Document Type : Research Paper
Authors
1 Department of Animal Sciences, Faculty of Agriculture, University of Tehran, Karaj, Iran
2 Department of animal science, Faculty of agriculture and natural sources, university of Tehran
3 Department of Animal Sciences, Faculty of Agriculture, University of Tehran, Karaj, Iran.
Abstract
Objective: The aim of this study was evaluation and comparison of diet formulated based on apparent metabolizable energy, total amino acids and standardized ileal digestible amino acids on productive performance, carcass characteristics and economic efficiency of broiler chickens.
Method: In this experiment 252 pieces one-day-old female broiler chicks of Ross 308 strain in the form of completely randomized design with 7 treatments with 6 replicates and 6 birds in each replicate was performed. The treatments included: 1. NRC 1994 tables based on total amino acids, 2 and 3. Prediction regression equations of NRC 1994 tables with NIR data and proximate analysis of nutrition laboratory based on total amino acids, 4 and 5. NIR data based on total amino acids and standardized ileal digestible amino acids, 6 and 7. Prediction regression equations of internal articles with proximate analysis data of nutrition laboratory based on total amino acids and standardized ileal digestible amino acids. The birds from age 1 to 45 days received the experimental diets. Production performance traits, carcass characteristics and economic efficiency of birds of different experimental treatments was calculated.
Results: Between the experimental treatments based on total amino acids and standardized ileal digestible amino acids in the whole rearing period, the highest mean weight gain (respectively 2789, 2774 and 2695 grams) belonged to treatments 6, 7 and 3 and the lowest mean weight gain (respectively 2535 and 2472 grams) belonged to treatments 1 and 4 (P<0.05). The lowest feed conversion ratio (respectively 1.66, 1.67 and 1.68) in treatments 7, 6 and 5 was observed (P<0.05) but between other treatments difference was not significant. Also in comparison of experimental treatments based on total amino acids and standardized ileal digestible amino acids the highest relative breast muscle weight (respectively 37.0, 36.71 and 36.53 percent) significantly belonged to experimental treatments 3, 7 and 6 (P<0.05) and the lowest relative breast muscle weight (32.65 percent) belonged to experimental treatment 4 (P<0.05). Comparison of diets adjusted based on standardized ileal digestible amino acids and total amino acids showed that the use of standardized ileal digestible amino acids in diet formulation led to profitability and more economic efficiency in broiler chickens. In such a way that experimental treatment 7 compared to treatment 6 caused increase of 101 Tomans profit per broiler. Also, between diets adjusted based on total amino acids and standardized ileal digestible amino acids, experimental treatment 7 had the highest percentage of profit and experimental treatment 4 had the lowest percentage of profit.
Conclusion: With regard to the data obtained from this research it seems the use of prediction regression equations obtained from national researches in addition to improvement of bird performance in the whole period and increase of carcass characteristics, leads to optimal consumption of feedstuffs and increase of economic efficiency in production units and the use of them in diet formulation compared to tables and data of NIR device is recommended.
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