Pullets had higher bursal and thymic weight indices and more antibody response to La Sota vaccination than broiler chickens (Gallus gallus domesticus)

Efficacy of clove and tulsi supplementation in drinking water in broiler immunity

BACKGROUND

Medicinal plants or their products are popular substitutes for antibiotics or other synthetic growth promoters for their beneficial effects and cost-effectiveness. Clove (Cv) and tulsi (Ts) are rich in phytochemicals and are used to augment the growth performance of poultry.

OBJECTIVES

The current investigation was carried out to evaluate the effects of Cv and Ts supplementation in drinking water on the morphologic and morphometric adaptations in the lymphoid organs.

METHODS

The experiment was conducted on 60 broiler chicks, divided into 4 homogenous groups (5 pens/group and 3 broilers/pen) named T0 (control), T1 (0.5% Cv and 2% Ts), T2 (1% Cv and 3% Ts) and T3 (1.5% Cv and 4% Ts). The treatments were administered from days 8 to 28. Lymphoid organs (thymus, spleen and bursa of Fabricius) were collected on days 14, 21 and 28 after sacrificing five broilers from each group.

RESULTS

The treatment groups had higher thymus and spleen weights on day 21, whereas the weights of the bursa of Fabricius were higher on days 14, 21 and 28. In the histomorphologic study, no noticeable difference in the histoarchitectures of the lymphoid organs was noticed. However, substantial differences in the cortico-medullary ratio and the number of follicles in the thymus and bursa of Fabricius, respectively, were found in the histomorphometric investigation.

CONCLUSION

The inclusion of Cv and Ts in drinking water augments the weight of lymphoid organs with histomorphometric adaptations that might improve the immune status in broilers.

Pullets had higher bursal and thymic weight indices and more antibody response to La Sota vaccination than broiler chickens (Gallus gallus domesticus)

This study investigated the immune responses to La Sota vaccination, used in protection of chickens against Newcastle disease, in light weight type breeds of chickens (pullets) and heavy weight type breeds of chickens (broilers) used in commercial poultry production. Seven-week-old 50 White Marshall broilers (Br) and 50 Isa Brown pullets (Pu) were randomly divided into four groups: vaccinated broilers chickens; (VBr), unvaccinated broiler chickens (UBr), and vaccinated pullet chickens (VPu) and unvaccinated pullet chickens (UPu). Chickens in groups VBr and VPu were vaccinated with La Sota vaccine, whereas groups UBr and UPu were not vaccinated. On day 0 post vaccination (PV), six chickens from group Br and Pu, and on day 4 PV, three chickens from each four groups were sacrificed and the bursa weight index (BWI), thymus weight index (TWI) and the splenic weight index (SWI) were obtained. The chickens were observed for clinical signs and lesions. Serum samples were collected from the chickens in all the groups on days 0, 7, 14, 21, 28 PV and assayed for haemagglutination inhibition (HI) antibodies. The BWI, TWI and SWI were 0.37 ± 0.05, 0.35 ± 0.17, 0.65 ± 0.26 for pullets and 0.11 ± 0.04, 0.13 ± 0.02, 0.36 ± 0.17 for broilers on day 0 PV. On day 4 PV there was no significant difference (p < .05) between the indices of the vaccinated and unvaccinated chickens. The geometrical mean antibody titres (GMT) of the pullets were 2 to 3 times higher than those of the broilers on days 7 to 28 PV. Vaccination did not produce clinical signs or lesions. The above observations show that naturally pullets produce higher antibodies than broilers because of their higher BWI.