Why is it so important to calve at 22-25 months?

The ultimate test of heifer management is to look at their average Age at First Calving (AFC). If this lies between 22-25 months there are some great benefits for your milking herd:

• Increased Yield over whole lifetime
• Better Udder Health in the First Lactation
• Decreased culling risk in the first lactation
• Increased likelihood to calve for a second time
• Improved economics compared to AFC of <22 and >26 months

What if you don’t achieve this?

It has been published that the average AFC for the UK is 29 months (median 28 months), ranging up to 42 months! This is not a great statistic! Calving beyond 25 months of age is associated with lost future milk and greater risk of culling or not even reaching a second lactation. So many herds in the world are not achieving their potential by allowing heifers to grow more slowly.

How to achieve AFC targets

It’s all in the raising! Good colostrum management, ad lib or >3 X daily feeding of milk to pre-wean calves, achieving 0.9kg/day pre-insemination growth and 0.5kg/day post-insemination growth are the keys to reaching first calving at 24 months. Any disease, parasites, insemination procedures, poor feed quality or poor feed access will affect this key performance indicator. It is up to us as advisors to work with farmers to minimise these risks and help them to reach their absolute potential! Together, we can do great things!

Where is the Evidence?

• Eastham N.T., Coates A., Cripps P., Richardson H., Smith R., Oikonomou G.,. 2018. “Associations between age at first calving and subsequent lactation performance in UK Holstein and Holstein-Friesian dairy cows.” PlosOne 13 (6): e0197764 2.
• Sherwin V.E., Hudson C.D., Henderson A., Green M.J.,. 2016. “The association between age at first calving and survival of first lactation heifers within dairy herds.” Animal 10 (11): 1877-1882 3.
• Adamczyk K., Makulska J., Jagusiak W., Węglarz A.,. 2017. “Associations between strain, herd size, age at first calving, culling reason and lifetime performance characteristics in Holstein-Friesian cows.” Animal 11 (2): 327-334 4.
• Hossein-Zadeh G. 2011. “Estimation of genetic and phenotypic relationships between age at first calving and productive performance in Iranian Holsteins.” Tropical Animal Health and Production 43 (5): 967-973 5.
• Pirlo G., Miglior F., Speroni M.,. 2011. “Effect of age at first calving on production traits and on difference between milk yield returns and rearing costs in Italian Holsteins.” Journal of Dairy Science 83 (3): 603-608 6.
• Elahi Torshizi M. 2016. “Effects of season and age at first calving on genetic and phenotypic characteristics of lactation curve parameters in Holstein cows.” Journal of Animal Science and Technology 58 (8): doi: 10.1186/s40781-016-0089-1 –