Glossary of Bull-related Reproductive Terms

A.I. (Artificial Insemination) – Placing semen in the reproductive tract by means other than natural service.

castrate – To remove the testicles conception – The fertilization of the ovum (egg). genes – Basic units of heredity that work in pairs (one from each parent) to determine traits and how a trait develops genotype – Genetic makeup of an individual. gonad – Testis of the male, ovary of the female heterozygous – Individual possessing unlike genes for a specific trait homozygous – Individual possesses like genes for a specific trait libido – Sex drive or the male’s desire to mate masculinity – Well-developed secondary sex characteristics in the neck, chest and shoulders of a bull phenotype – Characteristics of an animal that can be seen and/or measured pheromones – Chemical substances that attract the opposite sex prostate – Gland of the male reproductive tract located just behind the bladder that secretes a fluid that becomes a part of semen at ejaculation. recessive gene - A gene that has its phenotypic expression masked by its dominant allele when the two genes are present together in an individual. reference sire - Bull designated to be used as a benchmark in progeny testing other bulls (young sires). Progeny by reference sires in several herds enables comparisons to be made between bulls not producing progeny in the same herd(s). scrotal circumference - Measure of testes size obtained by measuring the distance around the testicles in the scrotum with a circular tape. Related to the bull’s semenproducing capacity and age at puberty of his daughters. scrotum - Pouch that contains the testicles. Also a thermoregulatory organ that contracts when cold and relaxes when warm, thus tending to keep the testes at a lower temperature than that of the body. semen - Fluid containing sperm that is ejaculated by the male. Secretions from the seminal vesicles, prostate gland, bulbourethral glands, and urethral glands provide most of the fluid. seminal vesicles - Accessory sex glands of the male that provide a portion of the fluid of semen. served - Female is bred but not guaranteed pregnant. service - To breed or mate. sterility - Inability to produce offspring. testosterone - Male sex hormone that stimulates the accessory sex glands, causes the male sex drive, and results in the development of masculine characteristics. soundness - Degree of freedom from injury or defect. steer - Bovine male castrated prior to puberty.

Designing BreeDing Programs For DiFFerent ranch oBjectives: selecting Bulls to sire the next generation

Reprinted from the 1996 TLBAA Breeders Handbook published by Texas Longhorn Trails Magazine

Most Texas Longhorn breeders are truly committed to producing the “best” cattle (as they perceive them) that they can produce. What constitutes “best” is the subject of much auction block rhetoric, show ring evaluation, promotional copy and never ending debate whenever Texas Longhorn breeders gather. Unlike most breeds of cattle in which production of seedstock is directly related to commercial beef production, the breeders of Texas Longhorn cattle enjoy many diverse opportunities to breed, produce and market their cattle while still promoting Texas Longhorns, in general. Breeders may choose from a wide variety of opportunities to breed, produce and market Texas Longhorn cattle depending upon their own unique interests and desires, without being forced to produce a specific type because the marketing channels dictate breed direction and selection strategy.

Designing a breeding program for a registered cattle operation really involves five basic steps:

A. Establishing a ranch direction and goals

B. Choosing what traits should be emphasized to accomplish the ranch goals

C. Determining how animals will be evaluated

D. Selecting parents for the next generation

E. Culling undesirable parents and potential parents

Dr. Bob Kropp Former Chairman, TLBAA Breed Advisory Committee

ESTABLISHING A RANCH DIRECTION OR RANCH GOALS.

For any breeding program to be successful, a sense of direction or purpose must be established and adhered to. Numerous opportunities exist for breeders of Texas Longhorn cattle to project their breeding efforts in the direction of not only their interests, but the interest of many other customers. Programs currently exist for breeders interested in the production of straight WR/US pedigreed cattle, cattle with exceptional horn length and lots of color, cattle needed for roping and other recreational markets, cattle geared for the lean meat industry as well as cattle being selected with the beef cattle industry as a primary focus.

Potential customers abound in each of these markets, but it is very difficult to satisfy all Texas Longhorn customers with the same animals. The beauty of the multi-faceted Texas Longhorn breed is that opportunities do exist to not only satisfy your personal interest, but at the same time satisfy the interests of many other customers who desire to own Texas Longhorn cattle. Therefore, it is essential that each individual program establish a specific ranch direction to aid the breeder in breeding stock selection, program emphasis and marketing strategy. An excellent example would be the WR cattle Company. But for this concept to be effective, other breeders of WR cattle must be willing to purchase high quality cattle from each other as well as from the Refuge. Since the WR breeders are not allowed to market their offspring through the Wichita Refuge Sale, there must exist other marketing avenues with breeder interest to purchase quality breeding stock.

CHOOSING THE TRAITS THAT SHOULD BE EMPHASIZED OR USED AS SELECTION CRITERIA IN A BREEDING PROGRAM.

Clearly, the traits of economic importance and traits that should be used as selection criteria depend upon the breeder’s perspective, which in turn must be consistent with ranch goals and direction. Of the different ranch breeding objectives listed above, each is unique in the traits that should be emphasized in a breeding program. How then does one determine the essential traits of emphasis?

First, take a close look at the animals perceived as “best” within the breed for the particular ranch direction or objective. If the goal is to provide the most useful cattle for a particular market and thus, customers within that market, then the information we require for selecting and evaluating the traits is precise knowledge of that market and customer’s needs. After all, we must satisfy our customer before we can reap financial benefit.

By paying close attention to the customers’ needs, desires, the traits that should be emphasized in any breeding program can be easily determined. If horn length, color and breed character are of primary importance, then these traits should be the primary focus of a breeding program. If added muscle and growth are of special interest, then selecting pressure should be directed to placing special emphasis on muscle and growth.

What do the customers within the market pay the most money for? Determining customer desires is the first step that must be accomplished after a definite ranch direction is established.

DETERMINING HOW ANIMALS WILL BE EVALUATED OR MORE SIMPLY, ESTABLISHMENT OF A RECORD KEEPING SYSTEM.

Within a breeding program, there must be some evaluation procedure for determining the superior animals from the inferior animals. If genetic progress is to be made, genetically superior animals must be retained for the next generation and genetically inferior animals must be removed from the population. We must be able to measure differences among animals in a herd or population in order to improve the traits of interest. These differences measured give us a means of making sound logical decisions necessary in the selection of superior animals for herd replacements. While our ability to measure, evaluate and select allows us to make genetic change, only wise use of the measurements, evaluations and selection will allow us to make genetic progress or improvement.

Selecting Parents For The Next Generation

The only real way a breeder can improve the genetic value of his/her herd is by selecting the animals to become parents. Other than establishing a ranch direction, selecting bulls to sire the next generation of offspring is the most important step in designing an effective breeding program.

Because bulls can produce more offspring per herd than cows, an individual bull will contribute more genetic material to a herd over time than an individual cow. For this reason, selection of bulls is much more important than selection of replacement females in terms of genetic progress.

The important thing to remember when buying a bull or selecting a young herd bull prospect from within your herd is what is really being sought is the value of the bull as a parent of the next and subsequent generations. It is mandatory that the sires selected for future use within a program excel in those traits considered to have the most economic importance to the program. If horn length, color and breed character are the primary economic importance, then these traits should be the primary focus for bull selection. Bulls that excel in horn length, color and desirable breed character should be selected to parent the next generation. If added muscle and growth are of economic importance, then bulls selected to become parents should excel the average of your herd in terms of muscle and growth. If you desire winning show cattle, then bulls that have been national winners or have sired national winners should be used to increase the likelihood that the offspring will possess the same conformational traits of the sire that resulted in winning national honors.

We know that genetic selection works because the traits of interest have a genetic component and are thus, inherited. Because these traits are inherited from the parent, superiority as well as inferiority can be and are transmitted to the offspring of the next generation. Selection of bulls that are superior or excel in the traits of economic value to your program is the most important thing that a Texas Longhorn breeder can do to improve the overall merit of their herd.

CULLING UNDESIRABLE PARENTS AND POTENTIAL PARENTS.

The removal of genetically inferior seedstock from the population is just as critical to herd and breed improvement as the selection of genetically superior animals. A progressive breeding program must be rather “cold blooded”, culling animals that do not perform to the level desired for retainment in the herd as future parents.

This is not to say that the animals culled from a particular herd are inferior to the population average. This is totally dependent upon the genetic level of each respective herd. The inferior cattle in one program may be genetically superior in another. But without objective recorded data, these decisions are arbitrary and very subjective.

Cattle breeding is relatively simple – “Breed the best to the best” based upon the criteria established for determining superiority within a specific ranch direction. A breeding program is really no different than a road map. We all want to arrive at a specific location, but are leaving from different locations via different modes of transportation. What matters is not how we get there, just that we arrive in sound financial position!

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