James and Robyn Mann, Donovans Dairy at Wye, Mt Gambier, SA, milk a 2000-plus self-replacing Friesian herd in a 116-bay rotary dairy.
Of the 4100-hectare irrigated farm, 1600ha is effective milking area with the remainder growing silage crops and lucerne and running steers, sheep, dry cows and heifers.
"We try to be self-sufficient in fodder and only buy in grain - nine kilograms of concentrate/cow/day," Mr Mann said.
Corn is grown on 10 per cent of the irrigated country, supplementing a regular renovation program of 10-15 per cent sown to ryegrass and white clover pasture.
Production averages 10,000 litres/cow, with 650 kilograms milk solids, from the split-calving herd - 1200 cows calve down in spring with the balance in autumn. Milk is picked up twice a day, year round.
Losing 10 per cent of calves annually caused them to rethink their calf-rearing practices.
"Scours, salmonella -you name it, we've probably had it," Mr Mann said.
That rethink led to installation of a self-cleaning ultraviolet pasteuriser in 2012 to treat the colostrum and blue milk before it was fed to calves.
"It was an under-$50,000 investment for the machine, re-plumbing and new vats," Mr Mann said. "Since then, calf rearing has become significantly easier."
Also less costly. The calf manager, Barb Habner, said losses this autumn were reduced to two calves in 600. Given the dairy workforce is 20 people, the infrastructure investment and emphasis on workplace systems and cleanliness of equipment and infrastructure has paid off.
Ms Habner was elevated to the role of manager several years ago and continues to follow workplace systems established by Robyn Mann. Written standard operating procedures are part of the employee induction process and regular workplace review.
Recent business change - led by chopper prices - led to retaining bull calves beyond 10 days. Between 350-400 steers are now reared to two-year-olds and turned off at 580-650kg.
It means the emphasis has shifted solely from rearing heifer calves. Most are retained for the herd, but a certain number are sold to the Chinese dairy heifer market each year.
"So, rearing bull calves alongside heifers has become part of our standard operating procedure," Mr Mann said.
Calves are collected from the paddock twice a day and cleanliness is emphasised from the collection point.
"We start with the colostrum being pasteurised and put tubes in VIR-KIL between each calf," Ms Habner said.
Colostrum is collected at the afternoon milking from fresh cows. It takes four hours to complete the process in the pasteuriser and, the following morning, colostrum is decanted into two-litre bottles. Temperature is maintained at 13 degrees Celsius.
"The collectors go out with iodine and bottles of pasteurised colostrum," Ms Habner said.
"Each calf gets four litres of colostrum, and they get iodine spray on the naval and where they're tagged on the ear.
"It doesn't matter if they've already had a suck off the cow - they still get that first four litres."
She estimates 80 per cent of calves receive that four litres of colostrum in their first six hours and 20 per cent within 12 hours.
They are then brought back to the calf-feeding shed, where they stay for one week to 14 days, mostly learning how to use the teat feeder and being matched into mobs of 10 with similar-sized sisters or brothers.
From the first day, grain, pasture hay and potable bore water is available to the calves.
James Mann creates his own grain mix, including canola, lupins, wheat, barley, best start pellets and a sweetener for palatability.
The two calf-feeding sheds - each with capacity for 140 - were purpose-built, with an emphasis on airflow while protecting the calves from draughts.
Wood chips are used for bedding and each pen has a plastic board to record any health issues.
"I also use a red collar or red paint around the neck of the calf to identify if they are on any treatments," Ms Habner said.
A recent innovation has included recording growth patterns and health issues against a genomic database set up for the herd. The emphasis is on identifying cow families that perform better or less than the herd norm.
By two weeks of age, the calves are in pens outside the shed, again with shelter from the wind, on woodchip bedding, and offered milk and ad-lib water, hay and grain.
The next stage is three kilometres away, where each mob of 10 calves is housed on 0.5ha and the regime of milk and ad-lib water, hay and grain continues.
"They get five litres of milk each in a feeder, for 12 weeks, up to 2kg of grain and ad-lib hay and water," Ms Habner said.
They stay in this area until 12 months of age.
Cleanliness is paramount. "Teats for the buckers and calfeteria are cleaned every day in the shed, but once in the paddock the calves are expected to build up an immune system," Ms Habner said.
"We start with new teats every calf season and everything is cleaned up between calving seasons - the sheds are cleaned, disinfected and aired out for a couple of months after calving season. New woodchips replace the old bedding."
During the season, if rain creates a muddy environment in the pens outside the calving shed, then the bedding is changed.
On the long-term calf-raising block, Ms Habner and her crew of calf rearers use a truck to transport a 1200-litre tank of milk and a 700kg grain feeder to the calves. The tank is cleaned daily.
Standard operating procedure means four drenches are applied - orally or by injection - in the first 12 months, along with 7-in-1 at weaning and pneumonia and pinkeye vaccinations. Each heifer also receives Multimin and B12 injections and another drench at pre-joining.
"If we're worried, we'll do a worm egg count," Mr Mann said.
Running the heifers in mobs of 10 allowed Ms Habner and her team to visually assess if any calves are dramatically below or above the average expected weight.
"They do well running in mobs of 10," she said. "At six months, I'll cull if the heifer doesn't make the target weight - whether she's too light or too heavy. We try to keep them the same size so they don't compete too much against each other for food."
At 12-months or 300kg, the heifers are taken by another team, responsible for getting them to 340kg-plus for joining, aiming to calve at 22-24 months at 580-620kg. To do that, the heifers are run in mobs of 100-200 and graze pasture supplemented by ad-lib silage.
"In 25 years of following this system, the heifers have consistently hit their target," Mr Mann said.