Use of whale meal and whale solubles as dietary protein for growing pigs and their effects on the accumulation of mercury in tissues

Abstract

The effects of supplementing the protein from wheat in diets for growing pigs with either whale meal, whale solubles, fish meal, meat and bone meal or with combinations of whale meal or whale solubles with fish meal or meat and bone meal, were studied in two experiments. The mercury concentration in the muscle and liver of pigs fed the whale products was also studied. Pigs fed diets containing whale solubles as the only protein concentrate, grew more slowly, required more food per unit of liveweight gain and tended to have less lean in their hams than pigs fed diets containing concentrate protein from whale meal and/or fish meal, whale meal and meat and bone meal, or whale solubles and fish meal. The differences in pig performance between diets containing whale meal or meat and bone meal were not significant. Whale meal and whale solubles contained 10.5 and 2.5 p.p.m. of mercury, respectively, and the concentration of mercury in the diet was correlated to the mercury concentration in the tissues of pigs fed the diet. The muscle and liver of pigs fed with protein from whale meal had higher concentrations of mercury than those of pigs fed diets with equal amounts of protein from whale solubles. All the pigs fed whale products in this experiment had a concentration of mercury in their tissues greater than the health standard for human feedstuffs.