Dairy products are major sources of conjugated linoleic acid (CLA); thus, an increase in CLA content can improve the quality value of dairy products. The objective of this work was to determine the effects of lactation time, feeding regimen, and ripening period on the level of CLA in processed cheese. CLA content in milk varied with the period of lactation; high in spring (April and May, about 6.8 mg CLA/g fat) and relatively low in mid summer and winter (about 4.3 mg CLA/g fat). The effects of dietary regimen and ripening period were determined in milk, which was obtained from March to May. After aging for 4 months, the cheese made from milk obtained from cows fed on pasture contained relatively higher levels of CLA compared to cheese made from milk obtained from cows fed indoors (8.12 mg CLA/g fat vs 6.76 mg CLA/g fat), but there was no difference in 7 month-aged cheeses. In both pasture and indoor feeding, 7 month-aged cheeses showed higher CLA content than 4 month-aged cheeses. The contents of stearic acid (C18:0) and linolenic acid (C18:3) were significantly higher in cheese from pasture fed cows compared to those in cows fed indoors. These findings should be helpful for the efficient production of functional dairy products with high CLA contents.

The objective of this study was to investigate effects of dietary level of CLA and the duration of feeding CLAcontaining diets on reproductive performance in sows and piglet growth rate. Tallow (3% in gestation diet and 5% in lactation diet, respectively) was incorporated as a fat source in control diet, and each 50% (dietary CLA level of 0.75% in gestation diet, and 1.50% in lactation diet, respectively) or 100% (dietary CLA level of 1.50% in gestation diet, and 2.50% in lactation diet, respectively) of tallow was replaced by a commercial CLA preparation containing 50% CLA isomers. Diets containing CLA were fed either from d 15 premating to weaning or d 74 post-mating to weaning. The level of dietary CLA and feeding duration did not affect litter size. High dietary level of CLA, however, decreased piglet weights at birth (p<0.01) and tended to decrease backfat thickness of sows at weaning. Longterm feeding of CLA-containing diets decreased piglet weights at weaning (p<0.05) and backfat thickness of sows at weaning (p<0.05). CLA supplemented in sow diet was transferred to fetus and piglets during pregnancy and nursing period, respectively. CLA contents of femoral muscle of piglets were 2.08 to 2.57 mg per g of fat at birth, and 2.36 to 4.47 mg at 10 days of age in CLA groups, while CLA was not detected in the control group. In conclusion, dietary supplementation of CLA tended to lower backfat thickness of sow and piglets' weight at birth or weaning, but did not affect total litter size. Dietary CLA was transferred efficiently during prenatal and postnatal periods of time through the placenta and milk, respectively.