商业种猪群的管理涉及对生殖生理学、遗传学、营养学、免疫学、疾病控制、环境和其他因素的全面了解。(所有。年代ee also page 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 . 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.