The Importance of Breeding Soundness Exams


Every Nebraska Cattlemen (NC) member carries insurance. There are all kinds – health, life, liability, crop, the list goes on. But there’s another kind of insurance, one that protects cow-calf producers against a failure that leads to open cows. It doesn’t require a lot of paperwork, an agent or expensive monthly premiums. It’s a bull breeding soundness exam (BSE).

Nebraska Cattlemen member Calvin Tolstedt, DVM, is part of the Alliance Animal Clinic’s veterinary care team. An Alliance native and 2007 graduate of Kansas State University, Tolstedt is a boots-on-the-ground guy whose special interest is beef cattle genetics, reproduction and artificial insemination.

Since about 90 percent of all beef cows are bred via natural service, there is a great demand for breeding soundness exams, particularly in the spring.

Tolstedt explains that an exam’s function is to determine semen quality and a bull’s ability to breed. He must be able to extend his penis. His eyes must be clean and his feet sound. A BSE covers these and all other parts of the bull.

Bulls that have been injured during the previous breeding season are given an inspection specific to their potential problems. This is one advantage of keeping a steady veterinary/client/ patient relationship with your local animal clinic.

Tolstedt emphasizes that bull feet and joints take a special beating due to the distance they must cover and the weight they carry. Additionally, sand cracks in hooves are a common problem that occur in the Panhandle. One item involving a genetic component is curly claw, a painful affliction causing added hoof growth on the outer claws of the hind feet. The claws grow quickly and curl when left untrimmed. The genetic predisposition to curly claw is exacerbated by stress. This problem seems to be lessening in the population due to rancher diligence, according to Tolstedt. Through genetic testing, hoof trimming and eff orts to observe soundness on a regular basis, several issues related to feet and legs are easing.


Reproductive Exams

Examination of the reproductive tract is crucial. Tolstedt explains that semen tests can be successfully done any time of the year, although a bull’s semen quality will naturally drop by about 15 percent from January through May. This is an evolutionary characteristic shared with several species. It’s tied to the fact that most animals best survive birth in spring weather, and male fertility has come to reflect that over millions of years.

Testicular size is always measured during a BSE. Yearling bulls need to measure 30 centimeters minimum, with a maximum ideal of 37 centimeters. Two-year-old bulls should ideally measure 34 to 38 centimeters. Testicles measuring larger than 40 centimeters, particularly on yearlings, are undesirable. Bulls with oversized testicles are late to mature and often won’t pass a test.

According to Tolstedt, very few bulls fail to pass a semen test. He reminds us that social dynamics affect pregnancy rates in a cow herd. Dominant bulls are not necessarily the most fertile ones in the pasture, but may service the most cows. Consider if the dominant bull is infertile altogether and has claimed all the cows for himself. It is a liability we assume when turning out bulls in multi-sire pastures.

“Breeding soundness exams are cheap insurance, in my mind,” he says.


Bulls and More Bulls

NC member Larry Rowden is the district sales manager for ABS and has been with the company for 41 years.

Rowden’s early interests in reproductive technology led him to a two-year staff position at Texas A&M University. When he moved to ABS in 1979, heat synchronization had just been cleared for use. ABS does not use the standard BSE applied on bulls that breed cows naturally, Rowden explains. Although the basics are still there, bulls in studs are used and handled differently in several ways.

Bulls used for artificial insemination (AI) are collected year-round. Exams on bulls coming into the studs are exhaustive and include vigorous health screening.


Standardized Requirements

All tests are conducted in accordance with “The Recommended Uniform Diagnostic Procedures for Qualifying Bulls for the Production of Semen,” as published by the American Association of Veterinary Laboratory Diagnosticians (AAVLD) or an equal procedure.

Mount animals are subject to the same health requirements, and blood and semen tests on specific diseases are conducted on each bull and mount animal several times per year.

Bulls entering the stud for the first time are isolated and tested more rigorously than long-term residents. Semen intended for export requires extensive testing of both the semen and bull prior to shipment.

Bulls are tested for tuberculosis, bovine brucellosis, bovine leptospirosis, bovine viral diarrhea virus (BVDV), bovine campylobacteriosis and bovine venereal trichomoniasis.

The semen is extended with tested and- approved extenders and antibiotics, including egg yolk with various additives such as citric acid, fructose or glycerol and heated whole milk. A variety of commercially available, approved extenders may also be used.

Rowden describes the ABS facilities as high tech and staff ed with veterinarian specialists and experts in foreign marketing requirements. All test results must be exact when exporting semen; repercussions from any mistakes or deviation from protocol are potentially devastating.

Working directly at the Madison, Wisc., ABS facility, James Meronek, DVM, MPH, is the service director. Meronek is an epidemiologist in diseases affecting population. Having served five years with the U.S. Department of Agriculture, he moved to ABS in 2012. Meronek’s experience enables him to track foreign animal diseases, investigating potential threats to livestock.

Being at “ground zero” with the cattle, he is familiar with daily livestock management. Bull care includes exercise, hoof trimming and nutritional rations to benefit the bulls’ health and reproductivity.

“A breeding soundness exam is a one shot in time,” Meronek says. “It does not predict future success.”

A necessary tool in your breeding program, breeding soundness exams must be followed up with continued management. Meronek also emphasizes the importance of disease testing to protect your cows.

There seems a great chasm between pasture bulls and AI stud bulls, certainly in the way they are handled. In the end, they are all sires of next year’s calf crop and all need adequate care.

By: By Patti Wilson, Contributing Writer of the Nebraska Cattleman Magazine
From the January 2021 Nebraska Cattleman

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