Standardized ileal amino acid digestibility of plant-based feedstuffs and phytase supplementation in broiler chicken diets / [Digestibilidade ileal estandardizada de aminoácidos de alimentos de origem vegetal e suplementação de fitase em dietas para frangos de corte]

The objective was to determine the standardized ileal amino acid digestibility (SIAAD) in soybean meal (SBM), corn + SBM, wheat + SBM and a protein free diet (PFD) associated with phytase. A total of 672 Cobb 500 (493±10g) male chicks were distributed in a completely randomized design with twelve treatments (PFD, PFD + SBM, PFD + corn + SBM and PFD + wheat + SBM, supplemented with 0, 500 and 1000 FTU), eight replicates and seven birds per cage from 14 to 23 days. Phytase supplementation at 500 FTU increased the SIAAD of methionine in SBM (P<0.05) and threonine in corn + SBM (P<0.05). There was no significant effect (P>0.05) for the SIAAD of methionine, arginine and histidine in wheat + SBM as the phytase supplementation. However, the SIAAD of lysine, threonine, isoleucine, phenylalanine, valine, cystine, alanine, aspartic acid, glutamic acid, glycine, serine and tyrosine differed (P<0.05). In general, the SIAAD for SBM, corn + SBM and wheat + SBM are 90.32, 88.65 and 83.97% (0 FTU); 91.31, 88.81 and 88.36% (500 FTU); and 91.36, 87.09 and 87.87% (1000 FTU). In conclusion, the efficacy of phytase for improve the SIAAD vary according to the feedstuff and level of supplementation.

Objetivou-se determinar a digestibilidade ileal estandardizada dos aminoácidos (SIAAD) do farelo de soja (FS), milho + FS, trigo + FS e uma dieta livre de proteína (PFD) com fitase. Um total de 672 pintos machos (493±10g), Cobb 500, foi distribuído em um delineamento inteiramente ao acaso, com 12 tratamentos (PFD, PFD + FS, PFD + milho + FS e PFD + trigo + FS, suplementados com 0, 500 e 1000 FTU), oito repetições e sete aves por gaiola, no período de 14 a 23 dias. A suplementação de fitase em 500 FTU aumentou o SIAAD da metionina do FS (P<0,05) e da treonina do milho + FS (P<0,05). Não houve efeito significativo (P>0,05) para o SIAAD de metionina, arginina e histidina no trigo + farelo de soja à medida que os níveis de fitase aumentaram. No entanto, o SIAAD de lisina, treonina, isoleucina, fenilalanina, valina, cistina, alanina, ácido aspártico, ácido glutâmico, glicina, serina e tirosina diferiu (P<0,05). Em geral, a SIAAD do FS, milho + FS e trigo + FS foi de 90,32, 88,65 e 83,97% sem a suplementação de fitase (0 FTU); 91,31, 88,81 e 88,36% (500 FTU); e 91,36, 87,09 e 87,87% (1000 FTU). Em conclusão, a eficácia da suplementação com fitase para aumentar a SIAAD varia de acordo com o alimento e o nível de suplementação.

Fat-Soluble Vitamin Supplementation Levels in Diets for Laying Hens from 28 to 44 Weeks of Age

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 (p0.05) 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.(AU)

Fat-Soluble Vitamin Supplementation Levels in Diets for Laying Hens from 28 to 44 Weeks of Age

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 (p0.05) 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.

Comparison between infrared and hot-blade beak trimming methods in white and brown pullets: performance, organ and bone development / [Comparativo entre debicagem infravermelha e por lâmina-quente em linhagens de frangas leves e semi-pesadas: desempenho, desenvolvimento ósseo e de órgãos]

The purpose of this study was to evaluate infrared beak trimming versus hot-blade beak trimming on performance, organ and bone development of laying pullets, using 240 birds, at 0-16 weeks of age, from two strains (white layer - Hy-Line W36 and brown layer - Hy-Line Brown). Infrared debeaking was performed on the first day of life in the hatchery, whereas hot-blade beak trimming was performed at eight days of age. Zootechnical performance at 6, 9, 12 and 15 weeks of age was analyzed. At the end of the trial, one Bird per experimental unit was euthanized for liver, gizzard, proventriculus, heart and small intestine relative weight evaluation. Both tibiotarsus were collected to measure bone breaking resistance, bone mineral content and bone densitometry. There was higher body weight and feed intake in both bird strains submitted to infrared beak trimming. Additionally, hot-blade white layers presented lower body development and feed intake. The debeaking methods did not influence relative organ weights or tibiotarsus parameters evaluated. We conclude that the infrared beak trimming method promotes better pullet body development than the conventional hot-blade method, improving feed intake, without compromising organ and bone development, being a more adequate debeaking method to be used in layer production.(AU)

Para avaliar a debicagem infravermelha versus a debicagem pelo método da lâmina quente no desempenho, no desenvolvimento de órgãos e na qualidade óssea de poedeiras em recria, foram utilizadas 240 aves, entre zero e 16 semanas de idade, em duas linhagens (branca - Hy-Line W36 e vermelha - Hy-Line Brown). A debicagem por infravermelho foi realizada no primeiro dia de vida no incubatório, enquanto a debicagem com lâmina quente foi realizada aos oito dias de idade. Analisou-se o desempenho zootécnico na sexta, nona, 12ª e 15ª semanas de idade. No final do estudo, uma ave por unidade experimental foi eutanasiada para avaliação do peso relativo do fígado, da moela, do proventrículo, do coração e do intestino delgado, e ossos do tibiotarso foram coletados para avaliação da resistência à ruptura, do conteúdo mineral e da densitometria óssea. Houve maior peso corporal e consumo alimentar nas aves pertencentes às duas linhagens quando submetidas à debicagem por infravermelho, sem haver influência sobre o peso relativo dos órgãos e a qualidade óssea. Conclui-se que o método de debicagem por radiação infravermelha promove melhor desenvolvimento corporal das frangas em relação à debicagem por lâmina quente, melhorando consumo de ração, sem comprometer o desenvolvimento de órgãos e ossos, sendo mais adequada para utilização na avicultura de postura comercial.(AU)

Digestible lysine requirements of broilers

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%).(AU)

Evaluation of nutrient excretion and retention in broilers submitted to different nutritional strategies

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.(AU)

Avaliação nutricional e energética do farelo de girassol para aves / Nutritional and energetic evaluation of sunflower meal in broiler diets

Foram realizados dois ensaios de metabolismo a fim de determinar a energia metabolizável aparente (EMA), por meio do método de coleta total de excretas com frangos, e a energia metabolizável verdadeira (EMV) e a digestibilidade verdadeira dos aminoácidos do farelo de girassol, por meio do método de alimentação forçada com galos cecectomizados. No primeiro ensaio, foi utilizado o delineamento experimental inteiramente ao acaso com 80 frangos Cobb, distribuídos em dois tratamentos, ração referência (RR) e RR mais 20 por cento de inclusão de farelo de girassol e oito repetições e cinco aves por unidade experimental. No segundo ensaio, foi utilizado o delineamento experimental inteiramente ao acaso com 14 galos Leghorn, distribuídos em dois tratamentos, farelo de girassol e jejum, sete repetições e um galo por unidade experimental. O farelo de girassol apresentou 90,0 por cento de matéria seca, 28,1 por cento de proteína bruta, 4.42kcal/kg de energia bruta, 22,4 por cento de fibra bruta, 2,9 por cento de extrato etéreo, 0,8 por cento de fósforo e 0,3 por cento de cálcio. A EMV, a EMV corrigida, a EMA e a EMA corrigida determinadas foram 3.013; 2.200; 2.141 e 1.983kcal/kg, respectivamente. A lisina foi o aminoácido essencial que apresentou a menor digestibilidade e a arginina, a maior.(AU)

Two experiments were carried out to determine apparent metabolizable energy (AME), by the method of total excreta collection using broilers; and true metabolizable energy (TME) and true amino acid digestibility of sunflower meal (SFM), by the method of forced feeding using cecectomized roosters. In the first experiment, a completely randomized experimental design, with two treatments (reference diet (RD) and RD plus 20 percent SFM inclusion) with eight replicates of five birds each, was applied. In the second experiment, a completely randomized experimental design, with two treatments (SFM vs. fasting) with seven replicates of one rooster each, was used. Sunflower meal presented 90,0 percent dry matter, 28.1 percent crude protein, 4,429kcal/kg crude energy, 22.4 percent crude fiber, 2.9 percent ether extract, 0.8 percent phosphorus, and 0.3 percent calcium. TME, nitrogen-corrected TME, AME, and nitrogen-corrected AME were: 3,013; 2,200; 2,141; and 1,983 kcal/kg, respectively. Lysine was the essential amino acid that presented the lowest digestibility, and arginine, the highest. It is important to constantly upgrade energy and nutrient values of feedstuffs used in feed formulation to supply poultry nutritional requirements.(AU)