Most liquid or winter milk dairy farmers are currently in the throes of calving. It is these cows that will provide high-quality fresh milk for the liquid market over the winter months, while their spring-calving cousins are enjoying their winter rest. Autumn-calving means winter breeding and no sooner will the cows be calved but attention will turn to getting these cows back in calf again. This article offers some tips for a top breeding season.

Heat detection

Heat detection during the winter is more difficult than heat detection in spring. There are a number of reason for this.

The first and most obvious is to do with cow genetics. Winter milk herds have a lower EBI than spring-calving herds.

It has been proven that lower-EBI cows express bulling activity for a shorter time compared with high-EBI animals.

Cows are less sure footed on concrete

The next main difference is to do with the environment winter milking herds are in. This refers to cubicle sheds with mostly concrete floors.

Cows are less sure footed on concrete compared with being in fields or on farm roadways so they express less bulling activity.

Heat detection is more difficult when cows are indoors.

Another reason for heat detection being more difficult in winter milking herds is that tail paint is less effective in winter.

This has probably got to do with moulting, more so than the weather, as cows lose hair in the spring moult that starts in April.

There is now a big selection of tools available for automating heat detection aids

Therefore, extra effort needs to be put into heat detection in autumn-calving herds.

Scratch cards and crayons are gaining in popularity but the main increase in heat detection aids for winter milk herds is coming from automation.

There is now a big selection of tools available for automating heat detection aids ranging from neck collars to ear tags to rumen boluses.

Costs range from around €30 to €200 depending on what the product does (many products measure for health as well as oestrus activity).

Whether using automated heat detection aids or not, recordkeeping is essential. Even automated aids are not foolproof and some level of “checking up” should be done to make sure heats are not being missed.

Farmers who keep good records and regularly assess how the breeding season is going, such as checking submission rates, non-return rates, etc, tend to have better outcomes compared with those who don’t.

Body condition score

During the breeding season is not the time to fix body condition score – it just won’t work. Prevention is better than cure.

I remember being on a large Scottish year-round calving farm a number of years ago.

There were over 1,000 cows in this farm and fertility was pretty good, with a calving interval of around 385 days. The farmer’s priority was to prevent fluctuations in body condition score (BCS).

What can farmers do to manage BCS? Well the first thing is to make sure they calve down in good order

The research is clear on this; cows that lose more than 0.5 of a BCS unit post-calving will have poorer fertility than cows that don’t. So on this Scottish farm, the farmer was trying to minimise change in BCS over lactation.

What can farmers do to manage BCS? Well the first thing is to make sure they calve down in good order.

This is critical. Ideal BCS at calving is 3 to 3.25. There is no benefit to calving down cows any higher than this.

Reducing loss post-calving is then the next step. Matching the cow’s diet with her energy requirements involves feeding good-quality silages supplemented with high energy and high-protein concentrate feeds.

Silage quality needs to be excellent, so target the best-quality silage to the early and mid-lactation cows.

In the UCD spring-calving herd, cows in low BCS regularly go on once-a-day milking

How much grain to feed depends on silage quality and milk yield. Be aware that feeding more meal to freshly calved cows is likely to increase milk yield, rather than hold BCS.

In the UCD spring-calving herd, cows in low BCS regularly go on once-a-day milking.

Using this practice in winter milking herds is less common but nonetheless useful.

Once a day reduces the cow’s yield, thereby proportioning more of her energy intake to maintenance and BCS gain than milk yield. It involves a mind-set change for many farmers to consider taking less milk as a positive thing.

Bull selection

As previously mentioned, the EBI of winter milking herds is lower than spring-calving herds.

When EBI was first introduced, there was a separate index for winter milking herds.

Over time this was discontinued as it was found that the things that make spring-calving herds profitable are the same things that make winter milking herds profitable.

That is mostly fertility and milk solids.

By virtue of the fact that the average winter milking cow has a lower EBI than a spring-calving cow suggests that farmers involved in winter milk have less faith in EBI.

Type, pedigree status and milk yield are often the main priorities for winter milk herds.

Breeding is a real passion for many farmers involved in winter milk

In many cases, herds have been built up over many generations of both farmers and cows with many bloodlines and cow families dating back decades.

Breeding is a real passion for many farmers involved in winter milk.

In many cases, chasing EBI would be incompatible with the breeding objectives outlined above.

However, it needs to be recognised that EBI is a profit-based index and there is more than sufficient evidence that suggests EBI is working.

So, winter milk herds have a choice to make; are they willing to accept the science and choose high-EBI bulls, or continue to breed a less profitable, but perhaps a physically more pleasing animal?

Perhaps winter milking herdowners should consider using high-EBI bulls on 75% to 80% of their cows

Farming is a business but most dairy farmers are farming because they love it and that is what gives dairy farming so much vibrancy and energy.

Perhaps winter milking herdowners should consider using high-EBI bulls on 75% to 80% of their cows, and continue to use their pedigree bulls and matched matings on the top 20% to 25% of their cows.

This would allow their passion for breeding pedigree cows to continue while at the same time ensuring that the majority of the herd are bred to the most profitable animals available.

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