4 tips on improving your lifetime daily yield in dairy herds

There has been a rise in lifetime daily yield for a fifth consecutive year, the University of Reading’s ninth annual key performance indicator report of 500 NMR recorded dairy herds shows.

Lifetime daily yield is the amount of milk a cow has produced each day of her whole life and is influenced by an animal’s age at first calving along with yield, fertility and health.

The study shows that farmers are continuing to make improvements in this area:

• The top 25% of herds are now achieving 14.7kg of milk a cow a day, up by 2.1kg a day from 12.6kg in 2010.
• The median – or mid-point – is 12.5kg a cow a day; a 2kg improvement from 2010.

See also: Metcalfe Farms wins Gold Cup award

Reading University’s James Hanks, who co-authored the report with Mohamad Kossaibati, says: “It shows us what is being achieved currently by one herd in four. 

“Looking at the trends is also valuable – there are bound to be ups and downs year on year, but as we build on the number of years of records in this survey, the data become increasingly valuable as a management tool.”

Dr Hanks believes the figure achieved by the top 25% of herds for each parameter can serve as a realistic target for producers in their discussions with vets and advisers.

Here we take a closer look at the parameters that influence LDY within the dataset to show how they can have an effect, and NMR vet Karen Bond offers advice on how other herds can improve in each of four key areas.

1. Age at first calving

• In the top 25% of herds, age at first calving is now 2.1 years, a reduction of nearly three months since the survey began.
• The midpoint has also fallen, by approximately six weeks to 2.3 years.

How it influences LDY

LDY includes the rearing period, so reaching rearing targets and reducing age at first calving will help to improve LDY – overall the cow has fewer unproductive days.

It has also been demonstrated that heifers that calve at 24/25 months have optimal fertility and maximum yield in their first lactation. Heifers that are bred later tend to have poorer subsequent fertility and so poorer longevity.

Target

• 24 months at first calving

How to improve

• Make sure heifers are well looked after right from the start. Calves have their best feed conversion rates pre-weaning so it is worth taking advantage of this by feeding plenty of good quality milk or milk replacer and a well-managed transition to hard feed will pay off.
• Weigh heifers regularly, targeting the optimum daily gain for the breed and weight at 15 months old when the heifer should be served to achieve age at first calving of 24 months.

2. Getting cows back in calf on target

• Calving interval in the top 25% of herds has fallen from 409 days to 388 days.

How it influences LDY

A cow that gets back in calf quickly has fewer days when milk yield is lower. This means she is producing good milk yields throughout her lactation and as she gets back in calf “on time” she is a fertile cow and likely to stay in the herd longer.

Target

• Served by day 80: 68%
• In calf by 100 days: 41%
• Calving Interval: 388 days

How to improve

• The biggest influence on submission rate is heat detection so having a successful heat-detection system in place is crucial.
• Other factors that promote LDY include good transition cow management, where cows enter their lactation in the correct body condition having had an easy calving and minimising negative energy balance. All will contribute to milk yield, cow health and fertility.

3. Fertility

• The midpoint for the 500 herds in the survey is now 34%, up from 26% in 2010

How it influences LDY

Similar to the benefits of getting cows back in calf – fewer services and fewer days of lower production towards the end of lactation.

Target

• 42% conception rate (based on the top 25% of herds)

How to improve

Conception rate is much more difficult to influence than submission rate, but there are still things you can do, Mrs Bond says.

• You need fertile cows, so breed replacements from your most fertile cows, not those with repeated services.
• You need healthy cows, as those with disease such as mastitis and lameness are less likely to hold to service.
• Good transition management is key, as the eggs that are going to be ovulated in early lactation have been produced in the dry period. 

4. Improving udder health

• The midpoint somatic cell count (SCC) for the 500-herd sample is now 178,000 cells/ml – 42,000 less than in 2010
• Particularly interesting is the reduction in the percent of chronic SCC cows in the herd. These are cows with consecutive monthly SCC tests above 200,000 cells/ml (see above).

How it influences LDY

Udder health will influence how long a cow stays in the herd – older cows will have higher LDYs as they have a higher proportion of productive days than a younger cow; and to become an older cow in the herd she must have good production, get back in calf and have a relatively disease-free track record.

Cows with high SCC and/or mastitis are more likely to be culled. It can also impact on conception rate and abortion if mastitis incidences are happening in early lactation.

Target

• <10% chronic cows (KPI report top 25% achieved 7%).
• Individual cow SCC <200,000 cells/ml (KPI report top 25% 142,000 cells/ml).

How to improve

• Work with your vet to understand your mastitis patterns. You need to know the origin of clinical mastitis and high SCCs; the dry period or lactation.
• It is important to identify the type of bacteria involved; whether they are contagious or environmental.
• Areas for improvement can then be prioritised. For example, don’t change your whole milking routine if you identify that the problem stems from the dry period.