WHEN it comes to the northern cattle industry, you need to know how to get your land management right, you need to get your profitability right, but you also need to get your genetics right.
This was Sarah Streeter's message to a bus-load of women graziers who toured the Burdekin last month.
"We are in an exciting time for genetic measurement and genomics in our tropical breeds. So let's grab the bull by the horns," she said.
Ms Streeter, a self-confessed science nerd, manages her family's property White Kangaroo Station in the Bowen-Collinsville area.
She is also an agricultural science graduate from the University of Queensland with a research career, and now sits on the North Queensland Beef Research Committee.
"When we're looking at the traits we want, we need to look at what is important to our business," she said.
"It may be weight on the ground; it could be having a polled breed."
The important point is that the traits selected needed to be measurable, repeatable and passed on from bulls to their progeny. A lot of research is placed on heritability, and there is no use selecting a trait if it is not going to be passed on to a bull's sons or daughters."
And there is also the relationship between traits - some traits are antagonistic.
"When you hone in on one trait, that trait can impact on another. For example, if you select for growth year after year, you often lose out on other traits, like fertility."
Early puberty and the fertility myth
Most cattle in northern Australia are Brahman or Brahman-infused, and there has been a lag compared with Angus, for example, when it comes to data and estimated breeding values (EBVs). One of the reasons is that generally bull buyers are not asking for that data. They are not paying for a premium product, so there is no incentive for seedstock producers to go down this path.
"But we are starting to see change, and a lot of people don't realise we are only just starting to recognise the importance of certain traits in northern beef herds," Ms Streeter said.
"Researchers are only just starting to tell us what is important, so we are still playing catch-up with the information we have been given."
Research has turned on its head the long-held belief that early puberty is an important trait that predicted life-time fertility.
Instead, the past 12 months has found that lactation anoestrus is the important trait in Brahman cattle in northern herds.
"When a cow is lactating, particularly a Brahman, she can have a mechanism that shuts down cycling, particularly when there is low nutrition. It is survival mechanism."
However, there is the highly heritable trait in some cows where they are genetically programmed to cycle during lactation.
"The Beef CRC found that the lactation anoestrus trait, particularly in first-calf heifers, is the biggest indicator of reproduction over a life time," Ms Streeter said.
The heritability of this trait is high, about 50 per cent in Brahmans, compared with the 200-day weight rate, also considered highly heritable, which sits between 30 and 40pc.
Improving Australia's northern herd
Ms Streeter said the information coming through now would take four to five years before it is seen in the herd. "We do have a real lag in the time it takes with animal breeding."
However, there was a body of new information on the productivity of the northern beef herd, and the CashCow project had benchmarked productivity traits, showing producers where they should be placing importance in their herds.
The focus was bulls passing on these traits.
"David Johnson from the Beef CRC has said that culling females for reproductive failure is not the most effective way to improve fertility in herds," Ms Streeter said.
"If we are not making the right decision in our bulls that can produce daughters that are still performing as seven to eight year olds, we will always be on the back foot.
"This newfound knowledge is now being used in bull selection. There has always been days to calving EBVs.
"This is always being improved and tweaked in Breedplan and we are starting to see more bulls coming through with data."
Ms Streeter said the Australian Brahman Breeders Association had been working on the Brahman Beef Information Nucleus project over the past three years to make gains in data collection.
Genotyping technology now available was giving the industry a better understanding of genes - there have been gene markers for tenderness, feed efficiency, marbling etc, for some time.
"The recently released SNP chip testing in Brahmans means you can submit a tail sample and get an array of information, including days to calving."
This genomic information was not replacing Breedplan, but was increasingly sitting alongside.
"It is not an expensive technology - $50 per animal - so there is no reason why an animal going into the saleyard shouldn't at least have this done."
The data currently had 30 per cent Breedplan accuracy.
"Now we have the detail and data that will show this genetic shift in tropical herds."
Bulls with no data
Despite these improvements, tropical breed bulls still lagged behind other breeds, particularly Angus, when it came to this data.
Ms Streeter was wary, however, about being "blinkered".
"We need to be wary about narrowing down the selection of bulls that only have data at this stage.
"It is important to have a wide genetic variety - if you are faced with only a few stock producers that have data, as we were three years ago, you are at risk of narrowing down the genetic diversity."
So rather than just selecting those bulls with data, commercial producers could look at bulls in a similar environment to their own and use "raw data" to inform their choice.
"Is the bull grazing on native pasture? What is the management structure it has grown up in? Are the cows reproducing under low nutrition? Look at its scrotal size. This is still a good indicator.
"Ask for data on the bull's dam.
"If she can show that she can still have a calf while lactating, then she has shown she has the lactation anoestrus genetic mechanism switched off. Ask these questions and you are still moving in the right direction."
Semen effects
Ms Streeter said it was not unusual to have semen-tested bulls soon after a sale firing blanks, while the vendor's test beforehand was completely different.
"Never fear - this is not uncommon, and there are several factors that can explain this.
"When at bull sales, you see bulls are lying down on concrete and that increased heat can affect their sperm. There is also a study, the Bull Power Project, that looked at the effect of long travel, co-mingling with other bulls.
"Bulls need to go through a full semen cycle to get back on track."
Other factors would cause long-term damage and the main one was heat on the testicles.
"When animals are fed, this can produce a lot of heat, particularly when they are grainfed long term."
The key was looking for a fit bull, not a fat bull.