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Context: Canola meal is a protein-rich feedstuff with an amino acid profile that is reasonably well balanced and has the potential to replace soybean meal in poultry diets. Aim: The objective of the present study was to investigate the relationship between the crude protein content and apparent ileal digestible amino acid contents of Australian canola meals. Methods: Thirteen canola meal samples, processed by expeller or solvent extractions, were collected. The digestibility assay diets were based on dextrose and contained canola meal as the sole source of protein. The proportions of dextrose and canola meal were varied in each diet to obtain ~200 g/kg crude protein. Each diet was fed to three cages of six 35-day-old broilers for 7 days. At the end of the assay, digesta from the terminal ileum was collected for digestibility determination. Key results: Crude protein contents were positively correlated with amino acid contents (P < 0.05 to 0.001), except that of serine (r = 0.43; P = 0.11). Significant correlations between the crude protein content and ileal digestible contents were observed for most of amino acids, with coefficients of >0.80 (P < 0.05 to 0.001). Low correlation coefficients were observed for lysine (r = 0.48; P = 0.11) and serine (r = 0.55; P = 0.06). The poor correlation for lysine may be reflective of reduced lysine availability during processing. Conclusions: The results showed that the crude protein content of canola meal could serve as a predictor of apparent ileal digestible content of most amino acids for broiler chickens. Implications: Regression equations developed in the present study could be used to predict the content of ileal digestible amino acids in canola meal by using analysed crude protein contents. Canola meal (CM) is a potentially important protein source for poultry. The amino acid profile of CM is reasonably well balanced, but digestibility of amino acids is key to the nutritional value of CM. Amino acid analysis and in vivo digestibility assays are costly and time consuming. The aim of this study was to determine whether the digestible amino acid content of CM could be deduced from its crude protein content, which is routinely determined. This article belongs to the Collection Sustainable Animal Agriculture for Developing Countries 2023. [ABSTRACT FROM AUTHOR]

This study was conducted to assess the effects of the supplementation of a multicarbohydrase-phytase complex (MCP) which contains xylanase, glucanase, arabinofuranosidase, and superdose phytase, and a combination of a xylanase-glucanase and a phytase (XGP) products in a corn-soybean diet with reduced apparent metabolizable energy (AME), digestible amino acids (DAA), and minerals (calcium and phosphorus) on egg production performance, egg quality, and economics of laying hens. Dekalb White layers (n = 480, BW = 1.56 ± 0.03 kg, 42 weeks old) with a mean hen-day egg production rate of 91.43 ± 1.31% were assigned to four diets with 15 replicates of eight layers per group: standard layer diet (SLD), low-density diet 1-(LD1, SLD less 65 kcal/kg AME, 2% DAA, 0.20% Ca, and 0.15% P) + MCP (0.01%), low-density diet 2-(LD2, SLD less 85 kcal/kg AME, 4% DAA, 0.20% Ca, and P) + MCP (0.01%), and LD2 + XGP (0.01% XG and 0.015% P). Diets supplemented with MCP and XGP had comparable production and egg quality to SLD. The LD1 + MCP, LD2 + MCP, and LD2 + XGP had a poor feed conversion ratio (FCR) and a higher mean daily feed intake (FI) than SLD. Eggshells were thicker for LD1 + MCP and LD2 + MCP than SLD and LD2 + XGP from 58 to 61 weeks of age. The income over feed cost (IOFC) was similar among layers fed the test diets. The findings indicated that enzyme supplementation compensated satisfactorily for the reduced amount of DAA and minerals in the diet. Reduction of 65–85 kcal/kg AME caused an adverse effect on FCR and FI of layers.

Simple Summary: Annually, various corn hybrids are introduced to the market for cultivation. Companies engaged in developing these technologies aim to enhance genetic traits, with a focus on creating productive hybrids capable of addressing the challenges of agriculture. The global corn market predominantly concerns livestock feed production, particularly for poultry farming, which seeks nutrient-rich raw materials with high digestibility for broilers. Nevertheless, when comparing the diverse transgenic technologies of corn, even when cultivated under the same conditions, significant differences were observed. Surprisingly, in the present study, the most productive corn transgenic technology in the field exhibited increased contamination by mycotoxins and a lower content of some important nutrients for poultry. This outcome highlights the critical need for a comprehensive assessment of the implications of transgenic technologies for nutritional composition and agricultural product safety, especially when intended for animal feed. Consequently, we concluded that the integration of nutritional considerations into the genetic improvement of transgenic corn, along with detailed information about resistance to Fusarium, holds great significance and may yield positive outcomes in the future. This approach ensures the production of nutritionally balanced, mycotoxin-safe, and economically viable livestock feed. Corn is one of the most produced cereals in the world and plays a major role in poultry nutrition. As there is limited scientific information regarding the impact of transgenic technology on the quality and nutrient composition of the grains, this study investigated the effect of three major transgenic corn varieties—VT PRO3®, PowerCore® ULTRA, and Agrisure® Viptera 3—on the field traits, nutrient composition, and mycotoxin contamination of corn grains cultivated in southern Brazil during three consecutive harvests. VT PRO3®, while demonstrating superior crop yield, showed susceptibility to mycotoxins, particularly fumonisins. In contrast, PowerCore® ULTRA, with the lowest yield, consistently exhibited lower levels of fumonisins. VT PRO3® had higher AMEn than the other varieties, while PowerCore® ULTRA had the highest total and digestible amino acid contents over the three years. The study's comprehensive analysis reveals the distinct impact of transgenic corn technologies on both productivity and nutritional levels. Balancing the crops yield, mycotoxin resistance, and nutritional content of corn is crucial to meet the demands of the poultry feed industry. Such insights are essential for decision-making, ensuring sustainability and efficiency in agricultural production as well as meeting the demands of the poultry industry. [ABSTRACT FROM AUTHOR]

Corn is one of the most produced cereals in the world and plays a major role in poultry nutrition. As there is limited scientific information regarding the impact of transgenic technology on the quality and nutrient composition of the grains, this study investigated the effect of three major transgenic corn varieties—VT PRO3®, PowerCore® ULTRA, and Agrisure® Viptera 3—on the field traits, nutrient composition, and mycotoxin contamination of corn grains cultivated in southern Brazil during three consecutive harvests. VT PRO3®, while demonstrating superior crop yield, showed susceptibility to mycotoxins, particularly fumonisins. In contrast, PowerCore® ULTRA, with the lowest yield, consistently exhibited lower levels of fumonisins. VT PRO3® had higher AMEn than the other varieties, while PowerCore® ULTRA had the highest total and digestible amino acid contents over the three years. The study’s comprehensive analysis reveals the distinct impact of transgenic corn technologies on both productivity and nutritional levels. Balancing the crops yield, mycotoxin resistance, and nutritional content of corn is crucial to meet the demands of the poultry feed industry. Such insights are essential for decision-making, ensuring sustainability and efficiency in agricultural production as well as meeting the demands of the poultry industry.

Abstract The progress in our understanding of the endogenous protein concept over the past century is reviewed. Non-dietary proteins found in the digesta at the terminal ileum of poultry, known as endogenous protein loss, are comprised of digestive secretions, mucus and sloughed gut epithelial cells. The measurement of this loss is of fundamental importance because it is an indicator of gut metabolism and is essential to adjust apparent estimates of ileal amino acid digestibility. The ileal endogenous amino acid losses comprise of two components, namely basal and specific losses. The basal losses are fixed and associated with feed dry matter intake, whereas the specific losses are variable and induced by the presence of dietary components such as fibre and anti-nutrients. Currently there is no methodology available to directly measure the specific endogenous losses and these losses are calculated by determining the basal and total (basal plus specific) losses and, then subtracting the basal losses from total losses. The seminal features, specific applications and shortcomings of available methodologies are briefly outlined as well as the practical challenges faced in using the published endogenous amino acid loss values for true digestibility corrections. The relevance of taurine as a component of endogenous protein flow in poultry is identified for the first time.

The effect of different types of low protein diets based on digestible amino acids on laying performance, egg quality, apparent nutrient digestibility and serum biochemical indexes were studied. 648 chickens were randomly divided into nine groups, with six replicates in each group and 12 chickens in each replicate, and 3 x 3 two factor design was adopted. The diet types were corn-soybean meal, corn-soybean meal-cotton meal and corn-soybean-peanut meal diets, and the protein levels were 16.4%, 14.4% and 12.4%. The results showed that reducing dietary protein level had no significant effect on production performance, egg quality, apparent nutrient digestibility, serum total protein, urea nitrogen and uric acid content (P>0.05). Corn-soybean-cotton meal and corn-soybean-peanut meal diets had no significant effect on production performance, egg quality, apparent digestibility and serum biochemical indexes (P>0.05). The interaction of diet type and protein level had no significant effect on egg quality and apparent digestibility of nutrients (P>0.05). Except for group 4 and group 5, the economic benefits of each experimental group were higher than those of the control group. The experiment indicates that the adaptive group are corn-soybean meal + protein level of 12.4%, corn-soybean mealcotton meal + protein level of 16.4%, corn-soybean meal-peanut meal + protein level of 14.4%. [ABSTRACT FROM AUTHOR]

The experiment was to study the effect of different types of low protein diets based on digestible amino acids on apparent digestibility, serum biochemical indexes and nitrogen pollutant emission in broilers. 648 one-day-old Hubbard broilers were randomly divided into 12 groups, with six replicates in each group and nine chickens in each replicate. The experiment used a 3×4 two-factor design. The diet types were corn-soybean meal, corn-soybean-cotton meal, and corn-soybean-peanut meal. The standard protein levels of each stage were 22%, 20% and 19%, and other protein levels were 1%, 2% and 3% lower than standard level, respectively. The experiment lasted for 6 w. The results showed that decreasing dietary protein level significantly decreased the content of indole, skatin, nitrogen and ammonia concentration in feces (P<0.05). Miscellaneous meal diet significantly increased ammonia concentration (P<0.05). The interaction of dietary type and protein concentration significantly reduced the content of indole, skatin and nitrogen as well as ammonia concentration in feces (P<0.05). The experiment indicates that feeding effect was best when corn-soybean meal-cottonmeal diet protein level was decreased by 1.5%, corn-soybean meal-cottonmeal diet protein level was decreased by 2%, and corn-soybean meal-peanut meal diet protein level was decreased by 2%. [ABSTRACT FROM AUTHOR]

The objectives of this study were to investigate the effects of extrusion on the chemical compositions, surface structure, and molecular structure of brewer's spent grain (BSG), as well as to determine the digestible energy (DE), metabolizable energy (ME), apparent total tract digestibility (ATTD) of nutrients and energy, and amino acid (AA) digestibility of extruded BSG when fed to growing pigs. Firstly, we determined the changes in chemical compositions and molecular structure of both non-extruded and extruded BSG. In Exp. 1, eighteen growing pigs were fed three different diets including one corn-soybean meal basal diet and two experimental diets containing 20% BSG with or without extrusion. Feces and urine were collected to determine the ATTD of nutrients and energy, DE, and ME of extruded or non-extruded BSG. In Exp. 2, eighteen growing pigs were fed three different diets including 30% BSG with or without extrusion, and an N-free diet. Ileal digesta was collected through the slaughter method to determine the apparent ileal digestibility (AID) and standardized ileal digestibility (SID) of AA of extruded or non-extruded BSG. The results showed that extrusion reduced the neutral detergent fiber, hemicellulose and cellulose contents in BSG, and increased the Arg, Asp, Glu, Ser, Tyr, total indispensable AA and total AA contents of BSG, altered the surface structure of BSG, increased the peak absorbance in amide I and amide II height, amide II and amide (I+II) area, α-helix height, decreased β-sheet height, and weakened band intensities in cellulosic compounds (CELC) area, structural carbohydrates (SCHO) area, carbohydrates area (CHO) peak 2 and 3 height, the area ratio of CELC: CHO and CELC: SCHO. Moreover, DE and ME values and ATTD of energy, dry matter, crude protein, acid detergent fiber, neutral detergent fiber, cellulose and hemicellulose increased (P < 0.05) when pigs were fed extruded BSG diets. The AID and SID of Arg, His, Lys, Val and Gly increased, whereas the AID and SID of Ile and Leu decreased when pigs were fed extrusion diets (P < 0.05). Our study found that the ATTD of nutrients and AA digestibility in pigs were positively correlated with the molecular structure of proteins, and negatively correlated with the molecular structure of carbohydrates (P < 0.05). These findings suggested that extrusion had the potential to improve the nutrient digestibility of BSG by altering its chemical compositions, surface structure, and molecular structure., (© The Author(s) 2024. Published by Oxford University Press on behalf of the American Society of Animal Science. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

The progress in our understanding of the endogenous protein concept over the past century is reviewed. Non-dietary proteins found in the digesta at the terminal ileum of poultry, known as endogenous protein loss, are comprised of digestive secretions, mucus and sloughed gut epithelial cells. The measurement of this loss is of fundamental importance because it is an indicator of gut metabolism and is essential to adjust apparent estimates of ileal amino acid digestibility. The ileal endogenous amino acid losses comprise of two components, namely basal and specific losses. The basal losses are fixed and associated with feed dry matter intake, whereas the specific losses are variable and induced by the presence of dietary components such as fibre and anti-nutrients. Currently there is no methodology available to directly measure the specific endogenous losses and these losses are calculated by determining the basal and total (basal plus specific) losses and, then subtracting the basal losses from total losses. The seminal features, specific applications and shortcomings of available methodologies are briefly outlined as well as the practical challenges faced in using the published endogenous amino acid loss values for true digestibility corrections. The relevance of taurine as a component of endogenous protein flow in poultry is identified for the first time. [ABSTRACT FROM AUTHOR]

This study aimed to find the digestible lysine (d.Lys), digestible sulfur amino acids (d.SAA), and digestible threonine (d.Thr) requirements to optimize body weight gain (BWG) and feed conversion ratio (FCR) via adaptive neuro-fuzzy inference systems (ANFIS) using either the Genetic algorithm (ANFIS-GA) or Particle Swarm Optimization algorithm (ANFIS-PSO) in Cobb-500 chicks from 1 to 10 d of age. The range of amino acids was 90 to 115% of the recommendations for male Cobb-500 chicks. The estimated dietary d.Lys, d.SAA, and d.Thr requirements by ANFIS-GA and ANFIS-PSO to optimize BWG were the same and were 12.10, 8.98, and 7.89 g/kg, respectively. The optimum BWG predicted by ANFIS-GA and ANFIS-PSO were 270 and 266 g, respectively for the 1 to 10 d period. The estimated dietary requirements of d.Lys, d.SAA, and d.Thr to minimize FCR at 0.995 by ANFIS-GA were 12.10, 8.98, and 7.89 g/kg, respectively. Although the estimated d.Lys and d.SAA requirements by ANFIS-PSO and ANFIS-GA were identical, the predicted d.Thr requirement by ANFIS-PSO was 0.01 g/kg higher than by ANFIS-GA to minimize FCR at 0.963. Comparison of goodness of fit in term of root mean square error revealed that the ANFIS-GA prediction was more accurate than ANFIS-PSO. This study demonstrates that the hybrid methodology of ANFIS-GA is as an effective and accurate approach to modeling and optimizing nutrient requirements. [ABSTRACT FROM AUTHOR]

This experiment was conducted to determine standardized ileal amino acid digestibility (SIAAD) of commonly used feed ingredients in poultry diets in Pakistan. These feed ingredients included corn, rice broken (RB), rice polishings (RP), wheat bran (WB), sunflower meal (SFM), cottonseed meal (CSM), guar meal (GM), soybean meal (SBM) from India and Argentine and fish meal (FM). The SIAAD of each ingredient was determined in triplicate using 21-days-old broilers. Day-old male broiler chicks (Hubbard× Hubbard) were reared on corn-SBM based diet from 1 to 13 days and thereafter birds were fed experimental diets from day 14 to 21. Each diet was fed to 36 birds kept in six replicate cages, each cage had six birds. In cereals, the SIAAD of corn’s amino acid (AA) (90.1%) was similar (p>0.05) to RB (89.0%). Isoleucine (97.8%) and lysine (96.9%) were highly digestible AA in corn and RB, respectively. Among cereal-by products, WB’s SIAAD (76.9%) was same (p>0.05) as RP (71.9%). Arginine from WB (82.5%) and RP (83.2%) was highly digestible. However, threonine in WB (72.7%) and leucine in RP (69.6%) were the lowest digestible AAs. In plant protein meals, AAs from Argentine-SBM (85.1%) and Indian-SBM (83.4%) had higher (p0.05). The SBM from plant protein meals had higher (p

Three experiments were carried out to determine the nutritional values and evaluate the performance of piglets fed on canola meal. In experiment I, a digestibility assay was conducted using fourteen barrow pigs, with an initial body weight of 20.62±3.30 kg. The evaluated feedstuff was canola meal, with a level of 250 g/kg in the basal diet (corn + soybean meal-based). The experimental unit consisted of one pig, with a total of seven experimental units per diet. The values as (fed basis) of digestible (DE) and metabolizable (ME) energy of canola meal were 2,995 kcal/kg and 2,796 kcal/kg, respectively. In experiment II, ileal digestibility assays were carried out to determine the apparent and true ileal digestibility coefficient and digestible amino acids. Three crossbred pigs were used, with a BW of 38.6±1.98 kg. The treatments consisted of two diets, with a single source of protein (canola meal) and one protein-free diet (OFD). The values of digestible amino acids in canola meal were as follows: lysine: 11.8 g/kg; methionine+cystine: 9.1 g/kg; threonine: 7.9 g/kg; tryptophan: 2.4 g/kg; leucine: 15.7 g/kg; and isoleucine: 8.7 g/kg. In experiment III, 60 piglets (BW= 15.08±0.72 kg to 30.26±2.78 kg) were allotted in a completely randomized design. The treatments consisted of four diets with increasing levels of canola meal (50, 100, 150 and 200 g/kg), six replicates and experimental unit consisted of two pigs. Additionally, a control diet was formulated containing 0.0 g/kg CM. Regression analysis indicates that there was no effect (P?0.05) of the level of canola meal inclusion on pigs performance. The performance results suggest that it is feasible to use up to 200 g/kg of canola meal in starting pigs diet, without impairing performance and the feeding cost.

This study analysed the effects of digestible lysine on the performance parameters, morphometry and quality of the breast muscle (Pectoralis major) of Cobb 500 broiler chickens aged 21 and 42 days. Two completely randomized experiments were performed, with five treatments and eight replications of 30 birds per treatment. The diets were adjusted according to the nutritional requirements for each phase of poultry development, with digestible lysine levels during the initial phase (birds aged 1 to 21 days) at 1.12, 1.19, 1.25, 1.31, and 1.37% and during the final phase (22 to 42 days) at 0.97, 1.02, 1.08, 1.13, and 1.19%. During the initial phase, lysine supplementation had a significant effect (P<0.05) on weight gain and red content in breast meat, with 1.24% and 1.29% digestible lysine resulting in maximum weight gain and red content, respectively. No significant difference (P>0.05) was observed in breast muscle morphometry, carcass yield, performance, or meat quality in birds aged 22-42 days for the different levels of lysine, suggesting that the lowest level of lysine tested did not have a negative impact on production characteristics even though it was below the recommended levels for this species. In conclusion, 1.24% digestible lysine is recommended for maximum weight gain at the initial phase of broiler chicken development (1-21 days) and 0.97% is sufficient to meet the nutritional requirements of birds at the final phase (22-42 days) without compromising production performance. [ABSTRACT FROM AUTHOR]

For the effective utilization of meals derived from the newly developed yellow-seeded canola varieties in turkeys’ diets, it is critical to determine their nutritive value and their impact on growth and digestive physiological responses and the potential benefit of enzyme supplementation. Thus, the standardised ileal amino acid digestibility ( SIAAD ) and nitrogen-corrected apparent metabolisable energy ( AME n ) content of B. napus yellow, B. juncea yellow and B. napus black canola meal ( CM ) and the effect of feeding 200 g/kg of the meals on growth performance and gut physiological responses with or without a multi-carbohydrase enzyme we determined. For the SIAAD assay, semi-purified diets containing the CM types were fed to turkeys of 21–28 d of age. For the AME n assay, diets containing 300 g/kg of the CM types without or with a multi-carbohydrase enzyme were fed to turkeys of 35–40 d of age. The growth performance study was a 5 × 2 factorial arrangement to evaluate the effects of feeding 200 g/kg of the CM types (i.e., Control, B. napus black from Canada and Poland, B. napus yellow, and B. juncea yellow) without or with enzyme on growth performance and gut physiological responses of turkeys. There were no differences among CM types in the SIAAD coefficients and AME n content. Standardised ileal digestible amino acids contents were higher in B. juncea meal (28.3, 15.5 and 14.6 g/kg for arginine, lysine, and threonine, respectively) compared to B. napus yellow (23.7, 18.5, and 14.6 g/kg) and B. napus black (21.5, 17.5, and 13.3 g/kg) meals. The AME n contents of B. juncea , B. napus yellow, and conventional B. napus black were 9.51, 9.28, and 8.97 MJ/kg, respectively. In the growth performance study, feed intake and body weight gain did not differ among treatments. However, during the starter phase, there was an effect of diet on the feed conversion ratio with B. napus black (Canada and Poland) having the highest. Feed conversion was improved by enzyme supplementation. There was a significant effect of enzyme supplementation on the content of short chain fatty acids in cecal digesta with an increase in acetic and butyric acids, the latter one known to be beneficial in controlling enteric pathogens and in improving gut health. In conclusion, 200 g/kg of all the CM types can be used effectively to replace soybean meal in diets for turkeys when diets are formulated on digestible amino acids and AME n basis. [ABSTRACT FROM AUTHOR]

Current experiment established different criteria to evaluate the requirements of digestible isoleucine for 22- and 42-day-old broilers by different regression models (quadratic, exponential and Linear Response Plateau) and, in the case of statistical significance, the comparison of means by Duncan’s test at 5% probability. A total of 1,920 Cobb 500 male broilers were used in an entirely randomized experimental design, with 6 treatments (6 digestible isoleucine levels: 0.6118; 0.6655; 0.7192; 0.7729; 0.8265 and 0.8802%) and 8 replications, with 40 broilers each. Data on performance and carcass characteristics were evaluated. Level 0.7192% of digestible isoleucine was considered standard. The digestible isoleucine level recommended for 22- and 42-day-old broilers is 0.7729%, corresponding to a digestible isoleucine:lysine ratio of 72%.

This study was conducted to determine the standardized ileal digestible lysine (SID Lys) requirements for white commercial layers in peak egg production phase. A total of two hundred eighty-eight 24 week-old Hy-Line W-36 layers were randomly assigned to one of six treatments groups, with eight replicates of six hens each. A basal diet, SID Lys-deficient, was graded supplemented with L-Lysine HCl (78.4%) in order to produce experimental treatments (6.0, 6.6, 7.2, 7.8, 8.4 and 9.0 g SID Lys/kg diet). Throughout the 16-week-feeding trial (24 to 40 weeks of age) hens had free access to water and mash feed. Data were analyzed as one-way ANOVA and optimum SID Lys level for each dependent variable assessed were estimated using polynomial and linear broken-line regression model. Feed intake and SID Lys intake were both linearly enhanced by graded SID Lys levels. According to linear broken-line regression model, the breakpoint for egg production, egg weight, and egg mass occurred at 8.14, 8.56 and 8.35 g SID Lys/kg diet, respectively. The breakpoint for feed conversion per egg mass (kg/kg) and per dozen of eggs (kg/dozen) occurred at 8.48 and 7.80 g SID Lys/kg diet, respectively. Eggshell weight and albumen weight were unaffected by dietary SID Lys supply. Weight gain and yolk weight reached optimum values at 8.33 and 8.03 g SID Lys/kg diet, respectively, according to linear broken-line regression model. In conclusion, SID Lys requirement for white commercial layers in peak egg production phase is 8.48 g/kg diet, which corresponds to an average daily SID Lys intake of 813 mg/hen.

This study was carried out to evaluate the effects of different digestible dietary lysine levels on performance and egg quality characteristics, from 25 to 41 weeks of age. One hundred twenty Hy-Line Brown layers were randomly distributed in five treatments with six replications of four birds each, totaling 30 experimental units. Experimental diets were based on corn and soybean meal, were isocaloric and isonutrient, with differences only in lysine levels (0.70, 0.75, 0.80, 0.85, and 0.90%). The study evaluated feed intake, lysine intake, energy consumption, egg production, egg weight, egg mass, and feed conversion. Internal egg quality was evaluated by Haugh unit, the percentages of yolk and albumen percentage, while external quality was measured by specific gravity, eggshell thickness and shell percentage. It was concluded that the level of 0.70% of digestible lysine or the intake of 708 mg bird-1 day-1 for Hy-Line Brown layers from 25 to 41 weeks of age can be enough to express the genetic potential.

This study evaluated the effect of three levels of digestible amino acids (DAA; 100, 107 and 114% of Cobb recommendations) on mRNA abundance of peptide (PepT1) and amino acid (AA) transporters in 480-day-old broilers during prestarter period. Jejunal mRNA levels of the PepT1 and bAT increased as DAA level increased from 100 to 114%. The expression of CAT1 mRNA in the jejunum was higher in birds fed 100% DAA diet. The transport systems BAT and yLAT1 were not affected by the dietary treatments. These results demonstrated that dietary content of protein and DAA differentially affected the expression of intestinal peptide and AA transporters to modulate absorption of peptide and AA in broilers. [ABSTRACT FROM AUTHOR]

Current experiment established different criteria to evaluate the requirements of digestible valine for broilers from 22 and 42 days of age, by different regression models (quadratic, exponential and Linear Response Plateau) and, in the case of statistical significance, the comparison of means byDuncantest at 5% probability. A total of 1,920 Cobb 500 male broilers were used and distributed in an entirely randomized experimental design, with 6 treatments (6 digestible valine levels: 0.7192, 0.7729, 0.8265, 0.8802, 0.9339 and 0.9876%) and 8 replications, with 40 broilers each. Data on performance and carcass characteristics were evaluated. The level of 0.8265% digestible valine was considered standard. The inclusion of 0.816, 0.848 and 0.903% of digestible valine levels, corresponding to digestible valine:lysine ratios of approximately 76.00%, 79.00% and 84.12%, provided best feed intake, weight gain and feed conversion ratio, respectively for broiler from 22 to 42 days of age.

Experiments were conducted to evaluate conventional canola meal (Conv CM) and a new increased-protein reduced-fiber CM (Test CM). The Test CM contained higher levels of all digestible amino acids than the Conv CM as determined in 2 precision-fed rooster assays wherein Single Comb White Leghorn roosters were fasted for 24 h and then tube-fed 30 g of Conv CM or Test CM. Excreta were then quantitatively collected for 48 hours. All diets in 2 broiler experiments then were formulated to be equal in AMEn and digestible amino acids based on values from precision-fed rooster assays. In Experiment 1, diets were corn and soybean meal based and contained zero, 10, 20, 30 or 40% Conv CM from 2 to 21 d of age and zero, 10, 20 or 30% Conv CM from 21 to 37 d of age. In the starter phase of Experiment 1 (2 to 21 d), there was a significant negative effect (P < 0.05) on weight gain and feed intake for CM levels in excess of 10%. In Experiment 2, both Conv CM and the new Test CM were evaluated. For the starter phase (2 to 19 d), the diets contained no CM or 8% Test CM or 8% Conv CM. For the grower phase (20 to 44 d), the chicks were fed diets that contained either no CM or 8, 16, or 24% of Test CM (Diets 2 to 4) or the same levels of Conv CM (Diets 5 to 7). The Test CM diets contained less soybean meal and less added fat than the Conv CM diets. There were no significant differences among dietary treatments for growth performance for either phase of Experiment 2. These results indicate that the new Test CM has increased levels of digestible amino acids compared to Conv CM and that up to 24% of either type of CM could be fed to broiler chickens during the grower phase with no statistical differences (P < 0.05) in performance when diets were formulated to be equal in AMEn and digestible amino acids. [ABSTRACT FROM AUTHOR]

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The objective of this experiment was to establish different criteria to evaluate the requirements of digestible tryptophan for broilers from 22 to 42 d of age, using different regression models (quadratic, exponential and Linear Response Plateau) and in case of statistical significance the comparison of means by Duncan test at 5% probability was also adopted. A total of 1,920 Cobb 500 male broilers were distributed in a completely randomized experimental design, with 6 treatments (6 digestible tryptophan levels: 0.1395, 0.1610, 0.1825, 0.2040, 0.2255 and 0.2470%) and 8 replications containing 40 broilers each. Performance and carcass characteristics were evaluated. The level of 0.2255% of digestible tryptophan numerically improves feed conversion, and the 0.1919% estimated by the quadratic equation significantly improves carcass yield.

The objective of this study was to estimate the digestible lysine requirement of Japanese quails in the egg-laying phase. A total of 336 female Japanese quails (Coturnix coturnix japonica) of average initial age of 207 days were distributed in a completely randomized experimental design, composed of 6 treatments (lysine levels) with 7 replicates and 8 birds per experimental unit, with duration of 84 days. Experimental diets were formulated from a basal diet, with corn and soybean meal, with 2.800 kcal ME/kg and 203.70 g/kg crude protein, showing levels of 9.50; 10.00; 10.50; 11.00; 11.50; and 12.00 g/kg digestible lysine; diets remained isoprotein and isocaloric. The following variables were studied: feed intake (FI); lysine intake (LI); egg production per bird per day (EPBD); egg production per bird housed (EPBH); production of marketable eggs (PME); egg weight (EW); egg mass (EM); utilization efficiency of lysine for egg mass production (UELEM); feed conversion per mass (FCEM); feed conversion per dozen eggs (FCDZ); bird availability (BA); percentages of yolk (Y), albumen (A) and shell (S); specific egg weight (SW); nitrogen ingested (NI); nitrogen excreted (NE); and nitrogen balance (NB). Significant effect was only observed for LI, EW, EM, UELEM, FCEM, Y, A and SW. The digestible lysine level estimated in diets for laying Japanese quails is 11.20 g digestible lysine/kg diet, corresponding to an average daily intake of 272.23 mg lysine.

Foi estudado o valor nutricional (digestibilidade total e ileal) de duas leveduras spray dry (cana-de-açúcar - LEV35 e cerveja+cana-de-açúcar - LEV40) e o efeito da sua inclusão em rações para suínos na fase de crescimento e terminação. Os valores de ED (kcal/kg) da LEV35 e da LEV40 foram 3.496 e 3.901 e EM (kcal/kg) foram 3.475 e 3.862, respectivamente. Os valores de lisina, metionina+cistina e treonina digestível para a levedura de cana-de-açúcar e da levedura de cerveja+cana-de-açúcar são 2,66 e 2,64, 1,11 e 1,03, 1,95 e 1,92, respectivamente. No desempenho foram utilizados 40 suínos com peso inicial de 34,39± 7,57kg (crescimento) e de 62,45± 5,68kg (terminação), distribuídos em delineamento inteiramente casualizado com cinco níveis de inclusão (0, 5, 10, 15 e20%) da LEV35. Na fase de crescimento, houve piora do GDP e da CA com o aumento da inclusão. Na fase de terminação, porém, houve efeito quadrático para o CDR, sendo o melhor nível 3.32%. Da mesma forma, ocorreu piora linear para o GDP, CA, peso de carcaça quente, rendimento de carcaça fria e peso de pernil. Os resultados sugerem que a adição de níveis crescentes da LEV35 pode prejudicar o desempenho dos suínos.The nutritional value of two spray dry yeast (sugar cane - SCYSD and brewer+sugar cane - BYSD) and their inclusion effects on growing and finishing pigs feeding was studied. The DE (kcal/kg) values for SCYSD and BYSD were 3.496 and 3.901 and for ME (kcal/kg) they were 3.475 and 3.862. The values of digestible lysine, methionine+cistine and threonine for SCYSD and BYSD were: 2.66 and 2.64%; 1.11 and 1.03%: 1.95 and 1.92%. 40 pigs with initial weight of 34.39±7.57kg (growing) and 62.45±5.68kg (finishing), allotted in a completely randomized design with five levels of SCYSD inclusion were used in the performance assay. In the growing phase, there was an impairing on DWG and F:G, however, in the finishing phase, DFI presented a quadratic effect, being 3.32% the best level and linear reduction of DWG, F:G, slaughter weight, hot carcass weight, cold carcass yield and ham weight. The results suggest that increasing levels of SCYSD may impair the performance of growing and finishing pigs.

The objective of this experiment was to evaluate the effect of two digestible lysine levels and four digestible arginine levels on laying hens from 24 to 48 weeks of age. Three hundred and twenty Lohmann LSL laying hens were allotted in a completely randomized design in a 2 × 4 factorial arrangement, with two levels of digestible lysine (700 and 900 mg/kg of diet) and four digestible arginine levels (700, 800, 900 and 1000 mg/kg of diet). Results indicated requirement of 884 and 830 mg of digestible arginine/kg of diet, considering an average feed intake of 95 g/hen/day and an average hen weight of 1.5 kg, aiming at lesser feed intake and better nutritional balance of nitrogen, respectively. High digestible lysine levels in the diet require higher digestible arginine supplementation for a better performance of hens.

This experiment was conducted to evaluate the use of different energy levels and amino acid recommendations on performance, carcass yield and intestinal morphometry of broilers from 42 to 57 days of age. We used 1,600 one-day old male broilers (Cobb 500) in a completely randomized design arranged in a 2x4 factorial scheme with 3,200 and 3,600 kcal ME/kg and four different feed programs. The metabolizable energy levels and the feed programs did not determine significant differences in carcass characteristics for choosing a level of energy or a feed program, thus the energy level and the recommendations of amino acids that determine the highest cost-benefit ratio should prevail. It was observed that 3,600 kcal ME/kg resulted in some improvement on performance and morphometry of the intestinal mucosa, also the fractioning of digestible amino acid requirements during two periods resulted in worse performance and intestinal villi height.

The objective of this study was to determine the coefficients of apparent and true digestibility of protein and amino acids of five feedstuffs (corn, wheat bran, soybean meal, corn gluten meal and fish meal) in 900 sex-reversed Nile tilapia (Oreochromis niloticus) of the Thai strain during the growth phase, with an initial weight of 315±8.45 g. A total of 750 fish were distributed according to a randomized block design (repetitions in time) into five treatments with six replicates of 25 fish each. The remaining 150 fish were fed a protein-free diet to measure endogenous protein and amino acid losses in order to determine the true digestibility of these components. Each tested diet contained a single protein source, which consisted of one of the evaluated feedstuffs. Digestibility was indirectly estimated using chromic oxide at 0.50% as marker. Digesta was collected from the last 5 cm of the distal intestine (between the ileal-rectal valve and the anus) using the dissection technique. Apparent digestibility coefficients of protein and amino acids were, on average, 74.69 and 73.62% for corn, 73.74 and 72.81% for wheat bran, 86.01 and 84.66% for soybean meal, 85.19 and 84.29% for corn gluten meal, 76.74 and 75.56% for fish meal, respectively. True digestibility coefficients of protein and amino acids were, on average, 85.21 and 83.97% for corn, 84.41 and 83.74% for wheat bran, 87.22 and 87.51% for soybean meal, 87.97 and 87.34% for corn gluten meal, and finally 79.58 and 78.44% for fish meal, respectively.

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.

Um experimento foi realizado com o objetivo de estabelecer critérios de avaliação das exigências de treonina digestível para frangos de corte de 22 a 42 dias de idade utilizando-se diferentes modelos de regressão (quadrático, exponencial e de retas segmentadas ou Linear Response Plateau). Foram utilizados 1.920 frangos de corte machos com 22 dias de idade, distribuídos em delineamento inteiramente ao acaso, com seis tratamentos (seis níveis de treonina digestível: 0,5904; 0,6441; 0,6977; 0,7514; 0,8051 e 0,8588%) e oito repetições de 40 aves. Utilizou-se como padrão o nível de 0,6977% de treonina digestível. Foram avaliados dados de desempenho e características de carcaça. Com base nos dados, o nível de 0,7642% de treonina digestível, correspondente às relação treonina:lisina digestível de 71,19%, promoveu o melhor resultado de conversão alimentar de acordo com o modelo Linear Response Plateau.The objective of this experiment was to establish different criteria for evaluation of the requirements of digestible threonine for broilers from 22 to 42 d of age, using different regression models (quadratic, exponential, and Linear Response Plateau). A total of 1,920 22-day-old male Cobb broilers were distributed in randomized experimental design, with six treatments (six threonine levels: 0.5904, 0.6441, 0.6977, 0.7514, 0.8051, and 0.8588%) and 8 replications containing 40 broilers each one. The level of 0.6977% digestible threonine was used as standard. Data on performance and carcass characteristics were evaluated. Based on the data, the threonine level of 0.7642%, corresponding to the threonine:digestible lysine ratio of 71.19% had the best result for feed conversion, according to the Linear Response Plateau model.

Foram determinados a composição química e aminoacídica e os coeficientes de digestibilidade verdadeira dos aminoácidos (CDVaa) de farinhas de penas e sangue para aves obtidas de diferentes fornecedores. Utilizaram-se 30 galos cecectomizados distribuídos em delineamento experimental inteiramente casualizado, com quatro farinhas de penas e sangue (farinhas 1, 2, 3 e 4) e um tratamento no qual as aves permaneceram em jejum, seis repetições sendo a unidade experimental composta por um galo. As variações na composição química das farinhas de penas e sangue podem estar relacionadas à falta de padronização no processamento a que são submetidas. Os coeficientes médios de digestibilidade verdadeira dos aminoácidos essenciais e não-essenciais para as farinhas de penas 1, 2, 3 e 4 são, respectivamente, 75,14 e 68,41; 73,34 e 67,17; 78,99 e 75,41; 78,55 e 73,40%.Chemical and amino acid composition and true digestibility coefficients of amino acids of feather and blood meals for birds from different suppliers were determined. Thirty cecectomized cocks were distributed in a completely randomized design, with 4 different feather and blood meals (meals 1, 2, 3 and 4) and one treatment in which the birds remained fasting, with six replications as the experimental unit composed of one rooster. The variations in the chemical composition of the feather and blood meals can be related to the lack of standardization in the processing to which they are submitted. Mean true digestibility coefficients of essential and non essential amino acid for feather and blood meals 1,2, 3 and 4 are 75.14 and 68.41; 73.34 and 67.17; 78.99 and 75.41; 78.55 and 73.40%, respectively.

A total of 3,760 Ross male broiler chicks were used in two trials, one in the pre-starter (1-11 days) phase and the other in the starter (12-22 days) phase. Birds were distributed in a completely randomized experimental design with a factorial arrangement of 5 digestible lysine levels × 2 environments (clean and dirty environment), with eight replicates per treatment. The following dietary digestible lysine levels used were: 1.06, 1.12, 1.18, 1.24 and 1.30% in the pre-starter phase, and 1.00, 1.06, 1.12, 1.18 and 1.24% in the starter phase. Minimal relation of digestible lysine:digestible methionine + cystine, threonine, tryptophan and arginine (72, 67, 19 and 108%, respectively) were maintained, as well as 2.088 and 2.002% of glycine+serine in the pre-starter and starter diets, respectively. Weight gain, feed intake and feed conversion were evaluated. In all phases, dietary digestible lysine levels significantly influenced broiler performance, and broilers reared in the clean environment presented better performance than those reared in the dirty environment. The recommended digestible lysine levels during the pre-starter and starter phases are 1.30 and 1.24% when broilers are reared in the clean enviroment and 1.26 and 1.165% in the dirty enviroment, respectively.

Avaliou-se o efeito de níveis de lisina digestível sobre o desempenho e a composição de carcaça de suínos machos castrados de alto potencial genético para deposição de carne. Foram utilizados 80 animais com peso inicial de 95,55 ± 1,04 distribuídos em delineamento experimental de blocos ao acaso, com cinco dietas (0,540; 0,642; 0,744; 0,846 e 0,948% de lisina digestível), oito repetições e dois animais por unidade experimental. As dietas experimentais e água foram fornecidas à vontade durante todo o período experimental. Os níveis de lisina digestível não influenciaram o consumo de ração diário e o peso de carcaça dos animais. O ganho de peso diário e a conversão alimentar melhoraram de forma quadrática até os níveis de lisina digestível estimados de 0,803 e 0,817%, respectivamente. Foi observado efeito linear crescente dos tratamentos sobre o consumo diário de lisina e sobre a quantidade de carne. Embora, a deposição diária de carne tenha aumentado de forma linear, o modelo LRP foi o que melhor se ajustou aos dados que permaneceram em um platô a partir do nível de lisina digestível de 0,803%. Os níveis de lisina digestível influenciaram a espessura de toucinho P2 dos animais que reduziu de forma linear. O nível de lisina digestível de 0,803%, que corresponde a consumo de 24,60 g/dia de lisina digestível, proporciona os melhores resultados de ganho de peso e deposição de carne, enquanto o nível de 0,817%, correspondente a consumo de 25,03 g/dia de lisina, proporciona melhor conversão alimentar e o de 0,948%, correspondente a consumo de 29,09 g/dia de lisina digestível, promove maior deposição de carne e espessura de toucinho em suínos machos castrados na fase dos 95 aos 125 kg.This work evaluated levels of digestible lysine on performance and carcass composition of barrows with high genetic potential for meat deposition. It was used 80 animals with initial body weight of 95.55 ± 1.04 kg, distributed in a completely randomized block design, with 5 diets (0.540; 0.642; 0.744; 0.846 and 0.948% of digestible lysine), eight replicates and two animals per experimental unit. The experimental diets and water were provided ad libitum throughout the experimental period. Digestible lysine levels did not change daily feed intake and carcass weight of the animals. Daily weight gain and feed conversion improved in a quadratic way up to the estimated levels of 0.803 and 0.871% of digestible lysine, respectively. It was observed an increasing linear effect of the treatments on daily lysine intake and amount of meat. Although daily meat deposition had increased in a linear way, the LRP was the model that best adjusted to the data which remained on a plateau from 0.803% of digestible lysine level. The levels of digestible lysine influenced the P2 backfat thickness of the animals which decreased in a linear way. The digestible lysine level of 0.803%, corresponding to an intake of 24.60 g/day of digestible lysine provides the best results of weight gain and meat deposition whereas the level of 0.817% corresponding to an intake of 25.30 g/day of lysine provides the best result of feed conversion, and the digestible lysine level of 0.948% corresponding to an intake of 29.09 g/day of digestible lysine provides the best results of meat deposition and backfat thickness of barrows from 95 to 125 kg.

The objective of this work was to estimate requirements of digestible methionine + cystine for broiler chickens from 1 to 42 days of age. It was carried out four experiments for each one of the following phases: pre-initial, initial, growing and final. The birds were distributed in a completely randomized experimental design, with six treatments and six replicates. Treatments consisted of a basal feed for each phase, deficient in digestible methionine + cystine and supplemented with DL-methionine to supply six levels of digestible methionine + cystine, resulting in different digestible methionine + cystine:digestible lysine ratios. In the pre-initial phase, levels of digestible methionine + cystine did not influence feed intake and feed conversion. However, weight gain responded in a quadratic way. In the initial phase, levels of digestible methionine + cystine had decreasing linear effect on feed intake whereas weight gain and feed conversion were influenced in a quadratic manner. In the growth and final phases, feed intake was not influenced by levels of digestible methionine + cystine, but weight gain and feed conversion presented quadratic response. The levels of 0.873; 0.755; 0.748 and 0.661% of digestible methionine + cystine in the diet or the daily intake of 183; 575; 1,104 and 1,212 mg of digestible methionine + cystine are recommended for the pre-initial, initial, growth and final phases, respectively, which corresponds to the ratios of 71; 70; 76 and 72% of digestible methionine + cystine to digestible lysine.Objetivou-se estimar as exigências de metionina + cistina digestível para frangos de corte machos de 1 a 42 dias de idade. Foram realizados quatro experimentos para cada uma das fases: pré-inicial, inicial, crescimento e final. As aves foram distribuídas em delineamento inteiramente casualizado, com seis tratamentos e seis repetições. Os tratamentos consistiram de uma ração basal para cada fase, deficiente em metionina + cistina e suplementada com DL-metionina para fornecer seis níveis de metionina + cistina digestível, resultando em diferentes relações metionina + cistina digestível:lisina digestível. Na fase pré-inicial, os níveis de metionina + cistina digestível não influenciaram o consumo de ração e a conversão alimentar. No entanto, o ganho de peso respondeu de forma quadrática. Na fase inicial, os níveis de metionina + cistina digestível tiveram efeito linear decrescente sobre o consumo de ração, enquanto o ganho de peso e a conversão alimentar foram influenciados de forma quadrática. Nas fases de crescimento e final, o consumo de ração não foi influenciado pelos níveis de metionina + cistina digestível, porém o ganho de peso e a conversão alimentar apresentaram resposta quadrática. Recomendam-se os níveis de 0,873; 0,755; 0,748 e 0.661% de metionina + cistina na dieta ou o consumo diário de 183, 575, 1.104 e 1.212 mg de metionina + cistina digestível nas fases pré-inicial, inicial, crescimento e final, respectivamente, que correspondem às relações de 71, 70, 76 e 72% de metionina + cistina digestível:lisina digestível.

Avaliaram-se os efeitos de níveis de aminoácidos sulfurados digestíveis (AASD) sobre o desempenho e a qualidade interna e externa de ovos de 360 poedeiras de 25 a 41 semanas de idade. Foram formuladas seis dietas experimentais: cinco continham 0,578; 0,636; 0,694; 0,752 ou 0,810% de AASD, e em uma o nível de AASD foi o usualmente recomendado, cada tratamento com cinco repetições de 12 aves, em quatro períodos de avaliação de 28 dias cada. Melhores resultados para produção de ovos, conversão alimentar, massa de ovos e ovos viáveis foram obtidos com as aves que consumiram 729; 751; 801 e 730mg AASD/dia, respectivamente. A elevação dos níveis de AASD resultou em aumentos lineares no consumo de ração, no ganho de peso, nas porcentagens de gema e no extrato etéreo na gema. Nos ovos armazenados por sete dias, houve aumento linear da porcentagem de gema e decréscimo linear da porcentagem de casca, unidade Haugh e peso específico com a elevação dos níveis de AASD. Conclui-se que, para melhores produção e qualidade interna e externa de ovos, é necessário o consumo de 752mg de AASD ou de 864mg de aminoácidos sulfurados totais por ave/dia.An experiment was conduct using 360 laying hens to evaluate the dietary levels of digestible sulfur amino acids (DSAA) on performance and egg quality of hens from 25 to 41 weeks of age. Five experimental diets were formulated containing 0.578, 0.636, 0.694, 0.752, and 0.810% of DSAA and one additional diet using the recommend level. Each treatment was replicated five times with 12 birds per replicate during four evaluation periods of 28 days each. The best results for egg production, feed conversion, egg mass yield, and viable eggs were obtained by birds that consumed 729, 751, 801, and 730 DSAA mg/day, respectively. Feed intake, weight gain, percentage of yolk, and lipid yolk linearly increased with increasing levels of DSAA. A linear increase in the percentage of yolk and a linear decrease on the percentage of shell weight, Haugh unit, and specific weight were observed with increasing levels of DSAA for eggs stored during seven days. It is concluded that for the best production and egg quality, a consumption of 752 mg of DSAA or 864 mg of total sulfur amino acid per bird per day is required.

O experimento foi conduzido para avaliar níveis de proteína bruta e arginina digestível na ração pré-inicial de frangos de corte e seus efeitos no desempenho das aves dos 7 aos 21 dias de idade. Foram utilizados 600 pintos da linhagem Cobb 500, distribuídos em delineamento de blocos casualizados em esquema fatorial 4 × 2, composto de quatro níveis de arginina digestível (1,363; 1,463; 1,563 e 1,663%) e dois níveis de proteína bruta (20 e 22%), totalizando oito tratamentos, cada um com cinco repetições de 15 aves. Avaliaram-se o ganho de peso, o consumo de ração, o índice de conversão alimentar, a biometria dos órgãos do trato gastrintestinal e a digestibilidade e retenção de matéria seca e nitrogênio. O maior ganho de peso na fase de 1 a 14 dias de idade foi obtido com a ração com 22% de proteína bruta. Os níveis de arginina digestível tiveram efeito quadrático na conversão alimentar na fase de 1 a 10 dias de idade. O peso do esôfago e inglúvio foi maior nas aves alimentadas com a ração com 20% de proteína bruta, no entanto, houve efeito quadrático dos níveis de arginina digestível sobre o comprimento do intestino aos 10 dias de idade e sobre o peso do esôfago + inglúvio aos 3 dias de idade. Houve interação entre os níveis de proteína bruta e arginina digestível para o peso relativo do fígado aos 14 dias, que respondeu de forma quadrática ao nível de 20% de proteína bruta, e para o comprimento de intestino, cujo maior valor foi obtido com os níveis de 22% de proteína bruta e 1,603% de arginina digestível. O balanço e a retenção de nitrogênio foram maiores no nível de 22% de proteína bruta. O nível de 1,363% de arginina digestível atende às exigências nutricionais dos frangos de corte na fase pré-inicial.This experiment was carried out to evaluate levels of crude protein and digestible arginine in pre-starter broiler ration and their effects on the performance of the broilers from 7 to 21 days of age. A total of 600 Cobb chicks was assigned to a block randomized design in a 4 × 2 factorial arrangement consisting of 4 levels of digestible arginine (1.363; 1.463; 1.563 and 1.663%) and two levels of crude protein (20 and 22%) with eight treatments, each one with five replicates of 15 broilers each. For the experiment, weight gain, feed intake, feed conversion ratio, gastrointestinal biometry, digestibility and retention of dry matter and nitrogen were evaluated. The highest weight gain from 1 to 14 days old was obtained with the 22% crude protein feed. The levels of digestible arginine had a quadratic effect in feed conversion from 1 to 10 days old. The esophagus and crop weights were higher for broilers fed 20% crude protein based diet; however, there was a quadratic effect of the digestible arginine levels on the intestine length at the age of 10 days and on the esophagus + crop weight at 3 days of age. At 14 days of age, there was interaction among crude protein and digestible arginine levels for liver relative weight, which showed quadratic response to 20% of crude protein, and for intestine length, whose highest value was obtained with 22% of crude protein and 1.603% of digestible arginine. Nitrogen balance and retention were the highest for levels of 22% of crude protein. The level of 1.363% of digestible arginine meets nutritional requirements of pre-starter broilers.

Avaliaram-se os efeitos dos níveis de lisina digestível da ração, com base no conceito de proteína ideal, no desempenho de alevinos de de tilápia-do-nilo (Oreochromis niloticus). Utilizaram-se 432 alevinos revertidos, linhagem tailandesa, com peso inicial de 1,12 ± 0,02 g, em delineamento inteiramente ao acaso, composto de 6 dietas, 6 repetições e 12 peixes por unidade experimental. Como tratamentos, avaliaram-se uma dieta basal com 29,12% de proteína bruta e 3.000 kcal de energia digestível/kg, suplementada com aminoácidos sintéticos, resultando em dietas com 0,95; 1,10; 1,25; 1,40; 1,55 e 1,70% de lisina digestível e relações mínimas entre metionina + cistina, treonina, triptofano, isoleucina e arginina com a lisina (66, 77, 23, 64 e 85%, respectivamente), com base em valores digestíveis. Os peixes foram mantidos em aquários de 130 litros, dotados de abastecimento de água, temperatura controlada e aeração individual, e alimentados à vontade em seis refeições diárias durante 30 dias. Avaliaram-se os parâmetros de desempenho, a composição corporal, a deposição de proteína e gordura corporais e a eficiência de retenção de nitrogênio dos peixes. A elevação do teor de lisina digestível na ração não influenciou a taxa de sobrevivência e o teor de gordura corporal dos peixes, mas melhorou de forma linear todos os demais parâmetros avaliados, com exceção da eficiência de utilização de lisina e a umidade corporal, que pioraram de forma quadrática e linear, respectivamente. O nível de 1,80% de lisina total (0,600% Mcal de ED) e o de 1,70% de lisina digestível (0,567% Mcal de ED) proporcionam os melhores resultados de desempenho e características de carcaça de alevinos de tilápia-do-nilo quando se utiliza o conceito de proteína ideal na formulação das rações experimentais.The effects of the digestible lysine level were assessed in feeds for Nile tilapia fingerlings (Oreochromis niloticus), based on the ideal protein concept. Four hundred and thirty two reverted fingerlings were used, average weight 1.12 ± 0.02 g, in a randomized complete design, consisting of 6 feeds, six replications and twelve fish per experimental unit. The diets consisted of a basal diet with 29.12% crude protein and 3,000 kcal/kg digestible energy, supplemented with synthetic amino acids, resulting in six diets with 0.95; 1.10; 1.25; 1.40; 1.55 and 1.70% digestible lysine and minimum ratios between methionine plus cystine, threonine, thryptophan, isoleucine, arginine with the lysine (66, 77, 23, 64 and 85%, respectively), based on digestible values. The fish were maintained in 130 liter aquaria equipped with individual water and controlled temperature and aeration. The fish were fed to apparent satiation, six times a day, for 30 days. Growth performance, body composition, body protein and fat deposition and nitrogen retention efficiency of the fish were evaluated. The increase in the dietary digestible lysine did not affect the survival rate and body fat level of the fishes. However, there was linear improvement in all the other parameters assessed, except lysine use efficiency and the body humidity, that showed quadratic and lineardecline, respectively. The levels of 1.80 (0.600% Mcal of DE) total lysine and 1.70% (0.567% Mcal of DE) digestible lysine, respectively, result in the best performance and carcass characteristics of Nile tilapia fingerlings, when the ideal protein concept is used to formulate the experimental diets.

Objetivou-se avaliar o desempenho (25 a 44 semanas de idade) e o balanço de nitrogênio de poedeiras comerciais alimentadas com rações contendo níveis de lisina digestível (0,700; 0,800 e 0,900%) combinados com os de treonina (0,500; 0,550 e 0,600%).O delineamento experimental foi inteiramente ao acaso em esquema fatorial 3x3 (níveis de lisina x de treonina), com cinco repetições de oito aves cada. Os dados foram submetidos à análise de variância e as médias comparadas pelo teste de Tukey. Observou-se aumento naingestão de lisina e de treonina (p < 0,05) com o acréscimo desses aminoácidos na ração. Os níveis de lisina e treonina não influenciaram a produção de ovos (p > 0,05), no entanto, o peso do ovo piorou com a inclusão de 0,550% de treonina digestível. Houve interação entre níveis de lisina e de treonina (p < 0,05) para conversão alimentar (kg kg-1). O balanço de nitrogênio piorou com o aumento de treonina na ração, somente para poedeiras com 35semanas de idade. Para produção e massa de ovos, os níveis recomendados são de 0,700 e 0,500% de lisina e treonina digestível na ração. Para se otimizar a conversão alimentar (kg kg-1), recomendam-se 0,800 e 0,550% de lisina e treonina digestível na ração.This research had the objective of evaluating the performanceand nitrogen balance of commercial laying hens between 25 and 44 weeks of age, fed diets containing different levels of digestible lysine (0.700, 0.800 and 0.900%) and combined with digestible threonine (0.500, 0.550 and 0.600%). The diets contained 16% crude protein. A randomized experimental design was used in a 3x3 factorial scheme (three levels of lysine x three levels of theronine), with five replicates. The experiment unit consisted of a cage witheight hens. Data were submitted to analysis of variance using the statistical software SAS. The different levels of lysine and theronine did not influence (p > 0.05) production, weightof the eggs and nitrogen balance. An interaction was verified between the levels of lysine and theronine (p < 0.05) in the diets regarding feed conversion (kg kg-1). The levels of 0.800 and 0.550% of digestible lysine and threonine, respectively, enhanced the feedconversion (kg kg-1) in diets of hens.

Avaliou-se o efeito dos níveis de treonina digestível, com base no conceito de proteína ideal, em rações com 1,35% de lisina digestível sobre o desempenho de alevinos de tilápia-do-nilo (Oreochromis niloticus). Utilizaram-se 432 alevinos revertidos de tilápia, linhagem tailandesa, com peso inicial de 1,64 ± 0,03 g, em delineamento inteiramente ao acaso, com seis tratamentos, cada um com seis repetições, e doze peixes por unidade experimental. Os tratamentos consistiram de cinco rações com diversas relações treonina:lisina digestível (69,0; 74,0; 79,0; 84,0 e 89,0%) e relação metionina + cistina:lisina digestível de 70,0% e uma ração com relação treonina:lisina digestível de 84,0% e de metionina + cistina:lisina digestível de 75,0%, todas isoenergéticas e isoprotéicas. Os peixes foram mantidos em 36 aquários de 130 L, dotados de abastecimento de água, temperatura controlada e aeração individuais, e alimentados à vontade, seis vezes ao dia, durante 30 dias. Avaliaram-se o desempenho, a composição corporal, as deposições de proteína e gordura e a eficiência de retenção de nitrogênio dos peixes. O consumo de ração, o teor de proteína corporal e a deposição de proteína corporal aumentaram de forma linear de acordo com a relação treonina:lisina na ração, contudo, não foram influenciados pelo aumento da relação metionina + cistina:lisina da ração. Os níveis de treonina total ou digestível que proporcionaram os melhores resultados de desempenho em alevinos de tilápia-do-nilo foram de 1,11 e 0,99%, enquanto os níveis que promoveram melhor deposição de proteína corporal foram de 1,43 e 1,28%, que correspondem às relações treonina:lisina total de 71,0 e 69,0% e treonina:lisina digestível de 90,0 e 89,0%.The effects of digestible threonine levels, based on ideal protein concept in diets with 1.35% of digestible lysine on Nile tilapia (Oreochromis niloticus) fingerlings performance. Four hundred thirty two reverted Nile tilapia, Thailand strain, with initial weight of 1.64 ± 0.03 g, were allotted to completely randomized design, with six diets and six replications with twelve fishes each. The five diets, isoenergetic isoproteic, consisted of various threonine:digestible lysine ratio (69.0, 74.0, 79.0, 84.0, and 89.0%) and methionine + cystine:digestible lysine ratio of 70.0% and one diet with threonine:digestible lysine of 84.0% and methionine + cystine:digestible lysine of 75.0%. The fish were kept in 36 aquariums of 130 L, equipped with water supply, controlled temperature and individual aeration, and ad libitum fed six times a day for 30 days. Performance, body composition, protein and fat depositions and nitrogen retention efficiency of fishes were evaluated. Consumption of feed, body protein content and body protein deposition increased in a linear fashion in accordance to threonine:digestible lysine in the diet, however, was not affected by the increase of dietary methionine + cystine:digestible lysine. Total or digestible threonine levels that provided the best results of performance of Nile tilapia fingerlings were 1.11 and 0.99%, while the levels that promoted better body protein deposition were 1.43 and 1.28%, which correspond to threonine:total lysine ratio of 71.0 and 69.0% and threonine:digestible lysine of 90.0 and 89.0%.

O objetivo deste trabalho foi verificar se a ingestão diária de diferentes quantidades de lisina digestível, pelas fêmeas suínas primíparas em lactação, influencia o desempenho produtivo, reprodutivo e o perfil sangüíneo dessas matrizes. Utilizaram-seinicialmente 50 porcas primíparas em lactação, distribuídas em 5 tratamentos (10 animais por tratamento), correspondendo a 0,88; 0,99; 1,04; 1,08 e 1,24% de lisina digestível na ração. Utilizou-se delineamento experimental de blocos ao acaso, sendo cada matrizconsiderada uma unidade experimental. Os resultados foram avaliados através de modelos estatísticos de análise de variância, utilizando-se a regressão linear ou quadrática conforme o melhor ajuste. As variáveis de desempenho das matrizes (perda de peso, perda de espessura de toucinho e intervalo desmama cio) e concentração de uréia no soro das matrizes durante a lactação não foram influenciadas (p > 0,05) pelos níveis de lisina da ração. Já as concentrações de creatinina e proteínas totais no soro das matrizes, foram influenciadas (p < 0,10 e p < 0,05, respectivamente) em determinados períodos pelos níveis de lisina digestível na ração. Conclui-se que nas condições em que o estudo foi realizado, os diferentes níveis de lisina não influenciaram o desempenho das matrizes, podendo-seutilizar o menor nível estudado.The objective of the study was evaluate, how the daily intake of different digestible lysine levels influence the productive and reproductive performance of first lactating sows, and theblood profile of creatine, urea and total protein. Fifty first lactating sows were used and distributed in five treatments (10 animals per treatment), correspondent to 0.88; 0.99; 1.04;1.08 and 1.24% of digestible lysine in the ration. These animals were distributed in a randomized block design with every sow as an experimental unit (10 replicates). The results were evaluated through statistical variance models, using linear or quadratic regressioncorresponding to the best adjustment. The performance variables of the sows (weight loss, back fat thickness and weaning-to-estrus interval) and the concentration of urea in the serum of the sows during the lactation weren’t influenced (p > 0.05) through the level of lysine in the ration. The concentrations of creatine and total protein in the serum of the sows were influenced (p < 0.10 and p < 0.05, respectively) in determined periods through the level of digestible lysine in the ration. In conclusion, the different levels of lysine did not influence the performance of the sows, and the lower level of lysine could be used.

Objetivou-se neste estudo determinar os coeficientes de digestibilidade ileal verdadeira da proteína e dos aminoácidos digestíveis de um extrato protéico de levedura utilizando-se duas técnicas - dieta isenta de proteína (DIP) e dieta com caseína hidrolisada enzimaticamente (CHE) - para determinação das perdas endógenas de proteína, aminoácidos e nitrogênio. Foram utilizados 12 suínos mestiços, machos castrados, com peso médio de 35 kg, submetidos previamente a cirurgia para implantação da cânula T simples. O delineamento experimental foi o inteiramente casualizado com três tratamentos (dieta com CHE; dieta isenta de proteína (DIP); e dieta com 23% do extrato protéico de levedura - ingrediente teste), quatro repetições e um animal por unidade experimental. As perdas endógenas de ácido glutâmico, ácido aspártico, lisina, arginina e serina diferiram entre as dietas; os maiores valores foram obtidos nos animais que receberam a dieta com CHE. O maior valor de perda endógena do aminoácido glicina foi determinado nos animais alimentados com a dieta DIP. Os coeficientes de digestibilidade ileal verdadeira de metionina, treonina, triptofano e serina determinados pelas perdas endógenas utilizando-se a dieta CHE foram superiores àqueles determinados utilizando a dieta DIP. As quantidades das secreções protéicas e de aminoácidos obtidas pela técnica da CHE foram maiores que as determinadas pela técnica da DIP. Os coeficientes de digestibilidade verdadeira da proteína foram menores e os dos aminoácidos, maiores, quando determinados pela técnica CHE.The objective of this study was to determine the true ileal digestibility coefficients of the protein and digestible amino acid of a yeast protein extract using two techniques - diet without protein (DIP) and diet with enzime-hydrolysed casein (CHE) - for the determination of protein amino acid and nitrogen losses. Twelve half-breed barrows were used, with average weight of 35 kg, previously submitted to a surgery for "T" simple cannula implantation. A completely randomized experimental design with three treatments, four replications and one animal per experimental unit was used. The treatments diets with CHE, DIP diet with 23% CP were constituted by yeast protein extract. Endogenous losses of glutamic acid, aspartic acid, lysine, arginine and serine differ among diets, the higher values were observed for animals consumed CHE diet. The higher endogenous losses values observed for glycine was determined in the animals fed DIP diet. The true ileal digestibility coefficients of methionine, threonine, tryptophan and serine determined with the endogenous losses using CHE diet were higher than those determined using DIP diet. The amounts of protein and amino acids secretions obtained by using CHE technique were higher than those obtained by the DIP technique. True protein digestibility coefficients of protein were lower and amino acid higher when determined by CHE technique.

Com o objetivo de avaliar o efeito dos níveis de metionina + cistina digestível, com base no conceito de proteína ideal, em dietas contendo níveis subótimos de lisina digestível (1,40%), foram utilizados 396 alevinos revertidos de tilápia (Oreochromis niloticus), da linhagem tailandesa, com peso inicial de 0,86 ± 0,02 g, em delineamento inteiramente ao acaso, composto de seis tratamentos, seis repetições por tratamento e 11 peixes por unidade experimental. Os tratamentos consistiram de cinco dietas com diferentes relações metionina + cistina:lisina digestível (59,5; 63,5; 67,5; 71,5 e 75,5%) e relação treonina:lisina digestível de 80,0%; e uma dieta contendo relação metionina + cistina:lisina digestível de 75,5% e treonina:lisina digestível de 85,0%, todas isoenergéticas e isoprotéicas. Os peixes foram alimentados ad libitum, em seis refeições diárias, durante 40 dias. Avaliaram-se os parâmetros de desempenho, a composição corporal, a deposição de proteína e gordura corporais e a eficiência de retenção de nitrogênio dos peixes.O aumento da relação metionina + cistina:lisina da dieta não influenciou as variáveis avaliadas, com exceção dos teores de gordura e umidade corporais, cujos efeitos foram quadráticos e aumentaram e diminuíram, respectivamente, até a relação estimada de 67,0 e 66,7%.Contudo, a elevação da relação treonina:lisina digestível nas dietas com relações metionina + cistina:lisina digestível de 75,5% proporcionou aos peixes melhor conversão alimentar e maior eficiência de retenção de nitrogênio e de utilização da proteína e lisina para ganho.Os níveis totais ou digestíveis de aminoácidos sulfurosos de 0,91 e 0,86%, que correspondem à relação metionina + cistina:lisina total e digestível de 57,2 e 59,5%, respectivamente, foram os que proporcionaram os melhores resultados de desempenho e características de carcaça de alevinos de tilápia-do-nilo.Three hundred and ninety six reverted Nile tilapia (Oreochromis niloticus), from Thailand strain, averaging initial weight of 0.86 ± 0.02 g were used to evaluate the effect of feeding methionine plus cystine:lysine levels, based on the ideal protein concept, with deficient levels of digestible lysine (1.40%). The experiment was analyzed as a completely randomized design, with six treatments, six replications by treatment and 11 fishes for experimental unit. The treatments consisted of five diets with different ratios of digestible methionine + cystine:lysine (59.5, 63.5, 67.5, 71.5 and 75.5%) and digestible threonine:lysine ratio of 80.0%; and one diet with the digestible methionine plus cystine:lysine ratio of 75.5% and threonine: digestible lysine ratio of 85.0%, all isoenitrogenous and isoprotein. The fishes were fed ad libitum six daily meals during 40 days. Performance parameters, body composition, body protein and fat deposition and nitrogen retention efficiency were evaluated. The increasing dietary digestible methionine plus cystine:lysine ratio did not affect the studied parameters, except for the body fat and humidity content, that showed quadratic effect, with quadratic maximum and minimum at 67.0 and 66.7%, respectively. However, it was observed treatment effect (75.5%) on feed:gain ratio, nitrogen retention efficiency and protein and lysine efficiency for growth. It was concluded that the total or digestible dietary sulfur amino acid level of 0.91 and 0.86%, that correspond to a total and digestible methionine plus cystine:lysine ratio of 57.2 and 59.5%, respectively, provided the best results of performance and carcass characteristics of Nile tilapia fingerlings.

Foi conduzido um experimento para avaliar a utilização de subprodutos do arroz em dietas formuladas com base nos conceitos de proteína bruta e ideal para frangos de corte de 1 a 42 dias de idade. Foram utilizados 720 pintos machos de 1 dia de idade da linhagem "Hybro", em delineamento inteiramente ao acaso, em esquema fatorial 3 × 2, composto de três dietas (sem subprodutos, farelo de arroz integral e quirera de arroz) e dois conceitos de formulação de rações (proteína bruta e ideal), totalizando seis tratamentos e quatro repetições de 30 aves. O ganho de peso, o consumo de ração e a conversão alimentar foram avaliados aos 21 e 42 dias e as características de carcaça aos 42 dias de idade. As aves alimentadas com dietas formuladas pelo conceito tradicional (baseado na proteína bruta) apresentaram melhor conversão alimentar e menor taxa de deposição de gordura abdominal.One experiment was conducted to evaluate the utilization of rice by-products in diets based on crude and ideal protein concepts for broilers from 1 to 42 days of age. Seven hundred and twenty male chicks, one day old, Hybro strain, were distributed in a completely randomized design in a 3 × 2 factorial arrangment, three diets (without by-product, whole rice meal and broken rice) and two ration formulation concepts (crude and ideal protein), totalizing six treatments and four replications of 30 birds. Weight gain, feed intake and feed:gain ratio were evaluated at 21 and 42 days, and carcass characteristics at 42 days of age. In conclusion, birds fed diets formulated by the traditional concept (based on crude protein) showed better feed:gain ratio and lower deposition rate of abdominal fat.

Objetivou-se avaliar o desempenho e as características de carcaça de frangos de corte no período de 22 a 42 dias alimentados com rações formuladas com diferentes relações lisina digestível:proteína bruta (PB). O delineamento foi inteiramente casualizado, segundo um modelo com dois critérios de classificação hierárquica. Foram utilizados 1.200 pintos de corte machos, linhagem Cobb, criados até 21 dias de idade. Depois desse período, as aves foram uniformizadas por peso (média de 879 ± 17 g) e distribuídas nas parcelas experimentais. As dietas foram isonutritivas, exceto quanto aos níveis de PB e lisina digestível, formuladas com dois níveis de PB (17,0 e 19,5%) e cinco relações lisina digestível:PB, correspondendo a 5,9; 6,4; 6,9; 7,4 e 7,9% em relação à ração com 17,0% de PB e 5,3; 5,7; 6,1; 6,5 e 6,9% em relação à ração com 19,5% de PB. Cada ração experimental foi fornecida a 20 aves em cada uma das seis repetições. Aos 42 dias, avaliaram-se as características de desempenho (ganho de peso, consumo de ração e conversão alimentar), quando duas aves de cada parcela foram abatidas para determinação dos rendimentos de carcaça, de cortes e de gordura abdominal. O consumo de ração diminuiu e a conversão alimentar melhorou linearmente de acordo com as relações avaliadas no nível de 17,0% PB. Não houve efeito significativo dos dois níveis de PB utilizados sobre o ganho de peso e os rendimentos de carcaça e de partes. A gordura abdominal reduziu linearmente no nível de 19,5% de PB. As relações ideais foram de 5,9% para 17,0% PB e 5,3% para 19,5% PB. O nível de PB da dieta pode ser reduzido para 17,0%, pois essa redução não afeta o desempenho das aves.This paper was developed to evaluate the performance and the carcass characteristics of broiler chickens over the period from 22 to 42 days, fed with diets formulated with different digestible lysine: crude protein (CP) ratio. A completely randomized experimental design was used, according to a model with two criteria of hierarchical rank. A total of 1,200 male broiler chicks of the Cobb strain, raised upy to 21 days of age, when the birds were uniformized with average weight of 879 ± 17 g and distributed into the experimental plots. The diets were isonutrient, except for the levels of CP and digestible lysine, formulated with two levels of CP 17.0 and 19.5%, and five digestible lysine : CP ratios, corresponding to 5.9; 6.4; 6.9; 7.4 and 7.9% within the diet of 17.0% CP and 5.3; 5.7; 6.1; 6.5 and 6.9% on the diet with 19.5% CP. Each experimental diet was supplied to 20 birds in each one of the six replicates. At 42 days, the performance characteristics (weight gain, feed consumption and feed conversion) were evaluated, and two birds from each plot were slaughtered for determination of carcass yield, cuts and abdominal fat. Feed consumption was reduced feed conversion improved linearly according to the ratios evaluated within the level of 17.0% CP. There was no significant effect of the two levels of CP used, on weight gain, characteristic carcass and cuts yield. Abdominal fat linearly reduced in the level of 19.5% CP. The ideal ratio was of 5.9% for 17.0% CP and 5.3% for 19.5% CP. The CP level of the diet can be reduced for 17.0%, with no effect on bird performance.

Um ensaio de digestibilidade foi conduzido para determinar a energia metabolizável (EMAn), os coeficientes de digestibilidade da matéria seca - MS (CDMS), a excreção e os coeficientes de retenção aparente do fósforo (P), nitrogênio (N), cálcio (Ca), potássio (K), cobre (Cu) e zinco (Zn). Duzentos e cinqüenta pintos de corte, machos, foram distribuídos em um esquema fatorial 3 ´ 3 + 1 (três níveis de fósforo disponível - 0,25; 0,34 e 0,45%, três níveis de proteína bruta (PB) - 15,0; 17,0 e 19,0% e uma ração controle com níveis nutricionais normais), com cinco repetições de cinco aves cada. Às rações com níveis reduzidos de fósforo disponível (Pd) foram adicionadas 500 FTU de fitase, reduzindo-se o teor de Ca em 17%. Com exceção da ração controle, as demais foram formuladas com base em aminoácidos digestíveis. Os valores energéticos das rações com 15 e 17% de PB, independentemente dos níveis de Pd utilizados ou da suplementação com a fitase, apresentaram maior EMAn que a ração controle, possivelmente devido à adição de aminoácidos suplementares. Os CDMS das rações com teores de proteína reduzidos e diferentes níveis de Pd foram superiores ao da ração controle. A redução da proteína na ração, associada a baixos níveis de Pd e suplementação com a enzima fitase, permitiu reduzir a excreção de minerais, que tiveram os melhores coeficientes de retenção, com exceção do Zn, que apresentou coeficiente de retenção inferior ao da ração controle. Porém, a excreção de todos os minerais estudados, comparada relativamente ao tratamento controle, foi minimizada quando foram utilizados níveis baixos de PB e do Pd na ração, suplementada com fitase. A manipulação dos níveis de proteína e P em rações suplementadas com aminoácidos e fitase pode reduzir, principalmente, a excreção de P, N e Cu, minimizando a poluição ambiental causada por esses elementos.A digestibility assay was carried out to determine the apparent metabolizable energy values (AMEn), dry matter digestibility coefficients (DMDC), the excretion and apparent retention coefficient of phosphorus (P), nitrogen (N), calcium (Ca), potassium (K), copper (Cu) and zinc (Zn), using 250 Cobb male broiler chickens receiving the treatments distributed in a factorial schedule 3 ´ 3 + 1 (available phosphorus level - 0.25; 0.34 and 0.45% and crude protein level [CP]- 15.0; 17.0 and 19.0% and a control diet, with normal nutritional levels), with five replicates of five birds each. In the diets with reduced levels of available phosphorus (aP), 500 FTU of phytase were added and calcium requirement was reduced in 17%. Except for control treatment, all the diets were formulated on digestible amino acids basis. The energetic values of the diets with 15.0 and 17.0% CP, independently of the aP levels used or the phytase supplementation, presented higher AMEn that the control diet possibility regarding to supplemental amino acids addition. The DMDC of the diets with reduced CP levels and different levels of aP were higher than the control diet. The CP reduction in the diet associated to lower aP levels and phytase enzyme supplementation allowed to reduce the minerals excretion, which showed better retention coefficients, except for Zinc that presented lower retention coefficient than the the control diet. However, all minerals excretion, as relatively compared to the control diet, was minimized when lower levels of CP and aP was used in the diet, supplemented with phytase. The manipulation of the protein and phosphorus levels in diets supplemented with amino acids and phytase could reduce mainly the excretion of nitrogen, P and Cu, minimizing the environment pollution caused by these elements.

O experimento foi realizado com o objetivo de avaliar diferentes níveis de energia e programas de alimentação sobre a qualidade de carcaça e carne de frangos de corte entre 42 e 57 dias de idade. Foram utilizados 1.600 pintos machos “Cobb”, em um delineamento inteiramente ao acaso, em esquema fatorial 2x4, sendo dois níveis de energia (3.200 e 3.600 kcal EM kg-1) e quatro programas de alimentação (recomendações de aminoácidos). Foram avaliados ascaracterísticas de carcaça (rendimento de carcaça, de peito e de coxas + sobrecoxas) e carne (cor, pH, perdas por cocção, força de cisalhamento, capacidade de retenção de água e análise sensorial)e os dados de desempenho (ganho de peso, consumo de ração, conversão alimentar e conversão calórica). Os níveis energéticos ou os diferentes programas de alimentação não determinaram diferenças expressivas na qualidade da carcaça ou de carne que justifiquem a escolha de um nível de energia ou de um programa alimentar, devendo prevalecer o nível energético e as recomendações de aminoácidos que determinem o maior custo-benefício. Observou-se que o nível de 3.600 kcal EM kg-1 proporcionou melhoria no desempenho das aves, enquanto que o fracionamento das exigências de aminoácidos digestíveis em dois períodos determinou piores resultados.This experiment was conducted to evaluate the use of different energy levels and amino acid recommendations on carcass and meat quality of broilers from 42 to 57 days of age. It was used 1,600 one-day old male broilers (Cobb) in a completely randomized design arranged in a factorial scheme 2x4 with 3,200 and 3,600 kcal ME kg-1 and four different feed programs. The experimental period was from 42 to 57 days of age. From 1 to 41 days of age all birds received the same diets based on corn and soybean meal. Data from carcass yield (output carcass, relation weight breast and thigh and overthigh with the carcass weight) and muscle quality (color, pH, cooking weight loss,shearing force, water holding capacity and sensorial analysis) and data from performance (weight gain, feed intake, feed:gain ratio and energy conversion) were evaluated. The energy levels and different feed programs did not determine differences on carcass meet quality tojustify the choice of amino acid levels and need to consider the energy levels and amino acid recommendations to determine the best cost-benefit. It was observed that 3,600 kcal ME kg-1 resulted in some improvement on performance, and the partition of digestible amino acid requirements during two periods resulted in worst performance.

Objetivou-se determinar os coeficientes de digestibilidade e os valores de aminoácidos digestíveis verdadeiros de 12 alimentos protéicos para aves. Utilizou-se o método de alimentação forçada, com galos Leghorne adultos cecectomizados, em um delineamento experimental inteiramente casualizado, com 12 tratamentos, seis repetições e um galo por unidade experimental. Os alimentos estudados foram: farelo de glúten de milho 22%, farelo de glúten de milho 60%, concentrado protéico de soja, soja integral extrusada parcialmente desengordurada, farinha de carne e ossos 36%, farinha de carne e ossos 45%, farinha de peixe, farinha de vísceras de aves de alto teor de gordura, farinha de penas, plasma sangüíneo 70%, plasma sangüíneo 78% e hemácias. Os valores médios dos coeficientes de digestibilidade verdadeira dos aminoácidos essenciais e não-essenciais, em porcentagem, foram, respectivamente, 83,32 e 87,20 para o farelo de glúten de milho 22%; 92,90 e 94,86 para o farelo de glúten de milho 60%; 91,10 e 90,19 para o concentrado protéico de soja; 88,90 e 88,91 para a soja integral extrusada parcialmente desengordurada; 88,63 e 85,94 para a farinha de carne e ossos 36%; 87,80 e 85,00 para a farinha de carne e ossos 45%; 89,39 e 87,32 para a farinha de peixe; 79,22 e 74,36 para a farinha de vísceras de aves de alto teor de gordura; 85,89 e 82,32 para a farinha de penas; 87,22 e 87,78 para o plasma sangüíneo 70%; 90,42 e 91,40 para o plasma sangüíneo 78%; e 95,25 e 94,31 para as hemácias.The true digestibility coefficients and the values of true amino acid digestibility of 12 protein meals were determined in Leghorn cecectomized roosters by the "forced feed" method. The experiment was analyzed as a complete randomized design with 12 treatments, six replicates and one rooster per experimental unit. The studied feedstuffs were as follows: corn gluten meal 22%, corn gluten meal 60%, soybean protein concentrate, partially defatted extruded whole soybean, meat and bone meal 36%, meat and bone meal 45%, fish meal, full fat poultry by-product meal, feather meal, spray-dried plasma 70%, spray-dried plasma 78% and erythrocytes. The average values of essential and non essential true amino acids digestibility coefficients, in percentage, were as follows: corn gluten meal 22%, 83.32 and 87.20; corn gluten meal 60%, 92.90 and 94.86; soybean protein concentrate, 91.10 and 90.19; partially defatted extruded whole soybean: 88.90 and 88.91, meat and bone meal, 36%, 88.63 and 85.94; meat and bone meal 45%, 87.80 and 85.00; fish meal, 89.39 and 87.32; full fat poultry by-product meal, 79.22 and 74.36; feather meal, 85.89 and 82.32; spray-dried plasma 70%, 87.22 and 87.78; spray-dried plasma 78%, 90.42 and 91.40; and erythrocytes, 95.25 and 94.31.

An experiment was carried out to evaluate different criteria in feed formulation based on digestible amino acids for broilers during the grower phase. Diets were formulated according to the recommendations for digestible methionine, methionine + cysteine, lysine, and threonine. A total number of six hundred Cobb 500 male day-old chicks were distributed in a completely randomized experimental design, with three formulation criteria supplying the recommendations established by Baker & Chung (1992), Degussa (1997), and Rostagno et al. (2000), with 4 replicates of 50 birds each. No significant differences were observed for weight gain and feed intake. However, feed conversion ratio improved when birds were fed the diets containing the profiles recommended by Baker & Chung (1992) and Degussa (1997). No difference was observed in terms of leg, wings, back, and head yields. Broilers fed with the profile of Baker & Chung (1992) presented worst breast yield, whereas those fed the Degussa (1997) standard had better carcass yield.

O experimento foi realizado com o objetivo de avaliar diferentes níveis de energia metabolizável e de programas de alimentação sobre o desempenho de frangos de corte no período de 42 a 57 dias de idade. Foram utilizados 1.600 pintos machos da linhagem Cobb, em um delineamento inteiramente ao acaso, em esquema fatorial 2 x 4, composto de dois níveis de energia (3.200 e 3.600 kcal EM/kg) e quatro programas de alimentação (recomendações de aminoácidos). As aves foram alimentadas com ração à base de milho e farelo de soja até os 41 dias de idade, quando foram pesadas, homogeneizadas e separadas por tratamento, dando-se início ao fornecimento das rações experimentais. Foram avaliados dados de ganho de peso, consumo de ração e conversão alimentar ao final de cada período experimental, a conversão calórica e o índice de eficiência produtiva para todo o período experimental. O nível de 3.600 kcal EM/kg melhorou o desempenho das aves, mas o fracionamento das exigências de aminoácidos digestíveis em dois períodos piorou os resultados. O desempenho no período de 50 a 57 dias de idade indicou que o abate tardio deve ser antecipado em uma semana, pois, após os 49 dias de idade, ocorre piora na conversão alimentar.The experiment was conducted to evaluate the effect of different energy levels and feeding programs on performance of broilers from 42 to 57 days of age. One thousand and six hundred 1-d male chicks (Cobb) were assigned to a completely randomized design with 2 x 4 factorial arrangement (two levels of energy: 3,200 and 3,600 kcal ME/kg and four different feeding programs: amino acid recomendations). From 1 to 41 days of age all birds were fed the same corn and soybean meal-based diet and, after, the experimental diets were fed. Weight gain, feed intake, feed:gain ratio at the end of each period, energy conversion and productive efficiency in the overall period were evaluated. The 3,600 kcal ME/kg level increased bird performance, but the partition of digestible amino acid requirements in both periods decreased performance. The performance from 50 to 57 days of age indicated that late slaughter must be anticipated one week, because after 49 days of age feed:gain ratio decreases.

This experiment was conducted to determine standardized ileal amino acid digestibility (SIAAD) of commonly used feed ingredients in poultry diets in Pakistan. These feed ingredients included corn, rice broken (RB), rice polishings (RP), wheat bran (WB), sunflower meal (SFM), cottonseed meal (CSM), guar meal (GM), soybean meal (SBM) from India and Argentine and fish meal (FM). The SIAAD of each ingredient was determined in triplicate using 21-days-old broilers. Day-old male broiler chicks (Hubbard? Hubbard) were reared on corn-SBM based diet from 1 to 13 days and thereafter birds were fed experimental diets from day 14 to 21. Each diet was fed to 36 birds kept in six replicate cages, each cage had six birds. In cereals, the SIAAD of corn's amino acid (AA) (90.1%) was similar (p>0.05) to RB (89.0%). Isoleucine (97.8%) and lysine (96.9%) were highly digestible AA in corn and RB, respectively. Among cereal-by products, WB's SIAAD (76.9%) was same (p>0.05) as RP (71.9%). Arginine from WB (82.5%) and RP (83.2%) was highly digestible. However, threonine in WB (72.7%) and leucine in RP (69.6%) were the lowest digestible AAs. In plant protein meals, AAs from Argentine-SBM (85.1%) and Indian-SBM (83.4%) had higher (p<0.5) SIAAD than other protein meals. However, SIAAD of SFM (77.1%) and CSM (71.7%) was intermediate while GM (60.3%) exhibited the lowest (p<0.05) SIAAD among all ingredients. Arginine from GM (76.9%), CSM (85.8%), SBM-India (89.5%) and SBM-Argentine (91.5%) was highly digestible from indispensable AAs. In SFM, methionine (91.4%) SIAAD was the greatest. The average SIAAD of FM was 77.6%. Alanine from FM had the highest (84.0%) but cysteine (62.8%) had the lowest SIAAD. In conclusion, cereals i.e. corn and RB had higher (p<0.05) SIAAD of the cereals by-products. The SIAAD of RP and WB was same (p>0.05). The SBM from plant protein meals had higher (p<0.05) SIAAD than other studied feed ingredients. However, the GM had the lowest (p<0.05) SIAAD among protein meals. [ABSTRACT FROM AUTHOR]