Determination of dominance-subordinance relationships among beef heifers in a dominance tube

Abstract

Two methods of observation of agonistic interactions were employed to determine if a short-cut method of dominance evaluation in cattle could be developed. The first method of observation involved the use of a dominance tube to test all combination-pairs of heifers forced head-to-head from two groups each of eight yearling beef heifers. Bouts were videotaped and later viewed independently by three observers. In Group I, there was complete agreement among observers in their classification of wins and losses, and only eight of 84 possible dyad-observer combinations were classified as “no decision”. In Group II, eight of 28 possible dyad win-loss determinations differed among the observers, and 14 of the 84 possible dyad-observer combinations were classified as “no decision”. The second method of determining dominance-subordinance relationships involved recording the spontaneous or unforced agonistic encounters before and after the tournament, and consisted of observing the heifers in a drylot on several occasions spanning a period of 2 months. The before, after and tournament dominance relationships agreed on all determined relationships in Group I, and Landau's index of linearity was 0.81. In Group II, Landau's index ranged from 0.33 to 0.86, and was indicative of the lack of agreement among observers and methods of dominance determination. The dominance tube method was not a fast, totally reliable, or convenient means of scoring dominance-subordinance relationships even among small groups of heifers.