Kestin et al. Flint et al. Larger numbers of treated chickens might also exhibit significant changes in these measurements. A trend for this effect on abdominal fat mass also was seen in the treated female layer-type chicken at all injected concentrations, although the effect was significant only at the 0.1 mg injection level. The reduction in abdominal fat was not observed in Trial 1, which used broiler type chickens.
Broiler chickens are fatter than layer-type chickens.
If an in vivo infusion of MAb affects abdominal fat mass, the total body fat of the infused chicken could influence this effect because of the increased MAb-binding mass available to the injected protein. Since the ages of injection were different between Trial I and II, these results also might suggest that if chickens receive a MAb injection at a young age, more extensive inhibition of adipose development could result. The proportion of the amount of MAb injected to the total adipose tissue mass also could be important. A larger more mature adipose tissue may be more resistant to the effects of MAb exposure than less mature adipose tissue with smaller or newly differentiated adipocytes. The reduction of fat pad mass could be caused by reduction or inhibition of cell number, cell size, or both, none of which were measured.