Management of commercial swine breeding herds involves a thorough understanding of reproductive physiology, genetics, nutrition, immunology, disease control, environment, and other factors. ( See also Abortion in Pigs.) The closed-herd concept, which emphasizes preventive medicine strategies along with herd protection, minimizes the risk of disease loss when combined with intensive management, sound nutrition, and genetic selection. The breeding program should be evaluated at specified intervals to ensure that progress in both efficiency and productivity is being made. Several efficiency/production parameters to review when analyzing herd reproductive performance are shown in Measures of Reproductive Performance in Swine Relative to Industry Averagesa. The postweaning performance of a breeding herd's offspring can be measured through assessment of such parameters as feed conversion ratio, average daily gain, total days to market, and postweaning death loss.
Problems on a swine farm can have a single cause or be caused by a combination of genetic, nutritional, environmental, health, and management factors. When investigating a herd problem, the practitioner can best benefit from remaining focused on the herd and not on individual animals. Accurate, up-to-date records are essential when investigating a herd problem. When analyzing a herd and its records, a certain percentage of “abnormal” animals and/or reproductive problems are to be expected.
