Ali Reza Ghiasvand; Hassan Shirzadi; Hossein Ali Ghasemi; Kamran Taherpour; Shokoufeh Hasanvand; Ali Khatibjoo
Abstract
Objective: The aim of this study was to determine the optimal arginine level in the diet of Japanese quails (Coturnix coturnix japonica) and evaluate its effects on growth performance, feed efficiency, and carcass yield using broken-line and quadratic regression models.
Method: For this purpose, a total ...
Read More
Objective: The aim of this study was to determine the optimal arginine level in the diet of Japanese quails (Coturnix coturnix japonica) and evaluate its effects on growth performance, feed efficiency, and carcass yield using broken-line and quadratic regression models.
Method: For this purpose, a total of 600 twenty-one-day-old Japanese quail chicks were divided into five different treatments with digestible arginine levels of 0.75%, 1.00%, 1.25%, 1.50%, and 1.75%. Six replicates were used for each treatment, with 20 quails per replicate. The experimental diets were similar in all essential nutrients except for arginine. The experiment was conducted from day 21 to day 35, and during the experimental period, various performance parameters, including body weight gain, feed efficiency, and carcass yield, were measured. Additionally, the effects of different arginine levels on the chemical composition of breast and thigh meat were evaluated.
Results: The results indicated that increasing arginine levels had a significant impact on body weight gain and feed efficiency in the quails (P<0.05). Specifically, the 1.25% arginine treatment showed the greatest body weight gain and feed efficiency compared to the other treatments (P<0.05). This treatment showed a significant difference compared to the 0.75% and 1.00% treatments (P<0.05), with no significant difference compared to the 1.50% arginine treatment. No significant changes in feed intake were observed (P>0.05), indicating that greater arginine levels improved feed utilization efficiency due to increased body weight gain. To estimate the arginine requirement, both broken-line linear and quadratic regression models were employed. The broken-line linear model with a single slope identified breakpoints at 1.15% for body weight gain and 1.21% for feed efficiency. Additionally, the quadratic broken-line model predicted breakpoints at 1.30% for body weight gain and 1.29% for feed efficiency. The quadratic regression model showed that at 1.37% arginine, the greatest body weight gain was observed, and at 1.36%, the greatest feed efficiency was recorded. For carcass yield, the 1.25% arginine treatment showed the greatest carcass yield on day 35, with a significant difference compared to the 0.75% and 1.75% treatments. Both broken-line and quadratic regression models indicated that the optimal arginine level for the greatest carcass yield was approximately 1.12% and 1.26%, respectively. Additionally, the quadratic regression model predicted that the optimal level for carcass yield was 1.32% arginine. However, the chemical composition of breast and thigh meat was not affected by the arginine levels, and no significant changes in dry matter, organic matter, and ash content were observed.
Conclusions: The results of this study indicated that the use of broken-line linear and quadratic regression models are effective tools for accurately estimating the arginine requirement in the diet of Japanese quails. Based on the findings, it is recommended that the optimal arginine level for improving growth performance and carcass yield in Japanese quails was set between 1.15% and 1.37%. These findings can contribute to optimizing dietary formulations in the quail farming industry, improving production efficiency, and reducing feed costs.