ABSTRACT The objective of this study was to determine the energy values and standardized ileal digestibility (SID) of amino acids of corn, corn protein meal (CPM), corn germ (CG), and dried distillers' grains with solubles (DDGS) in broiler diets. In the first experiment, the apparent metabolizable energy (AME) and nitrogen-corrected apparent metabolizable energy (AMEn) values were determined using the total excreta collection method. A total of 240 14-day-old broiler chicks were randomly distributed in a completely randomized design with five treatments, including four different feed ingredients and a reference diet, each with eight replicates of six birds. In the second experiment, to determine the coefficient values of amino acids, 240 birds aged 14 to 28 days were randomly assigned to five treatments, including four different feed ingredients and a nitrogen-free diet, each with eight replicates of six birds. At 28 days of age, birds were slaughtered, and the digesta were collected to determine the standardized ileal digestibility coefficients and, subsequently, the digestibility of amino acids. The AMEn for corn, CPM, CG, and DDGS is 3178, 2171, 2473, and 3398 kcal/kg, respectively. The metabolizability coefficient of the AMEn percentages are 68.03% for corn, 46.62% for CPM, 44.15% for CG, and 73.39% for DDGS. The average digestibility of essential amino acids in corn, CPM, CG, and DDGS is 92.55, 52.63, 73.07, and 81.51%, respectively. For non-essential amino acids, the average digestibility in corn, CPM, CG, and DDGS is 90.59, 54.36, 70.20, and 79.47%, respectively, with an overall average of 85.21%. SID (SID CPM , (CPM) CG (CG) distillers (DDGS diets experiment AME (AME nitrogencorrected nitrogen corrected (AMEn method 24 14dayold dayold day old treatments diet 1 2 nitrogenfree free age slaughtered subsequently 3178 2171 2473 339 kcalkg kcal kg kcal/kg respectively 6803 68 03 68.03 4662 46 62 46.62 4415 44 15 44.15 7339 73 39 73.39 9255 92 55 92.55 5263 52 63 52.63 7307 07 73.07 8151 81 51 81.51% nonessential non 9059 90 59 90.59 5436 54 36 54.36 7020 70 20 70.20 7947 79 47 79.47% 8521 85 21 85.21% (CPM (CG 317 217 247 33 680 6 0 68.0 466 4 46.6 441 44.1 733 7 3 73.3 925 9 5 92.5 526 52.6 730 73.0 815 8 81.51 905 90.5 543 54.3 702 70.2 794 79.47 852 85.21 31 68. 46. 44. 73. 92. 52. 81.5 90. 54. 70. 79.4 85.2 81. 79. 85.

ABSTRACT Apparent calcium (Ca) retention and digestibility coefficients are affected by limestone particle size in the diet of laying hens. This study aimed to determine the apparent retention and digestibility coefficients of Ca in limestone of different particle sizes in laying hens. The study comprised 288 Lohmann Brown laying hens (50 weeks of age; 1,964 ± 98 g) distributed in a completely randomized experimental design with a 3 × 2 factorial arrangement [three Ca concentrations (10, 20, and 30 g kg–1) × two limestone particle sizes (480 and 1,978 µm)] with eight repetitions per treatment and six birds per experimental unit. The experiment included five days for adaptation and five days for total excreta collection. All birds were slaughtered at the end of the ten days to collect the ileal contents. The total or ileal Ca content was plotted against the Ca of diets concentration using linear regression analysis. The regression line slope represented the apparent retention (CaR) and digestibility coefficients of Ca (CaD) in limestone. There was interaction between Ca concentration in the diet and limestone granulometry on CaD (p = 0.001) and CaR (p < 0.001). The CaD and CaR of fine- and coarse-grained limestone increased linearly with increasing Ca concentrations in the diet. The apparent digestibility coefficients estimated for laying hens fed with fine-grained and coarse-grained limestone were 0.72 and 0.35, respectively. The apparent retention coefficients estimated for laying hens fed fine-grained and coarse-grained limestone were 0.96 and 0.47, respectively.

ABSTRACT In this study, we evaluated how guanidinoacetic acid (GAA) addition in diets with various metabolizable energy (ME) contents affects the performance of broiler chickens. We also estimated the equivalence of GAA in ME. We distributed 1,280 one-day-old broilers in a completely randomized design with eight treatments, eight replicates, and twenty birds per experimental unit. Treatments were based on ME levels (2,775-2,875-2,975 kcal/kg; 2,850-2,950-3,050 kcal/kg; 2,925-3,025-3,125 kcal/kg; or 3,000-3,100-3,200 kcal/kg, from 1 to 7, 8 to 21, and 22 to 42 days of age) and the inclusion of GAA (0 or 600 mg/kg). Supplementation of GAA increased weight gain in broilers at an energy level of 2,908 kcal/kg and improved feed conversion ratio (FCR) at energy levels of 2,908 and 2,983 kcal/kg. There was a linear reduction in feed intake and an improvement in FCR of broilers with increasing levels of energy in diets, with and without GAA addition. Solving the equivalence equation, by applying each of the weighted average energy levels studied. indicates the GAA equivalence of 133, 103, 74, and 44 kcal/kg of diet. In conclusion, GAA supplementation improves broilers’ efficiency of energy use; the average ME equivalence of 600 mg/kg of GAA is 88.5 kcal/kg. study (GAA (ME chickens 1280 280 1,28 onedayold one day old treatments replicates unit 2,7752,8752,975 277528752975 2,775 2,875 2,975 2 775 875 975 (2,775-2,875-2,97 kcalkg kcal kg 2,8502,9503,050 285029503050 2,850 2,950 3,050 850 950 3 050 2,850-2,950-3,05 2,9253,0253,125 292530253125 2,925 3,025 3,125 925 025 125 2,925-3,025-3,12 3,0003,1003,200 300031003200 3,000 3,100 3,200 000 100 200 3,000-3,100-3,20 7 21 4 age 0 ( 60 mg/kg. mgkg . mg mg/kg) 2908 908 2,90 (FCR 2983 983 2,98 equation studied 133 103 74 diet conclusion use 885 88 5 88. 128 28 1,2 7752 8752 2,7752,8752,97 27752875297 2775 2,77 2875 2,87 2975 2,97 77 87 97 (2,775-2,875-2,9 8502 9503 2,8502,9503,05 28502950305 2850 2,85 2950 2,95 3050 3,05 85 95 05 2,850-2,950-3,0 9253 0253 2,9253,0253,12 29253025312 2925 2,92 3025 3,02 3125 3,12 92 02 12 2,925-3,025-3,1 0003 1003 3,0003,1003,20 30003100320 3000 3,00 3100 3,10 3200 3,20 00 10 20 3,000-3,100-3,2 6 290 90 2,9 298 98 13 1, 2,7752,8752,9 2775287529 277 2,7 287 2,8 297 9 (2,775-2,875-2, 2,8502,9503,0 2850295030 285 295 305 3,0 2,850-2,950-3, 2,9253,0253,1 2925302531 292 302 312 3,1 2,925-3,025-3, 3,0003,1003,2 3000310032 300 310 320 3,2 3,000-3,100-3, 29 2, 2,7752,8752, 277528752 27 (2,775-2,875-2 2,8502,9503, 285029503 30 3, 2,850-2,950-3 2,9253,0253, 292530253 31 2,925-3,025-3 3,0003,1003, 300031003 32 3,000-3,100-3 2,7752,8752 27752875 (2,775-2,875- 2,8502,9503 28502950 2,850-2,950- 2,9253,0253 29253025 2,925-3,025- 3,0003,1003 30003100 3,000-3,100- 2,7752,875 2775287 (2,775-2,875 2,8502,950 2850295 2,850-2,950 2,9253,025 2925302 2,925-3,025 3,0003,100 3000310 3,000-3,100 2,7752,87 277528 (2,775-2,87 2,8502,95 285029 2,850-2,95 2,9253,02 292530 2,925-3,02 3,0003,10 300031 3,000-3,10 2,7752,8 27752 (2,775-2,8 2,8502,9 28502 2,850-2,9 2,9253,0 29253 2,925-3,0 3,0003,1 30003 3,000-3,1 2,7752, (2,775-2, 2,8502, 2,850-2, 2,9253, 2,925-3, 3,0003, 3,000-3, 2,7752 (2,775-2 2,8502 2,850-2 2,9253 2,925-3 3,0003 3,000-3 (2,775- 2,850- 2,925- 3,000- (2,775 (2,77 (2,7 (2, (2

ABSTRACT The objective of this study was to evaluate whether the addition of different levels of capsaicin in the diet of female turkeys has beneficial effects on growth performance and the antioxidant and oxidant status in serum and meat. A total of 150 female turkeys were distributed in a completely randomized design with three treatments with five replicates per treatment and ten birds per experimental unit. Treatments were identified as control (without additive); T400 – basal diet containing 400 mg/kg of pepper extract per kg of feed; and T800 – basal diet supplemented with 800 mg/kg of pepper extract per kg of feed. Growth performance was measured on days 1 and 20 of the experiment. Blood samples were collected at 20 days of the experiment for analysis of the oxidant and antioxidant status, and at 20 days, five birds were euthanized per treatment for the analysis of the oxidant and antioxidant status of the meat. The turkeys fed diet supplemented with capsaicin had lower feed intake and better feed:gain ratio. Turkeys in the T800 treatment showed a reduction in serum levels of reactive oxygen species (ROS) and thiobarbituric acid, and this same effect was observed for ROS in their breast meat. Capsaicin supplementation improves feed conversion and reduces feed intake without altering weight gain in female turkeys. Furthermore, the addition of 800 g/ton reduces lipid peroxidation and protein oxidation in the serum and reduces protein oxidation in broiler turkey meat. meat 15 unit additive additive) T T40 40 mgkg mg T80 80 2 feedgain ratio (ROS acid Furthermore gton g ton T4 4 T8 8

ABSTRACT This report examines the effects of calcium anacardate (CA) on the morphology, histology, and proteomics of the testes and epididymal ducts of breeding quail. To that end, 22 140-day-old males were grouped in four treatments, each with different concentrations of CA: 0% (control), 0.25%, 0.50%, and 0.75%. The testicles of the animals were weighed and measured, and proteins from the testicles were separated by 1D SDS-PAGE and analyzed via mass spectrometry. Overall, 35 bands were identified in the testicular tissue gels of European quail. Of these, 13 were significantly different, with treatment 0.75% CA being different from the control in all bands. Significant differences among the mean heights of the seminiferous epithelium and diameters of the epididymal duct were observed. In the control group, the average height of the seminiferous epithelium was 71.2 µm, and in 0.75% CA, it was 45.6 µm. Supplementing feed with CA altered the expression of specific proteins, such as superoxide dismutase and heat shock proteins, of the seminal plasma of quail, in addition to facilitating histological alterations regarding the height of the seminiferous epithelium and the diameter of the epididymal duct, improving the reproductive parameters. (CA morphology histology quail end 2 140dayold dayold 140 day old treatments 0 control, , (control) 025 25 0.25% 050 50 0.50% 075 75 measured D SDSPAGE SDS PAGE spectrometry Overall 3 these 1 0.75 observed group 712 71 71. µm 456 45 6 45. parameters 14 (control 02 0.25 05 5 0.50 07 7 0.7 4 0.2 0.5 0.

ABSTRACT The objective of this study was to evaluate the effects of dietary supplementation of purified lignin on the performance, relative organ weights, serum metabolites, and gene expression profiles of broiler chickens subjected to cyclic heat stress (HS). At 22 days old, 280 broilers were distributed in a completely randomized design with four treatments, ten repetitions, and seven birds per experimental unit. The birds were subjected to daily cyclic HS. A high temperature of 32±1 °C was maintained for 10 h/day (08:00–18:00 h), while a temperature of 22±1 °C was maintained for the remaining time. Treatments were a basal diet or basal diet with the addition of 5, 10, or 15 g of purified lignin/kg of diet. Data were analyzed using one-way ANOVA and means were compared by Tukey's test at 0.05 significance. There was no effect of lignin supplementation on performance, carcass yield, relative weights of the bursa, spleen, and liver, or serum levels of glucose, triglycerides, uric acid, malondialdehyde, triiodothyronine, or tetraiodothyronine. The abundance of mRNA of heat shock protein 70, nuclear factor-κB, glutathione peroxidase, and Cu,Zn-superoxide dismutase in the liver was similarly unaffected by treatments. Purified lignin supplementation does not improve performance or the antioxidant response of broiler chickens subjected to HS.

ABSTRACT Three experiments were carried out to evaluate the effect of dietary combination of different enzymes (phytase + protease) on performance, metabolizable energy, and amino acid digestibility of broiler chickens fed diets with nutritional reduction. A total of 1,400, 336, and 384 male chickens were distributed in a completely randomized design, in the experiments of performance, metabolism, and digestibility, respectively. Treatments were divided as follows: positive control (PC), negative control - NC1 (PC minus 0.16% Ca, 0.15% available P (aP), and 0.5% crude protein (CP)), NC2 (PC minus 0.16% Ca, 0.15% aP, and 1% CP), NC1 added with phytase deriving from citrobacter and protease deriving from Bacillus licheniformis (CBE), NC1 added with phytase deriving from E. coli and protease deriving from microbial fermentation (SE), NC2 added with CBE, and NC2 added with SE. A protein-free diet was included in the digestibility experiment. The nutritional restriction did not affect feed intake of birds in the first experiment; however, the restriction inhibited body weight gain and feed conversion ratio in all phases. In experiment 2, the nutritional restriction decreased AME and AMEn values, although the addition of phytase and protease in diets improved both parameters, mainly in NC2. Treatment NC2 impaired the standardized digestibility of total essential amino acids of animals subjected to experiment 3, although the addition of enzymes helped to recover the digestibility to levels similar to PC. Supplementation of phytase in association with protease is effective to improve performance, energy metabolism, and standardized amino acid digestibility of broilers fed diets with nutrient restriction.

ABSTRACT This study was conducted to evaluate the effects of dietary supplementation with capsaicinoids on the performance and gene expression of broilers. At 18 days of age, 120 male broilers chickens (Cobb 500) were distributed in a completely randomized design with three treatments, eight replicates, and five birds per experimental unit. The treatments were a basal diet or basal diet with the addition of 1 or 2 mg of capsaicinoids/kg of diet. The birds had free access to water and feed throughout the experimental period (18 to 26 days of age). Broiler performance was evaluated at 26 days of age, and one bird per experimental unit was selected to collect serum and jejunum samples. Jejunum samples were used to analyze the mRNA content. Data were analyzed using one-way ANOVA, and the means were compared with Tukey’s test at a significance of 0.05. There was no effect of capsaicinoid supplementation on performance, serum metabolites, or the expression of glutathione peroxidase mRNA in the jejunum of broilers. However, broilers supplemented with capsaicinoids showed a higher mRNA expression of Cu, Zn-superoxide dismutase and a reduced mRNA expression of nuclear factor-κB in the jejunum. Supplementation with 1 and 2 mg/kg capsaicinoids did not improve the performance of broilers from 18 to 26 days of age but increased the mRNA expression of Cu, Zn-superoxide dismutase and reduced the mRNA expression of nuclear factor-κB in the jejunum of broilers.

ABSTRACT. The objective of this study was to determine choline chloride replacement effects by a vegetable choline source, compost by Trachyspermum amni, Citrullus colocynthis, Achyranthus aspera, and Azadirachta indica in broiler feed. These compounds are fonts of phosphatidylcholine, a high-disponible molecule for intestinal absorption and choline supply. A total of 640 animals were randomly allocated in a completely randomized design, with four treatments and eight repetitions (n = 20), and zootechnical performance (body weight, weight gain, feed conversion ratio, and productive efficiency index), carcass yield, cuts yield, and organs (heart, liver, proventriculus, gizzard, and small intestine) relative weights were evaluated. Were evaluated two choline chloride levels (600 and 800 mg kg-1) and two vegetable choline levels (100 and 200 mg kg-1), added in a corn-soybean meal basal diet, during 42 days of raising. Results revealed better feed conversion ratio (p < 0.001) and production efficiency index (p < 0.001) in broilers fed vegetable choline, with no differences on body weight (p = 0.372) and weight gain (p = 0.427) among broilers. Carcass, cuts yield, and organ relative weights do not alter (p > 0.05) due to different group of supplementations. Findings in this trial concludes vegetable choline can adequately replace choline chloride in broiler feed, with improvement on performance and no compromising carcass, cuts or organ development.

ABSTRACT The objective of this study was to evaluate the effects of dietary nucleotide supplementation on growth performance, serum immunoglobulin G (IgG) and uric acid levels, immune-related organs, and intestinal morphometric parameters of broiler chickens under pre- and post-inflammatory challenge with lipopolysaccharide (LPS). Ninety-six seven-day-old male broiler chicks were randomized in a 2×2 factorial design composed of two dietary types (supplemented with 0 and 0.3 g of purified nucleotides/kg of feed) and two inflammatory conditions (with and without LPS administration) with eight replicates per treatment and three birds per cage. The experimental period was divided into two phases: 7-20 days of age (pre-LPS challenge) and 21-35 days of age (post-LPS challenge). Data were analyzed using one-way and two-way ANOVA for the pre- and post-challenge phases, respectively. During the pre-challenge phase, dietary nucleotide supplementation improved body weight (982 vs. 1009 g/bird), daily weight gain (58.1 vs. 60.1 g/bird), feed conversion rate (1.28 vs. 1.25 g/g), and serum concentration of IgG (1.17 vs. 1.76 mg/mL) of broilers. During the post-challenge phase, nucleotide supplementation increased serum IgG of broilers at 28 days of age (3.01 vs. 4.34 mg/mL). For the intestinal morphometric parameters, nucleotide supplementation increased villus height (299.3 vs. 315.6 μm). Dietary nucleotide supplementation improves the performance of broilers from seven to 20 days of age (pre-LPS challenge). However, from 21 to 35 days of age, supplementation of 0.3 g of purified nucleotides/kg of feed, independent of inflammatory challenge, does not contribute to improve performance of broilers. Additionally, nucleotide supplementation increases IgG production and villus height in the jejunum of broilers.

ABSTRACT The objective of the present study was to compare the effects of corn processing on performance and intestinal parameters of weanling piglets. To accomplish our goal, 42 piglets (21 days-old, 7.18±1.0 kg body weight) were randomly allocated (seven pens/treatment; three pigs/pen) to one of two treatments: ground corn – corn ground through a hammer mill with a 1.0-mm screen after being ground by a hammer mill with a 3.0-mm screen, and extruded corn – corn was wet extruded after being ground by a hammer mill with a 2.0-mm screen and, after extrusion, it was ground by a hammer mill with a 1.0-mm screen. In both methods, corn from the same batch was used. Results were considered statistically significant when P<0.05 and a tendency when P<0.10. Analyses were performed using the GLIMMIX procedure of SAS. Pigs fed ground or extruded corn diet had similar growth performance. Duodenum and jejunum of pigs fed extruded corn had greater villus height compared with those of pigs fed ground corn. Crypt depth was not influenced by corn processing. Duodenum and jejunum of pigs fed extruded corn had greater villus:crypt ratio compared with those of pigs fed ground corn. In the duodenum, the expression of zonula occludens-1 (ZO-1) was greater, and the expression of Occludin-1 tended to be greater in pigs fed the extruded corn diets. There was no effect of corn processing on ZO-1 and Occludin-1 expression in the jejunum, nor TGF-β1 expression in duodenum and jejunum. There was no effect of the type of corn processing on colonic total bacteria or Enterobacteriaceae and Lactobacillus abundance. Piglets fed diets with ground corn or extruded corn have similar growth performance. However, piglets fed diets with extruded corn present improved intestinal morphology and tight junction protein expression compared with those fed ground corn.

RESUMO: Um experimento foi realizado para avaliar o efeito da diminuição dos níveis de vitamina D3 no premix e a suplementação de 1,25-dihidroxivitamina D3-glicosídeo (1,25(OH)2D3-glicosídeo) sobre o desempenho, rendimento de carcaça e qualidade óssea em frangos de corte de 42 dias. Machos Cobb500® de sete dias de idade foram distribuídos em delineamento inteiramente casualizado com seis tratamentos: uma dieta controle com inclusão de vitamina D3 no premix, sem suplementação de 1,25(OH)2D3-glicosídeo, e cinco dietas com níveis decrescentes de vitamina D3 (100%, 75%, 50%, 25% e 0% em relação ao controle) mais a adição de 1,25(OH)2D3-glicosídeo (50g ton-1 de dieta). Entre os principais resultados, foi observado que a redução do teor de vitamina D3 no premix quando adicionado 1,25(OH)2D3-glicosídeo não afetou (P>0,05) o desempenho, o rendimento da carcaça e as variáveis da qualidade óssea. No entanto, as variáveis do desempenho e o rendimento (consumo de ração, ganho de peso, conversão alimentar, peso da carcaça quente) e da qualidade dos ossos (peso seco, comprimento, matéria mineral e resistência à ruptura) de frangos alimentados com dietas sem vitamina D3 no premix, com a adição de 1,25(OH)2D3-glicosídeo como a única fonte de vitamina D, teve como resultado valores muito baixos (P<0,05) em comparação ao controle. Para os propósitos da presente pesquisa, concluiu-se que é possível a redução do teor de vitamina D3 no premix até 75% quando a dieta de frangos de corte machos é suplementada com 1,25(OH)2D3-glicosídeo. No entanto, o uso de 1,25(OH)2D3-glicosídeo como única fonte de vitamina D, conforme testado aqui, não é recomendado para dietas de frangos de corte.

ABSTRACT: An experiment was performed to evaluate the effect of decreased levels of vitamin D3 in the premix and 1,25-dyhydroxyvitamin D3-glycoside (1,25(OH)2D3-glycoside) supplementation on performance, carcass yield and bone quality in 42d old broilers. Seven-d-old male chickens Cobb500® were distributed in a randomized design with six treatments: a control diet with inclusion of vitamin D3 in the premix, without supplementation of 1,25(OH)2D3-glycoside, and five diets with decreased levels of vitamin D3 (100%, 75%, 50%, 25% and 0% about the control) plus the addition of 1,25(OH)2D3-glycoside, 50g ton-1 of diet. The main results were to reduce the tenor of Vitamin D3 in the premix when the addition of 1,25(OH)2D3-glycoside did not affect (P>0.05) the performance, carcass yield and bone quality variables. However, performance (feed intake, gain weight, feed conversion), yield (warm carcass weight) and bone quality (dry weight, length, mineral matter and breaking strength) of broilers fed with diets without vitamin D3 in the premix and with addition of 1,25(OH)2D3-glycoside, which was the single source of vitamin D, had as a result very low (P<0.05) values comparing to the control. For the purposes of the present research, it was concluded that is possible the reduction of vitamin D3 tenor in the premix up to 75% when the diet of male broilers is supplemented with 1,25(OH)2D3-glycoside. However, the use of 1,25(OH)2D3-glycoside as a single source of vitamin D, as tested here, is not recommended for broilers diets.

Resumo Objetivou-se determinar a exigência de metionina + cistina total para frangas na fase inicial e verificar seu efeito sobre a fase de postura. Na primeira fase experimental, 720 aves (50% Lohmann LSL e 50% Lohmann Brown) com uma semana de idade foram distribuídas em delineamento experimental inteiramente casualizado, em esquema fatorial 5 x 2 (níveis de met + cis e linhagens), com quatro repetições e 18 aves por repetição. Os níveis de met + cis total estudados foram 0,536; 0,616; 0,696; 0,776; e 0,856 %. Ao atingirem 22 semanas de idade, iniciou-se a segunda fase experimental, sendo utilizadas 240 aves (50% Lohmann LSL e 50% Lohmann Brown) provenientes da primeira fase experimental. A ração fornecida às aves nesta fase foi igual para todos os tratamentos. Na fase de produção avaliaram-se os efeitos residuais das dietas fornecidas no período inicial sobre os parâmetros produtivos. As exigências de metionina + cistina recomendadas para aves leves e semipesadas, no período de 1 a 6 semanas de idade, são de 0,778% de met + cis total (correspondendo a 0,700% de met + cis digestível) e 0,739% de met + cis total (correspondendo a 0,665% de met + cis digestível), respectivamente.

Abstract An experiment was carried out to evaluate the requirement of methionine +cystine for growing pullets at starter phase (1 to 6 weeks old) and its effect on the laying phase. In the first experiment, 720 birds (50% Lohmann LSL and 50% Lohmann Brown) at one week of age were distributed on a completely randomized design, 5 x 2 factorial arrangement (levels of met + cys and strain), with four replications and 18 birds each. The levels of total methionine + cystine studied were 0.536; 0.616; 0.696; 0.776; and 0.856 %. At 22 weeks of age, 240 birds were used for the second experimental phase. The diets given to birds at this phase was the same for all the treatments. In the production phase, the residual effects of the experimental diets provided during the initial phase on the production parameters were evaluated. The level of methionine + cystine recommended for white-egg and brown-egg pullets in the period from 1 to 6 weeks of age are 0.778 % of total methionine + cystine (0.700% met + cis digestible) and 0.739% of total methionine + cystine (0.665% of digestible methionine + cystine), respectively.

Resumo Objetivou-se determinar a exigência nutricional de cálcio e a melhor relação cálcio:fósforo em rações para poedeiras leves de 24 a 40 semanas de idade. Foram utilizadas 324 aves Hy-Line W-36, distribuídas em delineamento inteiramente casualizado, esquema fatorial 3x3, sendo três níveis de cálcio (3,9; 4,2 e 4,5 %) e três relações cálcio/fósforo (9,3; 10,53 e 12,12/1), totalizando nove tratamentos, seis repetições e seis aves por unidade experimental. Avaliou-se o desempenho produtivo, a qualidade do ovo, as características ósseas, o balanço de cálcio e fósforo e a mortalidade. Não houve interação (P>0,05) entre os níveis de cálcio e as relações cálcio/fósforo para nenhuma das variáveis, porém os níveis de cálcio promoveram efeito (P<0,05) sobre o peso e porcentagem da casca, cálcio na casca, ovos perdidos, consumo de cálcio e fósforo, cálcio e fósforo na excreta, cálcio e fósforo retido. A relação cálcio/fósforo influenciou significativamente (P<0,05) o consumo de ração, ganho de peso, conversão alimentar, consumo de cálcio e fósforo, fósforo na excreta e fósforo retido. Rações contendo 4,5% de cálcio e relação cálcio:fósforo de 12,12:1, correspondendo ao consumo de cálcio de 3,71 g/ave/dia e de fósforo de 306 mg/ave/dia, garantem desempenho satisfatório em rações para poedeiras leves no período de 24 a 40 semanas.

Abstract The objective of this study was to determine the nutritional requirement for calcium and the best calcium:phosphorus ratio in the diet for laying hens from 24 to 40 weeks of age. 324 Hy-Line W-36 birds were distributed in a completely randomized design in 3x3 factorial scheme, consisting of three levels of calcium (3.9, 4.2, and 4.5%) and three calcium:phosphorus ratios (9.3, 10.53, and 12.12:1) totaling nine treatments, six replicates and six birds each. We evaluated performance, egg quality, bone characteristics, balance of calcium and phosphorus, and mortality. There was no interaction (P> 0.05) between calcium levels and calcium:phosphorus ratio for the variables, but levels of calcium affected (P <0.05) weight and shell percentage, calcium in the shell, lost eggs, consumption of calcium and phosphorus, calcium and phosphorus excretion, and retained calcium and phosphorus. The calcium:phosphorus ratio affected significantly (P <0.05) feed intake, weight gain, feed conversion per dozen eggs, egg mass, calcium and phosphorus intake, phosphorus excretion, and retained phosphorus. Diets containing 4.5% calcium and the calcium:phosphorus ratio of 12,12:1, corresponding to a calcium intake of 3.71 g/hen/day and phosphorus of 306 mg/bird /day, guarantee satisfactory performance in diets for laying hens from 24 to 40 weeks.

Resumo Para determinar a relação ideal triptofano digestível:lisina digestível em dietas para poedeiras de 42 a 58 semanas de idade, 240 poedeiras Hy-Line W-36 com 42 semanas de idade foram distribuídas em delineamento inteiramente ao acaso com cinco tratamentos, oito repetições e seis aves por unidade experimental. Com 42 semanas de idade as aves foram submetidas aos tratamentos experimentais, que consistiram de dietas com quantidades iguais de nutrientes, exceto para o nível de triptofano digestível. Os níveis de triptofano digestível nas dietas experimentais foram 0,149; 0,160; 0,171; 0,182 e 0.193%, gerando relações triptofano digestível:lisina digestível de 21,5; 23,1; 24,6; 26,2 e 27,8%. O nível de lisina digestível nas dietas foi sub-ótimo (0,694%). As mesmas relações entre a lisina e outros aminoácidos foram mantidas em todas as dietas experimentais. A relação ideal triptofano digestpivel:lisina digestível foi estimada por meio dos parâmetros estudados utilizando análise de variância e análise de regressão polinomial (α = 0.05). A relação triptofano digestível:lisina digestível nas dietas influenciaram quadraticamente a produção de ovos, massa de ovos, conversão alimentar e a eficiência de utilização de lisina digestível para massa de ovos. No entanto, não houve efeito (P> 0,05) sobre o peso dos ovos, conversão alimentar por dúzia de ovos, eficiência de utilização de lisina digestível para número de ovos produzidos, porcentagem dos componentes dos ovos e ganho de peso. A relação ideal triptofano digestível:lisina digestível estimada para esses parâmetros variaram de 23,6 a 24,3%. A relação triptofano digestível:lisina digestível recomendada em dietas para poedeiras de 42 a 58 semanas de idade é 24,3%.

SUMMARY To determine the ideal digestible tryptophan-to-digestible lysine ratio in diets for laying hens of 42 to 58 weeks of age, 240 Hy-Line W-36 hens at 42 weeks of age were distributed in a completely randomized design with five treatments, eight replicates and six birds per experimental unit. At 42 weeks of age, the birds were subjected to experimental treatments that consisted of diets with equal amounts of nutrients, except for the digestible tryptophan level. The digestible tryptophan levels in the experimental diets were 0.149, 0.160, 0.171, 0.182 and 0.193%, generating digestible tryptophan-to-digestible lysine ratios of 21.5, 23.1, 24.6, 26.2 and 27.8%. The digestible lysine level in the diets was sub-optimal (0.694%). The same ratios between lysine and the other amino acids were maintained in all experimental diets. The ideal digestible tryptophan-to-digestible lysine ratio was estimated through the studied parameters using analysis of variance and polynomial regression analysis (α = 0.05). The digestible tryptophan-to-digestible lysine ratio in diets quadratically affected egg production, egg mass, feed conversion per egg mass and use efficiency of digestible lysine for egg mass. However, there were no effect (P>0.05) on egg weight, feed conversion per dozen eggs, use efficiency of digestible lysine for number of eggs produced, percentage of egg components and weight gain. The digestible tryptophan-to-digestible lysine ratio estimated for theses parameters ranged from 23.6 to 24.3%. The digestible tryptophan-to-digestible lysine ratio recommended in diets for laying hens of 42 to 58 weeks of age is 24.3%.