Breeding Herd Biology Homepage

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The breeding herd consists of replacement gilts, sows, and boars; the growing herd is made up of their progeny. Since the nutritional, environmental, and management needs of the breeding herd are quite different than those of the growing herd, these production phases are often segregated to separate premises and will be discussed separately here.

Breeding herd biology is a recursive cycle, which is dictated by female reproductive events. Farm managers plan to keep expensive facilities running at full capacity and factor in failure rates. For example, if the nursery can accomodate 200 pigs per week, 20 litters of 10 pigs each must be weaned per week. Perhaps 22 litters, each with 11 pigs born alive must be farrowed to account for normal losses. And 29 sows may need to be bred each week to maintain full capacity. If these sows are to farrow in a group, they need to all be in estrus at the same time, and boar power must be sufficient to meet this demand. This example implies the importance of setting and reaching productivity targets to minimize the costs of production. Achieving full productive capacity from the facilities is just as important as achieving the same from the animals. Discrepencies result in "bottlenecks" or unused spaced.

Copyright ©1997 by the University of Pennsylvania School of Veterinary Medicine
Faculty: Dr. Paul Pitcher
Student: Sandra Springer,'99