Pigs to Pork
SELECTION
Selecting the Boar
Richard Hollandbeck, Animal Sciences Department
AS-316 May, 1964
In selecting animals for replacements in the breeding herd, much emphasis should be placed on selection of sires. They leave a larger number of offspring in their lifetime than do the females . In a one-boar herd, he is responsible for one half the inheritance of all the offspring produced. For this reason a mistake in the selection of the boar can greatly handicap a breeding program.
Perhaps the most difficult, and certainly the least understood, problem of the swine industry is how to maintain high productivity in the breeding herd through successive generations. To improve the productive capacity with each successive generation, adds to this difficulty. There is no certain mark or set of visible characteristics to distinguish highly productive boars from those of lesser productivity. Neither is there a visible means to gauge in advance how well a boar will nick with a given sow herd. Yet a continually improving high level °t breeding performance is essential to the Profitable operation of the swine enterprise Producing market hogs or seed stock.
BREEDING--SCIENCE AND ART
Improving hogs through successive generations is both a science and an art.
Genetic research work since 1900 has added greatly to man’s knowledge of the mechanism by which specific characteristics are transited from one generation to the next. These results have given the knowledgeable breeder
considerable control over some aspects of his work. For example, now swirls, certain defects such as hernia, cryptorchidism, and certain color abnormalities are explainable and controllable by the breeder.
Geneticists’ studies at various Agricultural Experiment Stations indicate that an increase of 10 to 20 percent in overall performance can result by using a systematic crossbreeding program as compared to the production of straight bred pigs under the same conditions.
Crossbred pigs usually show more vigor and growthiness than their purebred parents. The largest benefit seems to result from the crossbred sow. Research indicates that in addition to increased overall production of the offspring, the use of the crossbred sow results in better reproductive rates and improved mothering ability. These advantages in increas ed performances are collectively referred to as "heterosis” or "hybrid vigor".
Heritability estimates have been determined for many of the economically important traits regarding type, conformation, and carcass characteristics; as well as for the productive aspects of rate of gain and feed utilization and reproductive efficiencies. By application of these technologies, the breeder can improve along well defined paths with predictable results.
The reproductive physiologists have added another wealth of information explaining body functions and how they relate to reproduction to insure maximum fertility and maximum opportunity for selection.