Reproductive disorders in pigs: a review on the crucial role of the environment

摘要

The term "reproductive disorders" covers a range of problems affecting the sow at the different steps in the reproduction cycle. The term "environment" relates to a number of conditions that "envelop" the sow during her life. During the reproduction cycle, the urogenital tract of the sow is subjected to successive and diverse challenges. Parturition is one of them. Trauma and/or infections can take place at this moment and have detrimental consequences at the onset of the subsequent oestrus cycle andthe next pregnancy. This is of particular importance when lactation is short, and leaves little time for the uterus to recover. The oestrus period and insemination are most critical stages. Reproductive efficiency is mainly determined by the healthinessof the uterus at the moment and the conditions of insemination. The environment offered to the breeding sow plays a pivotal role in that the various environmental components converge to either maintain or alter the integrity and good functioning of theuterus. Hence poor hygiene, especially if combined with poor housing, will generate discomfort, even pain and stressful conditions that negatively interfere with reproductive function. The probability that the sow's uterus will become infected increasesconsiderably under such conditions. Nutrition also plays a role. Both excessive and poor body condition may have a negative impact. Whereas the problem is expressed by the sow (e.g. regular return in oestrus) the cause, can also be the inadequate qualityof the semen. Careful hygiene must be ensured at the time of semen collection and preparation, and during insemination. This latter should be performed during standing oestrus and delayed inseminations should be avoided. Most of the above-cited requirements to prevent reproductive disorders concern the farmer's ability to consider and take action with regard to combinations of potential risk factors rather than to single ones in isolation.