Volume 17, Issue 1 (3-2026)
Res Anim Prod 2026, 17(1): 150-161 |
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Bardel Z, Saki A A, Mirzaie-Asl A. (2026). The Effect of Adding Sex Hormones and Medicinal Plant Extracts to the Diet on Offspring Sex and the pH Levels of Eggs and Blood in Laying Hen Breeders. Res Anim Prod. 17(1), 150-161. doi:10.61882/rap.2026.1546
URL: http://rap.sanru.ac.ir/article-1-1546-en.html
URL: http://rap.sanru.ac.ir/article-1-1546-en.html
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: (383 Views)
Extended Abstract
Background: In the laying hen industry, the slaughter of day-old male chicks not only raises ethical concerns but also results in significant economic losses. Costs would be reduced, and performance would be improved if only female chicks could be produced for the laying hen industry and only male chicks for the broiler industry. 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 alternative 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 in this research.
Methods: In this study, 100 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- a control diet (based on corn-soybean meal) 2- a control diet + 1 mg of testosterone/kg diet, 3- a control diet + 1 mg of progesterone/kg diet, 4- a control diet + 400 mg of dry fennel extract/kg diet, and 5- a control diet + 400 mg of dry garlic extract/kg diet. The experiment was conducted for 5 weeks.
During the experiment, the pH values of eggs (albumin and yolk) and plasma were measured weekly by a pH meter. At the end of the experiment, egg quality was evaluated based on the yolk index, albumin index, shape index, yolk percentage, albumen percentage, shell ratio, and Haugh unit. To determine genetic sex, DNA was extracted from the embryo tissues. Specific primers were designed for the CHD-1 gene. Then, the PCR reaction was performed using designed primers, and the PCR product was electrophoresed on the agarose gel. The obtained data were analyzed by the SAS statistical software.
Results: 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). The week significantly affected 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 from the control treatment. The effect of experimental treatments on plasma pH was not significant in the other weeks and in the entire period. The week significantly affected yolk and albumin pH. In the fourth week of the experimental period, the experimental treatments reduced the albumin pH compared to the control, so that its pH decreased significantly in the fennel and garlic extract treatments compared to the control. Albumin pH decreased by progesterone and testosterone treatments, but not significantly compared to the control. The yolk pH was not affected by the experimental treatments (P > 0.05). In the 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 all the treatments (P > 0.05).
Conclusion: The results of this experiment have shown that the use of testosterone and progesterone hormones and 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 a negative effect on egg quality. Changes in blood pH were observed in the first and third weeks, and changes in egg white pH were noticed in the fourth week. In this study, however, the effect of experimental treatments on sex was not through their effect on blood or egg pH.
It is recommended to conduct further research 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.
Background: In the laying hen industry, the slaughter of day-old male chicks not only raises ethical concerns but also results in significant economic losses. Costs would be reduced, and performance would be improved if only female chicks could be produced for the laying hen industry and only male chicks for the broiler industry. 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 alternative 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 in this research.
Methods: In this study, 100 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- a control diet (based on corn-soybean meal) 2- a control diet + 1 mg of testosterone/kg diet, 3- a control diet + 1 mg of progesterone/kg diet, 4- a control diet + 400 mg of dry fennel extract/kg diet, and 5- a control diet + 400 mg of dry garlic extract/kg diet. The experiment was conducted for 5 weeks.
During the experiment, the pH values of eggs (albumin and yolk) and plasma were measured weekly by a pH meter. At the end of the experiment, egg quality was evaluated based on the yolk index, albumin index, shape index, yolk percentage, albumen percentage, shell ratio, and Haugh unit. To determine genetic sex, DNA was extracted from the embryo tissues. Specific primers were designed for the CHD-1 gene. Then, the PCR reaction was performed using designed primers, and the PCR product was electrophoresed on the agarose gel. The obtained data were analyzed by the SAS statistical software.
Results: 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). The week significantly affected 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 from the control treatment. The effect of experimental treatments on plasma pH was not significant in the other weeks and in the entire period. The week significantly affected yolk and albumin pH. In the fourth week of the experimental period, the experimental treatments reduced the albumin pH compared to the control, so that its pH decreased significantly in the fennel and garlic extract treatments compared to the control. Albumin pH decreased by progesterone and testosterone treatments, but not significantly compared to the control. The yolk pH was not affected by the experimental treatments (P > 0.05). In the 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 all the treatments (P > 0.05).
Conclusion: The results of this experiment have shown that the use of testosterone and progesterone hormones and 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 a negative effect on egg quality. Changes in blood pH were observed in the first and third weeks, and changes in egg white pH were noticed in the fourth week. In this study, however, the effect of experimental treatments on sex was not through their effect on blood or egg pH.
It is recommended to conduct further research 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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