Two feeding trials were conducted with pigs to determine the effects of blueberry supplementation on plasma lipid levels and other indices of cardiovascular benefit. In the first trial, where basal diets contained a high level of plant-based components (70 % soya, oats and barley), supplementation with 1, 2 and 4 % blueberries resulted in a decrease in total, LDL-and HDL-cholesterol. The greatest reduction was observed in the 2 % blueberry-fed pigs, where total, LDL-and HDL-cholesterol were reduced 11·7, 15·1 and 8·3 %, respectively. In the second trial where basal diets contained only 20 % (w/w) of soya, oats and barley, the lipid-modulating effect of blueberries was attenuated, so that supplementation with 1·5 % blueberries reduced total cholesterol by 8 %, which occurred only in pigs whose diets had been supplemented with cholesterol (0·08 %), NaCl (0·11 %) and fructose (9 %). In the first feeding trial, blueberry supplementation had no effect on blood platelet activity. Blueberry supplementation also had no effect on the susceptibility of leucocyte DNA to oxidation in the first trial and no effect on the susceptibility of LDL to oxidation in the second trial. Results of these two feeding trials are discussed in relation to the effects of basal diet composition on lipid-modulating effects of blueberries.

Liquid cooled boar semen is highly susceptible to lipid peroxidation and capacitation in vitro during storage, which results in reduced fertility and litter sizes following artificial insemination (AI). Antioxidants can delay lipid peroxidation in vitro and therefore potentially extend the lifespan of stored semen. Lowbush blueberries (Vaccinium angustifolium Aiton) and their leaves contain high antioxidant capacity, making them potential candidates for preserving liquid cooled boar semen during storage. This study compared the reversible ability of blueberry extract, leaf extract, and the antioxidant quercetin to prevent capacitation of extended, cooled boar semen during storage for 1 week. The results indicated that blueberry leaf extract and quercetin were equally capable of delaying capacitation for 1 week and still allow capacitation to occur in vitro following incubation at 39°C. Blueberry extract also delayed capacitation but only during storage for 5 days; its effects were also reversible. Blueberry leaf extract and quercetin are potential supplements for storage of liquid cooled boar semen. 165

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