Trans fatty acids. 1. Growth, fertility, organ weights and nerve histology and conduction velocity in sows and offspring.

Effects of dietary trans fatty acids on the pre- and postnatal growth and development in pigs were studied with special emphasis on nervous tissue. In experiment 1, female pigs were fed partially hydrogenated fish oil (PHFO) (28% trans) or soybean oil (PHSBO) (36% trans), in comparison with lard (0% trans) from weaning (3 wk) through the first reproduction cycle (up to 2 yr). In experiment 2, female pigs were fed two fish oils (33 and 19% trans) in comparison with coconut oil (0% trans) in diets with low and high levels of linoleic acid (18:2n-6 cis, cis) from gestation until their offspring were three wk old. Compared with the trans-free fats, the trans-containing fats had no effect on growth and development, feed consumption and utilization or on the weight of the brain, heart, kidneys, liver, lungs or spleen in the adult sows and their offspring. No effects from the experimental fats were found on histology and conduction velocity of the peroneal nerve. An increased number of the sows fed PHFO had fertility problems compared with those fed lard and PHSBO in Expt. 1, but no similar effects were seen in Expt. 2. It is concluded that consumption of trans fatty acids with 18-22 carbon atoms from PHFO and with 18 carbon atoms from PHSBO at levels that were 5 to 12 times higher than those normally consumed by humans had no detrimental effects on female pigs or their offspring during pregnancy and lactation.