REPRODUCTION OF THE SOW - ENDOCRINE CHANG ES AND CONTROL .2.

The main endocrine events controlling gestation, parturition and retur n into oestrus after weaning have been described in the sow. Several p regnancy diagnosis are available. Diagnosis using ultrasonography exte nds in French commercial piggeries. Now, the use of prostaglandins all ows a better control of parturition. Return into oestrus of the sows a fter weaning depends on factors related to the sow itself, to the envi ronment, or to management pratices. Thus, delay of return into oestrus varies and remains poorly controlled. A better understanding of physi ological mechanisms involved in postweaning oestrus will lead to propo se management practices, to preserve the reproductive potential of the sow following each parturition and each lactation.