Heloisa Helena de Carvalho Mello

Metabolizable energy values of feedstuffs obtained from poultry at different ages

Four assays were carried out to determine the apparent metabolizable energy (AME) and the corrected apparent nitrogen metabolizable energy (AMEn) of ten feeds for poultry at different poultry ages. The feeds studied were: corn grain, soybean meal, ground sorghum, wheat bran, integral rice bran, two kinds of feather meal, two kinds of poultry viscera meal and spray-dried plasma. The method of total excreta collection was used to determine the AME and AMEn values. The broiler chicks were distributed on a completely randomized experimental design, with 11 treatments, six replications, with different number of animals by replication according to the assay. In the first assay, 528 male broiler chicks in the period from 10 to 17 days of age were used, with eight animals per replication. In the second assay, 396 male broiler chicks in the period from 26 to 33 days of age were used, with six animals per replication. In the third assay, 264 male broiler chicks in the period from 40 to 47 days of age were used, with four animals per replication. In the fourth assay, 132 roosters were used, with two animals per replicate. There was an effect of age on the AME and AMEn values of the following feeds: soybean meal, ground sorghum, integral rice bran, two kinds of feather meal and spray-dried plasma, where the oldest broilers provided the highest AME and AMEn values. Wheat bran was affected by age only for the AMEn values.

Níveis de lisina digestível em rações para poedeiras no período de 24 a 40 semanas de idade

The objective of this study wast to determine the requirement of digestible lysine for light-weight laying hens 24 to 40 weeks of age. Two hundred and sixteen Hy-Line W36 light-weight laying hens were allotted to a randomized complete blocks with six treatments, six blocks and six hens per experimental unit. The treatments consisted of a basal diet, with 14.54% crude protein, deficient in digestible lysine (0.545%), supplemented with six levels of L-lysine HCl (78%) 0.00; 0.059; 0.118; 0.177; 0.237 and 0.295%. Considering the digestibility of the lysine to be 97.6%, the amount of L-lysine. HCl added in each diet supplied 0.00; 0.045; 0.090; 0.135; 0.180 and 0.225 digestible lysine, respectively, resulting in diets with 0.545; 0.590; 0.635; 0.680; 0.725 and 0.770% digestible lysine. Feed intake, lysine intake, egg production, average egg weight, egg mass, feed conversion (kg feed/egg dozen), albumen index and final weight gain of the chickens showed a linear response with increase in the digestible lysine levels. There was a quadratic effect for the levels of digestible lysine on feed conversion/egg mass but no significant effect on Haugh Units, yolk index and egg components was detected. The digestible lysine requirement was estimated to be at least 0.770% of the diet, corresponding to the intake of 759 mg of lysine digestible/hen/day.

Exigência nutricional de lisina digestível para galinhas poedeiras de 54 a 70 semanas de idade

An experiment was performed to determine the dietary digestible lysine requirement of hens (Lohman LSL and Lohman Brown) from 54 to 70 weeks of age. Three hundred and sixty hens were randomly assigned to 5 × 2 factorial arrangement (Lys levels by hen strain), according to the dietary treatments withj six replicates (groups) of 6 birds. An experimental diet was formulated to contain deficient digestible lysine levels in order to be supplemented with lysine (L-Lys-HCL,78%) originating the five dietary treatments (0.555; 0.605; 0.655; 0.705 and 0.755% of digestible lysine). The parameters analyzed were egg production, egg weight, egg mass, feed intake, lysine intake, feed conversion, albumen weight, yolk weight and shell weight, Haugh unit, albumen index and yolk index, percentage of non-commercial eggs and body weight gain. There was linear effect of lysine levels to light laying hens on feed intake, lysine intake, yolk index, albumen weight, yolk weight and quadratic effect on egg production, egg weight, egg mass, feed conversion and shell weight. For brown-type laying hens, there was linear effect of lysine levels on lysine intake and egg weight and quadratic effect on egg production, egg mass, feed conversion and shell weight. The digestible lysine requirements were estimated through polynomial regression models. Estimates of digestible lysine requirements were calculated as 0.724 and 0.692% for light laying hens and brown-type laying hens, respectively, which corresponds to 784 and 748 mg/hen/day and 14.9 and 14.5 g of digestible lysine/g egg mass produced, in the period from 54 to 70 weeks of age.

Composição química e energética de alimentos de origem vegetal determinada em aves de diferentes idades

Four assays were carried out to determine the apparent metabolizable energy (AME) and nitrogen corrected apparent metabolizable energy (AMEn) of ten feedstuffs of vegetable origin for poultry at different ages. The chemical composition of the ten feedstuffs was also determined: 45% soybean meal, 48% soybean meal, extruded full-fat soybean, deactivated full-fat soybean, micronized full-fat soybean, deactivated soybean meal, soybean protein concentrate, corn gluten meal 21%, corn germ and broken rice. The method of total excreta collection was used and a randomized complete experimental design was used with 11 treatments and six replications, in the four assays. In the 1st, 2nd and 3rd assays broiler chicks were used aged 10 to 17, 26 to 33 and 40 to 47 days, respectively, and in the 4th assay roosters were used with 25 weeks of age. The AMEn values (as-fed basis) determined in the 1st, 2nd, 3rd and 4th assay were, respectively: 2069, 2148, 2272 and 2231 for 45% soybean meal; 2214, 2225, 2319 and 2247 for 48% soybean meal; 3322, 3331, 3405 and 3493 for extruded full-fat soybean; 3016, 3067, 3139 and 3388 for deactivated full-fat soybean; 3557, 3638, 3828 and 3869 for micronized full-fat soybean; 2292, 2348, 2518 and 2502 for deactivated soybean meal; 2356, 2399, 2509 and 2486 for soybean protein concentrate; 1826, 1882, 2110 and 1942 for corn gluten meal 21%; 2605, 2764, 2925 and 2832 for corn germ; and 2967, 3029, 3096 and 3026 for broken rice.

Determinação da composição química e energética do milheto e sua utilização em rações para frangos de corte de 1 a 21 dias de idade

This research was carried out to determine the nutritional value of pearl millet, and to evaluate their utilization as energetic source in broiler diets from 1 to 21 days old. Two experiment were conducted: in the first, the chemical composition (dry matter, crude protein, ether extract, calcium and phosphorus) and gross energy, apparent metabolizable energy corrected by nitrogen balance were determined. In the second experiment, the performance of broilers from 1 to 21 days old fed diets with 0, 10, 20, 30 and 40% of pearl millet were determined. A completely randomized design, in a 5 × 2 factorial arrangement (level of millet and sex), with four replicates and 20 birds per experimental unit, was used. The determined values of chemical composition were: dry matter (88.53%), gross energy (3,604 kcal/kg), crude protein (12.71%), crude fiber (5.40%), ether extract (3.10%), calcium (0.029%) and phosphorus (0.31%) and, in the second experiment, apparent metabolizable energy corrected by nitrogen balance (2,656 kcal/kg). The analyzed traits were: feed intake, weight gain and feed/gain ratio. The performance of broilers fed rations with higher levels pearl millet was better, which could be related to the increase of oil level in diet. The inclusion of pearl millet up to 20% is recommended in the rations for broilers from 1 to 21 days old.

Digestible tryptophan:digestible lysine ratio in diets for laying hens from 24 to 40 weeks of age

The objective of this study was to determine the ideal digestible tryptophan:digestible lysine ratio in diets for laying hens from 24 to 40 weeks of age. Two hundred and forty Hy-Line W-36 laying hens at 24 weeks of age were distributed in a completely randomized design, with five treatments, eight replicates and six birds per experimental unit. The digestible tryptophan levels in the experimental diets were 1.57; 1.68; 1.79; 1.90 and 2.01 g/kg, providing ratios of digestible tryptophan:digestible lysine of 0.215; 0.230; 0.245; 0.260 and 0.275. The increase in the levels of digestible tryptophan in the diet linearly improved the feed intake, digestible tryptophan intake, digestible lysine intake, egg production, egg mass, feed conversion per egg mass and utilization efficiency of digestible lysine for eggs mass. There were quadratic effects from the digestible tryptophan levels on egg weight. For the efficiency of utilization of digestible lysine for egg mass, there was better adjustment of the data to the LRP model. The level of digestible tryptophan in the diet from which the plateau occurred was 0.184%. This level corresponded to the intake of 142 mg/bird/day of digestible tryptophan and digestible tryptophan:digestible lysine ratio of 0.252. The ideal digestible tryptophan:digestible lysine ratio recommended in diets for laying hens from 24 to 40 weeks of age is 0.252 (25.2%).

Performance and intestinal characteristics of broiler chicken fed diet with glutamine in the diet without anticoccidials agents

Five hundred commercial male Cobb broilers were allotted in a randomized blocks design with five treatments, four replicates and 25 chicks per experimental unit in order to evaluate the effects of adding L-glutamine to the diet with no anticoccidial agents and growth promoters. Experimental diets contained L-glutamine at different levels (0.0; 5.0; 10.0; 15.0 or 20.0g/kg), through the experimental period. Experiment was conducted with broiler chicken from 1 to 42 days old. The parameters evaluated were feed intake, feed conversion ratio, body weight gain, mortality, digestibility coefficients of dry matter, crude protein and ether extract, carcass yield and intestinal mucosa structure of small intestine. The data obtained were submitted to polynomial regression analysis. Means were compared using Tukey test.Was considered a type I error set at P ≤ 0.05. The level of L-glutamine in the diet influenced feed conversion ratio of broilers at 1-7 days old, which was improved at 10.0g/kgL glutamine. Carcass yield and digestibility coefficients of the diet were not affected by the levels of glutamine in the diet. Adding L-glutamine influenced crypt depth in small intestine of broilers at 18 and 42 days old. It is recommended the addition of 10.0g/kg L-glutamine to the pre-started diet. Keywords: Amino acids. Additives.Birds. Coccidiosis. Intestinal integrity.

Digestible threonine to lysine ratio in diets for laying hens aged 24-40 weeks

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 formulated to be isonitrogenous and isocaloric with different contents of L-glutamic acid. Feed intake (g/hen/d), egg production (%), egg weight (g), egg mass (g/hen/d), feed conversion ratio (kg/dozen and kg/kg egg), eggshell weight (g), albumen weight (g), yolk weight (g) and body weight gain (g) were assessed. The maximum egg production was observed at 78% digestible threonine:digestible lysine ratio, while the best values of feed conversion ratio (kg/dozen egg) and feed conversion ratio (kg/kg of egg) were observed at 77.6% and 75%, respectively. Feed intake, egg mass and egg contents (yolk, albumen and eggshell) were not affected by treatments. The estimated digestible threonine:digestible lysine ratio of Hy-Line W36 laying hens at 24 to 40 weeks of age is 78%, corresponding to 5.70 g/kg of dietary digestible threonine.

Determination of digestible isoleucine: lysine ratio in diets for laying hens aged 42-58 weeks

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.

Nutritional requirement of methionine+cistine digestibles for laying hens during a period of 54 to 70 weeks of age

This research was carried out using 360 laying hens (180 Lohmann LSL and 180 Lohmann Brown), to establish the nutritional requirement of digestible methionine+cystine in the period from 54 to 70 weeks of age. A completely randomized experimental design, in a 5 × 2 factorial arrangement (5 levels of digestible methionine+cystine and 2 laying hen strain), with 6 replications and 6 hens per experimental unit, was used. The treatments consisted of diets supplemented with 5 levels of DL-methionine (98%), resulting in 0.492, 0.544, 0.596, 0.648 and 0.700% of digestible methionine+cystine in diets. The parameters analyzed were: egg production, egg weight, egg mass, feed intake, digestible methionine+cystine intake, feed conversion, egg components (albumen, yolk and shell), internal quality (Haugh unit, albumen index and yolk index), the percentage of eggs does not trade and the body weight gain. The levels of methionine+cystine digestibles studied influenced the egg production, egg weight, egg mass, feed intake, digestible methionine+cystine intake, feed conversion, weight yolk and shell, and the body weight gain. The requirements of digestible methionine+cistine were estimated by polynomial regression models. The digestible methionine+cystine requirement, estimated for the laying hens light-weight was of 0.645% in the ration, corresponding to daily intake per hen of 712 mg and 12.5 g of methionine+cystine digestibles/g egg mass produced. For the laying hens semi-heavy was of 0.655% in the ration, corresponding to daily intake per hen of 723 mg and 13.2 g of methionine+cystine digestibles/g egg mass produced.