A while back I wrote about seeking appropriate selection criteria when looking to build a herd from scratch.  I referenced 5 favorite books to come up with my criteria:
Comeback Farms by Greg Judy
Ranching Full-Time on Three Hours a Day by Cody Holmes
How to Not Go Broke Ranching by Walt Davis
Salad Bar Beef by Joel Salatin
Grass-Fed Cattle by Julius Ruechel

I included a bit of Success on the Small Farm by Haydn Pearson and today I’ll quote him further.  Also, I share a bit of advice I haven’t seen anywhere but on Throwback at Trapper Creek but have heard in conversation with old-timers.

For the most part these books assume you already have a herd and are looking to improve it.  Even if you don’t, play along by pretending you have a few and are looking at them with fresh eyes. Some animals are genetically predisposed to your climate, parasites, forages and management style.  You can’t always tell by looking which they are so fertility becomes a primary selection criteria.  If a cow doesn’t wean a calf she ate a year’s worth of food without paying for it.  The kinds of cows that need a year off between calves are not the kinds of cows we need to own. There are additional criteria involved here but this whole post really comes down to one action: Cull.

I’ll let Walt Davis start us off.

Fertility is a measure of the total well-being of an animal; it is not a single trait but rather the result of the many effects of many traits.

He goes on to say:

The simple way to select for fertility is to remove any animal with an obvious fault (prolapsed, bad udder, highly parasitized, crippled, or just hard doing), and then cull any animal that does not bring a live offspring to the weaning.  The heritability of fertility may be low, but if you sell all subfertile animals, you soon have a fertile herd.

Davis closes the chapter by discussing the culling method of a central Texas sheep farmer, Clifton Marek.

…after he has shipped lambs, he will call the sheep out of their paddock and take them for a walk down the road.  Whoever is leading the sheep sets a pretty quick pace, and Clifton watches as the flock stretches out; when he sees a distinct group of stragglers fall behind, he steps in and separates these sheep to be sold.  He will catch the animals that are heavily parasitized or have low-grade respiratory problems, bad feet, infections of any kind, foot rot, and just about any other condition that reduces the animal’s vitality; in a couple of hours, he has removed the vast majority of animals that either have problems or will have problems in the near future.

Here’s Greg Judy once again, this time on p. 247 of Comeback Farms:

If a cow misses calving, cull her.

If a cow gives you a runt calf, cull her.

Bad attitude or skittish cows should not be tolerated.  They will pass this same trait on to their offspring.

Cows that develop foot problems should be culled from the herd.

Cows that come through the winter with low body condition scores should be culled.

Cows that do not shed off early in the spring should be targedted for culling.

If a cow needs assistance calving, cull her from your herd.

He goes on to say that if you do not want to sell all of those cows immediately, simply mark down that you don’t want to keep any of their calves until your top producers provide your replacements.

Holmes describes the keeper cow this way on p. 11:

The best cow in the herd will raise exactly one calf every year and never miss.  She also will never eat a bite of grain, supplement, or require the use of machinery.  She will never require assistance at calving and will protect her calf from predators, but will not eat you for lunch when you bring her to the corrals.

All of this – and it will never be important that she wean off the biggest calf in the herd.  This will be the most profitable cow you could ever own.  Notice that I never mentioned hair color, genetics or EPDs.  That’s because if your cows meet the description I listed in the paragraph above, the rest doesn’t matter.

That sounds a lot like Judy’s list.  Holmes says it again on p. 13 ending with:

If you are culling consistently from within your herd, the oldest cows in your herd should have done all these good things and done them longer than any of the other cows.  This describes the cow that produces the heifers and bulls you will keep.

Salatin begins chapter 13: Choosing a Breed by saying breed doesn’t matter.  Each breed has good and bad points.

I think the ultimate goal is to find an animal “that works for me.”…obviously this can’t be done overnight, but by watching our animals we can gradually cull to the type that work under our program.

What criteria does Salatin use to cull?  For the rest of the chapter Salatin emphasizes the same list of cull criteria at some length.  I’ll summarize.  First he culls for fertility (calf every year).  Second, mothering instincts.  Third, parasite resistance.  Fourth, beauty (works hard, stays clean and shiny, doesn’t get fat).  Fifth, he culls for calf size (big enough to market, small enough to avoid health problems).  He ends the chapter with:

Let’s be committed to finding what “works for us,” and let that be the underpinnings of our “cow type.”

These people are serious about culling.

Matron (who knows all about culling cows) at Throwback at Trapper Creek wrote recently

I let the beef cows wean their calves, with the belief that if I keep heifers that weren’t weaned by their mothers, that I am moving my cow herd towards cows that need to have their calves weaned.

And much earlier:

Our cows wean the calves at about 8 months of age.

Matron has selected for cows wean their own calves.  Salatin talks about culling cows that allow last year’s calf to nurse.  There is always more you can do to improve a herd.  You work your whole life to get a group of efficient, fertile, healthy girls and realize it can be better still.

Haydn shared an anecdote about reaching the pinnacle of herd improvement that is worth bearing in mind.

At the beginning, the man had a herd of outstanding cows, a string of 15 or so that were a joy to behold – big, straight-backed cows with lots of capacity and large, well-swung udders.  But in any herd of good ones there are, of course, some that are better than others.  For years Bill R. had been building up his herd.  He liked cows and was a natural-born farmer.  He had made a point of always keeping his best cows and the best heifer calves from these topnotch producers.

One day an out-of-state buyer came along.  He offered Bill a big price for his half-dozen best cows.  He made an above-value offer for several two-year-olds and for the best calves.  It represented a lot of money.  Bill thought: “Suppose Buttercup fell and broke her leg.  Right now I can get $300 for her.  I guess I’d better take it.”

To condense a long and painful story, Bill sold off his best stock – after working many years to build himself a reputation as a breeder.  He had reached the point where farmers were coming from miles around to buy his calves and older cows.  That sale was 10 years ago.  Bill is on the way up again, but he isn’t at the top yet.  “The worst and most senseless thing I’ve done in 30 years of farming,” he said to me in commenting on the incident.

Keep the best.  Always keep the best.

Now, picture in your mind a whole herd of mixed cows. Some are fuzzy in July, some are slick. Some stand with their heads down and their eyes closed, some look at you alarmed, some continue to graze calmly. Some stand taller than you at the hip and spend all day eating grass, some are much smaller and are usually laying down chewing their cud. Some have a calf by their side, others don’t and don’t look pregnant. Do you see them? There is that one cow…she’s at least 14, you’ll have to check your notebook…she has always weaned a calf every year since she was 2. She is always in good condition and loses her winter coat by the end of April. You see that cow? The comparatively small one laying down over there? She is the future of your entire herd. Save her daughters and one of her sons. In a few years you will have a nice group of similar cows but there will still be some that stand out. Keep picking the very best.

As I said a months ago, I think you could do worse than to have all five of these books on your shelf. And Matron is pretty entertaining as well.