InCalf project leader Barry Zimmermann said that while farmers were focussed on feeding cows in early lactation to optimise milk production, it was also important to consider the impact of feeding on herd fertility. 

“Herd fertility is critical to the sustainability of any dairy herd and can represent thousands of dollars in production costs,” Dr Zimmermann said.

“Good herd fertility means farmers can cull cows on the basis of profit, rather than pregnancy, and have the choice to increase herd size or sell more animals in the future.

“Seasonal calving herds with high reproductive performance have more earlier-calved cows generating more milk income over feed costs than later-calved cows.

“Split-calving and year-round calving herds with high reproductive performance produce a higher average volume of milk each day due to fewer low-producing, stale cows,” he said.

Dr Zimmermann said cows normally lost condition in early lactation, but it was crucial to avoid excessive weight loss.

Losing an average of 1 condition score across the herd in early lactation drops the six-week in-calf rate by 4-5 per cent and increases the not-in-calf rate by 2-3 per cent.

This has a huge impact on a seasonal herd, with the annual cost estimated up to $8500 for a 230 cow herd. The cost for a 230 cow year-round calving herd is estimated at up to $6800, and up to $5500 for a split-calving herd.

“Through InCalf, we recommend aiming for an average decrease in body condition score of less than 0.6 across the herd after calving,” Dr Zimmermann said.

He said farmers could manage a herd’s nutrition and body condition by monitoring the condition of cows just before calving and again just before mating.
 
Other simple checks included monitoring daily milk yield, milk protein and milk fat levels.

“If this year’s protein levels are down compared with the same time last year, then the herd may need more energy in the diet,” Dr Zimmermann said.

Dairy Australia animal systems program manager David Nation said a new initiative called Season Set Up had pulled together a range of Dairy Australia-funded resources such as InCalf and Grains2milk to provide farmers with practical advice for feeding to manage body condition score and good herd fertility.

Dairy farmers can access further information by going to the Season Set Up section of this website.

Information about managing fertility can be found in the InCalf Book, especially in chapter 9, which can be downloaded from the InCalf website at www.incalf.com.au. A list of advisers who can help manage herd fertility is also available from the website.

For more information contact Sid Pickering on 03 9694 3894 or 0418 175 611 or email This email address is being protected from spam bots, you need Javascript enabled to view it