529 Late-Breaking: Effects of in Ovo Injection of High Yield Broilers with Nicotinamide Riboside on Pectoralis Major Morphometrics, Muscle Fiber Density, and mRNA Expression

The objective of this study was to determine the effects of in ovo injection of high yield broilers with nicotinamide riboside (NR) on broiler pectoralis major muscle (PMM) development, growth, and mRNA expression. Fertilized Cobb 700 broiler eggs were randomly assigned to 1 of 4 treatments within a 2×2 factorial design with NR dose (DOS; 0 or 2.5 mM) and injection location (LOC; albumen or yolk) as main effects. Eggs were injected with their assigned treatment at d 10 of incubation. Day-15 and -18 embryos and hatched chicks were euthanized, right PMM and muscle fiber morphometric measurements were collected, and left PMM were utilized for mRNA expression analysis of sirtuin-1 and cyclin D1, 2 and 3. There were no LOC×DOS interactions or main effects for d-15 and -18 PMM measurements (P > 0.23). There were LOC×DOS interactions for hatched chick PMM weight and length, and muscle fiber density (P < 0.04). When NR was injected into the albumen, PMM weight decreased (P = 0.02) and length and fiber density were unaffected (P > 0.33), while PMM weight and fiber density increased when NR was injected into the yolk (P < 0.05). There were no LOC×DOS interactions for all genes analyzed for d-15 and 18-embryos (P > 0.23), but NR embryos had greater expression of all genes (P < 0.03) except d-18 cyclin-D2 (P = 0.08). There were LOC×DOS interactions for hatched chick expression of all genes (P < 0.04). There was no difference in sirturin-1 expression when chicks were injected with 0 mM NR, but 2.5-mM yolk chicks had greater expression than 2.5-mM albumen chicks. When NR was injected into the albumen, expression of all cyclins was unaffected (P > 0.08), while expression increased when NR was injected into the yolk (P < 0.01). Increased expression of sirturin-1 and the cyclins may be responsible for NR catalyzed increase in PMM weight and fiber density.

Application of In-Ovo Injection of Some Substances for Manipulation of Sex and Improving Performance in Chicken

In intensive production, freshly hatched cockerels are culled in the layer hatchery (7 billion males each year), On the other hand, for meat production rearing female birds has not economic benefits because of male broiler chicks have a faster growth rate and better feed efficiency than females. In this regards several methods are being developed for sex determination in the chick embryo during the incubation period. But these methods need to be rapid, cost-efficient, and suitable practical for commercial use. Additionally, sex determination should be done before pain perception has evolved in chick embryos. Biotechnology by in ovo technique to sex determination of between male and female chicks or sex reversal could improve production and eliminate ethical dilemmas for poultry industries. In birds, the differentiation of embryonic gonads is not determined by genetic gender with the certainty that occurs in mammals and can be affected by early treatment with a steroid hormone. During the development of the chick embryo, the genotype of the zygote determines the nature of the gonads, which then caused male or female phenotype. The differentiation of gonads during the period called the "critical period of sexual differentiation" is accompanied by the beginning of secretion of sexual hormones. Namely, any change in the concentration of steroid hormones during the critical period affects the structure of the gonads. Many synthetic anti-aromatases such as federazole and non-synthetic in plants, mushrooms, and fruits containing natural flavonoids have been used in the experiments in ovo injection of anti-aromatase had no negative effect on the growth performance of sexual reversal female chickens. In conclusion, administration of an aromatase inhibitor causes testicular growth in the genetic female gender, and estrogen administration leads to the production of the left ovotestis in the genetic male gender. Therefore, in the early stages of embryonic development, sexual differentiation can be affected by changing the ratio of sexual hormones. In this review, effects of some substances applied by in ovo injection technique on sex reversal and performance in chicks.

RESPONSE OF BROILER CHICKEN TO INOVO ADMINISTRATION OF DIFFERENT LEVELS OF ROSEMARY OIL(ROSMARINUS OFFICINALIS)

This study was conducted to determine the percentage of hatchability, post-hatch growth performance, immune response of broiler subjected to in- ovo injection of different doses of rosemary oil. A total of 300 eggs of ross broiler strain were obtained.The experiment distributed into five treatment groups: T1, Negative Control T2, positive control (in ovo injection of 0.05 ml distilled water) T3, in ovo injection of 0.05ml of rosemary oil; T4, in ovo injection of 0.075 ml of rosemary oil; T5, in ovo injection of 0.1 ml of rosemary oil.Highest hatchability percentage was shown in 0.1ml rosemary oil -injected hatching eggs. The final weight of birds from 0.075 and 0.1 ml of rosemary oil-injected eggs was significantly (P < 0.05) highest through the experiment. Feed intake and feed conversion ratio were improved with in ovo administration of rosemary oil at 0.075 and 0.1 ml doses. In addition, the level of blood cholesterol and blood glucose were decreased (p<0.05) in birds from rosemary oil-injected eggs. The obtained data showed a positive effect of in-ovo injection of rosemary oil on stimulating bird's immunity.