The influence of dietary palm olein, fish oil and lard on the egg yolk and plasma lipid composition, and performances of laying hens.

The influence of dietary palm olein, in comparison to fish oil and lard, on lipid levels in egg yolk and blood plasma, the fatty acid composition of egg yolk, and various production parameters were studied. Brown Lohman laying hens (n=45) were randomly assigned into three groups of 15 birds, and treated with experimental diets with either 3% palm olein (PO), fish oil (FO) or lard (L) for 6 weeks. At the end of the experiment, feed consumption was significantly lower for hens fed the PO diet, except week 6 of the experiment. The concentration of plasma triglycerides was increased by all experimental diets, whereas there were no significant increases of plasma total lipid and total cholesterol concentrations only in the PO group. For yolk lipids a decrease in triglycerides in the FO and L groups was observed, while total cholesterol and total lipid were significantly decreased in the PO group. Feeding with the PO diet resulted in the lowest concentrations of palmitic, stearic and linoleic acid, as well as in the highest concentration of monounsaturated oleic acid in the yolk total lipid. It was concluded that the composition of yolk lipids did not closely match the concentrations of lipids observed in experimental diets or plasma. Based on the current work it seems that the PO diet modulates egg yolk lipid content best.

Identification of alpha 2 adrenoceptors in the blood vessels of the dental pulp.

Using selective agonists and antagonists of alpha2 adrenoceptors, attempts were made to identify the subtype alpha2 adrenoceptors in the blood vessels of the canine dental pulp. In chloralose-anaesthetized dogs, intra-arterial administration of noradrenaline and guanabenz in different doses produced a dose-related pulpal vasoconstriction which was measured using hydrogen-gas clearance. The vasoconstrictor response to noradrenaline was inhibited by phentolamine, a non-selective alpha adrenoceptor antagonist. The response to guanabenz was inhibited by rauwolscine, a highly selective alpha2 adrenoceptor antagonist. The results demonstrated that alpha2 adrenoceptors are present in the blood vessels of dog dental pulp.