An investigation into the effects of plasma lipids on blood clotting activity in laying hens
The lack of understanding the mechanism that causes liver hemorrhages has been an obstacle in reducing the incidence of Fatty Liver Hemorrhagic Syndrome (FLHS). The purpose of this thesis is to investigate the possible relationship between clotting factor activity and plasma lipid composition in normal and FLHS-susceptible laying hens. Lipid-depleted plasma showed significant decrease in Factor V, VII and X clotting activities. It was determined that omega-6 and omega-3 fatty acids increased and decreased, respectively, clotting activity. A crossover feeding trial further confirmed that laying hens fed a diet high in omega-6 fatty acids exhibited higher clotting activity compared to laying hens fed a diet high in omega-3 fatty acids. Positive associations were also seen between liver hemorrhage score and percentage of liver weight. This thesis demonstrated that lipids are important in blood clotting in laying hens, but changes in hemostasis may not cause liver hemorrhages and FLHS.