3 minute read
Is she ready to breed?
by Eric Tietze
farm help Making farming a little easier
Calving Age for Heifers
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By Klaire Howerton Is 2 years old too young to calve heifers?
On many operations in the Ozarks, producers aim to have their heifers produce their first calf at 2 years old, which means heifers are bred around 15 months of age.
On paper, heifers should calve at 2 years of age so they can pay for themselves and earn a profit over their productive lifetime. In reality, however, it can sometimes be better for the heifers if producers gauge breeding readiness off of things other than age.
“We have excellent tools to determine their readiness thanks to beef reproduction research and local veterinarians,” Eldon Cole, livestock field specialist with the University of Missouri Extension, explained.
Data acquired from pre-breeding exams offer producers tools to work with when it comes to decisions to breed an individual heifer or allow her to mature a bit longer. A veterinarian does a rectal examination to estimate puberty status using the uterine horns and ovaries during the exam, Cole explained. Status is determined via a 1 to 5 scoring system with a score of 1 being immature, and a score of 4 to 5 being ideal.
In addition to the tract scoring, Cole said, a veterinarian can also measure a heifer’s pelvic dimensions, with a target size of 150-square centimeters. If a producer has some heifers that are a bit on the younger side but meet the tract score and pelvic score parameters, it might be reasonable to include them in the breeding program after a consultation with the herd veterinarian.
When factoring in a heifer’s true age, some experts suggest it could be better to time a heifer’s first calf to 3 years of age, but to consider long-term effects when waiting this late.
According to Tom R. Troxel, professor and associate department head of Animal Science, and Shane Gadberry, associate professor of animal science with the University of Arkansas Division of Agriculture, it has been shown that during the early period of life, cows calving first at 2 years of age have more difficulties at calving and produce fewer calves and less calf weight at first calving than cows first calving at 3 years of age. Cows calving at 2 years of age in the long run, however, tend to recover and surpass the cumulative performance of cows calving first at 3 years of age. While age and size are generally the first things producers consider when it comes to the breeding readiness of their heifers, body condition also needs to be factored in. Heifers need to be hitting around a 5 or 6 Body Condition Score (BCS) at the time of their first calf, and it is important to maintain that condition throughout calving, lactation periods and re-breeding to help them be successful. It is highly recommended that producers separate heifers from mature cows and feed them more of a higher quality ration to keep up their BCS.
what do you say?
How do you evaluate your females for breeding?
“I really rely on my business partner and we have a very new and young herd. Therefore, at this point, we evaluate by culling for bad udders, disposition and bad feet.”
Bob Woods Muskogee County, Okla.
“In evaluating a prospective mother, we look for body structure and check the bloodlines for appropriate EPDs, such as efficiency while also checking utter placement and size.”
Jamie Harmon Adair County, Okla.
“Because we raise club lambs, we select ewes for what we believe our current showing preferences are, and match the ewe to the ram to get those results.”
Dustin Kendrick Boone County, Ark.
“We retain heifers for breeding and evaluate their potential first by genotype and then phenotype. If they have grown well at 1 year, I then use ultrasound to check them internally.”
