Magnesium Supplementation, Space and Docking Effects on Swine Performance and Behavior1

Abstract

Experiments were conducted with 300 growing-finishing swine in confinement on slotted floors to study the effects of adding .11% Mg from MgO to a ground yellow dent corn-soybean meal (soybean seeds without hulls, solvent-extracted ground) fortified diet (table 1). Also studied were the effects of crowding, i.e., 6.86 sq ft vs 4.57 sq ft per pig (.63 sq m vs .43 sq m). The higher population density reduced average daily gains (P < .01) in both tests, and increased feed/gain ratio (P< .05) in Experiment I. Pigs docked vs littermates with tails had similar performance in both population densities, with or without added Mg. In the high density populations, a significantly lower percentage of the pigs were observed to be standing and a higher percentage lying than in the low density populations. These differences were greater as the experiments progressed and the pigs increased in size. Magnesium did not significantly affect the percentage of pigs standing, lying, eating, or drinking in either the high or the low density groups.