Winter in southern Australia — June through August across Victoria, Tasmania, South Australia, southern New South Wales, and the south-west of Western Australia — is the season that defines the year for many livestock producers. It is when pasture grows most actively, when livestock energy demands peak, when ewes lamb or cows calve, when mud and cold create welfare and infrastructure challenges, and when the decisions made in autumn either pay off or create problems.

Done well, a southern Australian winter is a season of genuine productivity: pastures flush, livestock condition improves on green feed, lambs hit the ground in good conditions, and the year's primary feed production is locked in. Done poorly, it is a season of muddy paddocks, poor pasture utilisation, livestock struggling in nutritional deficits, and the beginning of problems that carry through to autumn the following year.

This guide covers every aspect of winter livestock management in southern Australia — grazing, nutrition, lambing/calving, health, infrastructure, and the regional variations that make management in Tasmania different from management in the South Australian mallee.

Understanding Southern Australian Winter

Winter climate characteristics across the southern zone:

Region June–August Rainfall Min Temperatures Frost Risk Key Challenge
Victoria (south-west) 150–250mm 4–8°C Moderate Pugging, waterlogged soils
Gippsland, VIC 150–300mm 4–9°C Low–moderate Wet soil management, mastitis
Tasmania 250–400mm 1–6°C Moderate–high Cold, wet, frost, alpine snow
SA (South East) 150–220mm 5–9°C Moderate Waterlogging, phosphorus response
SA (Mid North, Eyre) 80–150mm 5–10°C Low–moderate Lower rainfall, feed reliability
NSW (Southern Tablelands) 120–200mm -2–8°C High (frosts) Frost, hypothermia risk in lambs
NSW (Slopes) 100–180mm 3–9°C Moderate Frost, waterlogging in wetter years
SW WA 200–350mm 7–11°C Low Waterlogging, lupin and cereal cropping competition

The defining feature of southern Australian winter is the active growth of cool-season pasture species (ryegrass, phalaris, clovers, fescue) driven by cool temperatures, adequate soil moisture, and adequate soil phosphorus. In a good year, daily pasture growth rates can reach 40–80 kg dry matter/ha/day in the productive farmlands of Victoria, SA, and WA — the highest growth rates of the year.

Managing this rapid growth effectively — neither wasting it through under-utilisation nor degrading it through overgrazing and pugging — is the central challenge of winter livestock management.

Section 1: Winter Grazing Management

The Pugging Problem

Pugging — the physical damage caused by livestock hooves to waterlogged soil and pasture — is the dominant winter management challenge in wetter parts of southern Australia (high-rainfall Victoria, Tasmania, the South East of SA, and south-west WA).

Pugging impacts include: - Physical destruction of pasture plants (roots pulled from waterlogged soil) - Soil structural damage that persists for months to years - Increased pasture weed invasion in damaged areas - Reduced water infiltration into pugged soils - Pasture composition shift toward shallow-rooted annual species and away from deep-rooted perennials

Management strategies:

Standoff pads: A constructed area (concrete, rubble, compacted gravel, or wood chip) where livestock can be held during periods of wet, soft soil — typically the wettest 4–12 weeks of winter. Livestock are supplementary-fed on the standoff pad and returned to pasture as soils firm up. - Sizing: minimum 6–8m² per adult sheep, 12–15m² per adult cow - Water and shade/shelter must be provided on the pad - Investment: $800–$3,000 per livestock unit of space, depending on construction

Sacrifice paddocks: A paddock deliberately accepted as collateral damage — kept in livestock through the wettest period to allow all other paddocks to be spelled and recover. Fencing the sacrifice paddock from the rest of the farm is critical. Rotated year to year to allow recovery.

Laneways: Permanent gravel or rubber-mat laneways allow livestock to move between paddocks and to the milking shed (in dairy systems) without damaging pasture. Standard in dairy systems; increasingly important in sheep and beef operations in high-rainfall areas.

Rotational grazing in winter: Moving livestock frequently (every 3–7 days in fast-growing spring, every 7–14 days in slower winter growth) across a series of paddocks reduces the time any one paddock is grazed and reduces pugging risk compared to set stocking.

Pasture Measurement and Allocation

In winter, matching stocking rate to available feed is a daily management decision. Pasture measurement tools:

Pasture plate meter: A calibrated dropping plate measures pasture height and, through a formula, estimates dry matter per hectare. Essential tool for any serious dairy, beef, or sheep operation in a high-rainfall zone. - Average daily gain of each paddock × number of paddock days available = total available feed

Visual assessment: - Pre-grazing target for sheep: 1,500–2,000 kg DM/ha (approximately 8–10cm average height) - Post-grazing residual for sheep: 800–1,000 kg DM/ha (approximately 4–5cm) - Pre-grazing target for dairy cows: 2,200–2,800 kg DM/ha (approximately 10–14cm) - Post-grazing residual for dairy cows: 1,400–1,600 kg DM/ha (approximately 5–7cm)

Removing livestock from a paddock at the correct post-grazing residual is as important as the pre-grazing entry decision. Overgrazing in winter removes the leaf area needed for rapid regrowth and extends the rest period required before the next grazing.

Section 2: Nutrition in Winter

The Green Feed Paradox

Counter-intuitively, green winter pasture — while high in energy and protein — can create nutritional problems for livestock:

High moisture content: Green pasture in winter can be 80–90% water. Livestock physically cannot eat enough wet feed volume to meet high energy demands (late pregnancy, early lactation). Supplementary dry feed (hay, silage, grain) provides concentrated energy and dry matter to complement green pasture.

Hypomagnesaemia (grass tetany): Rapidly growing young green pasture in late winter/early spring is high in potassium and can be low in magnesium. Lactating cows and ewes are most at risk. Clinical signs: excitability, muscle tremors, collapse, death (often sudden). Prevention: magnesium supplementation through dusting hay with causmag, magnesium-containing fertiliser applications, or magnesium blocks. This is a critical management issue in southern Australia's high-rainfall zones.

Sub-acute ruminal acidosis (SARA): Highly digestible, low-fibre green pasture can cause acidosis in cattle. Providing dry roughage (hay, silage) in the diet reduces the risk.

Vitamin B12 deficiency: In cobalt-deficient soils (common in parts of SA and WA), vitamin B12 deficiency causes ill-thrift and "pine" in sheep and cattle on green feed. Test suspect soils; supplement with cobalt-containing lick blocks or cobalt injection.

Supplementary Feeding in Winter

When to supplement: - Pregnant ewes in the last 6 weeks of gestation need energy above what green pasture provides - Lactating dairy cows have energy requirements that cannot be met on green pasture alone - In years with a late or unreliable autumn break, pasture may not have established adequately and winter feed will be short - During prolonged wet periods when livestock are on standoff pads

Feed types and application:

Grain (energy supplement): - Oats: safest grain for sheep and cattle; low bloat and acidosis risk; 11 MJ ME/kg DM, 10% protein - Barley: higher energy than oats; more acidosis risk; introduce slowly - Wheat: highest energy; highest acidosis risk; not recommended for beginners - Feeding rate: 200–400g/head/day for pregnant ewes; up to 2–4 kg/head/day for finishing cattle

Lupins (protein + energy): - Excellent for ewes in late pregnancy; slow energy-release; 12.5 MJ ME/kg DM, 30% protein - Feed at 200–400g/head/day alongside hay

Hay: - Oaten hay, cereal hay, grass hay for roughage and dry matter - Lucerne hay for high energy + protein (excellent for dairy cows, lactating ewes) - Ensure adequate trough/feeder space: at least 30cm per sheep head, 60cm per cattle head at the feeding face

Section 3: Lambing Management

Lambing is the central event of winter for most southern Australian sheep producers. In the winter-dominant rainfall zone, most producers aim for late July–September lambing (joining rams in March for August lambing; April for September).

Pre-Lambing (June–July)

Nutrition of late-pregnant ewes: The last 4–6 weeks of pregnancy are critical. Lambs grow rapidly in this period, and ewes' energy requirements increase dramatically. Under-nutrition in this period causes: - Pregnancy toxaemia (twin lamb disease): ewes in negative energy balance collapse and die; highest risk in twin and triplet bearing ewes - Small, weak lambs with poor survival - Poor colostrum quality and volume - Reduced milk production post-lambing

Management: - Separate twin-bearing ewes (identified by ultrasound scanning) from single-bearing and dry ewes - Feed twin ewes: 0.5–1.0 kg lupins + ad lib good-quality hay; or access to the best green pasture available - Don't mob up ewes in pre-lambing paddock — allow space for ewes to avoid competition at feeders

Paddock selection for lambing: - Medium-quality, settled (not recently sown) pasture - Shelter from prevailing cold winds (south-westerlies in most of southern Australia) - Good access for observation without excessive disturbance - Not prone to waterlogging — lambs on waterlogged ground are at high hypothermia risk

At Lambing

Daily checking: Walk lambing paddocks at least twice daily during the peak period (weeks 2–4 of lambing). Early morning and mid-afternoon checks catch the majority of problems.

Critical first hours: The lamb must receive colostrum within 6 hours of birth and must be able to suckle within 12 hours. Colostrum provides passive immunity, energy, and warmth. A lamb that hasn't suckled within 6 hours is at serious risk.

Intervention situations: - Ewe in labour for more than 45 minutes without progress: assisted lambing required - Malpresented lamb (only the head, only one leg, or breech position): manual correction needed - Ewe rejecting lamb: bonding pen management - Hypothermic lamb (temperature below 37°C): warming before tube feeding

Hypothermia management: Hypothermia (body temperature below 38°C) is the number one killer of newborn lambs in wet, cold conditions.

Rewarming protocol: - Lambs above 37°C but cold: dry thoroughly; ensure they suckle - Lambs 32–37°C: stomach tube with colostrum or glucose solution (50ml/kg, 37°C warmed solution); place in warming box at 39–40°C - Lambs below 32°C: intraperitoneal (IP) injection of warm glucose solution (20ml/kg of 20% glucose warmed to 37°C) — only after warming; tube feeding a hypothermic lamb causes it to aspirate

Marking (tailing and castration): - Tail docking and castration: 2–10 days of age - Use a rubber ring, hot iron, or surgical method as appropriate - Dip navels at birth: 7% iodine to prevent joint ill and omphalitis - Tag lambs for NLIS and mob identification at marking time

Section 4: Winter Calving Management

For beef and dairy herds calving in late winter/early spring (July–September), winter management is critical.

Pre-calving Nutrition

Cows in the last trimester of pregnancy need adequate energy and protein to: - Support calf growth - Produce quality colostrum (minimum 2L within 6 hours of birth) - Maintain their own body condition for rapid cycling post-calving

Target: BCS 3.0–3.5 at calving. Cows below BCS 2.5 at calving have reduced colostrum quality, longer intervals to first heat, and reduced conception rates.

Calving Surveillance

Check heifers (first calvers) every 4–6 hours — they are at significantly higher risk of dystocia (difficult birth) than mature cows. Check all cows at least twice daily.

Normal calving progress: - Stage 1 (cervical dilation): 2–6 hours; cow restless but not straining - Stage 2 (calf delivery): 30–90 minutes of active straining; if feet are visible but no progress after 30 minutes, assistance required - Stage 3 (placenta passed): within 6–12 hours of calving; retained placenta (not passed after 12 hours) requires veterinary attention

Colostrum management: The first colostrum is the most critical feed a calf receives. If a calf cannot suckle, strip colostrum from the cow and stomach-tube the calf. A calf must receive minimum 10% of its body weight in colostrum in the first 6 hours.

Section 5: Winter Health Management

Vaccination Programs

Clostridial vaccination: All livestock should be on a clostridial vaccination program. Winter is when: - Pre-lambing boosters are due for ewes (4–6 weeks before lambing) - Lambs receive their primary course at 6–8 weeks and booster at 10–12 weeks - Pre-calving boosters are given to cows

Pneumonia in weaners: Winter is a high-risk period for respiratory disease in calves and weaner sheep: - Cold, wet, dusty conditions stress animals - Pneumonia vaccine (e.g., Bovishield for cattle; Ovipast for sheep) reduces risk in high-risk situations

Footrot management: Wet winter conditions accelerate the spread of footrot in sheep. - Regular footbathing (zinc sulphate 10% solution) through the wet period - Vaccinate with Footvax if introducing new animals or after a confirmed outbreak

Internal Parasites (Worms)

Winter is generally a lower-risk period for barber's pole worm (Haemonchus contortus) in southern Australia — it is a warm-weather worm. However: - Other species (Trichostrongylus, Teladorsagia) are significant in cool conditions - Weaners and stressed animals remain at higher risk year-round - Conduct WEC (worm egg counts) on weaners in July; drench if above threshold - Avoid routine drenching of all adults — drench based on WEC results

Section 6: Infrastructure in Winter

Shed and Yard Maintenance

  • Inspect and repair shed roofs before the wettest period (May–June)
  • Clear drainage channels around sheds and yards — blocked drains turn yards into mud baths
  • Check that electric light systems in sheds are functional (important for night-time lambing checks)

Road and Track Maintenance

  • Grade internal roads and tracks before winter rains where possible
  • Grade after winter rains when the ground is firming — muddy grading makes roads worse
  • Apply road base to the worst sections in summer when ground is firm

Trough and Water System Management

  • Insulate exposed water pipes in frost-prone areas (New England, Southern Tablelands, Alpine Victoria, Tasmania)
  • Check float valves regularly — silted or frozen float valves cause troughs to overflow or run dry
  • Ensure troughs in lambing paddocks are functional before the lambing period begins

Regional Highlight: Managing Winter in the Southern Tablelands of NSW

The Southern Tablelands (Braidwood, Goulburn, Young, Cootamundra districts) experience genuine winter cold, including regular frosts (up to -8°C minimum in some areas), occasional snowfall at higher elevations, and significant variation between valley floors (cold air drainage, frost hollows) and hillsides (warmer). This creates specific management requirements:

  • Frost hollow awareness: Don't locate lambing paddocks in frost hollow sites — these are the coldest, most dangerous spots on the farm for newborn lambs. Hillside paddocks with good air drainage and shelter from prevailing winds are far better.
  • Snow events: Occasional August/September snowfalls can cause significant livestock losses if animals are not in good condition and have shelter available.
  • Water freezing: Trough water can freeze solid overnight in July–August frosts. Use concrete troughs (retain more thermal mass) over poly troughs; add float valve boxes with insulation in extreme situations.

Conclusion

Winter management in southern Australia is demanding but well-supported by one of the most productive pasture growth seasons in the world. The farms that make the most of winter are those that have prepared livestock nutrition before lambing, invested in the infrastructure to manage wet soils (standoff pads, laneways), and keep a close eye on livestock welfare through the coldest and wettest weeks.

The investment of time and resources in winter management pays the largest dividends of any season. A good lambing, a well-managed pasture bank, and livestock in good condition coming out of winter set the entire year up for success.

For hypomagnesaemia (grass tetany) protocols and winter nutrition advice, contact Agriculture Victoria, NSW DPI, or PIRSA. For lambing and calving procedures, consult your local large animal vet.