Farm Ireland

Thursday 22 March 2018

Time for mid-term breeding programme review

The weather over the past month has proven to be a major challenge for breeding programmes centred on grass-based spring milk production.

We had poor grass growth, with low temperatures in April through mid-May. This has resulted in poorer submission rates and poor heat detection rates for repeats.

An increase in temperatures, with associated rainfall has resulted in a dramatic increase in grass growth rates.

Grass has now to be taken out of the rotation for silage to maintain grass quality.

However, heavy rainfall in the southwest has made grazing conditions difficult on many farms in Limerick and Kerry.

Breeding programmes are between week six and nine in the majority of spring calving herds. The majority of late calvers are now in milk production.

This is an opportune time to evaluate progress with your breeding programme. It is too late to evaluate the situation when the breeding season is finished.

Many farmers place a focus on submission rate in their breeding programme.

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This is understandable as cows have to be AI'd or bred to a stock bull to establish a pregnancy.

However, the use of hormones to induce heats is not the solution to an inefficient breeding programme.


It has been suggested that a better response was achieved by using progesterone devices inserted per vaginum than prostaglandins on the dairy demonstration farm in Kilkenny.

This suggests to me that the cows were stressed prior to breeding, which is not the correct pre-breeding approach to an AI programme.

Based on all cows calved greater than 40 days, you should now have in excess of 90pc of these cows bred to AI.

Now is the time to get a full picture of the reproductive status in your herd.

Scanning the reproductive tract of cows is an excellent way to assess if cows are returning to normal heat cycles post-calving.

Diagnostic ultrasonography by experienced personnel will enable you to take action on cows needing to be brought into the potential "in-calf cow" group.

Scanning results compiled over the past week reveal that an average 68pc of cows were in the "in-calf cow" group.

This group needs to be above 90pc in order to achieve a 90pc calving rate in a 14-week breeding period.

A feature encountered at this stage of the breeding season is the 10pc of cows submitted for AI which are not in heat.

Either inaccurate heat detection or pregnant cows presenting with signs of heat account for this phenomenon. Inseminating cows that are already pregnant can cause embryonic death.

After six to eight weeks of AI, most farmers will want to introduce a stock bull. Ensure that the bull introduced is fit and fertile.

Up to 10pc of stock bulls used can either be infertile or sub fertile. It is also important to ensure that you have sufficient bull power for the non-pregnant cows remaining in the herd.

Scanning your cows at the time you wish to introduce the stock bull will give you an accurate picture of the number of non-pregnant cows. Ideally, you should have one stock bull for every 40 "open" cows.


However, the stock bull will not detect heats in non-cycling cows, cows with uterine infections and those with embryonic death. Indeed, a stock bull will waste energy attending to cows showing irregular heats because of ovarian cysts. Address these problems before the stock bull is introduced.

Finally, it is essential that you keep screening your herd health for diseases such as BVD, IBR, liver fluke and stomach fluke.

The incidence of liver fluke and stomach fluke has increased dramatically in dairy herds in recent years.

Vaccination programmes against the various diseases will not be effective if the immune system is depressed because of liver or stomach fluke infestation.

In conclusion, it is now time to get a mid-term report for your breeding programme. Missed heats cost in excess of €200, but a stock bull or AI will not work if the cows are not fit to go in calf.

Dr Dan Ryan is a bovine reproductive physiologist and can be contacted at

Indo Farming