Heat detection is a year in-year out job that is vital for NZ dairy farms to get right. Studies show that on 75% of New Zealand farms heat detection is done pretty well, however, one of the main tools for measuring missed heats is the heat detection indicator on the Fertility Focus Report™ and that stops measuring 3 weeks into mating. What happens after those first 3 weeks?
The National Herd Fertility Study (Brownlie and McDougall, 2013) brought some important information to light for NZ dairy farmers. According to the National Herd Fertility Study’s report on heat detection performance throughout the mating period, the authors noted that submission rates fell below expected levels after the first 3 weeks of mating. There was an approximate 25% drop in heat detection efficiency after the first round (3 weeks) of mating.
Joyce Voogt, LIC Reproduction Solutions Manager concurs “It’s common for us to see a second-round slump in pregnancy rates in herd reports. This could partly explain the phenomenon.
Brownlie found that submission rates were more severely impacted than conception rates, which suggests that some cycling cows are going undetected after week 3 of mating. It’s important for farmers to remain vigilant right through the mating period to ensure no opportunity to get a cow in calf is missed.
In recent years farmers have continued to use secondary heat detection aids and do paddock checks in the second round of mating in an effort to make sure no girl slips through undetected. It’s a tiring job picking cows on heat, but it really pays dividends the next season when you get it right.”
Talk to your rural advisor for strategies to avoid heat detection fatigue in your team this year!