Diligence pays off in raised AI conception
Steady improvements in
conception rates are the
result of one Humberside-
based beef producers
diligent approach to
Jonathan Riley reports
OBSERVATION and careful management have improved pregnancy rates to AI from 60 to 90% and allowed a calving period of only six to eight weeks at Sandhall Farm, Skelton, Goole, Humberside.
Autumn calving is preferred by estate manager, Neville Thompson, because progeny can make use of spring grass at turnout. He estimates that about 80% of the calves growth is supplied by grass.
"As cows were served indoors, we tried AI and realised the potential savings in space and labour that a bull-less system could offer," explains Mr Thompson.
"To achieve adequate conception rates we required two bulls and every service had to be supervised to establish whether mating was successful. This meant there was considerable labour input."
AI was first used on the 85 autumn calving suckler cows five years ago, with pregnancy rates at 60%. Since then steady improvements have been made in breeding management to achieve a 90% pregnancy rate.
Cows calve in September and October and all are checked for retained placenta by the vet. This eliminates the chance of infection which could compromise fertility.
Straw is offered after calving, with silage introduced from mid-November. A month later 1kg of barley is fed, a rate that is sustained until February. This routine gradually increases the cows condition, which promotes fertility.
"Most cows then have one heat within three months of calving, but we believe it is crucial to serve to the second heat because it is stronger and more reliable. And we have found that if they do not conceive they take longer to come back into oestrus, which ruins the calving pattern."
During January the AI technician visits every day at lunchtime to catch cows at exactly the right stage of oestrus.
Throughout January and February Mr Thompson and his staff check cows six times a day for signs of heat. "Checking at feeding times is avoided because signs of heat can be overlooked when cows are jostling or excited."
If cows show heat signs for the first time in the morning, and are still riding at lunch time, they are not inseminated that day but left until the next days visit.
This is because eggs are shed at the end of standing heat and Mr Thompson believes serving within six hours of oestrus onset may be too early.
As the cow shows the standing heat her ear-tag number is chalked on the wall.
"As the number is recorded immediately, the chance of forgetting to record an oestrus is eliminated. When the AI man visits we have an instant record of cows to be served," says Mr Thompson.
"This management process helps restrict our calving period to only six to eight weeks," he adds.
Straw is offered after calving, with silage introduced from mid-November.
EFFECTIVE AI USE
• Observe cows frequently.
• Record heats immediately.
• Inseminate at the end of heat.