Influence of in ovo injection of nettle extract, mushroom extract, and their mixture on hatched chicks, performance, intestinal histology, and morphology of Ross 308 broiler chickens

In recent years, consideration has been given to changing the sex of a female bird to male because it has the functional characteristics of the male phenotype, and the technique of in ovo injection is used to achieve this. For this purpose, the production process of some sex hormones in broiler chickens is changed by injecting a substance containing anti-aromatase. The aromatase enzyme (Arom P450) is considered a key enzyme in estrogen synthesis. The administration of aromatase inhibitors leads to the inhibition of estrogen synthesis (a hormone responsible for ovarian structure and secondary sexual characteristics) in females and the production of males with female genotypes. Therefore, if aromatase enzyme expression is inhibited in some way, it can be expected that the percentage of male chicken production will increase. Aromatase inhibitors can be divided into two main groups in terms of production source, including synthesized and herbal compounds. Among the herbal extracts containing anti-aromatase are nettle root, button mushroom, garlic, green tea, and tomato. On the other hand, the results of some studies have shown that the performance indicators of male and female poultry during the breeding period, such as daily feed intake (DFI), daily weight gain (DWG), feed conversion ratio (FCR), as well as the activity of the digestive system, especially the small intestine, are different and the ability to use nutrients, growth rate and FCR are better in males than females. According to male poultry characteristics, if the number of males in the flock increases, more profitability can be achieved in the production process. Therefore, the objectives of the current study were to determine the effects of in ovo injection of nettle extract, mushroom extract, and their mixture on hatched chickens, performance, and intestinal indicators of Ross 308 broiler chickens. This study was conducted to investigate the in ovo injection effects of nettle and mushroom extracts, and their mixture on hatchability, the percentage of male chickens produced, and some intestinal parameters in broilers. 500 fertilized eggs were divided into five treatments and four replicates (25 eggs per replicate). Experimental treatments included: 1. Nettle hydroalcoholic extract (containing 300 micrograms of dry matter per 0.1 cc of injectable substance), 2. Mushroom hydroalcoholic extract (containing 500 micrograms of dry matter per 0.1 cc of injectable substance), 3. Mushroom and nettle extracts mixture (containing 400 micrograms of dry matter per 0.1 cc of injectable substance), 4. Positive control (distilled water), and 5. Negative control (eggs without any injection). The experimental design was a completely randomized block design. Samples were divided into five treatment groups, with each treatment group having four replications based on the gender segregation of the chicks into male and female. The experimental diet was used based on the requirements of the Ross strain during three periods, including starter, grower, and finisher. After the chickens were hatched, performance and intestinal indices were measured. The results showed that the number of hatched chicks was affected by experimental treatments. Therefore, the lowest hatch percentage was related to URE treatment chicks. The number of normally hatched male chickens, performance indices, and intestinal parameters were not affected by the experimental treatments (P>0.05). The lack of significant difference in the number of male chickens in the experimental treatments may be due to the incorrect selection of the concentration of the experimental extract. Furthermore, villi height, crypt width, and villi surface absorption area were not affected by experimental treatment (herbal extracts). In comparison, DWG and FCR significantly improved by the sex effect (P<0.05). Regarding the difference in the performance of male and female broiler chickens, it has been reported that these two sexes have a significant difference in DFI and FCR. It has also been reported that the increase in BWG and the weight of different parts of the carcass in males was higher than in females, which is consistent with the findings of the current research regarding all three indicators of DFI, DWG, and FCR. Although there was no significant increase in the number of hatched male chickens in this study, it is recommended to optimize the preparation and production conditions of plant extracts containing anti-aromatase by focusing on extracting the pure active ingredient to achieve a higher percentage of male chickens in the flock. This study was conducted to investigate the in-ovo injection effects of nettle and mushroom extracts and their mixture on hatchability, the percentage of male chickens produced and some intestinal parameters in broilers. 500 fertilized eggs were divided into 5 treatments and 4 replications (25 eggs per replication) in a completely randomized design. Experimental treatments consisted: 500 fertilized eggs were divided into 5 treatments and 4 replicates (25 eggs per replicate) in a completely randomized design. Experimental treatments consisted: 1- nettle hydroalcoholic extract (containing 300 micrograms of dry matter per 0.1 cc of Injectable substance), 2- mushroom hydroalcoholic extract (containing 500 micrograms of dry matter per 0.1 cc of Injectable substance), 3- mushroom and nettle extracts mixture (containing 400 micrograms of dry matter per 0.1 cc of Injectable substance), 4- positive control (distilled water) and 5- negative control (eggs without any injection). The experimental diet was used based on the requirements of the Ross strain during three periods, including starter, grower and finisher. After the chicken were hatched, performance and intestinal indices were measured. The results showed that the number of hatched chicks were affected by experimental treatment. So that, the lowest hatch percentage was related to URE treatment chicks. The number of normal hatched male chicken, periodic performance indices and intestinal parameters were not affected by the experimental treatments (P>0.05). The lack of significant difference in the number of male chicken in the experimental treatments may be due to the incorrect selection of the concentration of the experimental extract. Furthermore, villi heigh, crypt width and villi surface absorption area(VSA) were not affected by experimental treatment (herbal extracts). In comparison, DWG and FCR significantly improved by the sex effect (P<0.05). Regarding the difference in the performance of male and female broiler chicken, it has been reported that these two sexes have a significant difference in DFI and FCR. It has also been reported that the increase in BWG and the weight of different parts of the carcass in males was higher than females, which is consistent with the findings of the current research regarding all three indicators of DFI and DWG as well as the FCR. Although there was no significant increase in the number of hatched male chickens in this study, it is recommended to optimize the preparation and production conditions of plant extracts containing anti-aromatase by focusing on extracting the pure active ingredient to achieve a higher percentage of male chickens in the flock.Key words: nettle and mushroom extract, ant i-aromatase, broiler chicken, plant extract, in-ovo injection