Mitigating climate-change threat boosts herd efficiency (Feb 22)

Environmental challenges faced by one Dorset-based unit have seen dairy management evolve to maintain profitability and increase sustainability. And knowledge sharing, via a scholarship, is set to support other producers


TEXT KAREN WRIGHT



A definite shift to drier conditions during the 2010s placed increased reliance on bought-in feed to maintain the status quo for one Dorset-based Holstein herd, triggering a switch to a more sustainable system.


Ian Baggs returned to his family’s dairy business, based at Worgret Manor Farm near Wareham, in 2016 after graduating in civil engineering and managing water supply projects in the UK and overseas. During his first three years back, the unit experienced two of the driest summers on record.


“Like many dairy units, we’re seeing the consequences of warmer, drier conditions far more frequently,” says Ian, who farms with his parents and wider family. “But we’re also in a rain shadow, with low growing-season rainfall, and we’re on light land. In dry years ryegrass just doesn’t grow here, leaving us short on grazing and grass silage. “We needed to look at several areas and make some changes so the business remains viable and is managed more sustainably.”


Back in 2017 the herd comprised 280 cows on an all-year-round calving system, but this has been reduced to 250 cows, with a more autumn-focused calving pattern. The herd is housed in winter and rotationally grazed during summer, with buffer feed provided as required.


Climate challenges


The unit comprises 250 hectares plus short-term keep. A platform of 40 hectares provides some grazing for the milking herd, while river meadows and unimproved pasture, which are in a Higher Level Stewardship scheme, are used for grazing beef-cross cattle (reared to between 10 and 15 months) as well as dry cows and replacement heifers.


The past three years have seen the business evolve to meet climate challenges, alongside the production and environmental targets required by their own herd and the wider industry.


Forage cropping, breeding and altering the herd’s calving pattern are the three main areas put under the spotlight. “We needed to increase yield from home-grown forages by growing more drought-tolerant crops, and work out the most sustainable ways to include maize in the system,” he adds.


Maize makes up 50% of the winter ration. It’s a good source of energy and it’s drought tolerant, but Ian says it’s hard to grow sustainably. “We cover crop our home-grown maize using grasses or brassicas, to reduce nitrate leaching, and have done this in conjunction with Wessex Water.


Soil health


“We’ve also trialled ‘min-till’ maize, rather than using traditional ploughing. This has reduced establishment costs and there’s been no yield impact, and hopefully it is less detrimental to soil health, so it’s a step in the right direction.”


Ian acknowledges their situation isn’t unique, and he knows other UK dairy producers are facing similar challenges, which inspired him to apply for – and secure – a Nuffield Farming scholarship, sponsored by the Trehane Trust. He’ll spend some of 2022 looking at alternative grazed forages to ryegrass, and sustainable maize growing practices, in drier areas in Europe, North America, and Australia.


He’s also supporting his findings with experiences at home. “During the past two years we reseeded 40 hectares with herbal-ley mixtures. These deep-rooted crops can withstand drought far better than ryegrasses and the legume species reduce fertiliser requirements.” The species in these new leys proving most successful include cocksfoot and festulolium grasses, as well as red clover, chicory and plantain.


Herbal leys: mixtures have different dominant species


“We’ve lengthened the grazing rotation to 30 or more days, as the herbal species take longer to recover,” says Ian. “And there’s a variation in the dominant species, depending on whether we’ve cut it for silage or grazed it, so I will continue to monitor these swards. We can fine tune our herbal mixtures when we know what works best.”


He’s also trialled mob grazing maiden heifers in place of a third cut of silage in late August. This meant moving electric fencing and water trough daily, but the effort of this is easily offset by reduced silage making and feeding costs. And it has the added bonus of potentially sequestering carbon and increasing soil organic matter, which could improve drought tolerance. “Heifer growth rates are not affected, and we’ve seen more pollinators, beetles and worm casts,” says Ian.


The Baggs family are now breeding a smaller Holstein cow, with greater feed efficiency and improved milk solids production to satisfy their Arla milk contract. “We want the same or more milk solids from smaller cows that have better feed efficiency. These cattle are more sustainable as they make better use of feed and less is needed if we have a dry season,” says Ian.


Bovine TB breakdowns during several years resulted in the Baggs losing some of their better cows, so genomic testing replacement heifers and sire matching has been used to identify the best animals to breed replacements from and generate rapid improvements in stock quality. Up to two straws of sexed semen are used on the best animals, with those not making the cut bred to an Aberdeen Angus sire. All crossbred calves are reared on the farm. Alongside smaller stature and improved longevity, sire selection focuses on fertility, health and constituent values rather than yield. “There’s more to be gained from reducing vet and medicine costs, and improving fertility than increasing output,” says Ian. “We’re looking to breed healthy, efficient cows.”


“We are also shifting our calving pattern. Hot dry summers are stressful for cows and pastures here, so by moving to an autumn-focused system, most cows are dry in the most difficult months. We are working with nature, rather than against it.”


Steady production


The winter ration is based on grass and maize silage and brewers’ grains fed at the trough, with concentrates fed to yield through out-of-parlour feeders. The herd average yield is currently 9,500kg of milk, at 4.2% fat and 3.2% protein. “Production has held steady, but we’ve increased milk from forage to 3,600 litres, and reduced bought-in feed rate to 0.27 during the past three years.


“And we’re achieving good grass yields with half-rate fertiliser applications on the high-legume leys,” adds Ian, who believes there’s more room for improvement, and has set a target a yield of 4,000 litres of milk from forage. “I think this will come from more consistent forages, higher intakes from grazing, and a more efficient cow. I also want our system to support a more sustainable environment. We have a lot of work to do, but we are improving all the time.”

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