First calvers are more prone to mastitis than older cows. According to DairyNZ, farmers must choose a strategy that best suits their herd, farm team, and budget.
And with the majority of animals now spending their first two years of life away from the farm with a grazier, many farmers will have experienced disappointment or heard the horror stories about when they return, says McNeil, veterinarian and reproduction solutions manager for LIC.
McNeil says recent LIC research has identified heifer rearing as a significant contributor to the decline in the national herd's reproductive performance and six-week in calf rate, with 73% per cent of stock below their liveweight breeding value based targets by more than 5% at 22 months of age.
"This practice of rearing away from the farm can sometimes result in an 'out of sight - out of mind' culture, which is dangerous territory for any farm because the rearing of these animals in that first two years is crucial to their reproduction and production performance throughout life.
"By rearing young stock to their full potential, farmers will see improvements in their six-week in calf rate which is essential for improving farm profitability," McNeil says.
To make the monitoring and management of young stock easier, the cooperative has developed a new tool which will soon allow farmers to keep a closer eye on these important animals – called MINDA Weights.
The new tool will soon join Milk and Land & Feed on the new web-based MINDA system, and present farmers with their animals weight information in a simple way that makes it easier to track performance and identify any that require special attention or treatment.
"MINDA Weights presents young stock weight information exactly how a farmer would want to see it - in a practical format that is easy to understand and utilise for important management decisions such as preferential feeding or treatment.
"Its web-based platform also means they can share access with other farm staff, their vet, and their grazier, so everyone can monitor the animals growth."
MINDA Weights also incorporates new and more accurate liveweight targets based on liveweight breeding values that are set to each animal's genetic make up and the farm's dates for planned start of mating and calving.
This takes the guesswork out of looking at weight data, with all the calculations done by MINDA, Greg said.
"It provides farmers with targets that are specific to each of their animals and mobs, and by pegging the targets to the farm's planned starts for heifer mating and calving, the true impact of liveweights can be assessed.
"These events always occur at set times in seasonal herds and targets must be achieved by those dates, whether they are born early or late.
"MINDA will provide the farmer with more accurate information to assist them in ensuring all heifers reach puberty and meet their targets in time, and are ready and able to perform at their peak, right from the start.
"Then we'll start to see improved heifer rearing that will ultimately contribute to improvements in the six-week in-calf rate," McNeil says.
Incorporation of genetic makeup in the targets also recognises the growing diversity in the national dairy herd.
"The rise of KiwiCross, the increasing size of Jerseys and strain differences within the Holstein-Friesian breed all result in variation to the expected mature liveweights of animals within those breeds," McNeil says.
Currently undergoing customer testing, the new MINDA Weights will be available free to MINDApro customers, from MINDA Home next month.
Its web-based platform means farmers can access their young stock weights information anywhere, anytime and from any device with an internet connection.