Just like we're told not to judge a book by its cover, don't judge a heifer solely by her looks.
With the change in the weather and being fall and all, Alberta beef producers are
starting to wean calves. For those who retain replacement heifers, weaning includes
selecting heifers for the breeding herd, which comes with a price. Just like we're
told not to judge a book by its cover, beef producers shouldn't judge a heifer solely
by her looks.
Dr. Susan Markus with Lakeland College Applied Research, along with summer student Katrina Gallan, is working on a Heifer Development project to investigate the use of remote sensing, genomics, and other new technologies to better predict the success (stayability) of a replacement heifer in the cow herd.
To date, their checklist includes:
- Conformation - okay, here is where judgment is required. It is important to analyze
the feet and legs of the heifer (also evaluate her dam and sire), as those legs and
feet need to carry her around for the next six to eight years if she's going to pay
for herself. A producer also needs to evaluate the frame, muscling, and udder and
teats of the heifer by evaluating both those of her dam and what her sire has produced
in the past. If her mother had udder and teat issues or her father passed on poor
conformation, chances are they will be a recurring problem in the herd in the future. “I
like having to milk a cow to get the calf started” - said no beef producer ever!
- The heifer needs to be at 55-65 per cent of her mature body weight at breeding. The
lower percentage level (55 per cent) of mature body weight works if the heifers are
visually exposed to a bull prior to breeding season. The presence of a bull arouses
the heifers and can stimulate estrous. If the heifers are to be artificially inseminated
(AI'd) and they won't be seeing a bull, then those heifers likely need to be closer
to 65 per cent of their mature body weight when bred.
Reproductive tract assessment (reproductive tract scoring, RTS, on a scale of one
to five) can be done by a qualified vet using ultrasound at a reasonable price, comparable
to pregnancy checking. This scan will identify immature or abnormal ovaries and uterus
as well as find freemartins. It should be done no more than 60 days before breeding
or bull turn out dates. Just because a heifer is born single doesn't mean she is reproductively
sound. Cases have been found where a single-born heifer was a freemartin. The likely
explanation is that the heifer had a bull calf sibling, in utero that died and was
reabsorbed so was never known. The research found strong correlations between those
heifers who ended up open and their RTS being low. It is an excellent assessment to
avoid turning reproductively unsound females out to valuable pasture resources for
breeding.- Temperament - with time and proper handling, some animals will become more docile
but a heifer that is easily excitable likely won't improve. Based on remote sensing
rumen bolus technology that Dr. Markus' team has implemented in this project which
provides daily water intake frequency, internal temperature, and activity indicators
to alert for cycling (estrus), the flightier heifers (based on a chute exit score)
did not settle after processing and had elevated temperatures, reduced water and/or
feed intake for a longer time period, resulting in poorer gains. It always makes for
a more pleasant day when animals aren't jumping fences and getting the rest of the
herd riled up.
- Generally, hybrid vigour is an indicator of longevity and efficiency. In a commercial herd, knowing the breed composition of the females allows the manager to mate the females with another breed to maximize hybrid vigour of the offspring. Hybrid vigour is known to improve your weaning weights, disease susceptibility and hardiness of the offspring. Producers have been surprised by the breed compositions of some of their females when they have done a breed composition test. Assuming the breed composition based on coat colour alone fools many of us- it's something to consider to better sort females into breeding groups.
The financial risk of developing replacement heifers that don't perform is reduced when they are evaluated beyond their external conformation. A better understanding of what their genetic makeup is and ensuring that their reproductive tract will support a fetus are all worthwhile assessments. Identifying sub-fertile heifers early provides the opportunity to move them into a later breeding program to allow them to mature or market them at an optimal time and reduce the overall cost of the replacement heifer program on the ranch.