Cattleman's News Feed

One Block at a Time

Successful management of replacement females can be likened to a child’s game of tower building with alphabet blocks. So many blocks are stacked high and begging for gravity to bring them down. A solid foundation is critical for survival in the game, and one wrong move can bring the whole stack tumbling to the ground.
A solid foundation in heifer management begins long before weaning and stretches well past the calving date.  But, let’s back up to somewhere in the middle and talk pre-breeding. Have you done everything you can to make sure those heifers are ready to take the next step in becoming a valued asset in your cowherd?
Reproductive tract scoring and pelvic measurements are relatively easy and cost-effective actions to ensure yearling heifers are capable of becoming pregnant and then calve without difficulty. It also allows producers to identify heifers who might already be pregnant and those freemartins. Heifers can be old enough, weigh enough and look the part, but that’s not a guarantee that they are ready for breeding season.
“Producers should be reproductive tract scoring to make sure heifers are ready to go and get bred in a timely fashion,” said Voyd Brown, DVM, Barry County Veterinary Service, Cassville, Missouri. Brown spends a lot of time in the fall performing pre-breeding heifer examinations, which includes reproductive tract scoring and pelvic measurement.
Data clearly shows that heifers that get bred during the front end of the breeding season are more likely to have a longer lifetime in production, so knowing the pubertal status of a heifer prior to breeding gives her a better shot of conceiving earlier.
“The advantage almost gives you an extra calf by the time she leaves the herd,” Brown said.  
Palpating for reproductive tract scores (RTS) requires a trained professional to make an objective decision regarding the maturity of a heifer’s reproductive tract by examining the uterine horns and ovaries. Scores are ranked from 1 (immature) to 5 (cycling).
Pre-breeding heifer examinations should be completed when heifers reach 12 to 14 months of age and 30 to 45 days before the breeding season begins. The timing allows for producers to get an accurate snapshot of where the heifers’ maturity will be once the breeding season begins while allowing for enough time to make management changes if heifers aren’t where they need to be.
Before going into the breeding season, Brown suggests producers target 100 percent 3, 4 or 5 RTS as a basis, but the goal gets more specific depending on the breeding scenario.
“If I’m going to do a 5-day CIDR protocol, I want all of those girls to be 4s and 5s,” Brown explains. “With a 14-day CIDR protocol, we can handle 50 percent 3s and the rest 4 and 5.”
Nutrition is a critical component to the pubertal status of a heifer and can make the difference between cycling or not. Poor nutrition can also affect the female’s pelvic size, which can increase the incidences of or degree of calving difficulty.
“A lot of the times producers will have a group of heifers and put them on the backburner,” Brown says. “They may have been feeding them, but not enough and their tract scores will point that out.”
Brown reports a 5 percent pre-breeding heifer examination fail rate with his clients who stay on top of the nutritional component and do a good job developing heifers. The statistic includes culling for tract scores, free martins, pregnancy and pelvic size.
“Clients who don’t pay as much attention to nutrition can have much greater than 5 percent cull rate,” he says. “It’s not unusual to see 30 percent cull rate due to nutrition.”  
While a high cull rate is not ideal, in some cases the problem can be remedied before the breeding season. Heifers with RTS of 2 or 3 can be moved to 3, 4 and 5 with a nutritional boost during the 30- to 45-day window prior to breeding, according to Brown.
What’s the holdup?
Brown believes that producers’ hesitancy to perform heifer examinations is due to lack of understanding the value this added information brings to the table. He said one of his clients said it best when they calculated that the cost of $5 per head for heifer examinations on 30 head costs less than one emergency call for calving difficulty.
A large percentage of calving difficulty within a group of first-calf heifers, provided the producer made an appropriate bull selection decision, could indicate that pelvic measurements aren’t up to par.
Paying close attention to the calving distribution throughout the calving season can also indicate mismanagement prior to the breeding season. Ideally, producers should target at minimum 70 percent of calves to be born within the first 21 days of the calving season followed by 20 percent in the second 21 days and 10 percent or less during the last 21 days. Several factors can be to blame when herds don’t fall into this trend line, including the heifers’ sexual maturity.
“Maybe you had bull trouble or your heifers weren’t ready when the bulls were turned in,” Brown said.
In the end, heifer management is hard enough, why make it a bigger game of chance than it has to be. The information gathered from reproductive tract scores and pelvic measurements can keep producers from making a miscalculated judgment that sends their herd’s building blocks crashing down.