Two-hundred sixteen white laying hens were used to assess the ideal ratio of digestible threonine:lysine in diets for laying hens at 24 to 40 weeks of age. Birds were assigned to a randomized block design, with six treatments, six replicates per treatment and six birds per experimental unit. The cage was used as the blocking criterion. Experimental diets contained different digestible threonine:digestible lysine ratios (65, 70, 75, 80, 85 and 90%) with 142 g/kg of crude protein. Experimental diets were […]

This trial was conducted to determine the dietary digestible methionine + cystine requirement of Nile tilapia (550 to 700 g) based on the ideal protein concept. Six hundred fish were distributed in a completely randomized design with five treatments and four replicates, with 30 fish per experimental unit. The fish were fed diets containing approximately 262 g of digestible protein/kg, 3,040 kcal of digestible energy/kg and 7.90, 9.40, 10.90, 12.40 or 13.90 g of methionine + cystine/kg. The fish were […]

The objective of this study was to estimate the true digestibility coefficients of amino acids and digestible amino acid values of some poultry feedstuffs. The feedstuffs were: babassu meal, sunflower meal, corn gluten meal, babassu starchy meal, meat and bone meal, common beans, pearl millet and residues of cookies, pasta and bread. The precise feeding method of Sibbald was used with adult cecectomized Leghorn roosters distributed in a completely randomized design, consisting of ten treatments and six replications with a […]

The objective was to evaluate the effect of electrolyte balance in diets with reduced protein for semi-weighted Bovans Goldline laying hens in the second production cycle. The design was completely randomized with five treatments and seven replicates of six birds per experimental unit. Treatment 1 consisted of a control diet containing 165.0 g/kg crude protein (CP), formulated with the addition of DL-methionine to meet birds requirements during the experimental period. To compose the treatments 2-5 (BE149, BE167, BE185 and BE203), […]

The objective of the present study was to evaluate nutritional plans for boars. Four hundred animals of 67 to 135 days of age and initial weight of 27.75±1.61 kg were distributed in a randomized block design with seven nutritional plans for boars (9.0-8.0; 9.0-9.0; 10.0-9.0; 10.0-10.0; 11.0-10.0; 11.0-11.0 and 12.0-11.0 g/kg of digestible lysine from 67 to 107 days and from 108 to 135 days, respectively) with four repetitions and a control plan for barrows (11.0-10.0 g/kg of digestible lysine) […]

Avaliaram-se farinhas de sangue obtidas pelos métodos de processamento em tambor, convencional e atomização. As farinhas foram submetidas ao processo de extração e fracionamento da proteína para determinação do perfil do tamanho molecular, que foi comparado ao do sangue bovino in natura. Nas amostras, submetidas ou não ao processo de desengorduramento, foram realizadas análises da digestibilidade in vitro da proteína. Para determinação dos coeficientes de digestibilidade dos nutrientes in vivo, foram confeccionadas quatros rações, sendo uma sem farinha de sangue, […]

This study was conducted to determine the digestible lysine requirements of Nile tilapia fingerlings. Fish (n = 300; average initial weight = 1.44 g) were distributed 15 300-L aquariums, in a completely randomized design with five treatments and three replicates, and fed extruded diets containing 11.3, 13.7, 16.1, 18.4 or 20.8 g/kg of digestible lysine. The arginine:lysine ratio was maintained at 1.3:1. All fish were fed diets containing 281 g/kg of digestible protein and 3,372 kcal digestible energy/kg, hand-fed until […]

O experimento foi conduzido em delineamento inteiramente ao acaso para avaliar os efeitos da redução de proteína (PB) e da suplementação de aminoácidos essenciais sobre o desempenho e as características de carcaça de frangos de corte machos de linhagem comercial na fase de 1 a 21 dias de idade. Foram utilizados 720 frangos distribuídos em 4 tratamentos e seis repetições com 30 aves cada. Os níveis de PB utilizados foram 230, 210, 190 e 170 g/kg. Houve efeito linear decrescente […]

This study was developed to evaluate the effects of adding L-glutamine and L-glutamate in diets with no lactose or with 4.0 or 8.0% lactose inclusion for piglets weaned at 21 days old. One hundred and eight piglets with initial weight of 6.12±0.70 kg were allotted in a complete randomized block design, in a 3 × 2 factorial arrangement, with six treatments, six replicates, and three piglets per experimental unit. The experimental diets were supplied from 21 to 35 days. From […]

The objective of this study was to evaluate the effects of increasing dietary digestible tryptophan levels on performance and carcass traits of growing pigs. Fifty crossbred castrated male pigs, with average initial and final body weight of 29.0 ± 1.20 kg and 60.4 ± 1.95 kg were allotted in a completely randomized block design, with five treatments (0.125, 0.133, 0.141, 0.149, and 0.157% of digestible tryptophan, corresponding to digestible tryptophan:lysine relations of 15.0, 16.0, 17.0, 18.0, and 19.0%, respectively) and […]