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Published April 28, 2014, 10:53 AM

Ensure bulls are reproductively sound

Our thinking needs to move to the bulls in the herd, because it is time to start worrying. A bull that is not reproductively sound today more than likely will not be settling cows in June.

By: Kris Ringwall, Agweek

Our thinking needs to move to the bulls in the herd, because it is time to start worrying. A bull that is not reproductively sound today more than likely will not be settling cows in June.

The reproductive process in a bull is not something that can be turned on and off. In reality, a bull’s reproductive process never should turn off. If it does, to turn it on again is a major, time-consuming process. One could liken the problem to an engine that has the wrong fuel in it during the dead of winter and is stalled on a frozen highway 300 miles from the nearest service station.

As an optimist, one would think that the engine could get going again, even if it takes until the spring thaw. Any immediacy in getting the engine started probably will cost a lot of money and still take time, so don’t use the wrong fuel and save yourself a lot of stress and work.

Now is the time to check the bulls to avoid any crises management issues before the weather is nice, and the bulls are loaded on the trailer to service a pasture of cows. The cows often are the focus of attention because they have those nice-looking calves walking alongside and are the primary feeding group.

Only after all the cows and calves are fed do we wonder if the bulls have been fed. When one looks at how much bulls cost these days, they should get the same treatment as cows. How often does one drive by a producer’s lot to look at the cows only to notice that the bulls are eating on an old bale of hay in the bull pen? There aren’t that many bulls, so they end up nibbling on the outside of the bale, which eventually turns old.

This is not a good plan. It can lead to procrastination and missing an opportunity for the early diagnosis of a problem.

A bull has a very complex process called spermatogenesis. This process occurs in the testis and starts when a cell decides to become a sperm cell. From the onset, the bull requires at least 54 days to produce a viable sperm cell and another seven to 10 days for the sperm cell to arrive at the launch pad. That’s more than two months that is needed for a bull to initiate the ability to settle a cow.

Proper nutrition

To further complicate matters, we know one sperm cell is not nearly enough. In reality, the bull needs to produce billions of sperm cells in preparation for a day’s breeding. Obviously, awareness and expectation of bull fertility needs to be placed at the top of the managerial list today. Start by making sure the bulls have a complete nutritional program that is evident in good body conditioning. Do not hesitate to call your consulting nutritionist to ask for a re-evaluation.

Thin bulls, those with ribs showing and other bone structures very prominent, need a nutritional re-evaluation regardless of what is being fed.

Once the nutrition level is set, start asking questions. Has age taken a toll that has rendered some bulls incapable of a vigorous breeding schedule? Are structural problems and injuries created by day-to-day jostling evident?

Likewise, make sure one has not overcompensated and created bull couch potatoes.

These bulls are overpampered and overfed, and lack the physical conditioning or desire to get the job done when turned out with a group of cycling cows. Both over and underfeeding are not good.

A lot of effort is wasted on good cow management when bull management is lacking or nonexistent. Bulls need to be in good physical condition to meet the rigors of an active reproductive life. Exercise doesn’t hurt.

A thorough breeding exam is required, even for the healthiest-appearing male.

The exam should include a physical evaluation of the body condition, feet and legs, eyes and any indication of illness. A rectal exam to evaluate the prostate and other internal reproductive organs, plus an external examination of the testes, scrotum, penis and prepuce is required. A semen evaluation based on volume, color, motility and morphology should conclude the breeding soundness exam.

All these evaluations need to be done now, one to two months before bull turnout to acquire the needed replacements and correct other deficiencies in the bull pen. The last evaluation is done at bull turnout, which is making sure the bull wants to breed cows.

Editor’s note: Ringwall is a North Dakota State University Extension Service livestock specialist and the Dickinson Research Extension Center director.

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