How to ensure heifers calve at two years old >More in © Tim Scrivener For suckler cows to be most profitable, calving for the first time at 24 months old is considered optimum. Research suggests that calving heifers for the first time at two years of age is pivotal for reducing the cost of production and increasing lifetime reproductive performance. However, it is estimated that only 35% of English suckler herds meet this target. Nebraska is one of the biggest red meat-producing states in the US, and as such is known for its research ...