Fertility

Fertility: Management Versus Selection

After bragging up their cattle’s hair color, carcass characteristics, growth rates, EPDs, body lengths and heights, milking ability, and other relatively uneconomic trivia, beef cattle breeders eventually come around to the topic of fertility. Naturally, they all have positive claims regarding their livestock’s fertility. In that department my guess is we should expect only positive comments because it is a generally accepted fact that fertility is the most important economic trait. So what is the best way to improve fertility?

During the past five years I discovered that the techniques I had used to improve fertility missed the mark. In the old days I used to practice what is now conventionally recommended approaches for getting cows bred. It was not until I changed my management practice to a more Spartan approach and my cow herd hit the wall in the fertility department that I saw the error in my former management approach in selecting for fertility.

Conventional Practices

I recently visited the beef cattle operation at the Noble Foundation (www.noble.org) in Ardmore, Oklahoma. Noble is a private foundation that operates as a think tank/consulting service for agricultural producers in the area. During the past decade it has been developing another new beef cattle “breed,” which it named the “Noble Line.” Of course, the new breed is a composite that combines the “best” traits of three other beef breeds into a one-breed-does-all solution Nobel thinks the industry requires.

Over the years I’ve learned a lot from the specialists at Noble. I’ve been to their seminars. They’ve visited my ranch. I’ve had private meetings with them. They’ve given talks at local events and more. I have a lot of respect for their vast, diversified knowledge base. They are also Big Boys. They’ve given me blunt advice more than once in the past (which I always welcomed) so if they can dish it out, you can rest assured they can also handle a little critical analysis. I say that because I’m going to use their program as an example of managing for fertility compared to my current program in which I have finally learned how to select for fertility.

At Noble calves are weaned at seven to eight months of age. Weaned heifers are moved to a trap for at least 30 days and fed high-quality roughage plus corn/cottonseed meal until the winter forage pastures come on strong. If the winter forages don’t materialize, the heifers may go to bermudagrass pastures where they are supplemented with creep. By February or March the winter pastures are nearly always lush, so the heifers will be on pasture. By April 20, when the special low birth weight bulls (of a totally different breed from the one Noble is developing) are turned in for 60 days, the 13- to 14-month-old heifers will weigh 700 to 800 pounds. The heifers are bred to calve 30 days earlier than the mature cow herd.

During the summer the bred heifers get the best pastures. If forage quality and/or quantity declines, they are supplemented with 20% or 38% range cubes. If forage quantity falls too much, the heifers are fed hay and 20% cubes. The bred heifers will continue to be “babied” through the winter and through their first calving season, which starts in February. By the time they start calving they will weigh 900 to 1,100 pounds.

When the spring grasses are lush, the heifers are turned out and managed along with the mature cows. With this management approach the heifers get an extra 30 days following their first calf to start cycling with the mature cow’s 60-day breeding season in which only Noble Line bulls are used. From that point on, the mature cows and first calf heifers will be supplemented with cubes and hay--only when it’s required--to keep their body condition up through the winter months. Mature cows start calving the first of March.

With Noble’s program, between 80% and 100% of the heifers will get bred, 87% of the first calf heifers will breed back, and well over 95% of the mature cows will breed back.

The Spartan Approach

Ardmore, Oklahoma is about 100 miles west of my ranch and is at about the same latitude. My rainfall averages about 10 additional inches, but forages are very similar in both locations. I wean my heifers in the fall directly onto winter pastures. There they will winter without hay, grain, cubes, or protein licks. I rely on compensatory gain and exceptional pastures to provide good growth rates during the spring. My one and only 45-day breeding season commences on July 9, and only those heifers that meet my minimum cutoff weight will permanently merge into the mature cow herd. I use my own bulls on all of my cows. There is no such thing as a special “heifer bull.” All cows are rotated together through the pasture system without any preferences given. In the fall the calves are weaned, the cows are preg checked, and their pasture rotation continues through the winter without any hay, grain, cubes, or protein licks. All bred females lose some body condition during the winter, which they must recover in the spring before calving.

My Spartan program has resulted in a lot of culls. Only about 60% of the heifers make the first cut. Only about 80% of those heifers get bred. Only about 60% of the first calf heifers rebreed. Only about 80% of the mature cows breed back. But these “low fertility” numbers are not the result of my current management program, which selects for fertility; rather, they are a product of my former highly supplemented management program.

I have painfully discovered that many of my “great” cows, which were products of a program founded on supplementation, were not great cows after all. They couldn’t be because they were not in tune with my environment, which is why they required supplementation in order to perform. Consequently, via my linebreeding, retained-heifer program, my cattle type is currently undergoing dramatic change. My “surviving” cows are smaller framed with larger heart girths. They have more muscling and exceptional fleshing ability. As these “new” cows and their descendants come on line I expect to see significant improvements in the fertility department because they are literally survivors and descendants of survivors

My old conventional management program and Noble’s highly subsidized program cover up infertility because the environment is never allowed to challenge the females. With subsidies, only the very worst fertility problems can show up. With substantial subsidies, even Holsteins can survive in the harshest environments.

My overall goal is economic and environmental sustainability. An important aspect of attaining my goal is to have lower inputs per unit of production. To achieve my goal I must cut subsidies and breed cows that will work in my environment. If I subsidize my cows and never challenge them, then my ranch will never be economially sustainable nor will my cattle be environmentally sustainable. Consequently, I don’t create fertility through management inputs. Instead, I’m selecting for fertility and in time I’ll get it ... if I linebreed.

Ted E. Slanker, Jr., bulls@slanker.com

R.R. 2, Box 175, Powderly, Texas 75473-9740

903-732-4653 Ofc, 903-732-4151 Fax