The situation   

Two out of eight houses in an in-line complex yielded positive SE isolates on routine drag swab monitoring. An inspection of the facility showed mice droppings at three to four inch intervals along the length of all egg belts at 06H00 before commencing egg collection. There was no effective rodent control program in effect or committed to writing and placement of wax blocks and bait stations was as best haphazard.


Corrective action   

  • Management and supervisors on the farm were made aware of the level of mice in the perpetuation and dissemination of SE. A training program was instituted regarding cleanliness, biosecurity and related measures.
  • Manure was removed from all pits in the high-rise houses following a program which preserved beneficial insects. Removal of manure from the entire site deprived mice of habitat.
  • Accumulated junk and debris in work areas, corridors and plant rooms was removed and disposed of. Spare parts and equipment were removed from floors and placed in secure storage on racks, tools were hung from walls.
  • Accumulated biological material including egg remnants, feathers and dirt was removed from all work areas and especially the space under egg conveyors.
  • All openings were sealed with special attention to door gaps, defects in cladding and ventilation openings.
  • An intensive program of baiting was initiated both inside and outside houses using wax bait blocks placed in farm-fabricated plastic pipe T-stations. Blocks on nails were placed at 20 to 30 ft. intervals on the edge of aisles staggered down the length of the house and on ledges where there was evidence of mouse activity. Bait station were also placed at 30 ft. intervals along the aisles adjacent to the long walls and in the work area at the ends of the houses. Selection of baits was based on the advice of a university extension specialist. The program involved placement of second generation anticoagulants rotated at three month intervals with the use of a non-anticoagulant central nervous system toxin in each house at the time of flock depletion.
  • Twelve curiosity traps were placed in each house in work areas at the ends of the units, in corridors and along the aisles adjacent to the long walls to monitor for presence of mice. A recording system was initiated to determine trends in mouse catches from data noted when traps were cleared twice weekly. Management was required to inspect egg belts daily for the presence of droppings.