Dynamics of Macrophages in Laying Hens during Second and Third Production Cycles after Zinc Induced Molting
The influence of a non-feed removal molting program on certain parameters of cell mediated and humoral immune response of the laying birds during 2<SUP>nd</SUP> and 3<SUP>rd</SUP> production cycles were recorded. Birds at the end of their 1<SUP>st</SUP> production cycle were induced to molt through the supplementation of high dietary zinc oxide (3000mg/Kg) for their 2<SUP>nd</SUP> and 3<SUP>rd</SUP> production cycles. Macrophage engulfment (%) and engulfment/cell were significantly increased after the use of opsonized sheep red blood cells (SRBC) for co-incubation during 2<SUP>nd</SUP> production cycle. Lipopolysacchrides (LPS) greatly enhanced the production of nitric oxide, as compared to the SRBC stimulation during the 2<SUP>nd</SUP> production cycle. Zinc feeding strengthened the antibody response against Newcastle disease virus (NDV) and egg drop syndrome virus (EDS) at the peak of the 2<SUP>nd</SUP> and 3<SUP>rd</SUP> production cycles, but decreased at 5% production stages. NDV also provoked a better antibody response when compared to EDS. Zn concentration in plasma showed a positive correlation with an increase in egg production. Our results validate the strengthened immune response during the 2<SUP>nd</SUP> production cycle after zinc-induced molting.
- The journal of poultry science
The journal of poultry science 43(3), 286-295, 2006-07-25