نوع مقاله : مقاله پژوهشی
عنوان مقاله English
نویسندگان English
Introduction: Poultry meat is one of the most widely consumed sources of animal protein worldwide and plays a key role in meeting human dietary protein requirements. The consumption of poultry meat is essential in providing the body with the necessary amino acids and protein for its various functions, particularly in growth and tissue repair. In poultry farming, the growth and development of broiler chickens are significantly influenced by the quality of their diet, especially the availability of essential amino acids such as lysine, methionine, and threonine. These amino acids play vital roles in protein synthesis, enzymatic activity, and overall metabolic functions in chickens. Supplementing poultry diets with amino acids can substantially enhance their growth rate and feed conversion efficiency. However, during passage through the upper gastrointestinal tract, the absorption of free amino acids can be affected by factors such as pH, thereby reducing their bioavailability. Encapsulation involves enclosing amino acids within a protective coating that minimizes their degradation in the acidic gastric environment and facilitates their controlled release and absorption in the intestine. This process significantly enhances the health and performance of broiler chickens by improving their nutrient uptake. In broiler nutrition, encapsulated amino acids have been shown to improve feed quality, optimize nutrient absorption, and increase overall animal health. Furthermore, encapsulated amino acids are particularly beneficial when high-quality protein sources are limited or expensive, as they improve the gastrointestinal absorption of amino acids, thereby enhancing the quality of the ingested protein. Their use in poultry diets can also improve liver function, enhance enzymatic activity, increase blood protein levels, and support healthy metabolic processes. Additionally, encapsulated amino acids have been associated with reduced metabolic stress and improved immune function in chickens, which are critical factors for overall health, disease resistance, and performance. Considering these benefits, encapsulating amino acids presents a promising strategy for enhancing the efficiency of poultry production systems. Therefore, the present study aimed to evaluate the effects of encapsulated amino acids on growth performance, blood biochemical parameters, liver function, and immune‑related indices of broiler chickens, and to compare these effects with those of free amino acids.
Materials and Methods: In this study, a total of 1440 Arian broiler chickens were randomly assigned to six dietary group groups: AR (free amino acids), AP (a combination of four encapsulated amino acids), TP (encapsulated threonine), LP (encapsulated lysine), MP (encapsulated methionine), and CP (encapsulated choline chloride). All birds were vaccinated according to a standard vaccination program, which included vaccines for Newcastle disease and avian influenza. After a 42-day feeding trial, blood samples were collected from all groups to measure biochemical parameters such as total protein, glucose, lipid profile, and liver enzyme activities. These parameters were analyzed using an autoanalyzer to assess the effects of the different groups on the health and metabolic functions of the broiler chickens.
Results and Discussion: The results demonstrated that different dietary groups had varying effects on antibody titers, growth indices, biochemical blood parameters, and feed efficiency in broiler chickens. The influenza antibody titer was significantly higher in the TP group compared to other groups (P<0.05), suggesting enhanced immunity in this group. In contrast, no significant differences were observed in Newcastle disease antibody titers among the groups )P>0.05(.
Weight gain did not differ significantly among the TP, CP, LP, and AR groups; however, the MP and AP groups exhibited the lowest weight gain (P<0.0001) in some periods, indicating the limited effectiveness of these diets in supporting growth. The reduced growth performance in the AP group was likely due to an imbalanced amino acid composition or reduced bioavailability of certain amino acids. Feed intake was generally similar across groups )P>0.05(; however, during certain periods, the MP, AP, and LP groups consumed significantly less feed, while the CP group had the highest intake. Regarding feed conversion ratio (FCR), the LP group demonstrated the most efficient feed utilization in most periods (P<0.05), whereas the AP group had the highest FCR and the lowest feed efficiency in certain periods. Blood biochemical analyses revealed that the AR group had the highest levels of glucose, triglycerides, cholesterol, and LDL, while these parameters were significantly lower in the TP, CP, and LP groups(P<0.05). Additionally, total protein levels were higher in the LP group compared to AR group, and the TP and LP groups exhibited the highest globulin concentrations. Moreover, HDL levels were higher in all groups compared to AR, with the TP group showing the highest values. Overall, the TP and LP groups demonstrated superior performance in terms of blood parameters and immune response. The LP group exhibited better efficiency, whereas the TP group not only improved blood indices but also provided the highest immune response. Conversely, the MP and AP groups, due to reduced weight gain and lower feed efficiency, require reformulation to enhance their nutritional adequacy. These findings highlight the importance of precise dietary formulation to optimize broiler growth performance and health.
Conclusion: Based on the findings of this study, the use of encapsulated amino acids had positive effects on improving nutritional performance, blood parameters, and immune response in broiler chickens. The results indicated that encapsulating amino acids such as lysine and methionine enhanced nutrient utilization, increased absorption and stability of nutrients, and consequently improved feed conversion ratio in broilers. Notably, the LP and TP groups, which benefited from this technology, exhibited the best results in blood parameters, including total protein, triglycerides, cholesterol, and immune response. These findings suggest that amino acid encapsulation can serve as an effective strategy to enhance feed efficiency, broiler health, and productivity under various economic and nutritional conditions. Given these results, further research is warranted to confirm the beneficial effects of these amino acids and to gain a deeper understanding of their mechanisms of action.
کلیدواژهها English
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