Article Summary: Pasture keeps cows fitter and calmer than concrete, but only if you manage the details balance energy and protein through the season, top up minerals like magnesium and calcium around calving, use smart grazing and drench plans to curb parasites, and maintain well-designed races, shade, and water. Regular body-condition scoring, milk tests, and keen observation catch issues early so nutrition, welfare, and production stay in sync.
Pasture‑based dairying can look deceptively simple: open the gate, let the cows walk out, and watch the grass disappear. In truth, the link between grazing and animal health is intricate and deserves deliberate management. The good news is that when you get the basics right, pasture often works in your favour. Cows roam freely, breathe fresh air, and spend most of the day on a forgiving surface instead of concrete. Hooves stay sounder, joints experience less strain, and stress levels typically fall. All of these factors combine to lower the need for veterinary intervention and to keep milk flowing steadily.
Yet pasture is not a silver bullet. Seasonal swings in grass growth, shifts in nutrient composition, and the ever‑present challenge of parasites mean that health problems can creep in unless you stay alert. The sections below walk through the main issues to watch and the practical steps you can take to keep your herd thriving.
Why Pasture and Health Go Hand‑in‑Hand
Grazing gives cows the space to behave naturally. They can choose when to walk, lie down, ruminate, or simply interact with the herd. This activity keeps muscles toned and helps blood circulate through the lower limbs, reducing oedema and lameness. Fresh air lowers the bacterial load compared with enclosed sheds, which translates to fewer respiratory disorders.
Diet also matters. A mixed sward of ryegrass, clover, and herbs offers a broad range of vitamins, secondary plant compounds, and fibre types that stimulate rumen function. Cows produce more saliva when they chew long forage, which buffers the rumen and stabilises pH. That buffering, in turn, keeps acidosis at bay and supports better feed conversion.
Pasture’s benefits, however, depend on how you present it. Over‑grazed paddocks, long walks to and from the dairy, and a lack of shade can undo many advantages. Good layout and calm stock handling preserve the low‑stress environment that pasture was meant to provide.
Giving Cows Enough Energy and Protein
Energy drives milk, body maintenance, and reproduction. Protein builds the milk’s casein and supports muscle repair. In spring, lush ryegrass and clover usually supply ample protein sometimes too much but cows may struggle to consume enough dry matter quickly to meet their energy demands. Short grazing rounds and fresh breaks after each milking help cows hit high intakes of digestible leaf.
Watch body condition score (BCS) as your early warning system. Aim for a calving BCS near 5.0 on the 1–10 New Zealand scale, then limit loss to no more than one score in the first six weeks of lactation. If many cows slip below target, energy is short. Options include lengthening the round to lift residuals, shifting to more energy‑dense pasture, or feeding maize or cereal silage at the rail.
Later in the season, pasture protein often falls. Milk yield can plateau or dip unless you add a protein source. Undersown clover, chicory, or a short‑term summer legume stand can patch the gap. Alternatively, a modest top‑up of canola meal or distillers’ grains in the bail keeps litres steady without pushing feed costs through the roof.
Clean water underpins all of the above. A high‑producing cow may drink 70 litres or more on a warm day. Place troughs in every paddock, keep them clear of faeces and algae, and check flow rates so that cows can rehydrate quickly before their next break.
Fine‑Tuning Minerals and Trace Elements
Minerals are the small hinges on which big doors swing. Spring grass often contains plenty of potassium and nitrogen but not enough magnesium. This imbalance predisposes freshly calved cows to grass staggers (hypomagnesaemia). Dusting paddocks with 60–80 g of calcined mag oxide per cow or adding magnesium chloride flakes to water from three weeks pre‑calving until pasture growth slows is a cost‑effective safeguard.
Calcium deserves attention around calving. Offering ground limestone or commercial transition pellets helps the cow mobilise calcium stores smoothly, limiting the risk of milk fever. Phosphorus, sodium, and sulphur usually sit in the safe zone on well‑fertilised dairy farms, but keep an eye on soil tests.
Trace elements become critical where soils are naturally low, leached, or antagonised by high molybdenum or iron. Common deficiencies include:
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Selenium – white muscle disease in calves, lower fertility in cows
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Copper – coat fading, depressed growth, impaired immune response
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Cobalt (via vitamin B₁₂) – poor appetite, ill‑thrift in young stock
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Iodine – stillbirths and weak calves
Regular blood, liver, or milk testing pinpoints shortages before they hurt production. Supplements may be as simple as mineralised salt blocks, in‑water dispensers, or slow‑release bullets given in autumn and spring.
Staying Ahead of Parasites
Internal parasites thrive in warm, moist conditions and can quickly compromise growth in calves and heifers. A planned drenching programme still has its place, but over‑reliance on drenches invites resistance. Rotational grazing helps: young stock grazing ahead of older cattle encounter fewer infective larvae, and letting paddocks rest for 30 days or more starves out many worms.
Calves are most vulnerable. Where possible, allocate them the cleanest pasture either new grass or paddocks last grazed by adult cattle. Mixed grazing with sheep or deer further breaks the parasite life cycle because most worms are host‑specific. Keep faecal egg counts on file; they reveal when treatments are working and when you can safely extend the interval between drenches.
Adult cows rarely need routine drenching, but a mid‑lactation check keeps surprises to a minimum. If bulk milk or faecal samples point to a rising burden, strategic treatment pays its way by protecting milk‑solid output.
Supporting Cow Welfare with Good Infrastructure
Lameness undermines production and shortens a cow’s productive life. Well‑formed farm races reduce stone bruises and white‑line disease. Aim for a cambered surface that sheds water, use fine quarried rock rather than large river stones, and maintain a soft top layer for hoof cushioning. Regular scraping prevents slurry build‑up, which softens the horn and invites infection.
Shade and shelter matter in both extremes of weather. A stand of mature trees, moveable shade structures, or a simple shade‑cloth strung between posts can drop radiant heat load on hot days. In winter, a hedgerow or hay‑bale windbreak lets cows lie down without wind‑chill stealing body heat.
Fencing should funnel cows calmly to and from the dairy. Wide, gently curved lanes reduce pushing and jostling. If cows must queue, provide a flat loafing pad so that they do not stand for long on abrasive surfaces. Little touches like these save hooves, knees, and stress hormones.
Watching the Herd – Practical Monitoring
Close observation often alerts you to trouble before the data do. Train staff to notice subtle changes: a cow lagging at the back of the herd, a sudden drop in rumination time on a collar sensor, or a quieter demeanour at the feed face. Recording these notes in a simple app or diary builds a health history that complements formal metrics.
Combine what you see with structured checks. Monthly weighing of young stock confirms they are tracking towards target mating weights. Fortnightly BCS scoring of milkers highlights sub‑groups that might need preferential feeding. Bulk milk somatic cell counts flag mastitis risk at the herd level; individual quarter sampling pinpoints the cows responsible.
Post‑mortems, though never pleasant, can teach you a great deal. Work with your vet to investigate any unexpected deaths promptly. Findings often point back to a mineral gap, a parasite surge, or a hidden infection that you can address before more cows are lost.
Pulling It All Together
Pasture offers a strong platform for cow health, but it is not set‑and‑forget. Think of nutrition, minerals, parasites, and infrastructure as four pillars. Each supports the others. Miss one, and the system tilts. Stay proactive, keep records, and adjust grazing management with the season. When pasture and herd health move in step, you safeguard both milk production and long‑term profitability.
Until we meet again, Happy Farming!
- The Dedicated Team of Pasture.io, 2025-08-05