Manganese as a Possible Factor Influencing the Occurrence of Lameness in Pigs. ∗

Abstract

Impairment of the normal movement of the legs frequently occurs in swine. This condition is variously termed lameness, stiffness, posterior paralysis or incoordination, depending on its severity and etiology. A characteristic stiffness occurs in rickets in pigs, a condition in which there is abnormal bone development. Incoordination occurs in pigs as the result of vitamin A deficiency, in which there are degenerative changes in the central nervous system. In addition, however, lameness of one type or another occurs in some instances in which calcium, phosphorus, and vitamins A and D do not appear to be the limiting factors.

In the course of growth studies of pigs conducted by the authors during the past few years, a type of stiffness or lameness has been encountered which appears to be etiologically different from any of the forms described in the literature. This condition occurred in pigs which were fed similar rations, all of which were comprised of yellow corn, tankage, soy bean oil meal, ground alfalfa hay and salt. The pigs were fed individually and indoors but had access to direct sunlight at all times in outdoor paved pens.

The growth of the pigs was good but lameness occurred at about the time they reached a body weight of 150 pounds. The condition was at first characterized by a slightly halting gait, but it slowly progressed in severity until it was only with difficulty that the pigs could rise to their feet. The behavior of the pigs indicated that the condition was painful. Gross manifestations, in addition to stiffness, were enlarged hock joints and crooked legs which occurred even with some pigs which never became stiff. It should be noted that only 30 out of a total of 60 pigs receiving the above treatment were affected with stiffness.