An excerpt from Reproduction & Animal Health by Gearld Fry and Charles Walters
You have to know the inside of a bull before you can discern the validity of outside observations. I suppose I owe some parts of that observation to Monte Roberts, the rodeo star, horse trainer and author of The Man Who Listens to Horses. Roberts was a champion steer roper, bull dogger, bull rider and all-around cowboy before he took to training thoroughbreds for the horse racing track. His wife was a sculptor of the equine form. Artists used a form of linear measurement long before Bonsma and his disciples refined the idea to measure bovine conformation.
Roberts told of watching an artist sketching horses near one of the paddocks. “He was using a triangle to help maintain correct proportions,” wrote Roberts. “Imagine a horse seen from the side; and over that horse lay a triangle, its apex sitting as high as a horse’s head, and midway between head and tail. From that high point one line angles down at 45 degrees through the shoulder. Another angles down at 45 degrees through the hip. And the base line runs horizontally through both knees and hock.”
The objective is to achieve balance with the apex exactly in the middle. The baseline exceeds the length of the equilateral triangle in the thoroughbred. The sculptor’s scheme comes to mind when the measure of the bull is to be considered. I have refined my general presentation several times and now rely on what journalists call standing copy, which was presented to the readership of Acres U.S.A. in January 2000.
It is common knowledge that the amount of hormones produced by a bull (testosterone) and the female (estrogen) determines the amount of meat a carcass has on it at a year of age, hanging or live. The size of the testes determines that for the bull, and the ovary determines it for the female. For either to achieve that maturity level, you must choose and mate animals with that genetic ability. When you choose and breed for desired traits for two or three generations of matings, those traits become homozygous, and the traits you have chosen to achieve are the muscle patterns needed for carcass and a profit.
The procedures for linear measuring were developed and researched in Montana and Nebraska more than 20 years ago. The purpose for the research was to develop a standard for reproductive performance and maintenance efficiency and to bring to the surface structural defects, packaged with a quality carcass that is acceptable and profitable. Today we can measure young cattle at 10 to 14 months of age and know with accuracy how they will perform as seed stock or in the feedlot. Failure to choose for reproductive performance and maintenance efficiency will lead to traits being selected via single-trait selection, and that leads to low performance in production areas. These two traits must be in place for other selected traits to work with accuracy and for the animal to stay in balance.
When one uses linear measuring to build a herd of females, they will have calved at two years of age, and 95 percent will breed back to have a calf at three years. When you have selected the proper traits in the sire and matched the dam’s weakness with his strengths, then 80 percent or more of the progeny will qualify to go back in the herd as building blocks for the next generation. By the third generation, you have built a herd that is equaled by only a few and is not only acceptable but is in demand. You will be producing bulls that will sire both seed stock sons and daughters. You have bred into those cows and bulls the ability to be predictable and repeatable with performance.
Linear measuring of yearling bulls and heifers has been in use for over 20 years since its development. Its most important function is to help choose accurately for reproductive efficiency and maintenance efficiency, resulting in carcass production. Man chooses the best of his animals for replacement or sale with the eye. The ones he chooses are the most phenotypical as far as what the eye has been trained to see. However, since choosing by eye is very subjective, sometimes the wrong animals are kept in the herd. Linear measurement is a tool, which allows the producer to make a more objective decision that the eye alone can’t make.
Cattle that win in the show ring normally will not work in the pasture. They tend to fall apart when they are put out on grass. Have you ever wondered why? It is because these animals have not been chosen for the reproductive and maintenance efficiency; they usually are hard keepers and cannot perform on grass alone.
Linear measurement of your males and females can help you select so that you can produce an animal that is efficient and predictable. There is a specific pattern the male and female should fit for best performance.
