Effect of two brooding systems and four stocking densities on immune response and stress indicators of broiler chicks during the brooding period

This experiment investigated the effects of the brooding system (BS) and stocking density (SD) on the immune response of 1-14-day-old broiler chicks. A 3672 one-day-old Cobb 500 chicks were raised in two BSs (conventional floor brooding system (CFBS) and the newly developed multi-tier closed brooding system (NDBS)) at four different SDs (30, 60, 90, and 120 chicks/m(2)), resulting in a 2 x 4 factorial arrangement. Immunity data on lymphoid organ weights, maternal antibody titres to IBV, IBDV, and NDV, and stress indicators were collected on days 6 and 12. The results showed that CFBS and NDBS had similar effects on the relative development of chick lymphoid organs (Bursa, spleen, and thymus), the durability of the maternal humoral immune response against IBDV, and the maintenance of normal levels of stress indicators. Birds in CFBS outperformed NDBS in terms of the durability of maternal immunity to IBV and NDV. Birds in NDBS had a higher liver weight percentage than CFBS. Maternal immunity, lymphoid organ weights %, glucose and cholesterol concentrations were not altered by SD. In contrast to relative weights, differences in absolute lymphoid weights (g) were attributed to differences in live weights. An increase in SD per area unit resulted in an increase in heterophils and a decrease in lymphocyte percentage resulted in an increase in the ratio of heterophils to lymphocytes(H:L). In conclusion, birds in the higher SD had lower live weights and higher H:L ratios. Smarter brooding systems are needed to usher in a new era for the poultry industry.

Automated summary

This experiment investigated the effects of the brooding system and stocking density on the immune response of broiler chicks. The results showed that the two brooding systems had similar effects on the development of chick lymphoid organs and the maintenance of normal stress levels. The higher stocking density resulted in lower live weights and higher ratios of heterophils to lymphocytes. Smarter brooding systems are needed for the poultry industry.