRoss (2000), with six repetitions and 40 birds per repetition (20 males and 20 females). The results showed that the four diets were able to provide the requirements of the birds, since no significant differences were seen among the treatments on the performance in the two phases and on the carcass yield and cuts at 42 days of age. Males had better yields of feet, head and neck, and lower percentage of abdominal fat (p<0.05). The best cost/benefit ratio was seen for the profile established by Rostagno et al. (2000) when diets were evaluated in an ideal protein situation.

Foram realizados dois experimentos utilizando-se 520 pintos machos de um dia para avaliar o efeito da proteína bruta (PB) e do balanço eletrolítico (Na + K- Cl) sobre o desempenho de frangos de corte no período inicial. O Experimento I (1 a 7 dias de idade das aves) foi realizado em baterias, utilizando-se 160 pintos machos "Cobb", no Experimento II (1 a 21 dias) foram utilizados 360 pintos machos "Aviam Farms" que foram alojados em um galpão experimental dividido em box. Nos dois experimentos as aves foram aquecidas com lâmpadas infravermelhas e receberam água e ração à vontade. O delineamento foi inteiramente casualizado, em um esquema fatorial 2 x 2 (PB x balanço eletrolítico - BE), com 5 repetições e 8 aves por unidade experimental no Experimento I e fatorial 2 x 3 (PB x BE), com 3 repetições e 20 aves por unidade experimental no Experimento II. Os níveis de K foram mantidos constantes, oscilando-se o Na e o Cl para obter os balanços eletrolíticos desejados. Os parâmetro de desempenho (consumo de ração, ganho de peso e conversão alimentar) foram analisados no final de cada fase experimental. Em ambos os experimentos não houve interação entre PB e BE. Os níveis de 21,0 e 23,5% de PB não afetaram o desempenho das aves. Em dietas pré-iniciais e iniciais o melhor desempenho foi atingido com 260 mEq/kg.

Two experiment were carried out using 520 one-day old male broilers to evaluate the effect of crude protein and of electrolytic balance ( Na+K-Cl) in starter diet on broilers performance. The experiment I (1 to 7 days of age) was accomplished in batteries, being used 160 one-day old male 'Cobb", in the experiment II (1 to 21 days of age), used 360 one-day old male "Avian Farms" that were housed in an shed experimental, divide in box. In the two experiments, the birds were heated with infrared lamps and they received water and ration at large. Experimental designs were completely randomized factorial 2x2 (proteins levels and Mongin of number) with five replications of eight birds each for experiment I and factorial 2x3 (proteins levels and Mongin of number) with three replications of twenty birds each for experiment II. The level of potassium was maintained constant, the levels of Na and Cl were varied to obtain the electrolytic balance. The performances parameters (feed intake (g), weight gain (g) and feed:gain) were analyzed in the end of each experimental phase. In both experiments there was no interaction between crude protein and electrolytic balance. The crude protein levels (21 and 23,5 %) did not influenced the broilers performance. In pre-starter and starter diets the best performance was obtained with electrolytic balance of 260 mEq/kg.

Dois experimentos foram realizados com o objetivo de avaliar os efeitos de diferentes níveis de aminoácidos e de cálcio sobre o desempenho e excreção de cálcio de duas linhagens de frangos de corte (Cobb e Avian Farms) na fase inicial de criação. Foram avaliados os dados de desempenho (consumo de ração, ganho de peso e conversão alimentar) e excreção de cálcio. Foram utilizadas 540 aves, em cada experimento, distribuídas em delineamento inteiramente casualizado, em esquema fatorial 3x2, ou seja, 3 perfis de aminoácidos (metionina, metionina+cistina, lisina e treonina - 100%, 125% e 150% dos níveis do NRC,1994) e 2 níveis de cálcio (75% e 100% dos níveis do NRC,1994), com 30 aves por repetição. Analisou-se o cálcio excretado das aves, e para tanto, utilizou-se 72 aves, em cada experimento, alojadas em gaiolas, seguindo o mesmo delineamento descrito anteriormente. Não houve interação entre os tratamentos estudados. Para a linhagem Avian Farms, o ganho de peso diminuiu com a elevação dos níveis de aminoácidos e ocorreu menor excreção de cálcio com menor nível de cálcio da dieta. A linhagem Cobb não foi influenciada pelos tratamentos em nenhum dos parâmetros estudados.

Two experiments were conducted to evaluate the performance and calcium excretion of broilers fed the diets with different amino acids (AA) and calcium (Ca) levels in the initial phase. In each experiments, male broilers, Cobb or Avian Farms, were randomly assigned to six treatments in a three X two factorial arrangement, considering the factors AA (100, 125 and 150% NRC, 1994) and Ca (75 and 100% NRC, 1994), in three replications of 30 birds each. The studied AA were methionine, methionine + cystine, lysine and threonine. The performance of the birds was analyzed according weight gain, feed intake and feed conversion. The lower calcium level reduced calcium excretion and increasing amino acids levels reduced weight gain in Avian Farms strain. The Cobb strain was not affected by treatments.

Foram conduzidos dois experimentos, utilizando-se 712 pintos de corte para avaliar o efeito do balanço eletrolítico (Na+K-Cl) em rações pré-iniciais (1-7 dias) de frangos de corte. As rações à base de milho e farelo de soja, com 21,5 % de proteína e 2.900 kcal EM/kg, foram oferecidas à vontade. No experimento I, o nível de K foi fixado e os níveis de Na e Cl foram manipulados, em 4 tratamentos com 8 repetições de 16 aves cada. No experimento II, níveis mais elevados de Na e K foram usados, com 4 tratamentos e 5 repetições de 10 aves cada. Em ambos os experimentos, os balanços eletrolíticos foram de 40; 140; 240 e 340 mEq/kg de ração. O balanço eletrolítico causou um efeito quadrático no ganho de peso e na conversão alimentar e um aumento linear no consumo de alimento quando o balanço eletrolítico foi aumentado pela suplementação de Na, indicando que esse íon estimula o consumo de alimento das aves nesse período. Porém, o consumo de alimento foi máximo em 202 mEq/kg, quando os níveis de K e Na foram simultaneamente aumentados na dieta, indicando que o limite superior de consumo de alimento é deprimido em função do K em excesso. O balanço eletrolítico ideal foi entre 246 e 277 mEq/kg obtidos pela manipulação dos níveis de Na e Cl.

Two experiments were carried out using 712 day-old chicks to evaluate the electrolytic balance (Na+K-Cl) in pre-starter (1-7 days) broiler diets. The feed, based on corn and soybean meal with 21.5 % protein and 2,900 kcal ME/kg, was offered ad libitum. In experiment I, K level was fixed, and Na and Cl levels were changed, using four 4 treatments and eight replicates of 16 birds. In experiment II, increasing levels of Na and K were used, with a total of four treatments and five repetitions of 10 birds. In both experiments, the dietary electrolytic balance was 40; 140; 240 and 340 mEq/kg. Electrolytic balance caused a quadratic effect on weight gain and feed:gain ratio, and a linear increase in feed intake when the electrolytic balance was increased by the single supplementation of Na, indicating that this ion stimulates feed intake of birds at this stage. However, feed intake was maximum for 202 mEq/kg, when K and Na levels were concurrently increased in the diet, indicating that there is a limit over which feed intake is depressed as a function of excessive K. The ideal electrolytic dietary balance was between 246 and 277 mEq/kg, obtained by the manipulation of Na and Cl levels.

O experimento teve como objetivo verificar a ação da apramicina (10 ppm) e dos ácidos fórmico + propiônico (0,0; 0,1 e 0,2%) no desempenho de frangos de corte sexados. A mistura dos ácidos orgânicos foi de 1:1. O delineamento foi inteiramente casualizado, em esquema fatorial 2 x 3 x 2 (apramicina x ácidos orgânicos x sexos), com 4 repetições de 45 aves por parcela, totalizando 2.160 pintos Cobb de 1 dia. As aves receberam ração à vontade. Na fase inicial, a adição da apramicina (10 ppm) e 0,1% dos ácidos orgânicos, isoladamente, melhorou o ganho de peso das aves. A adição conjunta dos produtos não promoveu ganho acumulado. Na presença da apramicina, a adição dos ácidos orgânicos piorou a conversão alimentar. Nas fases final e total, os dados de desempenho não apresentaram diferenças significativas. O rendimento de carcaça foi prejudicado com a adição conjunta da apramicina e 0,1% dos ácidos orgânicos.

A trial was carried out to study isolated or combined effect of Apramicin (10ppm) and formic + propionic acids (0.0; 0.1 and 0.2%) supplementation in broilers diets. Acids mixtures were blended in a 1:1 ratio. A completely randomized design was utilized in a 2 x 3 x 2 factorial scheme (apramicim x organic acids x sex) with 4 replicates of 45 birds per experimental unit, with 2160-day-old Cobb chicks. Birds were fed "ad libitum". In the initial phase, the supplementation of apramicin and organic acids (0.1%) alone, increased (p<0,05) body weight gain. Combined supplementation did not promote an accumulative effect. However, apramicin in the presence of organic acids supplementation decreased feed efficiency. In the final and total phases, broilers performance parameters were not affected by treatment. Combined supplementation of apramicin and organic acids (0,1%) decreased carcass yield.