RESUMO Este estudo objetivou avaliar os efeitos da enzima fitase e dos grãos secos de destilaria com solúveis (distillers dried grains with solubles - DDGS) sobre digestibilidade, desempenho e viabilidade econômica de suínos em crescimento. Foram realizados dois experimentos, com uma dieta de referência (RD) à base de milho e farelo de soja; RD + 200 g kg -1 DDGS (DDGS); RD + 1.000 unidades de fitase (PHY); e RD + 200 g kg -1 DDGS + 1.000 unidades de fitase (D + P). No experimento 1, oito suínos machos castrados com peso de 29,35 ± 5,74 kg foram usados através do método de coleta total, com repetição no tempo para avaliação da digestibilidade. No experimento 2, 40 suínos machos castrados 47,65 ± 3,99 kg, com cinco repetições de dois animais por unidade experimental foram usados para avaliação de desempenho e viabilidade econômica. DDGS aumentou a excreção de nitrogênio e energia nas fezes e na urina, prejudicando os coeficientes de digestibilidade e a metabolizabilidade da energia. Os animais que consumiram dietas com DDGS apresentaram pior desempenho enquanto a fitase não afetou os resultados. As dietas com a inclusão de 200 g kg -1 DDGS e 1.000 unidades de fitase não diferem no custo por quilograma em relação à dieta de controle.

ABSTRACT This study aimed to evaluate the effects of phytase enzyme and distillers dried grains with solubles (DDGS) on the digestibility, performance and economic viability of growing pigs. Two experiments were conducted with a reference diet (RD) based on corn and soybean meal: RD with 200 g kg -1 DDGS (DDGS); RD + 1,000 units of phytase (PHY); and RD + 200 g kg-1 DDGS + 1,000 units of phytase (D+P). In experiment 1, eight castrated male pigs weighing 29.35 ± 5.74 kg were used through the total collection method and replicates in time for digestibility evaluation. In experiment 2, 40 castrated male pigs 47.65 ± 3.99 kg, with five replicates of two animals per experimental unit, were used for performance and economic evaluation. DDGS increased the excretion of nitrogen and energy in feces and urine, impairing the digestibility coefficients and metabolizability of dietary energy. The animals that consumed diets with DDGS presented the worst performance, while phytase did not influence the results. Diets with the inclusion of 200 g kg -1 DDGS and 1,000 units of phytase did not differ in cost per kilogram compared to the control diet.

ABSTRACT Two experiments were conducted to evaluate the digestibility and energy of distillers dried grains with solubles (DDGS) from corn and sorghum with or without xylanase enzyme in diets for pigs. The values of dry matter (DM), organic matter (OM), crude protein (CP), mineral matter (MM), ether extract (EE), neutral detergent fiber (NDF), gross (GE), digestible (DE), metabolizable energy (ME), and digestibility coefficients (DC) were determined. In the experiment 1, we used eight barrows of 26.15±3.45 kg with repeated measures in three periods of five days of collection. The treatments consisted of a reference diet (RD); RD with 200 g kg−1 corn DDGS or sorghum DDGS; and RD with 400 g kg−1 corn DDGS or sorghum DDGS. Corn DDGS showed higher values of DE, ME, and DC of EE, GE, and CP. Inclusions of 400 g kg−1 of the test ingredients resulted in higher values of DE and ME and trend for higher DC of DM, OM, and CP. In experiment 2, nine barrows weighing 34.91±1.46 kg were fed RD, 200 g kg−1 corn DDGS or 200 g kg−1 corn DDGS plus xylanase enzyme. The inclusion of xylanase did not influence the digestibility and energy values in diets containing corn DDGS. Values of DE and ME of corn DDGS were 3,477 and 3,277 kcal kg−1, respectively, for the substitution of 200 g kg−1 and 3,761 and 3,068 kcal kg−1 for the substitution of 400 g kg−1 RD. For sorghum DDGS, DE and ME values were 3,030 and 2,863 kcal kg−1, respectively, for replacement of 200 g kg−1 and 3,398 and 3,296 kcal kg−1 for substitution of 400 g kg−1 RD. Levels of up to 400 g kg−1 do not influence the DE and ME of the diets but impair the digestibility coefficient of DM, OM, CP, EE, MM, and NDF. The use of xylanase enzyme in diets containing 200 g kg−1 of corn DDGS does not affect the digestibility of the diets.

ABSTRACT The objective of this study was to estimate the growth parameters of body weight and body nutrient deposition in males and females of one meat- (Coturnix coturnix coturnix) and two laying-type quail strains (Coturnix coturnix japonica), designated either yellow or red, using the Gompertz model. A total of 1350 quail from 1 to 42 days of age were used and they were distributed in a completely randomized design, with five replications for each strain. The parameters of body weight and body composition of the quail were analyzed weekly and evaluated using the Gompertz equation; growth rates and body nutrient deposition were evaluated through derivative equations. The three strains evaluated showed differences in their potential, growth rates, and body chemical composition. The composition up to 42 days of age was not sufficient to adjust the fat deposition data using Gompertz. Due to the period evaluated, the Gompertz model allowed to verify that females have higher body growth rates when compared with males of the same strains, with accelerated growth up to 14 and 21 days of age for males and females, respectively. Regarding the laying strain, the red has greater growth, with similar potential in depositing protein and water in the carcass, but they are more precocious in the deposition of these nutrients.

ABSTRACT The objective of this study was to determine the digestibility coefficient (DC) of nutrients and the digestible energy (DE), and metabolizable energy (ME) values of distillers dried grains with solubles (DDGS) produced in Brazil by different methods. Eight barrows with 23.3±4.1 kg were housed in metabolic cages in a randomized block design and fed diets containing 0, 200, 400, and 600 g kg–1 of corn DDGS. We determined the digestibility of dry matter (DM), organic matter (OM), crude protein (CP), ether extract (EE), mineral matter (MM), neutral detergent fiber (NDF), and gross energy (GE) by the total collection (TC) and chromium oxide marker (Cr) methods. Distillers dried grains with solubles provided the respective DM, OM, CP, EE, MM, NDF, and GE values of 910, 863, 286, 66.9, 46.8, 500 g kg–1, and 4,780 kcal kg–1. The DE and ME values of DDGS were 3,739 and 3,401 kcal kg–1 and 3,691 and 3,213 kcal kg–1 as determined by TC and Cr methods, respectively. The growing inclusion of DDGS did not affect the DE or ME values. The digestibility coefficients of DM, OM, CP, EE, MM, and NDF were 767, 765, 827, 691, 883, and 821 g kg–1, respectively, by the total collection method. The Cr underestimated the values of all variables compared with TC method. Levels up to 600 g kg–1 of the test ingredient do not influence the DE and ME of DDGS, but compromises the digestibility coefficients of DM, OM, and NDF.

ABSTRACT The objective of this study was to determine the nutritional value of glycerin for pigs using different inclusion levels of this test ingredient and the methodologies of total collection and chromium oxide marker. Eight barrows were distributed individually into metabolic cages, in a randomized-block experimental design, and fed diets containing 0, 50, 100, and 150 g kg−1 plant-derived crude glycerin. The feed digestibility methodologies of total feces and urine collection and chromium oxide marker were analyzed. Inclusion of up to 150 g kg−1 crude glycerin improved the digestibility coefficients of organic matter and energy of the diets. The collection method based on the use of chromium oxide marker underestimates the digestibility coefficient of ash and the energy values of glycerin in relation to the total collection method, but yields similar results to those obtained with the total collection method for the dry matter, organic matter, crude protein, ether extract, and neutral detergent fiber assessed.

ABSTRACT The objective of this study was to evaluate performance and carcass and meat characteristics of finishing pigs fed diets with different levels of glycerin, while maintaining the electrolyte balance. Forty barrows with an initial weight of 97.76±13.44 kg were distributed, in a randomized block design, into four treatments with five replicates. Treatments consisted of diets containing 0, 5, 10, and 15% glycerin. Inclusions of salt and sodium bicarbonate were adjusted to balance the sodium content and maintain the same electrolyte balance of the diets as a function of glycerin inclusions. In vivo backfat thickness, daily feed intake, daily weight gain, and feed conversion were measured. After the animals were slaughtered, pH and temperature were measured 45 min and 24 h postmortem, and backfat thickness, loin-eye area, drip loss, and colorimetry were determined. Glycerin inclusion levels did not influence the performance of barrows. Hot carcass weight, dressing percentage, and lightness had higher values when pigs were fed diets containing 2.32, 2.43, and 2.61% glycerin, respectively. The other carcass and meat characteristics were not influenced. Glycerin can be used in finishing pig diets without compromising results of performance or carcass and meat characteristics up to the inclusion level of 15%.

The objective of this study was to estimate the nutrient requirements of digestible threonine for meat-type quails (Coturnix coturnix sp) in the growth phase. A total of 1350 not sexed meat-type quails were distributed in a completely randomized design with six threonine levels (10.80, 11.50, 12.20, 12.90, 13.60 and 14.30 g/kg as fed), five replications and 45 quails per experimental unit, from 1 to 14 days of age. The threonine levels in the diet had a quadratic effect on body weight, feed intake and weight gain. Estimates for highest body weight (79.41 g), feed intake (128.96 g/bird) and weight gain (70.73 g) were observed with diets containing 12.60 g/kg of digestible threonine. According to the LRP model, the threonine intake was estimated at 13.40 g/kg of digestible threonine. Protein deposition rate and energy retained in the carcass showed quadratic effect, with estimated digestible threonine levels of 11.80 and 12.00 g/kg in the diet for maximum protein deposition rate (2.00 g/bird) and retained energy in the carcass (15.88 kcal/g), respectively. There was a linear effect on feed cost per kg of live weight gain as threonine levels were increased. Nutritional requirement of digestible threonine for meat-type quails for maximum growth is 12.60 g/kg, corresponding to a digestible threonine:digestible lysine ratio of 67.02.

The objective of this experiment was to estimate the digestible tryptophan (DTrp) requirements for growing meat quails. In the first experiment (1-14 days of age), 1,950 quails were distributed in a completely randomized design, with six levels of DTrp (0.27; 0.30; 0.33; 0.36; 0.39 and 0.42% of diet), five replications and 65 quails per experimental unit. There was a linear increase of feed intake, tryptophan intake, weight gain and body weight with the DTrp levels increase. In the second experiment (15-35 days of age), 1,350 quails were distributed in a completely randomized design, with six levels of DTrp (0.22; 0.25; 0.28; 0.31; 0.34 and 0.37% of diet), five replications and 45 quails per experimental unit. There was a linear increase for tryptophan intake, carcass yield, ash levels and protein deposition rate with the DTrp levels increase. In the third experiment (28-35 days of age), conducted to determine the nitrogen balance, 150 males were housed in galvanized wire cages featuring drinker, feeder and individual metal tray lined with plastic to collect the excreta. The design was completely randomized, with six levels of DTrp (0.22; 0.25; 0.28; 0.31; 0.34 and 0.37% of diet), five replicates and five quails per experimental unit. Linear decrease was observed on the nitrogen balance and metabolization coefficient with the DTrp levels increase. The nutritional requirement of digestible tryptophan for maximum growing of meat quail, in the period from 1 to 14 days of age, is higher or equal to 0.42%; in the period from 15 to 35 days, it is 0.22%.

Este experimento foi realizado para estimar a exigência de energia metabolizável (EM) para codornas de corte de 1 a 14 dias de idade. Foram utilizadas 1.140 aves com 1 dia de idade, distribuídas em delineamento inteiramente casualizado, com cinco tratamentos (2.750; 2.850; 2.950; 3.050 e 3.150 kcal de EM/kg de ração), seis repetições e 38 aves por unidade experimental. Observou-se redução linear dos níveis de energia no peso corporal, consumo de ração e ganho de peso das aves. A conversão alimentar foi influenciada de forma quadrática, com melhor estimativa obtida com 2.997 kcal de EM/kg de ração. Enquanto o teor de proteína bruta não sofreu diferença, o teor de água diminuiu e o de extrato etéreo aumentou de forma linear com os níveis crescentes de EM. Os níveis de EM tiveram efeito quadrático sobre a taxa de deposição de proteína e eficiência de deposição de proteína nos cortes. A exigência de EM de codornas de corte na fase inicial de crescimento é de 2.997 kcal de EM/kg, que corresponde à relação energia metabolizável:proteína bruta de 108,9.

This experiment was carried out to estimate the metabolizable energy (ME) requirements for meat quails from 1 to 14 days of age. A total of 1,140 1-day old meat quails were distributed in a completely randomized design, with five treatments (2,750; 2,850; 2,950; 3,050 and 3,150 kcal of ME/kg), six replications and 38 quails per experimental unit. There was linear reduction of energy levels in body weight, feed intake and weight gain of birds. The feed conversion ratio showed a quadratic effect, with the best estimate obtained with 2,997 kcal of ME/kg. Whereas crude protein content did not differ, water content decreased and ether extract increased linearly with the increasing levels of ME. The ME levels showed a quadratic effect on daily protein accretion rate and daily protein accretion efficiency. The ME requirements for meat quail in the initial growing stage is 2,997 kcal/kg, corresponding to a metabolizable energy/crude protein relation of 108.9.

Foram conduzidos dois experimentos com o objetivo de avaliar os efeitos da suplementação enzimática das rações à base de milho e farelo de soja sobre o desempenho e metabolizabilidade dos nutrientes em codornas de corte. Os tratamentos foram: controle positivo para atendimento das exigências; controle positivo suplementado com complexo enzimático e controles negativos suplementados reduzidos em 2 e 4% nos teores de energia metabolizável e aminoácidos. Na fase inicial, observou-se aumento no consumo de ração (p < 0,05) no tratamento controle negativo reduzido em 4% na energia metabolizável e aminoácidos em comparação aos tratamentos controle positivos. Na fase de crescimento o consumo de ração, conversão alimentar e rendimento de carcaça não diferiram (p > 0,05). Conclui-se que o complexo enzimático pode ser utilizado em dietas reduzidas em energia metabolizável e aminoácidos sem prejudicar o desempenho de codornas de corte. No ensaio de metabolismo, não foram observadas diferenças (p > 0,05) entre os tratamentos para os coeficientes de metabolização das matérias seca e orgânica, proteína bruta e energia bruta. O coeficiente de metabolização da FDN melhorou (p < 0,05) com a adição de enzimas.

Two experiments were carried out to evaluate the effects of enzyme supplementation (xylanase + β-glucanase) of diets based on corn and soybean meal on: performance in initial (1-14 days) and growing (15-35 days) phases, and nutrient metabolization of meat-type quails. The treatments were: positive control to meet the nutritional requirements of the specie; positive control supplemented with enzyme complex; and negative controls with two reduced supplementation levels of metabolizable energy and amino acids (by 2% and 4%). In the initial phase, the negative control treatment reduced by 4% of metabolizable energy and amino acids increased feed intake (p < 0.05), compared to positive controls. In the growing phase, there were no differences (p > 0.05) in feed intake, feed conversion ratio and carcass traits. In conclusion, this supplementation can be used successfully in diets with reduced metabolizable energy and amino acid contents for meat-type quails. In the metabolism trial, there were no differences (p > 0.05) in metabolizable coefficients of dry matter, organic matter, crude protein and gross energy among treatments. The metabolization coefficient of NDF improved (p < 0.05) with enzyme supplementation.

O objetivo neste trabalho foi estimar as exigências de lisina digestível e de energia metabolizável (EM) para codornas de corte (Coturnix coturnix sp) em crescimento. Foram utilizadas 1.680 codornas de 4 a 35 dias de idade, não-sexadas, em delineamento experimental inteiramente casualizado em esquema fatorial 4 × 4 (LD = 0,92; 1,12; 1,32 e 1,52% × EM = 2.800; 2.900; 3.000 e 3.100 kcal/kg de ração), totalizando 16 dietas, avaliadas com 3 repetições de 35 codornas por unidade experimental. O aumento dos níveis de lisina digestível na ração provocou aumento linear do peso corporal, do ganho de peso, do consumo de lisina e do rendimento de peito e redução do teor de água nos cortes. Quando houve aumento dos níveis de energia metabolizável na ração, observou-se redução linear no consumo de lisina e aumento do peso corporal e do rendimento de gordura abdominal. O aumento simultâneo dos níveis de lisina e energia metabolizável na ração, no entanto, provocou redução linear no consumo de ração e melhora linear da conversão alimentar no período de 4 a 35 dias, mas aumentou o teor de gordura nos cortes. A exigência nutricional de lisina digestível para máximo crescimento de codornas de corte é maior ou igual a 1,52%. O nível de 2.800 kcal/kg de EM na ração é suficiente para bom desempenho das aves, contudo, para melhor conversão alimentar, são necessário níveis mais elevados.

The objective of this experiment was to estimate the digestible lysine and metabolizable energy (ME) requirements for growing meat quails (Coturnix coturnix sp). A total of 1,680 quails from 4 to 35 days of age of both sexes were used in a complete random experimental design in a 4 × 4 factorial scheme (DL = 0.92; 1.12; 1.32 and 1.52% × ME = 2,800; 2,900; 3,000 and 3,100 kcal/kg of the ration) totaling 16 diets evaluated with 3 replications of 35 quails per experimental diet. Increase of the levels of digestible lysine in the diet linearly increased body weight, weight gain, lysine intake and breast yield and reduced water content in the cuts. When levels of metabolizable energy were increased in the diet, it was observed a linear reduction on consumption of lysine and an increase of body weight and abdominal fat yield. However, The simultaneous increase of levels of lysine and metabolizable energy in the diet linearly reduced feed intake and linearly improved feed conversion in the 4-35 day period, but it increased fat content in the cuts. The nutritional requirement of digestible lysine for maximum growth of meat quails is greater than or equal to 1.52%. The level of 2,800 kcal/kg ME in ration is sufficient to allow a good performance of the birds, however, for a better feed conversion, greater levels are needed.

O objetivo neste estudo foi obter estimativas de parâmetros genéticos para as características peso do ovo, produção de ovos em 189 dias de postura e dia do primeiro ovo em codornas de três linhagens de postura e uma de corte. Os dados foram analisados por meio de procedimentos bayesianos usando amostragem de Gibbs. As estimativas de herdabilidade para peso do ovo, produção de ovos em 189 dias de postura e dia do primeiro ovo foram, respectivamente, para a linhagem amarela, 0,31; 0,84 e 0,53; azul, 0,14; 0,82 e 0,60; vermelha, 0,70; 0,96 e 0,75; e de corte, 0,73; 0,96 e 0,72. As correlações genéticas entre peso do ovo e produção de ovos em 189 dias de postura, peso do ovo e dia do primeiro ovo e, produção de ovos em 189 dias de postura e dia do primeiro ovo foram, para amarela, 0,58; -0,77; e -0,90; azul, 0,09; -0,01; e -0,95; vermelha, 0,09; 0,03; e -0,76; e de corte, -0,18; 0,19 e -0,91. A partir das probabilidades de superposição das distribuições posteriories dos parâmetros, as linhagens dividem-se em dois grupos distintos: um com as linhagens amarela e azul e outro com as linhagens vermelha e de corte.

The objective of this research was to estimate genetic parameters for the traits egg weight, egg production in 189 days and age at first egg in three laying quails and one meat line of quails. Data was analyzed by Bayesian procedures using Gibbs sampling. The heritability estimates for egg weight, egg production in 189 days and age at first egg, were, respectively, for yellow line, 0.31, 0.84 and 0.53; for blue line, 0.14, 0.82 and 0.60; for red line, 0.70, 0.96 and 0.75; and for meat line, 0.73, 0.96 and 0.72. Genetic correlation between egg weight and egg production in 189 days, egg weight and day at first egg and egg production in 189 days and day at first egg were for yellow line, 0.58, -0.77 and -0.90; for blue line, 0.09, -0.01 and -0.95; for red line, 0.09, 0.03 and -0.76 and for meat line, -0.18, 0.19 and -0.91, respectively. Based on the probabilities of posterior parameter distribution overlap, the lines are divided in two different groups: one group with the yellow and blue lines and another with the red and meat lines.

Foram conduzidos três experimentos com o objetivo de estimar as exigências nutricionais de cálcio e fósforo disponível de codornas de corte em crescimento. No experimento 1 (1-14 dias de idade), 1.250 codornas de corte foram distribuídas em esquema fatorial 5 × 5 (níveis de cálcio = 0,65; 0,76; 0,87; 0,98 e 1,09% × níveis de fósforo = 0,12; 0,22; 0,32; 0,42 e 0,52%), totalizando 25 tratamentos com duas repetições e 25 aves por unidade experimental. Os níveis de cálcio não influenciaram o desempenho das aves, mas os níveis de fósforo afetaram de forma quadrática o peso corporal, o ganho de peso e a densitometria óptica, com estimativa de exigência em 0,41%. No experimento 2 (15-35 dias de idade), 1.500 codornas de corte foram distribuídas em esquema fatorial 5 × 5 (níveis de cálcio = 0,61; 0,71; 0,81; 0,91 e 1,01% × níveis de fósforo = 0,29; 0,34; 0,39; 0,44 e 0,49%), totalizando 25 tratamentos com duas repetições e 30 aves por unidade experimental. Os níveis de fósforo influenciaram de forma quadrática a densitometria óptica, e a exigência de fósforo foi estimada em 0,41%. No experimento 3, realizado para avaliação do balanço de cálcio e fósforo (28-35 dias de idade), constatou-se efeito linear crescente dos níveis de cálcio das dietas sobre a ingestão e excreção de cálcio e nenhum efeito dos níveis de cálcio sobre o desempenho nas fases de 1 a 14 e de 15 a 35 dias de idade. Os níveis 0,65% e 0,61% são suficientes para atender às exigências nutricionais de cordornas de corte nas fases de 1 a 14 e de 15 a 35 dias de idade, e o nível de 0,41% de fósforo disponível é o que promove máximo desempenho dessas aves.

Three experiments were carried out to estimate the calcium and phosphorus requirements of meat quail. In the first experiment (1-14 days of age), 1,250 meat quails were placed in a 5 × 5 factorial arrangement (calcium levels = 0.65, 0.76, 0.87, 0.98 and 1.09% × phosphorus levels = 0.12, 0.22, 0.32, 0.42 and 0.52%), totaling 25 treatments, with two replications of 25 birds per experimental unit. The different calcium levels did not affect bird performance. Body weight, weight gain and optic density were influenced in a quadratic form by phosphorus levels and the phosphorus requirement was estimated at 0.41%. The levels of 0.65% calcium and 0.41% phosphorus in diet were enough to meet the requirement of initial phase meat quail. In the second experiment (15-35 days of age), 1,500 meat quails were placed in a 5 × 5 factorial arrangement (calcium levels = 0.61, 0.71, 0.81, 0.91 and 1.01% × phosphorus levels = 0.29, 0.34, 0.39, 0.44 and 0.49%), totaling 25 treatments, with two replications of 30 birds per experimental unit. Differences were not observed of the calcium and phosphorus levels on bird performance. Optic density was influenced in a quadratic form by phosphorus levels and the phosphorus requirement was estimated at 0.41%. In the third experiment, to assess the calcium and phosphorus balance (28-35 days of age), a linear effect was observed on the calcium intake and excretion with the increase in the calcium levels in the diets. The levels of 0.61% calcium and 0.41% phosphorus in the diet were enough to meet the requirement of finishing meat quail. The calcium levels did not affect bird performance at 1-14 and 15-35 days of age, showing, respectively, 0.65 and 0.61% calcium levels were enough to meet the of meat quail requirement. The estimate of 0.41% phosphorus promoted performance of finishing meat quail.

Para avaliar o efeito do probiótico (Lactobacillus sp.) associado a diferentes níveis de proteína bruta (PB) sobre o desempenho, as exigências nutricionais de PB, o rendimento de carcaça e de cortes de codornas de corte, foram utilizadas 2.304 codornas de corte, distribuídas em esquema fatorial 2 × 4 (com e sem probiótico e 15, 20, 25 ou 30% de PB), com duas repetições por nível de PB, repetido duas vezes no tempo (dois períodos experimentais), totalizando 32 unidades experimentais. A adição do probiótico reduziu o consumo de ração e melhorou a conversão alimentar no período de 1 a 7 dias de idade. De acordo com os pesos médios do modelo Linear Response Plateau (LRP), aos 7 e aos 14 dias, as estimativas de exigência foram de 27% de PB e aos 21, 28 e 35 dias, 22 a 24% de PB. A adição do probiótico não influenciou o rendimento de carcaça e de cortes. Para o rendimento de carcaça, a exigência de PB, de acordo com o modelo quadrático, foi estimada em 23,53%, mas, pelo modelo LRP, a estimativa reduziu para 17,13% de PB. Nas condições ambientais em que as codornas foram criadas, a adição do probiótico não influenciou o desempenho, as exigências nutricionais de PB e o rendimento de carcaça de codornas de corte. As exigências de PB para aves de até 14 dias de idade são de 27% e, após esta idade, reduzem para 22 a 24%.

To evaluate the effect of probiotic (Lactobacillus sp.) associated with different crude protein (CP) levels on performance, CP nutritional requirements, carcass and cut yields of meat quails, a total of 2304 meat quails were distributed in a 2 × 4 factorial design (with and without probiotic and four CP levels - 15, 20, 25 and 30%), with two replications per treatment, repeated twice in time (two experimental periods), totalizing 32 experimental units. The addition of probiotic decreased the feed intake and improved the feed conversion rate at 1 to 7 days of age. According to the mean weight of the LRP model, at 7 and 14 days, the requirement estimations were of 27% of CP and at 21, 28 and 35 days, the requirements were from 22 to 24% of CP. The addition of probiotic did not influence carcass and cut yields. For the carcass yield, the CP requirement, according to the quadratic model, was estimated in 23.53%; however, in relation to LRP, the estimative decrease to 17.13% of CP. It was possible to conclude that in the environmental conditions evaluated, the addition of probiotic did not influence the performance, CP nutritional requirement and carcass yield of meat quails. The CP requirements for birds of up to 14 days of age were of 27% and, after this age, there are evidences of reduction to values from 22 to 24%.