Effect of in ovo inoculation of vitamin E on expression of Hsp-70 m RNA and juvenile growth in coloured broiler chicken

The effect of in ovo inoculation of vitamin E (Vit E) at 18^th day of incubation on expression of Hsp-70 mRNA and body weight during post natal life at 6 weeks of age was studied in PB-2, a coloured broiler parent line. A total of 108 fertile eggs, 18 for each treatment were inoculated with varying concentrations of Vitamin E (a-tocopherol) with sham and un-injected control. The body weights at different Vit E concentrations were not significant at day old, 2^nd, 4^th and 6^th weeks of age. The hatchability did not vary significantly among the sham control, normal control and treatment groups. The expression of Hsp-70 mRNA varied significantly (P≤0.05) between the tissues. However, varying concentrations of in ovo inoculation of Vit E had no significant (P=0.968) effect on m RNA expression. The interaction between treatment and tissue was not significant (P=0.257). The mRNA expression ranged from 40.62 in control to 40.0 in 25 μg treatment. The Hsp-70 mRNA expression in heart and liver was 42.93±2.38 and 41.76±1.87 in relation to the internal control GAPDH expressed in terms of 40-”Ct. The Hsp-70 mRNA expression was significantly (P>0.05) higher in heart and liver compared to the other tissues. Muscle expressed significantly (P>0.05) low levels of Hsp-70 mRNA. The study concludes that, in ovo inoculation of VitE has revealed positive trends though not significant in terms hatchability, growth and Hsp-70 gene expression. The Hsp-70 mRNA expression was significantly higher in heart and liver, the important organs involved in stress management in birds. The dose of Vit. E was not sufficient to elucidate any significant effect on Hsp-70 m RNA expression, which needs further studies with higher dosage to determine the optimum level of Vit E.