Toxicosis in sows and their pigs caused by feeding rations containing polybrominated biphenyls to sows during pregnancy and lactation

Abstract

The toxicity and the distribution of polybrominated biphenyls (PBB) were investigated by feeding rations containing different concentrations of PBB to sows during pregnancy and lactation. Sows and newborn pigs were clinically unaffected. Mortality was increased among pigs nursing sows fed rations containing PBB. Although transplacental passage of PBB resulted in an appreciable amount of PBB in tissues of newborn pigs, far more PBB were transferred to the pigs through the milk. On a body-weight basis, nursing pigs consumed PBB in concentrations similar to the concentrations given to the sows. The highest tissue concentrations of PBB (fat basis) were found in the liver, followed by the adipose tissue, kidney, and brain. Dietary concentrations of 10 mg of PBB/kg of feed increased serum concentrations of alkaline phosphatase, alanine aminotransferase, and thyroid hormones of pigs, whereas dietary concentrations of 100 or 200 mg of PBB/kg of feed caused those values to decrease. Gross pathologic changes consisted of increased weight of the thyroid gland of newborn pigs and increased weight of the liver of 4-week-old pigs. Histologically, thyroid glands of newborn pigs were slightly hyperplastic, and the colloid was scant and vacuolated. In the liver, lesions consisted of fatty change and centrolobular necrosis; changes were more severe in the sows than in the pigs nursing those sows. Measuring serum concentrations of ornithine carbamoyltransferase was the most effective clinical test in assessing the degree of liver damage in the pigs.