Selecting replacement females is important for long-term sustainability and productivity of your cow herd. The wrong kind of females won’t generate as much cash flow and may cost more than you can afford in additional inputs.

One solution to finding the right kind is to retain nearly all heifer calves, roughing them through winter and exposing them to a bull for a short time — one or two cycles. This allows the bulls and your ranch environment to sort out your best replacements, meaning only the most efficient and early-maturing heifers become cows. If you preg-check early, the ones that didn’t breed can be sold at the peak of the yearling market.

But what should you look for in those heifers? We've pulled together 11 considerations to evaluate when looking at what to keep, and what to cull.

1. Look for outliers. If you make selections at weaning, rather than keeping more heifers than you need and letting nature sort them, first cull off any outliers — too big, too small, too tall. Heifers with an “average” size and build usually end up being your best and most fertile cows. Many producers make the mistake of keeping the biggest heifers and end up with cows that are too large.

2. Factor in age. Choose the older heifers, not the biggest. Those born early in the calving period had fertile mothers. Choosing heifers born from the first or second cycle puts more emphasis on fertility and keeps calving interval tight. Younger heifers born later in the calving season have less time to mature enough to have a cycle or two before breeding time.

3. Consider disposition. Evaluate disposition, and cull any that are flighty or nervous. Some of those wild ones are obvious, but one way to check is to sort them quietly in an alley. Bring each heifer to the other end alone to see how it responds to being handled by itself. If you push her, almost any heifer will try to get away. But when you back off, it’s easy to see if she settles down or stays wild and scared.

4. Evaluate conformation. Evaluate feet and leg structure and general conformation. Any problems you can see in weanlings will probably get worse as they mature. Pick heifers that look feminine rather than blocky, coarse and masculine. You don’t want a heifer that looks like a steer; her endocrine balance may be off, and there’s more chance she’ll come up open.

You also don’t want a heifer that’s extremely long-necked or too short-necked, which makes her look like a male. Many people pick their biggest, most muscular heifers, but this leads to bigger-framed cattle that are not as fertile.

5. Look for good fleshing. You want easy-fleshing cattle, but this is harder to evaluate at weaning because a fat heifer may have a dam that milked too well. The dam may be thin. It’s easier to evaluate a heifer’s fleshing ability after her first winter, before her first breeding season. A heifer going into breeding season without enough fat won’t breed and probably won’t last in a difficult environment. She’ll fall apart when she’s lactating and raising a calf.

6. Don’t forget about her mother. Evaluate the dam. Are her feet and udder sound? Does mom have good temperament? Do you have production records and weights on her calves? Has she had a calf every year? You don’t know what a heifer out of a first calver will be like, but you have an idea about calves from a 10-year-old cow that’s always been fertile and has good calves. There are many things you can’t tell about the heifer’s potential without evaluating her mother. Choose daughters from cows that have produced for several years and haven’t missed a calf — calving early every year.

7. Size up the udders. Udder structure is hard to judge on weanlings or yearlings, but you’ll find outliers that are obviously undesirable, such as heifers with teats that will be too long or fat.

8. Watch for fast shedders. If you are making your decisions after they’ve gone through winter, select heifers that shed quickest. This is an indicator of health and vitality. A highly productive, feminine, fertile heifer will be one of the first to shed in the spring, and has a soft, smooth hair coat compared to a male.

9. Check on pelvic width. Some producers palpate and measure pelvic width in heifers, since some females don’t have a very wide birth canal. Selecting heifers with adequate pelvic size prevents calving issues, and you could also detect something abnormal like a bone spur. You can often tell if heifers have adequate width through the pins just by looking at them, but measuring them after they reach puberty can be helpful.

10. Consider that rear slope. There should also be adequate slope from hooks to pins. This is one of the most important factors for ease of calving, but it’s often overlooked by cattle breeders. All wild ungulates (elk, deer, moose, bison, etc.) have a sloping rear end. Cattle that are level from hooks to pins have a serious man-made fault.

Lack of slope and a smaller birth canal also makes drainage from the reproductive tract more difficult. The short tail head also moves the anus forward, with vulva tipped forward. Like a “windsucking” mare, fecal material falls into the vagina. Many of these sharp-tailed, level-pinned cows come up open or are harder to calve. If there is adequate slope, the birth canal is more open and has more room.

11. And watch the hind leg. Many producers also tend to choose cattle that are straight in the hind leg, but this is unnatural. All wild animals are cow-hocked and have some angle to the hock joint when viewed from the side, which is stronger structure than straight hind legs or post-legged. We need to copy Mother Nature.

A straight hind leg changes the angle of the leg, rotating the pin. When the hooks and pins are level, the hind legs are straight — construction that often won’t hold up — and changes the angle of the pelvis. This makes it more difficult for the calf to come up through it in a natural arc. The calf’s feet tend to jam up against the backbone and tail head.

Smith Thomas is a rancher and freelance writer based in Salmon, Idaho.