Best cows developed from good heifers

By KRISTY HEMMINGSEN | East Texas Edition

March 28, 2002 -- "Everyone wants good cows," stated L.R. Sprott, Extension beef specialist. "Good cows are females that wean a calf annually throughout their lifetime. And a cow's ability to do this depends heavily on her performance as a heifer. Thus, good heifers make for good cows."

Sprott who recently spoke at the East Texas Beef Cattle Shortcourse in Tyler said there is no question that selecting the right heifers, rearing them properly, and getting them bred early in their first breeding season has long-term positive impacts on herd production and profitability.

He first explained that a fertile heifer will be a fertile cow. He said fertile heifers are defined as those that get pregnant, but most importantly, do so in their first breeding season.

"Heifers with the best chance of doing this are those that are born in the first 60 days of the calving season," explained Sprott. "These heifers are excellent prospects for replacement females because they are the oldest and have more time to grow and reach puberty compared to their younger herd mates.

"I recommend that heifers should be around 2-years-old at their first calving," said Sprott.

But, in order to reach puberty and breed at 15 months of age (and calve at 2-years of age), Sprott said a heifer must achieve a target weight that is 65 to 70 percent of her expected mature weight before the start of first breeding.

"It is especially important that she reach this weight and start cycling before the start of breeding because the first puberal estrus (heat) is less fertile than subsequent heat periods that she will have during breeding," he pointed out.

"Certainly, those more fertile heat periods are critical to achieving good pregnancy rates."

Adequate nutrition will allow the heifers a better chance to reach their target weight, which, Sprott added, will vary among breeds and between different herds. "Not all heifers are equal," he explained. "It is going to take good grazing, good hay, and good supplements to achieve a heifer's target weight, and such management will increase pregnancy rates in replacement heifers."

As far as heifers that fail to become pregnant, Sprott strongly encouraged producers to "cull" these particular heifers. He pointed out research that shows open heifers held over for a second chance made the cost per pregnancy be twice the cost per pregnancy in those that conceived during the first attempt at breeding.

"The most fertile cattle will settle at their first or second gestation," explained Sprott. "The least fertile will acquire more than two services. ... Culling helps establish fewer and fewer sub-fertile cattle throughout your herd."

The specialist noted it is good to track a heifer's fertility by recording when the heifer first conceived, having her pregnancy tested annually, and keeping records.

Sprott added that additional steps toward achieving early conception and calving in heifers may include: giving heifers appropriate vaccines which protect against reproductive diseases and use internal parasite control; and use estrous synchronization at first breeding to force heifers to cycle at least twice in the first 21 days of breeding (once at the time of synchrony, and again 21 days later for those not conceiving at synchrony).

By following the heifer management advice on an annual basis, Sprott said results should be a set of mature cows that any producer would be proud to own.

"These steps place a lot of pressure on heifers to perform," concluded Sprott. "But those that can perform, without question, are very fertile, more productive and more profitable. Those that cannot perform under these conditions are less fertile (maybe sterile), less productive, and less profitable. What kind of females do you want to own?