Fuelling higher milk yields in spring calving herd

Grazed grass is a fantastic source of feed for cows, but in order to maximise the performance of spring calving herds, it is vital that supplementary feeding compliments the fluctuating levels of sugar and protein in grass throughout the grazing season.

Dairy Nutrition
Gwyn Evans 2

For Welsh farmer, Gwyn Evans, switching to a specialised low protein concentrate during the spring and summer months has resulted in significant improvements in peak milk yields and overall cow performance.

“We turn out freshly calved cows to grass from early February and historically would supplement throughout the season with a 16% and 18% protein concentrate, fed through the parlour,” explains Gwyn. “During the early spring, when grass protein levels are at their highest, there was too much protein in the cow’s overall diet, and they weren’t converting this surplus protein into a tangible gain – be it milk yield or constituents.

Gwyn currently milks 380 Jersey crossbred cows, based on a 138-hectare grazing platform at Dyffryn Arth in Llanon, near Aberystwyth. The herd’s service period starts on 1st May, with all cows served to conventional semen before any outliers are put to bulls.

Switching dairy concentrate

“This year we switched to a low protein concentrate, specifically designed to benefit spring calving herds and made to complement grass throughout the grazing season. Last year our average yields were around 4,500 litres, but now, by taking a more targeted approach to feeding and introducing the new concentrate, they stand at 5,246 litres - with 4.71% butterfat and 4.01% protein.”

Calving strategy

“The aim is to get as many cows and heifers in-calf within the first three weeks, but we will do another three-week round of AI for any that haven’t conceived,” says Gwyn. “After that, remainders will go with the bulls for another six weeks. This year we achieved good conceptions rates for a Jersey herd, with only 10.2% empty.

"We aim to have a nice tight calving block starting in early February and ending in April. As soon as a cow calves, they will be turned out to grass to make the most of early spring grazing. All of our youngstock are outwintered on another block of land we manage away from the home farm.”

Managing grassland

The herd is rotationally grazed during the spring and summer months, and Gwyn has a dedicated approach when it comes to measuring grass covers and managing performance of grazing leys.

“I use a plate meter to assess grass growth every week and put this data into our Agrinet software to help guide grass management decisions,” continues Gwyn. “The aim is to produce about 13 tonne DM/hectare a year and we like to keep grass covers of our paddocks quite high – following the old adage that ‘grass grows grass’. Cows will be moved on from a paddock once they have grazed down to about 1,600kg DM/hectare.

“Our reseeding policy is guided by grass ley performance, rather than age of a ley, focusing on leys that are failing to produce the quality and quantity of the grass we need. This year, we started having fresh grass samples taken by our ForFarmers account manager, Elliw Griffiths, and this has provided more data to help identify poorly performing areas.”

Gwyn aims to take three cuts of grass silage each season, with high quality, big bale silage forming the cornerstone of the herd’s ration during the housed period.

Forage to milk

“When cows are coming indoors in late November or early December, we will feed 4kg of big bale silage and supplement with a bit of concentrate through the parlour,” says Gwyn. “As cows start to dry off, we will switch them on to some less potent, clamped silage and cut back on the concentrate, ready for calving in February.

“Historically, when cows were out grazing, we would supplement grass with 0.6 tonnes per head of high protein concentrate during the grazing period. In order to reduce our feed costs, after cows hit their production peak in the summer, we would cut out concentrate use altogether, but milk yields would tail off quickly and dramatically. It was far from an ideal situation.”

Improving performance of the herd

Gwyn was already looking into ways to try and improve the situation of the farm when he met Elliw Griffiths at a local farmer discussion group in January 2020 and invited her to come along and visit the family farm.

“I was impressed with Elliw’s approach - we talked through a number of options and she got a ForFarmers nutritionist out on the farm to look over the cows’ diet,” explains Gwyn. “Elliw suggested we tried a new range of low protein concentrates – which also contain minerals and Levucell live yeast - that were specifically designed to support spring calving herds and grazing systems.

“The plan was to feed ForFarmers GrazeMate, with a 12% protein content, during the early part of the grazing season when grass protein levels were high. GrazeLate, with a 14% protein content, would then be fed when grass protein levels dip later in the year. This provided a level of flexibility in our concentrate feeding to best complement grass and ensure optimum protein utilisation. Elliw started taking fresh grass samples and checking urea levels of our milk to assess overall protein intakes during the grazing season so that we could adjusting concentrate use accordingly and be more targeted with our feeding.”

As well as introducing a lower protein concentrate into the herd’s diet, Gwyn also adapted feeding rates, providing an increased level of supplementary feed fed throughout the grazing period.

Targeted approach leads to results

“We now feed between 0.8-0.9 tonne per cow over the course of the grazing season and keep concentrate going during throughout the summer,” says Gwyn. “Cows seem to get off to a great start in the season with the new diet, hit higher levels of peak production – they increased by as much a 5 litres per cow – and then this momentum carries through for the rest of the season.

While the switch to GrazeMate and GrazeLate has been a positive move, Gwyn has also been impressed with Elliw’s input and advice.

“It has been much more than just selling us a product,” concludes Gwyn. “Elliw has provided support during our transition to the new diet and supplied us with valuable nutritional insights that she has gathered by analysing grass and milk urea. This has helped us to be more targeted in our approach and get the very best out of the cows.