Close the door to mycotoxins to maximize the reproductive performance of sows and boars
1. Mycotoxins affect the reproductive performance of gilts, sows, and boars
Pigs are generally the most sensitive farm animals to mycotoxins. Among the different families of mycotoxins, zearalenone is the one that is responsible the most for reproductive disorders in swine. Zearalenone is produced by Fusarium fungi, which frequently contaminate maize, wheat, oats, and barley, mainly when they are growing at the crop stage. Zearalenone and its derivatives are estrogenic toxins, which means they can compete effectively for the specific binding sites of the oestrogen receptors. The oestrogenic syndrome in swine primarily affects the reproductive tract and mammary gland, and it induces infertility, vaginal and rectal prolapses, swollen vulvas and other breeding problems. Zearalenone can also cause pseudopregnancy in sows and gilts. It can cause a female to exhibit a normal standing heat but does not allow the animal to conceive or experience repeated oestrus every21 days. This leads to the producer assuming that the sow has settled. Mycotoxin can also induce early puberty in gilts, although the affected gilts will continue to have heats but they will be infertile and without ovulation. Zearalenone has also been known to cause the oestrus period to last up to 80 days in some cases, when the sows have been fed low levels of the mycotoxin. Zearalenone intoxication in boars can lead to enlarged mammae, and atrophied testes, and their semen quality and quantity may also be affected.
ZEA is rapidly and well absorbed after oral administration (80-85%), and there is an important entero-hepatic cycle effect on the fate of ZEA. The particularly high sensitivity of swine to ZEA is partly related to the fact that swine convert ZEA into α-zearalenol, which is a more estrogenically active molecule than its parent compound.