نوع مقاله : مقاله پژوهشی
عنوان مقاله English
نویسندگان English
Introduction: By-products from the dairy industry, particularly whey (the liquid residue remaining after cheese production), are often considered waste despite their high nutritional value. However, its dried powder form can be used in poultry nutrition. Whey powder improves protein and fat digestibility in monogastric animals, thereby enhancing feed efficiency. Therefore, due to its high biological value, balanced protein quality, bioactive components, and prebiotic properties, whey powder may help mitigate the negative effects of stocking density stress. As a result, it can contribute to improved bird performance. Additionally, corn gluten, due to its affordability, favorable nutritional value, and easy accessibility, can reduce feeding costs while supplying part of the energy and protein requirements of poultry. Increasing stocking density is considered a management strategy to enhance production and efficiency in poultry farming. However, despite its advantages, high stocking density may lead to reduced performance, increased mortality rates, leg disorders, and decreased bird welfare. Based on previous research and reviews, there is currently no information regarding optimal levels of whey powder and corn gluten under varying stocking densities for the Arian strain, specifically concerning growth performance and blood metabolites. Considering the critical role of gastrointestinal health in broiler growth and efficiency, evaluating the combined effects of these two feed sources (whey powder and corn gluten) in broiler diets under both standard and high stocking densities represents a scientifically and economically grounded nutritional and management decision. The goal is to optimize growth performance, essential amino acid profile of the diet, biological value of consumed protein (improved absorption), and blood metabolites by reducing stocking density-induced stress. Accordingly, the present study aims to investigate the effects of different levels of whey powder and corn gluten under varying flock stocking densities on the growth performance and blood metabolites of Arian broiler chickens.
Materials and Methods: A total of 600 one-day-old male Arian broiler chicks were used in this study. The study was conducted as a completely randomized design with a 2×2×2 factorial arrangement, involving 8 treatments, 5 replicates per treatment, and 13 chicks per replicate under standard stocking density conditions, and 17 chicks per replicate under high stocking density conditions, starting from one day of age. A total of 40 experimental units (pens), each measuring 100 × 100 cm with a height of 80 cm (1 m² floor area), were used. The experimental treatments included: 1. Zero percent whey powder and zero percent corn gluten at 13 chicks per replicate (control group) 2. Zero percent whey powder and zero percent corn gluten at 17 chicks per replicate 3. 6% whey powder at 13 chicks per replicate 4. 6% whey powder at 17 chicks per replicate 5. 3% corn gluten at 13 chicks per replicate 6. 3% corn gluten at 17 chicks per replicate 7. 6% whey powder combined with 3% corn gluten at 13 chicks per replicate 8. 6% whey powder combined with 3% corn gluten at 17 chicks per replicate. The diets for the starter, grower, and finisher phases were formulated based on corn and soybean meal according to the nutritional requirements of the Arian strain. Feed intake and body weight gain were recorded weekly, and feed conversion ratio was calculated using the data on feed intake and weight gain. To evaluate blood metabolites, blood samples were collected from the jugular vein at slaughter and analyzed using a centrifuge and an autoanalyzer device. Statistical analysis of the data was performed using SAS software.
Results and Discussion: The interaction effects of whey powder, corn gluten, and stocking density over the entire period significantly increased feed intake in broiler chickens compared to the control, with the highest feed intake observed in the treatment containing 6% whey powder, 3% corn gluten, and 17 chicks per square meter (P < 0.05). Other performance indicators, including feed conversion ratio, average weight gain, and final body weight, were not affected by the interaction effects of the experimental treatments. The main effects of whey powder and corn gluten did not have a significant impact on the blood metabolites of broiler chickens (P > 0.05). Blood metabolites were not affected by the interaction effects of whey powder, corn gluten, and stocking density (P > 0.05). The simultaneous use of whey powder and corn gluten, particularly under varying stocking densities, may contribute to improved growth performance in broiler chickens. Managing stocking density along with the use of nutritional additives can help improve the lipid profile of broiler chickens, but the direct effects of whey powder and corn gluten on blood metabolites require further investigation.
Conclusion: The present study demonstrated that the inclusion of whey powder and corn gluten in the diet, combined with appropriate stocking density management, can positively affect growth performance and certain metabolic indices in Arian broiler chickens. Specifically, whey powder and stocking density significantly improved feed intake and growth parameters, while the combination of corn gluten with stocking density reduced blood LDL levels, which may indicate improved metabolic health. Although some blood metabolites were not affected by the treatments, the overall results suggest that simultaneous adjustment of dietary composition and environmental conditions can enhance productivity and health in broiler chickens. These findings may provide valuable insights for optimizing feeding and rearing strategies in the poultry industry. Overall, the results indicate that incorporating 6% whey powder and 3% corn gluten into the diet at a stocking density of 17 birds per square meter can improve the performance of Arian broiler chickens.
کلیدواژهها English
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