Research update: How has timed AI fared on suckler cows?

Currently, the amount of suckler farms in Ireland using AI is low; somewhere in the region of 25% of progeny from the suckler herd are bred from AI, while the remaining 75% are served by a stock bull.

Some of the reasons for this can be attributed to part-time farming, poor-handling facilities or land fragmentation.

Each individual farm is different. However, every effort should be made to improve genetics in the suckler herd. Genetic information is available to help farmers identify animals that have superior genetics that can – in turn – increase the profitability of the offspring they are producing.

However, according to Teagasc, there has been increasing interest in the use of oestrous or heat synchronisation programmes, which allow the use of timed AI (TAI).

This involves all treated cows being inseminated at a pre-determined time, regardless of signs of heat.

Teagasc, together with UCD and the Agri-Food and Biosciences Institute (AFBI) of Northern Ireland, conducted a series of on-farm synchronisation studies, funded by the Department of Agriculture, Food and the Marine (DAFM).

The research

The work involved 85 herds located throughout Ireland, with 2,200 cows enrolled in the studies.

For the purpose of the studies, three different synchronisation protocols were compared, all of which used a progesterone pessary (PRID E, CEVA Animal Health) inserted for seven days.

suckler BDGP

All cows were subjected to a single TAI at 72 hours after PRID removal, regardless of signs of heat. Suckler farmers were free to use the semen of their choice, and thus semen from a large number of bulls was used across the farms.

Despite this, pregnancy rates ranged from 50-70%, with a very acceptable overall average pregnancy rate of 55% achieved to a single timed insemination.

Synchronisation, Teagasc says, also led to a more condensed calving pattern and subsequent breeding period in the following season.

In a typical herd, almost 80% of all synchronised cows were pregnant within 23 days of the start of the breeding season.

According to Teagasc, while many herds elected to AI cows that repeated, others turned out stock bulls. Using stock bulls is very efficient from a labour and stock bull use point of view and allows a herd to use maternal genetics through TAI and focus on terminal traits in their stock bull(s).

For comprehensive information on these topics, farmers are encouraged to contact their local Teagasc advisor and veterinary surgeon.

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