A SURVEY FOR CATTLE GRUBS (Diptera: Hypoderma SPP.) IN SLAUGHTERED CATTLE IN MANITOBA PACKING PLANTS, 1980

Abstract

In 1980, 65 615 cattle were surveyed for cattle grubs between 12 Feb. and 27 June in three Manitoba packing plants. Steers represented 60.2% of the sample, heifers 25.0%, cows 11.6%, calves 2.3% and bulls 0.9%. The majority of the animals examined originated from Manitoba and Saskatchewan, but 222 steers from Alberta were also inspected. Live grubs were first detected on 12 Mar. with peak intensity of infection (5.7 grubs per animal) occurring during mid-May. For steers and heifers of known origin, 11.0% and 10.1%, respectively, from Manitoba carried 4.1 and 3.7 grubs per animal while 5.6% and 7.8% from Saskatchewan carried 3.7 and 2.9 grubs per animal during the period 10 Mar. −27 June. 5.8% of the steers from Alberta carried an average of 2.4 grubs per animal. A total of 8250 grubs were identified as Hypoderma bovis; no H. lineatum were detected. Key words: Cattle grubs, slaughtered cattle, Manitoba packing plants