NÍVEIS DE PROTEÍNA PARA FRANGAS SEMIPESADAS NO PERÍODO DE UMA A DEZOITO SEMANAS DE IDADE

Desenvolveram-se dois experimentos com o objetivo de avaliar diferentes níveis dietéticos de proteína bruta para frangas semipesadas. No primeiro experimento, as aves com dois dias de idade foram alimentadas até seis semanas com dietas contendo sete níveis de proteína (14%, 15%, 16%,17%, 18%, 19% e 20%) e com 3,0 Mcal de EM. No segundo experimento, a alimentação das aves constitui de dietas contendo quatro níveis de proteína (14%, 15%, 16% e 17%) e 2,9 Mcal de energia metabolizável da sétima a décima oitava semana. Após esse período, avaliou-se o desempenho produtivo dessas aves, no período de vinte e seis a trinta e oito semanas de idade. De uma a seis semanas de idade, o nível de 20% de PB proporcionou melhor desempenho. No segundo experimento, houve efeito significativo para o consumo de proteína e ganho de peso (efeito linear crescente) e efeito linear decrescente para conversão alimentar e eficiência protéica. Os níveis de proteína na fase de recria não influenciaram as variáveis avaliadas na fase de produção. Apenas houve efeito linear crescente para peso da casca. Com isso pode-se concluir que, para o período de sete a dezoito semanas de idade, a utilização de um nível de 14% de proteína bruta não afeta o desempenho das aves na fase de produção. PALAVRAS-CHAVES: Aves, cria, produção de ovos, recria e qualidade do ovo

Scientific progress in the production of monogastric in the first decade of the twenty-first century

Significant progress in the area of animal production is due to the development of researches on genetics, environment, health, management and nutrition. The search for better management conditions that benefit animal welfare resulted in changes to the installation. The genetic improvement more productive animals has encouraged the number of searches to reduce the incidence of diseases, mainly of metabolic origin. The incorporation in products with higher bioavailability as industrial amino acid and organic minerals, the inclusion of products modifiers enteric of microflora as probiotic, prebiotic, symbiotic, nucleotides and exogenous enzymes, has benefited the use of nutrients are not well absorbed and often unavailable in the diet. Biotechnology latest as nutrition in egg and molecular biology has been used for the benefit of the increase animal productivity

Valores energéticos e composição bromatológica dos fenos de jureminha, feijão bravo e maniçoba para aves

Um experimento foi conduzido para determinação dos valores de energia metabolizável aparente (EMA) e energia metabolizável aparente corrigida pelo balanço de nitrogênio (EMAn) e da composição química dos fenos de feijão-bravo (FFB), jureminha (FJ) e maniçoba (FM) para uso na alimentação de aves. Duzentos e oitenta pintos com 17 dias de idade foram distribuídos aleatoriamente em sete tratamentos, em esquema fatorial 3 x 2 + 1 (três tipos de feno x dois níveis de substituição da dieta-referência + dieta-referência), com quatro repetições de dez aves. Os níveis de EMA e EMAn dos fenos de jureminha, feijão-bravo e maniçoba foram 3.205 e 2.911, 2.990 e 2.648, 2.728 e 2.419, determinados com 15% de substituição da dieta-referência pelo alimento e 2.678 e 2.371, 2.875 e 2.523, 2.277 e 1.956 com substituição de 30%, respectivamente, e evidenciaram influência do nível de substituição da dieta-referência sobre os valores de EMA e EMAn das dietas. Os valores de EMA e EMAn, para aves, dos fenos de jureminha e feijão-bravo são superiores aos do feno de maniçoba.An experiment was carried out to determine the apparent metabolizable energy (AME), apparent metabolizable energy corrected for nitrogen balance (AMEn) and chemical composition of bravo bean hay (HBB), jureminha hay (HJ) and maniçoba hay (HM) for use in birds feeding. Two hundred and eighty, 17 days old broiler chicks were distributed according to a completely randomized design, into seven treatments organized in a factorial arrangement 3 x 2 + 1 (three hay types x two levels of substitution of the reference diet + reference diet), with four repetitions of 10 birds each. The contents of AME and AMEn of jureminha, bravo bean and maniçoba hays were 3.205 and 2.911, 2.990 and 2.648, 2.728 and 2.419, respectively, when the ingredients test substituted 15% of the reference diet, and 2.678 and 2.371, 2.875 and 2.523, 2.277 and 1.956, respectively, when the ingredients test substituted 30% of the reference diet. Therefore, the level of substitution of the reference diet by the ingredient test affects AME and AMEn. Jureminha and bravo bean hays presented higher AME and AMEn values than maniçoba hay for bird feeding

Mathematical models to describe the growth curves of white-egg layers

The aim of this study was to compare mathematical models describing growth curves of white-egg layers at different population densities. To fit the models, 4,000 growing white-egg layers were utilized. The experimental design was completely randomized, with population densities of 71, 68, 65, 62, and 59 birds per cage in the starter phase and 19, 17, 15, 13, and 11 birds per cage in the grower phase, with 10 replicates each. Birds were weighed weekly to determine the average body weight and the weight gain. Gompertz and Logistic models were utilized to estimate their growth. The data analysis was carried out using the PROC NLMIXED procedure of the SAS® statistical computer software to estimate the parameters of the equation because mixed models were employed. The mean squared error, the coefficient of determination, and Akaike’s information criterion were used to evaluate the quality of fit of the models. The studied models converged for the description of the growth of the birds at the different densities studied, showing that they were appropriate for estimating the growth of white-egg layers housed at different population densities. The Gompertz model showed a better fit than the Logistic model

Protein and energy for maintenance and gain of European quail fed different energy sources and housed at two temperatures

The objective of this study was to evaluate whether replacing corn starch (CS) energy with isolated soy protein (ISP) and soybean oil (SO) and the ambient temperature affect the protein and energy requirements for maintenance and gain of European quail. Thus, a total of 432 European quail from 10 to 30 days of age, distributed in a completely randomized design, were used to estimate the protein and energy requirements for maintenance through the comparative slaughter methodology. The treatments consisted of three diets formulated with the replacement of CS, corresponding to 15% of the metabolizable energy in the diet, with ISP and SO, two controlled temperatures (26 and 35 °C), and three levels of feed supply (ad libitum, and 70 and 40% of ad libitum intake), with four replicates of six birds. Protein and energy requirements for weight gain were determined from 160 European quail, slaughtered every five days at 10, 15, 20, 25, and 30 days of age. Birds were housed in four groups of 40 birds in a room with thermoneutral temperature (26 °C). The energy sources of the feed and temperatures studied affected protein and energy requirements for maintenance and gain of European quail. Replacing CS energy by 15% of dietary energy with SO results in lower protein and energy maintenance requirements for European quail at both temperatures. The protein and energy weight gain requirements of quail fed SO as an energy source is higher than CS and IS

Effects of different proteases on commercial laying hens at peak production

We evaluated the effect of adding proteases in diets of laying hens at peak production on the performance, egg quality, relative weight of digestive organs, and intestinal morphometry. Hy-Line W36 layer hens (390; 28-39 weeks old) were distributed in five treatments, with 13 animals each, with six replicates. The treatments were: control (standard formulation without nutritional reduction or protease inclusion), negative control A - NCA (nutritional reduction according to protease A matrix, without protease), negative control B - NCB (nutritional reduction according to protease B matrix, without protease), NCA + protease A, and NCB + protease B. The experimental period lasted 12 weeks, divided into three cycles of 28 days. Hens subjected to treatments (NCA and NCB) showed a decrease in feed intake. However, the addition of proteases A and B promoted improvement in this trait. The diets NCA and NCB had a negative influence on the production rate of the hens, but the diet supplementation with protease B resulted in significant improvement on egg laying rate. Hens subjected to nutritional reduction presented the worst results regarding mass and conversion by egg mass. However, the addition of enzymes reversed these results. Although the diets did not affect the relative weights of yolk, albumen, eggshell, Haugh unit, and specific gravity of the eggs, a higher eggshell thickness was observed in hens that received NCA, NCB, and NCB + protease B diets. The diets did not influence the relative weights of digestive organs and the small intestine morphometry. Hens fed diets supplemented with A and B have performance recovered in relation to those that received diets with reduced levels of nutrient

Electrolyte balance in diets with reduced protein for semi-weighted laying hens in the second production cycle

The objective was to evaluate the effect of electrolyte balance in diets with reduced protein for semi-weighted Bovans Goldline laying hens in the second production cycle. The design was completely randomized with five treatments and seven replicates of six birds per experimental unit. Treatment 1 consisted of a control diet containing 165.0 g/kg crude protein (CP), formulated with the addition of DL-methionine to meet birds requirements during the experimental period. To compose the treatments 2-5 (BE149, BE167, BE185 and BE203), a basal diet with reduced protein (135.0 g/kg CP) supplemented with synthetic amino acids DL-methionine, L-lysine, L- threonine, L-valine and L-tryptophan was formulated. This basal diet was supplemented with potassium carbonate, to replace the inert, so as to provide four levels of potassium (5.86, 6.56, 7.26 and 7.96 g/kg) corresponding to the electrolyte balance of 171, 149, 167, 185 and 203 meq/kg, respectively. There was increased linear effect for feed intake and decreasing linear effect for albumen weight and yolk percentage and quadratic effect for conversion per dozen and per egg mass. Crude protein is recommended at 135.0g/kg with 6.77 g/kg potassium and electrolyte balance of 172.51meq/kg in the diet of semi-weighted laying hens in the second production cycle

Níveis de cálcio em dietas para poedeiras semipesadas após o pico de postura Levels of calcium in diets for brown layers post-peak production

Um experimento foi conduzido com o objetivo de estudar os efeitos dos níveis de cálcio nas rações sobre o desempenho e a qualidade de ovos de poedeiras comerciais. Foram utilizadas 216 poedeiras da linhagem Lohmann Brown no período de 39 a 55 semanas de idade. O delineamento utilizado foi inteiramente casualizado, composto de seis níveis de cálcio (3,0; 3,4; 3,8; 4,2; 4,6; 5,0%) e seis repetições de seis aves por parcela. Os níveis de cálcio avaliados não influenciaram os parâmetros produtivos, mas afetaram significativamente as porcentagens de albúmen e casca do ovo. O aumento do cálcio na dieta promove incremento na qualidade da casca do ovo em relação aos demais componentes do ovo. Recomenda-se nível de 4,3% de cálcio em dietas para poedeiras semipesadas após o pico de postura.<br>Two hundred and sixteen layers were raised from 39 to 55 weeks of age to study the effects of levels of calcium in the rations on performance and eggs quality of brown commercial layers. A completely randomized experimental design were used with six levels of calcium (3.0; 3.4; 3.8; 4.2; 4.6 and 5.0%) and six replicates of six layers hens. There was no effect of calcium levels on hen performance, however significantly affected the percentage of albumen and egg shell. The increase of calcium in the diet promoted increment in egg shell quality in relationship to other eggs components. The calcium level of 4.3% is recommended for brown layer hens after production peak

Nutritional potassium requirement for laying Japanese quails

The objective of this study was to evaluate the potassium requirement for laying Japanese quails. Two hundred and forty quails were distributed in a randomized block design, with five treatments and six replicates, with eight birds each. The treatments consisted of a basal diet deficient in potassium (K) (2.50 g/kg), supplemented with potassium carbonate, to replace the inert, to reach levels of 2.50, 3.50, 4.50, 5.50 and 6.50 (g/kg) of K in the diet. There was a quadratic effect of K levels on feed intake, egg production, egg mass and feed conversion per egg mass and per egg dozen, estimating the requirements of 4.26, 4.41, 4.38, 4.43 and 4.48 (g/kg) of K diet, respectively. There was no significant effect on the levels of K in the diet on egg weight, albumen weight, percentage of yolk or shell and yolk color. However, yolk and shell weights reduced and the albumen percentage increased linearly with increasing levels of K in the diet. Despite the reduction of shell weight, the increased levels of K did not influence the specific gravity and shell thickness. The use of 4.41 g/kg of potassium is recommended in the diet for laying Japanese quails