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52a Reunião Anual da Sociedade Brasileira de Zootecnia Zootecnia: Otimizando Recursos e Potencialidades Belo Horizonte – MG, 19 a 23 de Julho de 2015 Efeito da alimentação sequencial sobre o desempenho de frangos de corte1 Gustavo Dias Lovato2*, Alexandre de Mello Kessler3, Andrea Machado Leal Ribeiro3, Rodrigo Borille2, Rafael Dal Forno Gianluppi2, Priscila Moraes2, Marcos Speroni Ceron2 1 Parte da tese de doutorado do primeiro autor, financiada pela CNPq. Doutorando do Programa de Pós-Graduação em Zootecnia – UFRGS, Porto Alegre, Brasil, Bolsista do CNPq. *e-mail: [email protected]; 3 Professor Titular Departamento de Zootecnia - UFRGS. 2 Resumo: Cento e noventa e dois frangos de corte com 800 g de peso vivo inicial e 21 dias de idade foram utilizados em um experimento para avaliar o efeito da alimentação sequencial sobre o seu desempenho. Os animais foram distribuídos em 4 tratamentos: tratamento 1, dieta A, fornecida durante todo o período do dia (AA); tratamento 2, dieta A fornecida das 7:00 as 17:00 e dieta B fornecida das 17:00 as 7:00 (AB); tratamento 3, dieta B fornecida das 7:00 as 17:00 e dieta A das 17:00 as 7:00 (BA); tratamento 4, dieta B fornecida durante todo o período do dia (BB). Foram utilizadas 32 baterias com seis aves cada, com oito repetições por tratamento. A dieta A foi formulada para atender 100% das exigências em aminoácidos digestíveis da fase e a dieta B, formulada para atender 80% dos aminoácidos digestíveis. O peso final, consumo de ração, ganho de peso diário, consumo no dia, consumo na noite e conversão alimentar apresentaram diferença entre os tratamentos AA e BB avaliados. Os animais alimentados com a dieta B consumiram mais ração do que aqueles animais alimentados com a dieta A, independente do período de fornecimento. A alimentação sequencial reduz o uso de proteína bruta na dieta intermitente sem prejuízos ao ganho de peso mas com ligeiro aumento da conversão alimentar. Palavras–chave: aminoácidos, avicultura, nutrição, proteína bruta Effect of sequential feeding on performance of broiler chickens Abstract: One hundred and ninety two broilers with 800 g of initial body weight and 21 days of age were used in an experiment to evaluate the effect of sequential feeding on their performance. The animals were distributed into four treatments: treatment 1, diet A provided all day period (AA); treatment 2, diet A provided from 7:00 to 17:00h and diet B provided from 17:00 to 7:00h (AB); treatment 3, diet B provided from 7:00 to 17:00h and diet A from 17:00 to 7:00h (BA); treatment 4, diet B provided all day period (BB). Thirty two batteries were used with six birds each, with eight replications/treatment. Diet A was formulated to meet the birds requirements in 100% for digestible amino acids and diet B diet formulated to meet 80% of the required digestible amino acids. The final weight, feed intake, daily weight gain, consumption in the day and at night and feed conversion showed differences between the AA and BB treatments. The broilers fed diet B consumed more feed than those animals fed diet A, independently of the supply period. The sequential feeding reduces the use of crude protein in the diet without intermittent reducing weight gain but with and slight increase in feed conversion. Keywords: amino acids, poultry production, nutrition, crude protein Introduction The use of nutritional strategies that optimize the supply and usage of amino acids, and reduce formulation costs in diets for broiler chickens have been studied and in general have shown favorable results. In poultry production systems, a strategy that has been explored is the sequential feeding (Gous and Du Preez, 1975). This strategy consists in the provision of diets with different nutritional contents in alternating manner for a specified period of time. Several studies have reported that sequential feeding has a positive effect on welfare and carcass quality without depressing the performance of broiler chickens (Bizeray et al., 2002). In addition, the sequential feeding improves the utilization of dietary nitrogen and can modulate growth (Sirri and Meluzzi, 2012), which are extremely important aspects in the production of pigs, where the effects of sequential feeding have not been studied. In Europe, the use of sequential feeding with different nutritional values of feeds has been practiced to switch the use of wheat grain, for example, with a complementary diet rich in protein. Some studies have addressed the sequential power has been effective in reducing mortality and the housing lesion scores, and improve the quality of broiler meat (Bizeray et al., 2002). Although some studies have reported that sequential feeding may induce slight reductions in weight gain compared to complete diets or shorter sequences (Shariatmadari and Forbes, 1993), other studies indicate improvements in the utilization of the dietary nitrogen and in growth modulation ( Sirri and Meluzzi, 2012). In Brazil such food strategy has rarely been explored as formulation cost reduction tool and ________________________________________________________________________________________________________________________________________________ Página - 1 - de 3 52a Reunião Anual da Sociedade Brasileira de Zootecnia Zootecnia: Otimizando Recursos e Potencialidades Belo Horizonte – MG, 19 a 23 de Julho de 2015 nutrient excretion. This study aims to evaluate the effects of sequential feeding strategy on performance in growing broilers. Material e Methods The experiment was conducted on Animal Science Teaching Laboratory of UFRGS. One hundred ninetytwo birds with 21 days of age were housed for 12 days in 32 cages with 6 broilers each equipped with drinking and feeding devices in an experimental room with climate control. Two different diets were used: Diet A, formulated with 100% of requirements in digestible amino acids; Diet B, formulated to meet 80% of requirements requirements in digestible amino acids, both formulated in accordance with the recommendations of the Brazilian Tables for Poultry and Swine (Rostagno et al., 2011). The diets were formulated based on ideal protein concept and nutritional levels are shown in Table 1. These diets were distributed in four treatments: Treatment 1, diet A provided all day period (AA); Treatment 2, diet A provided from 7:00 to 17:00h and diet B provided from 17:00 to 7:00h (AB); Treatment 3, diet B provided from 7:00 to 17:00h and diet A from 17:00 to 7:00h (BA); Treatment 4, diet B provided all day period (BB). The lighting program was 20 hours light starting at 02:00 and ending at 22:00, totalizing 10 hours of light at each change of feed. Tabela 1. Nutritional composition of the diets used in the experiment Nutrients Units Metabolizable energy Mcal/kg Crude protein % Dry matter % Ether extract % Crude fiber % Digestible Lysine % Digestible Methionine % Digestible Met+Cysl % Digestible Threonine % Digestible Triptophan % Digestible Arginine % Digestible Valine % Calcium % Available Phosphorus % Diet A 3.15 20.27 87.84 7.22 2.80 1.13 0.54 0.82 0.73 0.23 1.27 0.86 0.76 0.36 Diet B 3.15 16.32 87.48 5.34 2.45 0.90 0.43 0.66 0.58 0.17 0.97 0.69 0.76 0.37 The birds were weighed at the beginning and end of the experimental period, and from these values was determined daily weight gain. Feed intake was measured every day, by the amount of feed supplied less the feed remaining present in feeders in each ration exchange hours. With these measures it was possible to determine the feed intake in day and night time. The experimental design was completely randomized, with four treatments, eight replicates and six birds per repetition, and the cage was the experimental unit. The data were submitted to normality test and those who submit normal distribution were subjected to analysis of variance using the GLM procedure. When detected significant differences, they will be compared by Tukey test at 5% significance level. Statistical analyzes were performed with SAS statistical software 9.0. Results and Discussion Performance results are presented in Table 2. The final weight, feed intake, daily weight gain, day and night time consumption and feed conversion showed differences among the treatments (P <0.05). The final live weight (FLW), daily feed intake (DFI) and average daily gain (ADG) differed between AA and BB treatments (P <0.05), but there was no difference between AB and BA treatments for the same variables (P> 0.05). Feed intake during the day (FIday) of BA and BB, who consumed the B diet during the day, were 5% higher compared to treatments that consumed the diet in the same period, however only the BA treatment differed from treatments AB and AA (P <0.05). With feed intake during the night (FInight), the same behavior was observed with the treatments that consumed the diet B overnight ate 4.5% more feed (P <0.05) than treatments that ingested the diet A. These results corroborate the results of Shariatmadari and Forbes (1993) demonstrating the existence of a regulatory mechanism in intake when dietary amino acids are limiting. Feed conversion (FC) differ between treatment AA, AB and BA treatments, which also differ BB treatment (P <0.05). The observed results were similar to published literature (Bizeray et al, 2002;. Bouvarel et al., 2004; Sirri and Meluzzi, 2012), demonstrating that sequential feeding have consistent effects on the modulation of growth. In a ________________________________________________________________________________________________________________________________________________ Página - 2 - de 3 52a Reunião Anual da Sociedade Brasileira de Zootecnia Zootecnia: Otimizando Recursos e Potencialidades Belo Horizonte – MG, 19 a 23 de Julho de 2015 digestive and metabolic approach, the action of sequential feeding induces rapid adjustments in protein synthesis and lipogenesis, especially when changes occur in the protein concentration. The hypothesis for this phenomena is the protein turnover rate that can vary rapidly with the need to form new proteins in different parts of the body. Usually, after a meal occurs an instantaneous increase in the concentrations of amino acids in the plasma, but this increase is small due to the protein digestion speed. After entering the blood, the amino acids are absorbed by almost all body cells, where are used to form body protein. However, many intracellular proteins are broken down again into amino acids by lysosomal digestive enzymes. These amino acids are taken back out of the cell and probably will form new proteins in other parts of the body. It is possible that the amino acids from this reversed metabolism are used in the formation of muscle proteins, thus producing a sparing effect on dietary protein. In general, the sequential feeding reduces the protein in the intermittent diet without reducing performance, with a slight increase in feed conversion. Additionally, the diet B with low protein and aminoacid levels has increased consumption compared to diet A, regardless of the time of day, indicating that the birds appear to regulate its consumption not only by the energy level but also by the level of amino acids in the diet. Table 2. Performance of broilers under sequential feeding programs Tratamentos PVi, g FLW, g DFI, g/d AWG, g/d FIday, g/d FInight, g/d FC, g/g AA1 846.3 1930 a2 150.6b 98.6a 68.3c 82.4b 1.53a AB 845.8 1910 ab 155.1ab 96.7ab 68.7bc 86.5a 1.60b BA 846.4 1914 ab 155.1ab 97.1ab 72.4a 82.7b 1.59b BB 845.9 1866 b 158.2a 92.7b 71.9ba 86.3a 1.71c se 9.95 38.01 5.05 3.53 2.39 3.01 0.02 Probability 0.99 0.01 0.04 0.02 <0.01 0.01 <0.01 1 AA: diet A provided all day period; AB: diet A provided from 7:00 to 17:00h and diet B provided from 17:00 to 7:00h; BA: diet B provided from 7:00 to 17:00h and diet A from 17:00 to 7:00h; BB: diet B provided all day period (BB). 2 Different letters in the same column indicates significant mean differences by Tukey test at 5% probability. Conclusions The sequential feeding reduces the use of dietary crude protein and amino acids without loss to weight gain and final body weight in broilers from 21 to 33 days old. The sequential feeding slightly increases feed conversion in broilers when compared with the normal feed management. References Bizeray, D.; Leterrier, C.; Constantin, P.; Picard, M.; Faure, J. M. 2002. Sequential feeding can increase activity and improve gait score in meat-type chickens. Poultry Science 81:1798-1806. Bouvarel, I.; Barrier-Guillot, B.; Larroude, P.; Boutten, B.; Leterrier, C.; Merlet, F.; Vilariño, M.; Roffidal, L.; Tesseraud, S.; Castaing, J.; Picard, M. 2004. Sequential feeding programs for broiler chickens: twenty-four- and forty-eight-hour cycles. Poultry Science 83:49-60. Gous, R. M.; Du Preez, J. J. 1975. The sequential feeding of growing chickens. British Journal of Nutrition 34:113118. Rostagno, H.S. 2011. Tabelas brasileiras para aves e suínos: composição de alimentos e exigências nutricionais. Viçosa: Editora UFV. 186p. Shariatmadari, F.; Forbes, J. M. 1993. Growth and food intake responses to diets of different protein contents and a choice between diets containing two concentrations of protein in broiler and layer strains of chicken. British Poultry Science 34:959-970. Sirri, F.; Meluzzi, A. 2012.Effect of sequential feeding on nitrogen excretion, productivity, and meat quality of broiler chickens. Poultry Science 91:316-321. ________________________________________________________________________________________________________________________________________________ Página - 3 - de 3