Background and Aim: Many environmental factors exist that influence embryonic development which is missing in the poultry industry, such as light in incubation facilities or hatcheries. Light plays an important role in the growth and development of chick embryos, whereas dark environments can lead to hatching failure or embryo distortion. Therefore, this study aimed to demonstrate the importance of light and its various colors on the growth and development of broiler chick embryos. Materials and Methods: Four treatments were used to study the impact of various light colors on the growth of embryos and their neurophysiological traits: Dark without light (D), red light (RL), blue light (BL), and green light (GL), with three replicates per treatment (25 eggs/replicate) for a total of 300 fertile Ross 308 eggs. Each treatment was assigned to one incubator (75 eggs/incubator), whereas all other conditions were kept the same. Results: The results showed a significant increase (p<0.01) in embryonic development for embryo weight, chick body weight, hatchability, and embryo index for RL, BL, and especially GL. RL, BL, and especially GL significantly increased (p<0.01) neurophysiological traits of the neurons, brain weight, and brain index. Conclusion: The use of light during the embryonic period affects the development of the embryo and its neurophysiological traits.

Background: Sexual differentiation can occur after exposure to aromatase into the left gonad at 6.5 days of incubation. Aromatase inhibitors work by inhibiting the action of the aromatase, which converts androgens into estrogens by a process called aromatization. Objectives:The aim of this study was to investigate the effect of in ovo exposure to the aromatase inhibitor from tomato and garlic extract on sexual differentiation and embryonic development in chicken embryos.Methods: Three hundred eggs divided into five groups: Control 1 (CO; no injection); control 2 distilled water, DW; 0.1 ml/egg); garlic extract (GAR; 0.1 mg/egg); tomato extract (TOM; 0.1 mg/egg); and garlic and tomato extract mixed (ATM, 0.1 ml/egg).The solution was prepared and injected into the albumin from the thin end of the eggs on day five by using a 1 ml syringe with a 23-gauge needle. The embryonic test (embryo/egg weight) conducted at 7, 14 and 17 days of incubation. After hatching, feather sexing conducted to determine the initial male. Chicks sex was later confirmed on day 42 by an optical microscope lens. Results:The results revealed that there was a significant increase (p < 0.01) in embryonic growth traits in all experimental treatments as compared to control treatments.There was a significant increase (p < 0.01) in the percentage of hatchability for all experimental treatments compared to control treatments and a significant increase (p < 0.01) in chick quality including one-day-old chick length and body weight. All experimental treatments showed a significant increase (p < 0.01) in the male-to-female ratio compared to control treatments. Conclusions:The effect of in ovo exposure to aromatase inhibitors stimulated femaleto-male sex reversal and improved embryonic development.

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This study was carried out on a poultry farm in the Department of Animal Production – College of Agriculture - University of Anbar, the experiment aimed to determine broiler chicks' undesired behavior, including fear, gathering, and isolation. Seventy-five unsexed chicks were used that belong to strain Ross 308 with the age of one day. Chicks were randomly distributed to five replications, each replicate contained 15 chicks. The fear behavior was studied by observing the situation in which the chicks of each repeater are present at different times of the day when observing the chicks, we counted the number of isolated chicks, that is, located at the corners of the field, and recorded them, considering that they were very afraid. Chicks that are a little far from the corner were considered Medium afraid, and those that are farther away from the corner are a little afraid. As for the chicks that are spread out, far from the corners and walls, they are considered natural and not afraid, this is what was applied to each repeater (color) and at each of the specified times to take Data per day during the trial period. The results showed significant differences between the treatments in each of the traits of fear, grouping, and isolation due to the natural stimulator (sound) to broiler chicks.