Fertility is proof in the P pudding

North Queensland beef producers Peter and Anne Finlay know that to get the most out of their land they can’t ignore the importance of phosphorous (P) supplementation, so they take a year‑round approach to providing this important nutrient for their cattle.

It’s been their focus for the past 25 years as they knew their soil was P deficient when they purchased ‘Julia Park’ at Torrens Creek.

Deficient soils in many northern production systems can lead to insufficient P in the pasture to meet animals’ requirements for vital functions such as building bones and teeth, and producing milk.

The Finlays feed cattle P year‑round, adjusting the level of supplementation to suit the season and breeding requirements.

During the wet season, while there is green feed, cattle have access to a 50/50 mix of Kynophos – which is 21% P – and salt lick, fed in tyre troughs.

“Breeder intakes during this time are around 46g/head a day, equating to about 10g of P/head a day to match breeder requirements,” Peter said.

“This costs us roughly 30¢/ head a week.

“As it starts to dry off I put out a 27% urea lick loose mix that also contains 12.5% Kynophos, even before it’s needed, to make sure the cattle have it in their system.

“Cattle intakes of the dry season lick increase to around 200g/head a day, which costs us around $1.12/head a week.”

The Finlays leave the mixture of P and salt out during the dry so cattle can self‑regulate intake of either lick as required.

“As we control mate, we have very few wet cows during the dry spring period, so I’ve always felt that the 12.5% Kynophos they are getting with the urea lick is adequate,” he said.

Fertility and weight

Peter contributes this P program to strong calving and weaning weights with a five‑year average of 72% branding and 69% weaning rates.

“Considering four of the past five years have been very poor seasons with reduced feed quality, I’m quite happy with those rates,” he said.

“On this country, if you aren’t feeding P, weaning rates could be as low as 50%, you’ll struggle to produce enough heifers as replacements and growth rates will be back to blazes, so it’s crucial to keep it up.”

On top of strong fertility, Peter said P also helps with weight gain, allowing them to turn-off their steers at 26–28 months at between 380–400kg, even in lighter seasons.

Part of the puzzle

Peter has used programs such as MLA’s NutritionEDGE to guide herd nutrition strategies.

He said P is just one part of their total management approach.

“We’re constantly looking at tweaks we can make, such as cross‑breeding for better fertility and weight gain, rotational grazing strategies and pasture improvement.”