Trial assesses benefits of early nutrition in Wagyu calves

A recent trial undertaken by stud and commercial producers Jeremy and Carmen Cooper has shown promising results with Wagyu calves that were fed a specialist high-energy ration from 10 days of age.

The on-farm trial by the Coopers, who own Circle 8 bulls at Marulan, put the concept of whole-life nutrition to the test, following their visit to Japan in 2019 as part of the Australian Wagyu Association's Wagyu Fellowship program.

While there were many elements of the labour-intensive Japanese style of production that couldn't be replicated in Australia, one of the big takeaways from the tour was the ability to stimulate adipocytes, or fat cells, which leads to increased marbling.

"The Wagyu is no different to any other breed of cattle, apart from their inherent genetic ability or propensity to produce high yielding, well-marbled carcases," Mr Cooper said.

"Genetics, plus environment, equals phenotype, which is the physical expression of the genotype, so if the environment is at its optimum, you get an optimum outcome.

"Environment is critical because the heritability of carcase traits makes up about 20pc, which means 80pc of the carcase outcome is dictated by the environment.

"What we learnt was that the fat cells need to be turned on before 200 days, or six months. That will determine the level of intramuscular fat, which, in Wagyu cattle, determines the return.

"If a Wagyu has the genetic potential for a marbling score of 12, you can get that outcome by adding starch early, and feeding from birth to harvest."

RELATED READING: Genomics, EBVs spur global demand for Aussie Waygu sires

It's a widely-used practice in Japan, where calves are harvested from their mothers at five days and fed pellets for up to six months, then a grain a roughage ration.

"From five days to 12 months of age, they make them grow by one kilogram a day," Mr Cooper said.

"That's when they're sold to the next finisher, who then feed them to gain about 0.8kg per day, to about 30 months of age. In Japan, they believe a steer at 30 months would have the maximum expression of marbling."

The focus on early nutrition optimises rumen development, and it's proving successful when it comes to growth rates and marbling.

A typical fullblood Wagyu steer in an Australian production averages 417kg at 36 months, with an AUS MEAT marbling score of 7.4, and 18 per cent IMF.

In the Zenkyo Wagyu Show competition, steers achieve an average of 480kg, a beef marbling score of 8.4 and 43 per cent IMF, at 24 months.

"That's double the amount of marbling, and they're 12 months younger," Mr Cooper said.

In Mr Cooper's trial, calves were introduced to the feeder at 10 days of age, and fed an average of 800 grams per day, beginning with a specially-formulated creep crumble designed for Wagyu calves.

Over the 273-day trial (213 days pre-weaning and 60 days post-weaning) the creep-fed calves grew an average of 100g per head per day faster than the calves from the control group.

RELATED READING: High-value Wagyu production at Pittsworth

"The research is showing that early ruminant intervention has a correlation to early marbling," Mr Cooper said.

"In Japan, the staff density per animal is very high - they might have one staff member to every four cows and a lot of farms have 20 head or less.

"In Australia labour is too expensive, we're not set up to have cattle in sheds, and we have bigger numbers.

"I wanted to create a Japanese outcome from a carcase standpoint, within the constraints of an Australian production system."

RELATED READING: Strong domestic and export demand for Wagyu genetics

The steers are now on feed at Lillyvale Feedlot, and next step for the trial is assessing carcase feedback data, which will be available after processing in mid-2022.

While he hasn't got the full data back, Mr Cooper already has plans to creep feed all of his Wagyu calves from now on.

Another goal is to be taking DNA samples at one month of age, using the gene sequence to identify calves with a high potential for marbling.

While this trial focused on steers for finishing, creep feeding can also have a big impact on fertility and longevity in the females, Mr Cooper said.

"We're still trying to add milk and maternal traits in the Wagyu. In Japan the cattle don't have to have a lot of milk because they're weaned at five days, but in Australia we can't do that. We need to be concentrating on fertility for profitability, and we understand that early weaning, developing the rumen, also makes the females more efficient breeders."