Field observations of the prevention of breech strike in merino sheep by jetting with aldrin, BHC, dieldrin and endrin.

Abstract

Aldrin and dieldrin (both at 0.1 and 0.05 per cent.) and endrin (0.05 per cent.) protected ewes against breech strike for periods ranging from four weeks to nine weeks. BHC was inferior to both aldrin and dieldrin. In both trials breech strike continued to occur in the controls during the time these observations were made, although after the sixth week the majority were restrikes. Both aldrin and dieldrin gave good protection against breech strike for four weeks when used at a dilution of 0.1 per cent. during a severe wave. After the sixth week the rate of breech strike in sheep treated with aldrin and dieldrin was similar to that in the controls throughout this trial. ·BHC at 0·l per cent. proved inferior to both aldrin and dieldrin.