Know what a good transition is worth. Getting the three weeks before calving right reduces or eliminates downer cows, speeds recovery after calving, minimises condition loss, and cuts post-calving ketosis, metritis, lameness and mastitis. Cows peak higher and earlier, convert feed to milk more efficiently, and cycle sooner with better 3-week and 6-week in-calf rates.

Treat transition as six weeks, not three. The official transition period is the 3 weeks before calving, but what you do in those weeks directly drives the 3 weeks after calving and flows on through the rest of lactation.

Understand what is physically happening to her. The calf takes up space, so she cannot eat as much while it draws nutrient out of her. She is innately vulnerable and far more sensitive to stress. Hormones are shifting and inflammation is a normal part of calving preparation. Colostrum production has already started, putting strain on the udder.

Watch for three metabolic imbalances, not one. Low calcium (hypocalcaemia, down cows) is the obvious one. Ketosis is the second, and it is liver and energy related rather than mineral related. Ruminal acidosis is the third and gets very little air time, but stabilising the rumen takes real pressure off the cow.

Treat calcium, phosphorus and magnesium as three strings on one puppet. Pull one and the others move. Low calcium changes phosphorus and magnesium metabolism, so you need to know what all three are doing. Parathyroid hormone and vitamin D sit behind that balance, particularly for calcium and phosphorus.

Watch calcium's effect on the immune system. High calcium draw with low calcium availability knocks immune function. If you are seeing more metritis, mastitis or other immune dysfunction, look at calcium first.

Know the ketone-calcium trap. Neutrophils carry a lot of calcium around the cow. High blood ketones or subclinical ketosis knock neutrophil levels down, which knocks down her ability to transport calcium — so a ketosis problem shows up as a calcium problem.

Give the rumen time to adapt. A diet change takes at least 10 to 14 days for the rumen microbes to adjust, because different microbes digest different feeds. Aim for a full 21-day transition when changing cows from crop to silage, or onto more grass. Early in a change the rumen simply cannot release the nutrient from that feed efficiently.

Allow time for rumen papillae to regrow. Papillae shrink over the dry period because she is processing far less energy. They need time to grow back before she starts lactating and has to process much more. Set a hard minimum of 14 days pre-calving on the transition diet.

Prepare the liver. Feed goes into the rumen, microbes break it open, nutrients enter the blood and the liver burns them as fuel. You want that fire burning hot and clean — not a dirty fire choked with fat and throwing off ketone bodies. A poorly prepared liver means heavy condition loss, slow recovery, low rumination and low appetite.

BOX 1 — Herbage test the transition feed. Test anything making up more than a quarter of the diet: maize silage, grass silage, and the paddocks the cows will graze. Test energy (ME), crude protein and NDF; calcium, magnesium and phosphorus; and potassium, sodium, chloride and sulfur so you can run a full DCAD calculation.

Choose your paddocks and silages carefully. Avoid effluent paddocks and any paddock you know is high in potassium, because potassium throws out the DCAD. Avoid silages high in butyric acid — they can trigger ketosis, so keep them away from transition and freshly calved cows. Test a few paddocks so you can pick the one with the lowest potassium.

BOX 2 — Set the dry matter allocation. Plan for roughly 2.5 to 2.8% of liveweight, with smaller cows at the higher proportion. A 320 kg Jersey works out around 9 kg DM and a 600 kg Friesian or Holstein around 15 kg DM, allowing about 10% wastage.

Set the energy and protein targets. Energy: 90 to 130 MJ ME as fed. Crude protein: 14 to 16%, higher than has been traditionally aimed for, because it drives gluconeogenesis through the liver. Avoid relying on high non-protein nitrogen — nitrogen-fuelled pasture alone can leave key amino acids short, which matters most on high production farms.

Use effective fibre to fill the gap. Holding energy between 90 and 130 MJ ME while keeping cows full is a conundrum, and ad-lib hay solves it: high in fibre, relatively low in ME. Feed a small amount of grass and a bit of silage once a day, then let them eat as much hay or straw as they want so they stay full, happy and ruminating.

BOX 3 — Calculate macro minerals as a percentage of total diet. Calcium 0.8 to 1%. Phosphorus 0.3%. Sulfur 0.4 to 0.6%. Magnesium 0.3%. Work through these with your local consultant — the numbers matter.

Get potassium below 2.5% to balance the DCAD. Bring in more maize silage or other low-potassium feeds and cut the grass right back, then add a DCAD salt on top to pull it down further. DCAD is the dietary cation anion difference — the difference between the positively charged cations and the negatively charged anions in the diet.

BOX 4 — Plan trace minerals from four inputs: per-cow production (higher producers need more), previous blood history (low selenium, high copper, low zinc), the feed test (high iron or sulfur will antagonise trace minerals), and health history (mastitis or metritis after calving suggests immune support is needed).

Cover antioxidant function with copper, zinc and manganese. These tie up the oxidative species that damage the immune system, the organs and the reproductive system. Oxidants come from poor quality feed, soil ingestion, stress on the cow, and an unstable rumen.

Use vitamin E and selenium to bring inflammation down fast. Inflammation before calving is normal and useful, but it needs to fall away quickly afterwards before it turns unhelpful. Vitamin E and selenium drive that, leaving her far less susceptible to metritis and other immune issues.

Add cobalt and iodine for liver and hormonal function. Cobalt converts to B12, which supports a range of liver processes including gluconeogenesis. Iodine sits alongside the cow's hormonal processes.

Use chromium for energy metabolism. Chromium improves insulin sensitivity and pushes back against the insulin resistance behind rapid condition loss after calving. It helps her signal naturally to stop mobilising condition and start relying on what she is eating, which lifts appetite and fills the rumen.

Use boron as a catalyst for the macro minerals. Boron improves uptake of calcium, magnesium and phosphorus, helps stabilise or reduce hypocalcaemia, and improves how much calcium and phosphorus goes back into bone storage.

Use biotin for gluconeogenesis as well as hooves. Biotin (vitamin H) is well known for hoof keratin strength, but it is also critical for gluconeogenesis when the cow is mobilising condition and fighting for energy. Biotin normally has to be released from grass by rumen microbes, so extra biotin helps most when the rumen is under pressure from diet change.

Add targeted products only where the problem calls for them. Betaine is a methyl donor that spares methionine in the liver — use it for over-conditioned cows, ketosis or rapid post-calving weight loss, particularly in high performance herds. Choline and B-group vitamins do a similar job. Sweeteners and palatants are worth including to lift intake, because appetite is the hard part in transition and early lactation.

BOX 5 — Never let cows get hungry. Cortisol research shows hunger is the single biggest stress on a cow, ahead of people, weather and heat. Do not leave transition cows without feed for more than 4 hours, which is the strongest argument for ad-lib fibre available at all times.

Manage around the weather rather than trying to control it. Wet and windy is the worst combination. For close-up cows within four or five days of calving, make a close-up group and put them somewhere sheltered with dry hard ground to rest on. Their appetite is already low, so they cannot eat their way out of the energy cost of bad weather.

Reduce people pressure and stop reshuffling mobs. Cut out unnecessary interaction with transition cows. Separating cows out and mixing them into a group they do not know is a major stressor — ideally the mobs cows dry off in are the mobs they calve in.

Keep the routine identical. Cows are like three-year-olds: they do not like change. Consistency equals safety, and safety equals peace and calm. Feed at the same time, bring them to the shed at the same time, and keep as much the same as you can through a period when she already feels vulnerable.