Comparison of dietary selenium fed to grower-finisher pigs from various regions of the United States on resulting tissue Se

A study was conducted to evaluate the mineralcontentofporktissuewithparticularemphasis on Se between various states (regions) having different diet (grain) indigenous Se concentrations. The study involved 19 states in the north, central, and southern regions of the United States, with committee members of NCR-42 and S-1012 (formerly S-288). A total of 62 pigs were used, with collaborators sending 100-g sam- ples each of loin, heart, and liver, and a 3- to 4-g sample of hair (collected along the topline) from two to five market-weight pigs to a common laboratory for analy- sis. Diets at each station were formulated with locally purchased soybean meal and grain that was either grownornormallyfedtopigswithintheirstate.Tissues were analyzed for Se, but only the loin was analyzed for the macro- and micromineral elements. Correlation of dietary minerals to the tissue element was deter- mined. The results demonstrated differences in tissue Se among states (P 0.90; P < 0.01). States in the west- central region of the United States and west of the Mississippi river had higher dietary Se and tissue Se concentrations than states in the eastern section of the Corn Belt, east of the Mississippi river, and along the East Coast. Generally, states did not differ greatly in their loin macro- and micromineral concentrations. The simple correlation of dietary minerals to their corres- ponding loin mineral concentration was generally non- significant, but most macrominerals had decreasing mineral concentrations when the dietary mineral level was higher. These results indicate that regional differ- ences in tissue Se were influenced more by the indige- nous Se content of the diet (grain) fed to the pigs than from sodium selenite.