Get more from rations to help cut emissions

Dry matter intakes, dry matter intakes and dry matter intakes – these are the three most important indicators of technical efficiency on dairy farms, according to Kite Consulting national nutritionist Tim Davies

Speaking at an Arla Carbon Reduction Project meeting at New Farm, Marksbury, Bath, he explained that boosting intakes would not only bring production benefits, but also reduce carbon emissions, delivering a win-win for producers.

“Farmers probably don’t give much thought to carbon reduction as they’re thinking about milk production, but carbon emissions are linked to both production and efficiency.

“And if you can improve health and dry matter intakes (DMI), you can produce more milk from less input and thus reduce emissions.”

Mr Davies explained that a dairy system was like a pipeline – in order to achieve efficiency, producers needed to first identify any kinks in the line and remove any production barriers for cows. As such, recognising any limitations to dry matter intakes was crucial.

“Half of a dairy farm’s carbon emissions comes from the rumen, and a quarter is linked back to feed use – fuel and electricity only make up a very small part,” he said.

Consequently, addressing feed use and efficiency was just one way the industry could help meet government targets to reduce total carbon emissions by 80% across agriculture by 2030.

“There is huge variation within similar systems in terms of carbon emissions – some stand at 800g/litre of milk and others at 1.7kg/litre – it’s not about changing your system, but about improving your system.”

Dry matter intakes

Dry matter intakes can be hugely variable even within a herd, with some cows eating 26-28kg a day and some 16-18kg.

“Those at the bottom end are the cows to work on,” he said. “You’ll know which cows these are – they’re the low yielders, lame cows or stale animals. If you focus on improving their dry matter intakes, you can make big improvements.

“You don’t need to feed more concentrates to get more milk, the key is to push dry matter intakes – something which is often the kink in the pipeline to efficiency.”

Mr Davies explained that systems often inadvertently put barriers in front of cows which prevented them from recognising their potential – for example, incorrect cubicle dimensions or poor feed barrier design that stopped cows from lying and feeding.

Dairy facts at a glance:

• A cow with a displaced abomasum will be 70% more likely to be culled for poor fertility
• It takes the rumen wall six weeks to recover after acidosis
• A cow does not reach positive calcium balance until six weeks post-calving
• For every 10 minute decrease in average daily feed time, cows are twice as likely to get metritis
• Increasing potassium in the dry cow diet from 1% to 2% will increase milk fever incidence from 10% to 50%
• Soya has a very high footprint at 7.5kg CO2 for every kg, versus 0.7kg CO2/kg of rape
• By-products have a carbon footprint of 10% of that of the original product 

“The secret to producing lots of milk is getting cows into cubicles and resting – the more rest, the more milk produced, the more they will eat and consequently the better the health.”

And a lot can be done to improve cow comfort and resting times on farm, including ensuring correct neck rail and brisket board placement. “Can you add chopped straw to mats or mattresses to increase comfort? Ask what you can do to improve your system.” Mr Davies stressed.

He advised three main areas to consider when assessing building set-up for maximising cow efficiency:

A – Air and ventilation: The inside of the shed should smell the same as the outside.
B – Barrier and bunk space: Ensure feed trough/barrier set-up and space a cow is sufficient to encourage intakes.
C – Cow comfort: Is lunging space sufficient? Can mattresses be improved to promote lying?

Dry cow management

Mr Davies explained that stress was also a huge influencer to efficiency. As cows come close to calving, there is normally a 30% reduction in immunity, however when cows are placed under stress, stress hormones go up, resulting in a 60-70% reduction instead. And in fat cows, the immune system can be switched off completely.

“Immune suppression is a big area – it is all linked to health and efficiency and ultimately if a cow drops dead, she is worth nothing and it is bad for your carbon footprint.”

Research has found that a 10-minute reduction in average daily feeding time meant cows were twice as likely to develop metritis, and increasing stocking rates results in a reduction in milk yields.

To reduce stress before calving Mr Davies recommended:

• Providing 100sq/ft (30.48sq/m) of straw yard space for every dry cow. This will make a big difference in terms of improved health. Even increasing space to 80sq/ft (24.38sq/m) a cow will be a big help.
• Providing 30in (76.2cm) of trough space a cow.
• Not moving cows from two weeks before calving – movement during this time has the biggest adverse effect on cow health.

Case study: J A W Bendall and Sons, New Farm, Marksbury

Good cow comfort and access to fresh feed is helping Somerset producer Stephen Bendall achieve good DMIs and reduce problems post-calving.

Presenting cows with a well-balanced diet, which is presented in such a way that it cannot be sorted, is hugely important, said Mr Davies.

“At New Farm, straw is well chopped in both the dry and milking cow ration so cows cannot sort – if this didn’t happen, the whole system would break down.”

Dry cows receive 5kg chopped straw a day and the milkers 1kg of straw. The dry cow diet consists of 14kg of the milking cow ration, 3kg maize silage, 5-6kg wheat straw, 0.50kg of a high protein concentrate, 0.10kg dry cow minerals, 0.25kg magnesium chloride, 0.25kg ammonium chloride and 4kg water.

Mr Bendall says chopping straw using a precision chopper is really important to the health of the whole herd. “If you don’t chop, you’d definitely see problems,” he said. Currently milking cows are achieving DMIs of 24.5kg a cow a day and dry cows, 12kg a cow a day.

Mr Davies says an ideal chop length is 2-3 inches, so it mixes in well and encourages cows to eat more. “Providing dry cows with easily accessible, fresh food every day is also hugely important to reduce stress.”

At New Farm, dry cow troughs are cleaned out every day and food always put in front of cows, something which Mr Bendall said helped cows start up well after calving.

However, Mr Davies said one of the main drivers for good intakes in the milking herd was excellent cow comfort. Rubber has been fitted in the feed passage and foam mats placed on top of old, hardened mattresses that had reduced cow comfort. Consequently Mr Bendall has seen increased cubicle lying times.

Dairy 2020

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This article is one of a series supporting the Dairy 2020 initiative, a cross-industry project to help secure a thriving and sustainable future for the UK dairy industry by 2020 and beyond.