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Avoiding the ‘dilution factor’

Sector News Sector News30-8-2019

Adding an amino acid-based product to rations has helped one Staffordshire-based dairy business to increase milk yields while also maintaining butterfat levels. We visited the herd to find out more.

Increasing yields without incurring a ‘dilution factor’ on butterfat levels and fertility is the aim of one Staffordshire-based dairying family. And the Royalls know that in order to achieve this goal, they need to pay close attention to both the cows and their diet.

James Royall runs the 250-cow herd – in partnership with his brother Michael, father Martin and uncle Christopher – near Alsagers Bank. Managed on an all year-round calving system, the herd is currently averaging 10,500 litres at 4.0% butterfat and 3.3% protein. Milk is sold to Tesco, on a Muller contract. Cows are fed a simple diet comprising grass silage, straw and forage balancing concentrate in the feed trough. And a 17%-protein high-energy balanced blend is fed to yield in the parlour. 

Cows are strip grazed during the summer, but are buffer fed when grass growth slows. Milk yields have steadily increased during the past few years, due to better genetics and improved silage quality. But yields leapt up during the winter after a revised feeding regime was implemented.

From left to right: Clive Slawson, James Royall and Christopher Royall
From left to right: Clive Slawson, James Royall and Christopher Royall

High quality silage

“The altitude here – 200 metres above sea level – can mean that grass growth is slow to get started,” explains James. “But we took first-cut silage a week earlier than usual in 2018, in the middle of May. Second cut was hit by the hot, dry weather and we round baled that for dry cows and young stock. But the quality returned for our third cut.”

The result has been high quality, more palatable clamp silage, with values of 10.9 MJ/kg ME, 14.3% CP, and 68% D value, at 32.9% dry matter. 

“You can see the structural fibre in the silage grass. It smells good and you can really tell from the intakes that the cows love it,” explains James. 

“During the winter, cows were fed a diet, comprising 36kg grass silage and 0.5kgs of straw and concentrate, which had a total protein content of 25%. This provided maintenance plus 24 litres and they were then topped up to yield with concentrate fed through the parlour.”

But as the milk yields increased the Royalls were worried about the ‘dilution factor’ on milk constituents and so James spoke to ForFarmers’ Clive Slawson. “We analysed the silage, using dry NIR, and used this information to help build a diet that supported butterfat production as milk yields increased,” explains Clive. “Milk fat is affected by a number of dietary factors, including fibre digestion, rumen activity and fat content. Ensuring that cows have enough structural fibre by including, for example, hay or straw in the ration, is important, as is checking that there is enough of the right type of fat in the diet. 

Yield increase

“While producing and feeding top quality forage is vital, rumen protected fats can play their part in helping to support milk constituent levels. Products that we had tried at Waste Farm during the past year had little impact. But in the autumn we added ForFarmers’ FatBoost and saw yields increase and fat percentages remain strong.”

Increasing the intake of rumen protected fats, such as C16, and increasing dietary fibre levels are the common nutritional recommendations when trying to reduce milk fat depression. “But FatBoost is an amino acid feed product that can also help influence milk butterfat levels by limiting the negative effect that polyunsaturated fatty acids can have on rumen bacteria.”

Clive monitors cow health, welfare and performance using ForFarmers’ Visiolac milk analysis and insight reports, which use NMR data.

“We’re keen to optimise rumen function,” adds James. “We want the cows to produce the butterfat. Soon after adding this amino-acid product to the ration, it was easy to see that rumen function was improved. Dung was looking smoother and showed signs of better digestion.”

Feeding for fat: milk constituents have remained strong during the winter
Feeding for fat: milk constituents have remained strong during the winter

Calving index

Cows milked really well during the winter, with yields up by an average of 10% and butterfat percentages remaining strong at more than 4% fat. The Royalls have also cut some of the less effective and economically viable fats from the herd’s diet, while keeping Lintec for high omega three levels. And they are confident about pushing yields even further. “I definitely feel that we have the room to go higher,” says James. “We’re currently installing a new parlour, which will cut milking time in half, reduce standing time for the cows, and free up more time for feeding and ruminating.”

The family also wants to focus on reducing the unit’s calving index – from 402 to 380 days. And a new calf shed has been built with automatic feeders. The family is looking to automate some of the other jobs on the farm, such as pushing the feed up to the barrier.  “With the investments we’re making in infrastructure and the continued development of the cows’ diet, I know that we have the potential to increase yields even further without effecting fat and protein levels,” says James.