Greenmount Hill Farm bags 90pc in-calf rate after double AI service
Ninety per cent of suckler heifer replacements at Greenmount Hill Farm are in calf after just two AI services. The 15-month-old heifers, in calf to a bull in the top 1pc for calving ease, are due to calve down over a three-week period.
This breeding success was achieved by combining the best practices in the local suckler industry with those used in large-scale heifer operations in the USA.
Getting the heifers in calf involved heat detection and AI for five consecutive days. Any heifer not AI'd was given a single prostaglandin injection which induced heat over the next four days.
As a result, 31 heifers were AI'd once over a nine-day period, significantly reducing the amount of heat detection required. Any heifer that repeated three weeks later was AI'd again. However, success was not just about the AI programme. It was about making the right management decisions based on the right information. So what were the right decisions?
- Replacement heifers for the Greenmount suckler herd are first identified before they are born.
- Heifers are only selected from cows with hybrid vigour and that have acceptable teat and udder traits as 'problem' udders are highly heritable.
- Only heifers born early in the calving period are selected as these are born to the most fertile cows.
- Any heifers that do not have acceptable live-weight gain while suckling are rejected as their mothers did not have adequate milk.
- Finally, any unusually large heifers are also rejected in an effort to reduce the mature weight of the cow herd.
Post weaning management
- After weaning, heifers are managed to attain 60-65pc of their mature weight at bulling to ensure the maximum number of heifers having had at least one, and preferably two, cycles before mating commences.
- Widely used AI sires with proven calving ease are selected to mate with 15-month-old heifers. This year, the AI sire is in the top 1pc of the breed for small birth weight, short gestation length, calving ease and calving value.
- No more than two opportunities to conceive are given to select fertile heifers that calve down in a short period.
Dr Norman Weatherup is a beef technologist at the College of Agriculture, Food and Rural Enterprise (CAFRE), Greenmount Campus, Co Antrim