ABSTRACT This study aimed to evaluate the effects of different exogenous protease and carbohydrase in broiler diets on the nitrogen-corrected apparent metabolizable energy (AMEn) and standardized ileal amino acid digestibility (SIAAD) of soybean meals (SBM) in two Brazilian regions (Minas Gerais-MG and Rio Grande do Sul-RS). The total excreta collection of 528 14-d-old chicks was used to determine AMEn in a completely randomized design in a 2 (SBM MG and RS) x 5 (enzyme A, B, C, D and basal diet) + 1 (reference diet, RD) factorial arrangement, totaling 11 treatments, 8 repetitions, and 6 birds per experimental unit. Two experimental treatments (T1 and T6) without enzyme supplementation formulated with SBM MG and RS were used as negative control (NC). The RD without the inclusion of SBM MG and RS was used to correct the nitrogen balance. To determine the SIAAD, ileal content was collected from of broilers and the same experimental design and treatments of the previous trial were used except for the RD, which was replaced with a nitrogen-free diet (NFD) to quantify the excretion of endogenous amino acids. Soybean meal from MG showed the highest levels (p<0.05) of AME and AMEn (3,188 kcal/kg and 2,700 kcal/kg, respectively) in comparison to SBM RS (3,121 kcal/kg and 2,549 kcal/kg, respectively) and, when supplemented with the exogenous enzyme C, also improved the SIAAD (p<0.05), as compared to other enzymes.

ABSTRACT This study aimed to examine the impact of levels of dietary supplementation with fat-soluble vitamins on the production performance and egg quality of laying hens. Three hundred Hy-Line White W-36 laying hens were evaluated from 28 to 44 weeks of age. The birds were allotted to one of six treatments in a randomized block design with 10 replicates with five birds each. Performance and egg quality parameters were evaluated in four 28-day periods. A corn and soybean meal-based basal diet was formulated so as to meet the nutritional requirements of the animals, with the exception of fat-soluble vitamins. The treatments consisted of dietary supplementation with 0%, 33.3%, 66.7%, 100.0%, 133.3% or 166.7% of fat-soluble vitamins (100% supplementation consisted of 7500 IU, 2000 IU, 10 IU and 1.8 mg of vitamins A, D3, E and K per kilogram of diet, respectively). Eggshell weight, shell thickness, shell strength, feed intake, egg weight, feed conversion per egg mass and feed conversion per dozen eggs showed a quadratic response (p≤0.05) to the treatments, whereas egg mass responded linearly. Optimal results were obtained at an average fat-soluble vitamin supplementation level of 109%, which corresponds to 8175 IU of vitamin A, 2180 IU of vitamin D3, 10.9 IU of vitamin E and 1.96 mg of vitamin K per kilogram of diet.

ABSTRACT Two trials were performed to evaluate the effects of an enzyme complex (EC) on broiler performance, metabolizable energy, and phosphorus and nitrogen balance. In the first trial, 960 one-day-old male Cobb broilers were randomly distributed in a 3 x 2 factorial arrangement (three nutritional levels and the inclusion or not of EC), totaling six treatments with eight replicates of 20 birds per pen, and reared until 42 days of age. The control diet was formulated to meet the broilers' nutritional requirements. The other diets contained reduced available phosphorus (P), metabolizable energy, and amino acid levels, considering 100% and 150% of the EC nutritional matrix. The inclusion of the EC (200 g/ton) resulted in better broiler performance, improving weight gain in 4% and feed conversion ratio in 3% (p< 0.05). In the second trial, 240 male broilers were randomly distributed into the same treatments with eight replicates of five birds per cage. The method of total excreta collection was used. There was an interaction (p< 0.05) between diets and EC for P intake, nitrogen (N) intake, and N retention. The EC supplementation improved nitrogen-corrected apparent metabolizable energy values in 2.02% (p< 0.05). Significant effects were observed on phosphorus and nitrogen balance (p< 0.05). Phosphorus retention improved in 10.26%, nitrogen retention increased in 5.3%, while nitrogen excretion decreased in 3.3%. Based on the results of the present study, we recommend the addition of 200 g/t of the enzyme complex to broiler diets, considering nutrient reduction based on 100% of the EC nutritional matrix.

ABSTRACT This study aimed at evaluating four dietary L-Glutamine (L-Gln) or L-Gln plus L-Glutamate (L-Glu) supplementation programs on the performance, breast yield, and uniformity of broilers. A total of 2,112 one-d-old male Cobb 500(r) broilers were distributed according to a randomized block design in a 2 × 4 factorial arrangement (L-Gln or L-Gln plus L-Glu × 4 supplementation programs), totaling eight treatments with 12 replicates of 22 broilers each. The supplementation programs consisted of the dietary inclusion or not of 0.4% of L-Gln or L-Gln plus L-Glu for four different periods: 0 days (negative control), 9d, 21d, and 42d. Feed intake (FI, g), body weight gain (BWG, g), feed conversion ratio (FCR, kg/kg), coefficient of variation of body weight (CV, %), body weight uniformity (UNIF, %), breast weight (BW, g), breast yield (BY, %), coefficient of variation of breast weight (CVB), breast uniformity (UNIFB), coefficient of variation of breast yield (CVBY), and breast yield uniformity (UNIFBY) were evaluated. Birds fed the diets treatments supplemented with L-Gln or L-Gln plus L-Glu for 9d presented 3% higher BWG (p<0.05) compared with the controls. The L-Gln or L-Gln plus L-Glu supplementation until broilers were 21 days old resulted in 14, 10, 16, and 12% improvements (p<0.05) in CV, UNIF, CVBY, UNIFBY, respectively. The supplementation of 0.4% L-Gln (L-Gln 99%) or L-Gln plus L-Glu (minimum 95%) to pre-starter and starter broiler diets is recommended to improve body weight gain and uniformity.

ABSTRACTThe objective of this experiment was to evaluate the performance of 64- to 79-wk-old laying hens fed diets supplemented with an enzyme complex (EC) and containing increasing sunflower meal (SFM) levels. A total of 384 Hy-Line Brown layers were distributed according to a randomized block design in a 4 × 2 factorial arrangement (four levels of SFM, and inclusion or not of EC), with eight replicates of six birds each unit. The levels of SFM inclusion were 0, 8, 16 and 24%, utilized in two distinct diets. Diets were calculated to meet all the nutritional requirements of birds, except for the nutrients that would be made available by the nutritional matrix of the enzyme complex, with or without utilization of EC. The parameters analyzed were feed intake (g/bird/day), egg production (%/bird/day), egg weight, egg mass (g/bird/day), feed conversion ratio per egg mass, feed conversion ratio per dozen eggs, body weight gain, egg components (yolk, albumen and eggshell) and the economic efficiency index (EEI). There was no interaction between EC addition and the SFM levels in the diet. The addition of EC in the diets of laying hens did not affect egg productive or components parameters. The increase in the SFM levels in the diet presented quadratic effect on egg production and feed conversion ratio per dozen eggs, with calculated optimal sunflower meal inclusion levels of 6.72% and 5.83%, respectively, for each parameter. The best economic efficiency per dozen eggs was obtained with the diet with 16.0% SFM and EC inclusion, whereas per egg mass with the diet with of 24.0% SFM and no EC addition.

The objective of this study was to evaluate the performance of male broilers between 21 and 42 days of age fed diets supplemented with an enzyme blend (EB) and containing graded levels of sunflower meal (SFM). In total, 1920 male Cobb broilers were distributed according to a randomized block experimental design in a 4 x 3 factorial arrangement (four SFM dietary levels vs. three feed formulations) with eight replicates of 20 birds each. Dietary SFM inclusion levels were 0, 8, 16, and 24%. Feed formulation included one negative control diet (NC) formulated to supply broiler nutritional requirements, considering EB nutritional matrix values; a diet formulated as the first one, but with the addition of 0.5% EB (NC+EB); and the third diet (positive control - PC) was calculated to supply broiler requirements. Feed intake, weight gain, feed conversion ratio, and carcass parameters were evaluated. There was no effect of EB dietary supplementation on the evaluated performance or carcass parameters (p > 0.05). Increasing dietary addition of SFM reduced weight gain and worsened feed conversion ratio (p > 0.05). The best EEI was obtained with the NC+EB diet containing 8.0% SFM.

Modern broilers have been submitted to continuous genetic improvement, and therefore, their nutritional requirements must be constantly updated to ensure their performance. Two experiments were carried out to evaluate different digestible lysine levels for starter (1021 days) and grower (22-35 days) phases. The experiments were carried out with male and female Cobb 500 broilers, distributed according to a randomized block experimental design in a 5x2 factorial arrangement (5 increasing digestible lysine levels x 2 sexes), totaling 10 treatments, with 8 replicates of 22 and 20 birds during the starter and grower phase, respectively. Digestible lysine levels of 1.06, 1.12, 1.18, 1.24, and 1.30 were used in the starter diets (10-21 days) and 0.9, 0.98, 1.04, 1.10, and 1.16% in the grower diets (22-35 days). Based on the statistical analyses of the evaluated performance parameters, digestible lysine requirements for maximum performance were determined as 1.22% for males and 1.24% for females in the starter phase, and 1.16% for both sexes in the grower phase. Carcass and performance results indicate that digestible lysine requirements vary with sex and evaluated production parameter. Considering the most relevant broiler production parameters, in 22- to 35-d-old males, digestible lysine requirement for breast meat yield (1.16%) was higher than those for feed conversion ratio (1.07%) and weight gain (1.05%).

An experiment was carried out to evaluate the effects of different nutritional strategies on nitrogen (N), phosphorus (P) and calcium (Ca) balance and on copper (Cu), manganese (Mn) and zinc (Zn) excretion in broilers during the periods of 1 to 21 days and 1 to 46 days of age. Four hundred male Cobb-500 broilers were used. A randomized block experimental design was applied, including five treatments with eight replicates of 10 birds each. A five-phase feeding program was adopted (1-8, 9-21, 22-33, 34-40 and 41-46 days of age). Treatments consisted of a control diet (C) with typical protein level and low amino acid supplementation; a reduced-protein diet supplemented with synthetic amino acids formulated on ideal protein concept (IP); C with phytase (C+PHY) supplementation; C with inorganic-organic mineral supplementation (C+MIN); and a diet formulated on ideal protein (IP) basis, and supplemented with phytase and organic and inorganic minerals (IP+PHY+MIN). IP and IP+PHY+MIN diets reduced nitrogen excretion in 13.6 and 13.1% respectively, and promoted the same nitrogen retention (g/bird) and retention efficiency as compared to the diet with typical crude protein level. C+PHY and IP+PHY+MIN reduced phosphorus, calcium and manganese excretion, and improved phosphorus retention. C+MIN and IP+PHY+MIN reduced manganese excretion, but did not influence copper or zinc excretion.

An experiment was carried out at the Department of Animal Science of the Federal University of Viçosa, Brazil, to evaluate the effects of different nutritional plans on the performance of male and female Ross broilers. A completely randomized experimental design with a 6x2 factorial arrangement (six nutritional plans x two sexes) with six replicates of 20 birds per experimental unit was applied. The nutritional plans adopted for males and females included 3, 5, or 28 feeds, and the other 3 plans included 28 feeds containing 92.5, 100, and 107.5% of digestible lysine requirements established according to a mathematical model developed exclusively for Ross broilers. The results showed that the tested 28-feed feeding programs are equivalent, and allow similar performance as compared to 3- and 5-feed feeding programs. Based on the lysine levels included in the different nutritional plans, it was possible to fit the equations: Y = -0.0079x + 1.2435 (R² = 0.981) for males and Y = -0.0084x + 1.1925 (R² = 0.978) for females, where "Y" is digestible lysine level (%) and "x" is average age in days. These equations are specific for multiple-phase feeding programs. The performance of male and female broilers fed the lysine levels established by the mathematical models was similar as to that of birds fed the other nutritional plans. This demonstrates that it is possible to determine broiler lysine.

A trial was carried out at the Animal Science Department of the Federal University of Viçosa to evaluate the performance of heavy and light layers. During four periods of twenty-eight days, 432 layers in the second production cycle, being 216 Hy Line W36 (light birds) and 216 Hy Line Brown (heavy birds), were used. A completely randomized experimental design with a 1+(4x2x2) factorial arrangement (one control treatment, four oil sources, two inclusion levels, and two genetic lines) with four replicates of six birds per experimental unit, was applied. The treatments consisted of diets containing 16.5% crude protein, formulated to supply the nutritional requirements, and the inclusion of each oil source at 2 or 4%. Soybean, canola, linseed and fish oils were used. The control diet did not contain any oil. The studied parameters were: feed intake (g/hen/day), egg production (%), egg weight (g), egg mass (g/hen/day), feed conversion ratio (kg feed /dozen of eggs and per kg eggs). Oil levels and sources did not influence egg mass, feed conversion ratio (per kg eggs and dozen eggs), or egg production. During the first three periods, independently of oil source or genetics, eggs from layers fed 4% oil were the heaviest, except for those of light birds fed soybean oil during the third period, which egg weight was similar for the 2 and 4% levels. Light layers presented lower feed intake and better feed conversion ratio (per kg eggs and dozen eggs) as compared to heavy layers, and there was no influence of the evaluated oil sources on feed intake.

An experiment was carried out to evaluate the effects of different levels of digestible lysine in the diets of male and female broilers on protein and fat deposition. A total of 2160 Avian Farms broilers. A completely randomized experimental design was applied, and treatments consisted of the effects of three digestible lysine levels nested within each sex, with 12 replicates and 30 birds per experimental unit. The adopted digestible lysine levels corresponded to 92.5, 100.0, and 107.5% of the nutritional requirements of phases 1 to 21 days, 22 to 42 days, and 43 to 56 days of age, respectively. In each phase, the experimental diets contained similar calorie and protein levels within each sex. No significant effects of lysine levels were found on dry matter and fat percentages in the carcass of birds during the evaluated periods. Also, there were no significant effects of lysine levels on protein and fat deposition in males or females. However, males presented higher protein deposition and lower fat deposition than females during the total experimental period. Gompertz equations showed that females deposit more fat and less protein than males, and that this affected the fall in the curve of protein deposition, when the curve of fat deposition was still rising. Therefore, it was concluded that the older the broilers at slaughter, the higher their body fat content and the lower their body protein content, particularly in females.

Two experiments were carried out to evaluate the effects of the dietary inclusion of different dietary sunflower meal (SFM) levels (0% and 20%), with or without the supplementation of an enzyme complex (EC) (cellulase, β-glucanase, xylanase, and phytase) on broiler performance, carcass and cuts yields, economics, and dietary AMEn values. A randomized block experimental design, with a 2x2 factorial arrangement of eight replicates of 20 birds each, was used to test performance. A completely randomized experimental design with a 2x2 factorial arrangement of eight replicates of four birds each was used to test metabolism. No interaction effects between SFM and EC were observed on performance. Although SFM significantly reduced feed intake in the starter phase and total period, weight gain was not different in these phases. Feed: gain ratio improved with the use of SFM in all phases, probably due to the dietary inclusion of oil, which may have improved digestibility. There was a significant increase in weight gain with the use of EC in the starter phase, which is possibly explained by the immature digestive system of birds at this age. There were no SFM or EC significant effects on carcass or cuts yields. There was no significant effect of the addition of EC on dietary AMEn values; however, EC significantly improved the apparent metabolizability coefficients of phosphorus and calcium.

Three experiments were conducted to determine the nutritional requirements of potassium (K) for male Ross broiler chickens, from 8 to 21, 22 to 42 and 43 to 53 days of age. The following parameters were evaluated: body weight gain (BWG), feed intake (FI) and feed conversion ratio (FCR). In each experiment, a completely randomized experimental design was used, with six treatments (K levels), and six, eight and eight numbers of replicates, and eight, five and four birds per pen, respectively. The experimental diets were basal diets deficient in K but supplemented with K carbonate to result in levels of 0.30, 0.44, 0.58, 0.72, 0.86 and 1.00% K. Estimated requirements for BWG were 0.628, 0.714 and 0.798% K, for the periods 8-21, 22-42 and 43-53 d, respectively.

Foi realizada uma revisão bibliográfica sobre as pesquisas brasileiras na área de nutrição avícola, entre 1994 a l999. Nesse período, foi publicado um total de 496 trabalhos, com uma média de 82,7 trabalhos/ ano. Os trabalhos na área de nutrição revelaram que 64,52% foram realizados com frangos de corte; 24,19%, com poedoiras e aves de reposição; 3,93%, com matrizes pesadas; e 7,66%, com outras aves. Com relação às publicações em forma de resumos expandidos, foram publicados 226 e 163 resumos, nos Anais das Reuniões Anuais da Fundação APINCO de Ciência e Tecnologia Avícolas e da Sociedade Brasileira de Zootecnia, respectivamente. Na Revista da Sociedade Brasileira de Zootecnia e no Arquivo Brasileiro de Medicina Veterinária e Zootecnia foram publicados, respectivamente, 65 e 34 trabalhos completos. Os pesquisadores das instituições UFV, UNESP-Jaboticabal e UFRGS publicaram no total 104, 92 e 46 trabalhos. As pesquisas concentraram-se principalmente nas áreas de proteína/aminoácidos (21,77%), avaliação de alimentos (21,77%), minerais (19,15%) e aditivos (16,33%).

A literature review of the papers published in the area of poultry nutrition was done considering Brazilian publications from the period of 1994 to 1999. During this period a total of 496 papers were published, with an average of 82. 7 papers/year. The publications in nutrition revealed that 64. 52% were made with broiler chickens, 24. 19% with laying hens and replacement birds, 3.93% with broiler breeders and 7.66% with other type of birds. Considering the publications in the form of summary, 226 and 163, were published in the Proceedings of Fundação APINCO de Ciência e Tecnologia Avícola and Sociedade Brasileira de Zootecnia, respectively. In the Revista da Sociedade Brasileira de Zootecnia and Arquivo Brasileiro de Medicina Veterinária e Zootecnia were published, 65 and 34 papers, respectively. Researches in the Universities UFV, UNESP-Jaboticabal and UFRGS, accounted for a total 104, 92 and 46 papers, respectively. The papers in poultry nutrition concentrated mainly in the area of protein/amino acid (21.77%), feedstuffs evaluation (21.77%), minerals (19.15%) and additives (16.33%).