The effects of a number of management practices on chiller beef production in Victoria

Abstract

Data are presented from a detailed factorial experiment conducted on a private property in the Western District of Victoria and involving 72 grade Aberdeen Angus cattle and their dams. The relative contribution to daily liveweight increase and economy of production of sex (steer v. spayed heifer), sire (stud v. grade bull), level of supplementary feeding (high v. moderate v. low), season of birth (autumn v. spring), and year of birth (1954 v. 1955 control v. 1955 stilboestrol-implanted) was determined. Season of birth (autumn>>spring, P < 0.001) was easily the greatest single factor affecting daily liveweight gain, carcass beef production per week, and cash value of beef produced per week, followed in order of importance by sex (steers>>heifers, P < 0.001), and level of supplementary feeding (high >moderate = low, P<0 .001). Quality of the sire had no demonstrable effect on any factor studied. Year of birth slightly affected cash value of beef produced per week (P<0.05), but only because of yearly price fluctuations. Interactions between the main variates were relatively unimportant, but the spring-born calf was much more dependent on heavy supplementary feeding than was the autumn-born. Economy of production was dependent on calving at the correct time (autumn) and the reduction of supplementary feeding to a minimum. The value of the factorial experimental design for field studies of this type is briefly discussed.