Phosphorus supplements study shows big promise
Field trial shows strong weight, health benefits
A HEALTHY 268 per cent return on investment, and a 120-kilogram live weight differential. These are some mighty numbers.
Many soils of northern Australia are typically deficient in phosphorus, impacting weight gain and fertility.
Phosphorus feed supplements to counter this are not a new thing, but for the first time the benefits of wet season supplementation of heifers and calves are being quantified, producing some enticing data from a four-year trial at the Victoria River research station, also known as Kidman Springs, south-west of Katherine.
Tim Schatz, principal livestock research officer with Northern Territory Department of Primary Industries and Resources, presented results from the study, exploring the effects of phosphorus supplementation on brahman females at a field day held at Kidman Springs this month.
Mr Schatz said the study had been able to successfully quantify the production and economic benefits of wet season phosphorus supplements.
“Now we are starting to put some figures on the cost-benefit of phosphorus supplementation, and we can tell producers how many extra kilograms of calves get weaned, what the improvement in pregnancy rates are, and how many more heifers die when you don’t supplement them. It’s taking a lot of the guesswork out of it,” Mr Schatz said.
The study saw wet season phosphorus supplements delivered via mineral loose lick to a P+ group but not to the P- group since 2014, with both groups pastured in acutely phosphorus deficient paddocks, and swapping paddocks each year.
The results of the study, showing dramatically improved body condition in phosphorus-supplemented heifers, could have some significant outcomes for the quality of the Northern Australia herd.
Mr Schatz said being able to see that impressive hard data on return on investment, rather than simply relying on anecdotal reports, would hopefully lead to increased use of the supplements by Northern Australian beef cattle producers in areas where phosphorus levels are typically low.
“It’s massive, really: when you see a 120kg difference in live weight between heifers when they wean their calves: because live weight is a big determining factor in whether they will get back in calf again,” he said.
“You see these big differences in pregnancy and weaning rates, and then it all flows through into the kilograms of calves that you wean from each treatment,
the differences are massive.
“The calves are significantly heavier, so that’s more profits for producers.”
The strong results from the study have exceeded the researchers’ expectations.
“We didn’t expect the result to be as big as it has been,” Mr Schatz said. “I expected a difference, but when you see the un-supplemented ones compared to the supplemented ones when you go to wean the calves, the difference in body condition, it just slaps you in the face it’s so big.”
While grass is plentiful and high in protein during the wet season, phosphorus is limiting. However, the wet season tends to present some logistical dramas for producers, such as getting bogged, or swollen creeks cutting access.
Combine that with a lack of data around the real return on investment of making sure the supplement is delivered, and it’s understandably discouraged many producers from using the product during the wet season.
“Lots of producers, when they realise the benefit, are finding ways to get the supplement out, whether it’s by putting dumps of it out there in the dry season to feed out during the wet, or putting bulk bags out at the start of the wet,” he said.
An important first step was to properly assess whether station soils were in fact phosphorus deficient, as the supplement would not deliver benefits if phosphorus levels on property were already adequate.
Cattle blood tests for inorganic phosphorus are currently the most accurate way to determine phosphorus levels on site.
“In really broad terms, if you know the country type, and if the soils are typically low in phosphorus, and if you look at the cattle and your first calf heifers are really skinny when you wean the calves, and have brittle bones, then you’re almost certain to benefit from some phosphorus
❝ The calves are significantly heavier, so that’s more profits for producers.
— Tim Schatz
supplementation,” he said.
The study will soon enter a follow-on phase, at Katherine Research Station, looking at generational effects of phosphorus uptake.
“We are wondering what the in utero, or carry-over effects are, from being born from mothers that have low phosphorus status,” he said.
“We are starting a trial shortly where we are going to put the calves from both treatment [P+ and P-] into a pen feeding trial and compare their performance.”
EXCELLENT RESULTS: Tim Schatz, Principal Livestock Research Officer with NTDPIR.
P- test group, first calf heifers in February 2017.
AREA OF NEED: Phosphorus levels.
P+ Test group, first calf heifers February 2017.