1- Department of Animal Science, Faculty of Agriculture, Bu-Ali Sina University, Hamadan, Iran
2- Department of Plant Biotechnology, Faculty of Agriculture, Bu-Ali Sina University, Hamedan, Iran
2- Department of Plant Biotechnology, Faculty of Agriculture, Bu-Ali Sina University, Hamedan, Iran
Abstract: (8 Views)
Introduction and Objective: In the laying hen industry, the slaughter of day-old male chicks not only raises ethical concerns but also results in significant economic losses. If only female chicks could be produced for the laying hen industry and only male chicks for the broiler industry, costs would be reduced and performance would be improved. Research is exploring ways to influence the sex of offspring in poultry. Several studies have examined the effects of steroid hormone injections on the sex of offspring and have shown that the sex of poultry can be affected to some extent by this method. However, injection methods can cause high stress in birds, which necessitates the investigation of alternative and less stressful techniques. One of these alternatives methods is nutrition. The effect of hormones in poultry feed on the offspring sex ratio has not yet been thoroughly studied, and only a small number of studies have addressed this issue. However, further research in this field is needed to reach a definitive conclusion. These studies have suggested that the effect of hormones is through changes in blood hormone levels, but the exact mechanism of this process remains unknown. In addition, various studies have reported the effects of phytoestrogens in feed on steroid hormones, and some studies have shown their effects on embryonic sex when injected intra-amniotically. The effect of medicinal plants in poultry feed on offspring sex remains unknown. In humans and some animals, pH has been implicated in sex determination, but data on their effect on poultry offspring sex are scarce. This study aimed to investigate the effect of testosterone and progesterone, as well as garlic and fennel extracts, on sex ratio and egg and blood pH in layer breeder hens. Additionally, the relationship between offspring sex and blood and egg pH was examined.
Material and Methods: In this study, one hundred Hy-Line W80 layer breeder hens were used in five treatments, five replicates, and four hens in each replicate in a completely randomized design. The experimental treatments included: 1- Control diet (based on corn-soybean meal) 2- Control diet + 1 mg testosterone/kg diet 3- Control diet + 1 mg progesterone/kg diet 4- Control diet + 400 mg dry fennel extract/kg diet and 5- Control diet + 400 mg dry garlic extract/kg diet. The experiment was conducted for 5 weeks.
During the experiment, the pH of eggs (albumin and yolk) and pH of plasma was measured weekly by pH meter. At the end of the experiment, egg quality was evaluated based on yolk index, albumin index, shape index, yolk percentage, albumen percentage, shell ratio, and Haugh unit. To determine genetic sex, DNA was extracted from embryo tissues. Specific primers were designed for the CHD-1 gene. Then, PCR reaction was performed by the designed primers and the PCR product was electrophoresed on agarose gel. The obtained data were analyzed by SAS statistical software.
Results: The results of this experiment have shown that the male sex ratio increased by testosterone treatment and the female sex ratio increased by progesterone, fennel and garlic treatments compared to the control group in a near significant manner (P=0.0565). Week had a significant effect on plasma pH. In the first week of the experimental period, plasma pH in different treatments decreased significantly compared to the control. In the third week, plasma pH in progesterone treatment increased significantly compared to the control, but testosterone, fennel and garlic treatments did not show a significant difference with the control treatment. In other weeks and in the entire period, the effect of experimental treatments on plasma pH was not significant. Week had a significant effect on yolk and albumin pH. In the fourth week of the experimental period, the experimental treatments reduced the pH of the albumin compared to the control, so that the pH of the albumin in the fennel extract and garlic extract treatments decreased significantly compared to the control. Albumin pH decreased by progesterone and testosterone treatments, but not significantly compared with the control. The pH of the yolk was not affected by the experimental treatments (P>0.05). In other weeks and throughout the experimental period, the pH of the egg albumin and yolk in the different treatments did not show a significant difference compared to the control treatment The egg quality traits (average shell thickness, shell ratio, shape index, yolk index, albumin index, yolk percentage, albumin percentage and Haugh unit) were also not affected by any of the treatments (P>0.05).
Conclusion: The results of this experiment have shown that the use of testosterone and progesterone hormones, garlic and fennel extracts in the diet of laying hens in the amounts used could affect the sex ratio of the offspring to some extent without having a negative effect on egg quality. In the first and third weeks, changes in blood pH were observed, and in the fourth week, changes in egg white pH were observed, however, in this study, the effect of experimental treatments on sex was not through their effect on blood or egg pH.
It is recommended that further resear
ch be conducted using different bird species under different environmental conditions or over a longer period of time to better understand the relationship between sex, blood pH and egg pH.
Material and Methods: In this study, one hundred Hy-Line W80 layer breeder hens were used in five treatments, five replicates, and four hens in each replicate in a completely randomized design. The experimental treatments included: 1- Control diet (based on corn-soybean meal) 2- Control diet + 1 mg testosterone/kg diet 3- Control diet + 1 mg progesterone/kg diet 4- Control diet + 400 mg dry fennel extract/kg diet and 5- Control diet + 400 mg dry garlic extract/kg diet. The experiment was conducted for 5 weeks.
During the experiment, the pH of eggs (albumin and yolk) and pH of plasma was measured weekly by pH meter. At the end of the experiment, egg quality was evaluated based on yolk index, albumin index, shape index, yolk percentage, albumen percentage, shell ratio, and Haugh unit. To determine genetic sex, DNA was extracted from embryo tissues. Specific primers were designed for the CHD-1 gene. Then, PCR reaction was performed by the designed primers and the PCR product was electrophoresed on agarose gel. The obtained data were analyzed by SAS statistical software.
Results: The results of this experiment have shown that the male sex ratio increased by testosterone treatment and the female sex ratio increased by progesterone, fennel and garlic treatments compared to the control group in a near significant manner (P=0.0565). Week had a significant effect on plasma pH. In the first week of the experimental period, plasma pH in different treatments decreased significantly compared to the control. In the third week, plasma pH in progesterone treatment increased significantly compared to the control, but testosterone, fennel and garlic treatments did not show a significant difference with the control treatment. In other weeks and in the entire period, the effect of experimental treatments on plasma pH was not significant. Week had a significant effect on yolk and albumin pH. In the fourth week of the experimental period, the experimental treatments reduced the pH of the albumin compared to the control, so that the pH of the albumin in the fennel extract and garlic extract treatments decreased significantly compared to the control. Albumin pH decreased by progesterone and testosterone treatments, but not significantly compared with the control. The pH of the yolk was not affected by the experimental treatments (P>0.05). In other weeks and throughout the experimental period, the pH of the egg albumin and yolk in the different treatments did not show a significant difference compared to the control treatment The egg quality traits (average shell thickness, shell ratio, shape index, yolk index, albumin index, yolk percentage, albumin percentage and Haugh unit) were also not affected by any of the treatments (P>0.05).
Conclusion: The results of this experiment have shown that the use of testosterone and progesterone hormones, garlic and fennel extracts in the diet of laying hens in the amounts used could affect the sex ratio of the offspring to some extent without having a negative effect on egg quality. In the first and third weeks, changes in blood pH were observed, and in the fourth week, changes in egg white pH were observed, however, in this study, the effect of experimental treatments on sex was not through their effect on blood or egg pH.
It is recommended that further resear
ch be conducted using different bird species under different environmental conditions or over a longer period of time to better understand the relationship between sex, blood pH and egg pH.
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