Make the most of your herd tests during peak milking

Vats around the country are filling up with milk as cows reach peak lactation post-calving. It’s a particularly busy time in the farming calendar, but amid the chaos, there are still opportunities for reflection. 

Now is an ideal time for the first herd test of the season to gain data on milk production and herd health.

Co-op Veterinary Programme Manager Mike Shallcrass says herd test results can help farmers assess a cow’s productivity and health status, particularly in the lead-up to mating.

“Herd testing can help farmers determine the best approach for their farm. It’s a balance of keeping somatic cell counts down, keeping milk production levels high, and improving body condition scores so that cows are in the best condition to get back in-calf,” Co-op Veterinary Programme Manager Mike Shallcrass says.

“While a herd test will only provide a snapshot of a particular day, the information is still very useful for farmers to assess individual variation between their cows and seasonal trends. The somatic cell count data can provide data for immediate action, but there is also a long-term, big picture element to the herd testing,” Mike says.

“By conducting around four herd tests throughout the season, farmers build up a database of knowledge about their cows’ milk production, and which cows are producing better quality milk. This information is invaluable for breeding and management decisions.”

Reinforcing approaches

By herd testing now, at peak lactation, farmers can also assess the success of their dry cow treatment approach and plan for the future.

“Farmers should expect their herd’s somatic cell counts to be the lowest they’re likely to be in the whole season in the first herd test. This is the first piece of production information farmers tend to get about their herd after dry off,” Mike says.

“If there were cases of sub-clinical mastitis heading into dry off, the herd test results will indicate if the infection cured over the dry period. If the somatic cell counts are still high in those particular cows, despite treatment, then it’s likely they’re not going to be able to be cured. At this point, farmers can start to make decisions about whether these cows should be moved into a separate mob or if they’re better off being culled.”

Preparing for mating

Combined with body condition scores, herd test results can also provide farmers with useful information around nutrition and feed, heading into the mating season.

“As an industry, we’re getting a better handle on the importance and impact of feeding cows well and improving milk production. Herd testing can help farmers determine the best approach for their farm in preparing cows for mating after the transition period from calving. It’s a balance of keeping somatic cell counts down, keeping milk production levels high, and improving body condition scores so that cows are in the best condition to get back in-calf. Some farms will drop to once-a-day milking ahead of mating, which can have a short-term impact on milk production but long-term benefits over multiple seasons with improved reproduction and unlocking the potential of the herd faster,” Mike says. 

Head into your local Farm Source store to find out more about herd testing and milk quality visits or visit nzfarmsource.co.nz/milkquality

¹ DairyNZ Measuring Breeding Worth Performance. https://www.dairynz.co.nz/ animal/breeding-decisions/measuringbreeding-worth-performance/