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 ...
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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.
Mohsen Zaker_Jafari; Mehrdad Mohammadi; Maziar Mohiti-Asli
Abstract
The effect of chick initial body weight and dietary nutrients density on growth performance and immune response were investigated using 360 Ross 308 one-day-old straight run chicks (mixed sex) in a completely randomized design with 2×3 factorial arrangement of treatments, four replicates and 15 ...
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The effect of chick initial body weight and dietary nutrients density on growth performance and immune response were investigated using 360 Ross 308 one-day-old straight run chicks (mixed sex) in a completely randomized design with 2×3 factorial arrangement of treatments, four replicates and 15 birds per replicate. The initial body weight of chicks was grouped as 42±1 g (standard weight); 38±1 g (light weight; 10% under standard weight); 46±1 g (heavy weight; 10% over standard weight) while the nutrients density of the diet was either 5% lower than the nutritional recommendation of Ross 308 (typical commercial diet in Iran), or as recommended by Ross 308 manual (high-density diet). Chickens fed the high-density diet had higher daily weight gain and lower conversion ratio than chickens fed the typical diets (P<0.05). The effect of dietary density and initial body weight of chicks on carcass components and weight of internal organs were not significant except for heart. Broilers fed the high-density diet and heavy weight had higher antibody titers to sheep red blood cell (P<0.05). Light chicks fed the high-density diets had greater total anti sheep red blood cell and immunoglobulin G titers than light chicks fed the typical diets (P<0.05). Results indicate that feeding light chicks with high-density diets increases their growth rate compared to the chicks with standard or heavy weights. Moreover, feeding diets with a high density of nutrients to light chicks can improve immune responses.
Ahmad Hassanabadi
Abstract
Effect of different dietary levels of nucleotide supplementation on performance, carcass characteristics, immune system status, small intestine morphology and ileal microbial population of broiler chickens was evaluated using 308 one-day-old mixed-sex Ross 308 broilers in a completely randomized design ...
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Effect of different dietary levels of nucleotide supplementation on performance, carcass characteristics, immune system status, small intestine morphology and ileal microbial population of broiler chickens was evaluated using 308 one-day-old mixed-sex Ross 308 broilers in a completely randomized design with 4 treatments and 7 replicates of 11 chicks in each, up to 42 days of age. Experimental treatments included a corn-soybean meal basal diet (control), and the basal diet containing 0.05, 0.1 and 0.2 percent nucleotide supplementation. The results showed that feed intake, body weight gain and feed conversion ratio of the broilers were not significantly affected by experimental treatments. Results of humeral immune system response at 35 days of age showed that the blood serum IgM concentration in 0.2 percent nucleotide group was higher than 0.05 percent group(P< 0.05). Also, Serum IgG concentration in this age in 0.05 percent nucleotide group was higher than 0.2 percent group(P< 0.05). At 42 days of age, serum IgG concentration in 0.1 percent nucleotide treatment was lower than control group (P< 0.05). The cellular immune system response of chicks fed diet supplemented with 0.1 percent nucleotide at 48 hours after Phytohemagglutinin-P injection was higher than control treatment (P<0.05). On the basis of current experiment results, supplementation of broiler dietswith nucleotide improves cellular immune system response but has no significant effect on other parameters of broiler chickens.