Heifers are not cows, especially when it comes to their nutritional needs prior to breeding. Bob Larson, DVM, PhD. Dipl. ACT, Dipl. ACVPM, Kansas State University, told participants at this month’s 2013 K-State Cow-Calf Conference that the important difference between pre-breeding cows and heifers is that heifers are still using nutrients to grow and mature in addition to putting on body weight so that they can prepare for breeding.
Larson gave an example of beef heifers weaned on Oct. 25 at 500 pounds. “The target at breeding would be 780 pounds, which is 65% of their mature cow weight (approximately 1,200 pounds) by May 1,” he said.
So from weaning to breeding, heifers need to gain 1.5 pounds per day. “While heifers may meet this goal on high-quality green grass, they will fall far short of that gain if grazing dormant forage or fed moderate to good quality hay,” he explained.
To get them to gain 1.5 pounds per day, even if good quality forage is available, will require a small amount of supplemental grain or by-product feed (for example 4.5 pounds per day dried distiller’s grain). “Often the forage available is moderate to poor quality and heifers on those forages will require even more supplemental feed to meet their gain requirements to reach appropriate breeding weight.”
Leading up to the breeding season, the primary difference between growing heifers and maintaining cows that are in good body condition is that good quality forage alone will usually provide appropriate levels of energy and protein for cows, but is not adequate for growing heifers.
Read more about creating beef heifer momentum in the January 2013 issue of Bovine Veterinarian here.