RESUMO Objetivou-se com este estudo avaliar os efeitos da restrição temporária de lisina na dieta sobre o desempenho e viabilidade econômica de leitões em fase de creche. Foram utilizados 144 leitões, distribuídos em blocos ao acaso, com dois tratamentos e 12 repetições. Os tratamentos foram controle-lis, nível de lisina recomendado dos 21 aos 32 e 32 aos 42 dias de idade e baixa-lis, 90% do nível de lisina das dietas controle-lis. Dos 42 aos 62 dias, todos os animais receberam dieta controle. De 21 a 32 dias, leitões alimentados com baixa-lis tiveram pior ganho médio diário (GMD), conversão alimentar e peso corporal aos 32 dias (P≤0,05). Dos 32 aos 42 dias, leitões alimentados com baixa-lis apresentaram menor consumo médio de ração diário, GMD e peso aos 42 dias (P≤0,05). Dos 21 aos 62 dias, leitões alimentados com baixa-lis apresentaram GMD e peso corporal final menores (P≤0,05) quando comparados aos alimentados com controle-lis. At 27 and 29 days of age, pigs fed the low-lys diet had a higher (P≤0.05) incidence of diarrhea Aos 27 e 29 dias, leitões alimentados com baixa-lis apresentaram maior (P≤0.05) indicência de diarreia. O menor custo de alimentação e o maior índice de eficiência econômica foram registrados para baixa-lis. No entanto, os suínos alimentados com controle-lis apresentaram rentabilidade 3,9% maior. Como conclusão, a restrição temporária de lisina nas dietas de leitões piora o desempenho e diminui a viabilidade econômica.

ABSTRACT To evaluate the effects of temporary dietary lysine restriction on nursery pigs’ growth performance and its economic viability compared to control diets, 144 piglets (21-d-old) were assigned to randomized blocks, with two treatments and twelve replicates. The treatments were control-lys: lysine level as recommended from 21-32 and 32-42 days and low-lys: 90% of the lysine level of the control-lys diets. From 42 to 62 days, all animals received a control diet. From 21 to 32 days, pigs fed low-lys had worse average daily gain (ADG), feed conversion, and 32-d body weight (BW; P ≤ 0.05). From 32 to 42 days, pigs fed low-lys had lower average daily feed intake, ADG, and 42-d BW (P ≤ 0.05). From 42 to 62 days, pigs had similar performance (P > 0.05). Overall (21 to 62 days), pigs fed the low-lys had lower (P <0.05) ADG and final BW. At 27 and 29 days, pigs fed the low-lys diet had a higher (P≤0.05) incidence of diarrhea. The lowest feed cost and the highest economic efficiency index were recorded for the low-lys treatment. However, pigs fed the control-lys presented a 3.9% higher profitability. In conclusion, a temporary reduction of lysine in the diets of nursery pigs followed by an unrestricted diet in the subsequent period led to worse growth performance and lower economic viability.

ABSTRACT: This study was undertaken to evaluate the effects of dietary calcium levels and supplementation with organic trace minerals selenium, copper, iron, zinc and manganese on performance, tissue deposition and litter mineral concentration. A total of 2,496 one-day-old male Cobb 500 broilers were randomly assigned to a 3 × 4 factorial experimental design with three levels of dietary Ca [8, 10 and 12 g kg–1, while maintaining the same Ca:nPP (non-phytate phosphorus) ratio (2:1)] and four levels of micromineral supplementation (0.62, 0.72, 0.82 and 0.92 g kg–1). There was a total of 12 treatments, with eight replicates of 26 birds per pen. Micromineral supplementation (MS) was achieved by adding different levels of the product Bioplex TR Se® and Ca supplementation was achieved by adding increasing levels of limestone and dicalcium phosphate. An interaction between Ca and MS levels was observed (p < 0.05) for the parameters of performance, liver Cu concentration, breast Se and Cu concentrations and litter Se, Mn and Zn concentrations. No interactions were observed (p > 0.05) for Ca, P or ash concentrations in the tibia, which were influenced only by dietary Ca levels (p < 0.05). The Ca level of 10 g kg–1 promoted higher Ca and P concentration in the tibia and lower micromineral excretion in the litter. The combination of MS level of 0.82 g kg–1 with Ca level of 10 g kg–1 led to the best BWG response. The supplementation conditions that led to higher micromineral levels in the liver and breast varied for each mineral.

The assay was carried out to determine the effect of phytase supplementation on performance of broilers from 1 to 21 and 1 to 40 days of age. Twelve hundred and fifty male broilers (Ross) were distributed in a randomized experimental design, with five treatments, 10 repetitions and 25 birds per experimental unit. The treatments consisted of evaluating the phytase supplementation in diets with reductions in nutritional levels, compared with the positive control. The nutrient contents in negative controls one and two were reduced progressively and these diets were supplemented with phytase levels of 250 and 500 ftu/kg of the diet, respectively. Two diets were formulated: pre-starter/starter, 1-21 days, and growth/finishing, from 21 to 40 days). In both phases, with the phytase supplementation in diets that had their nutritional levels reduced (negative control one + 250 ftu and negative control two + 500 ftu), feed intake, weight gain and feed conversion of the birds were similar to the positive control. In the period from 1 to 40 days of age, with the diets supplemented with phytase, the productive efficiency index of the birds was similar to that of the positive control group. Supplementation with 250 ftu/kg and 500 ftu/kg phytase in diets with reduced nutritional levels improved broiler performance, resulting in parameters similar to those shown by broilers fed with the diet with normal levels of nutrients.

The objective of this study was to estimate the values of apparent metabolizable energy and apparent metabolizable energy corrected for nitrogen balance and determine the chemical composition of the following feedstuffs: babassu meal, sunflower meal, corn gluten meal, babassu starch flour, meat and bones meal, beans, millet, cookies residue, pasta residue and bread-making residue. The traditional method of excreta collection was used with broilers in the period of 14 to 24 days of age, which were distributed in a completely randomized design with eleven treatments and six replicates of six birds each. Each feedstuff replaced the reference diet at levels of 30 or 40% depending on the type of feedstuff. Chicks were housed in cages fitted with trays to collect the excreta. The apparent metabolizable energy corrected for nitrogen balance (kcal/kg) on the natural matter of feedstuffs were: babassu meal, 1,116; sunflower meal, 1,607; corn gluten meal, 3,826; babassu flour starch, 1,731; meat and bone flour, 2,524; common beans, 693; millet, 3,046; cookies residue, 3,351; pasta residue, 3,543 and bread-making residue, 3,494.

Objetivou-se avaliar o efeito da adição da enzima xilanase (Econase XT25) sobre o metabolismo de nutrientes e o desempenho de poedeiras no período de 24 a 48 semanas de idade. Foram utilizadas 288 poedeiras, distribuídas em delineamento experimental inteiramente casualizado em arranjo fatorial 2 × 2, com dois níveis de energia metabolizável (2.900 e 2.755 kcal/kg) combinados ou não com a adição de xilanase (37,5 g/t de ração), totalizando quatro tratamentos (controle positivo; controle negativo; controle positivo + xilanase; e controle negativo + xilanase), avaliados com 12 repetições de 6 aves por unidade experimental. As dietas controle positivo e controle positivo + xilanase foram formuladas seguindo as recomendações das Tabelas Brasileiras (100% de energia metabolizável), enquanto as dietas controle negativo e controle negativo + xilanase foram calculadas reduzindo 5% da energia metabolizável. A adição da enzima xilanase à dieta controle negativo proporcionou produção de ovos e massa de ovos semelhante às observadas no grupo controle positivo. A redução de 5% de energia metabolizável ocasionou diminuição na produção de ovos, na massa de ovos, piora da conversão alimentar e aumento do consumo de ração. A composição dos ovos não foram influenciada pelas dietas. Os valores médios de energia metabolizável aparente corrigida são maiores em dietas com maior nível de energia metabolizável. A adição de xilanase melhorou a utilização da energia e a produção de ovos em dietas para galinhas poedeiras.

The objective of this study was to evaluate the effect of the addition of xylanase enzyme (Econase XT25) on the metabolism of nutrients and the performance of laying hens from 24 to 48 weeks of age. It was used 288 laying hens, distributed in a completely randomized design in a 2 × 2 factorial arrangement, with two levels of metabolizable energy (2,900 and 2,755 kcal/kg) combined or not with addition of xylanase enzyme (37.5 g/t of ration), totaling four treatments (positive control, negative control, positive control + xylanase; and negative control + xylanase), evaluated with 12 replicates of 6 birds per experimental unit. Positive control and positive control + xylanase diets were formulated following the recommendations by Tabelas Brasileiras (100% metabolizable energy) while negative control and negative control + xilanase diets were calculated by reducing 5% of metabolizable energy. The addition of xylanase enzyme to the negative control diet provided egg production and egg mass similar to the ones observed in the positive control group. Reduction of 5% of metabolizable energy resulted in a decrease in egg production, in egg mass, worsening in feed conversion and increase in feed intake. Composition of the eggs was not affected by the diets. The average values of corrected apparent metabolizable energy are higher in diets with higher level of metabolizable energy. The addition of enzyme xylanase improved the use of energy and egg production in diets for laying hens.