Fthenakis G C, Mavrogianni V S, Gallidis E, Papadopoulos E
Veterinary Faculty, University of Thessaly, 43100 Karditsa, Greece.
Veterinary Faculty, University of Thessaly, 43100 Karditsa, Greece.
Vet Parasitol. 2015 Feb 28;208(1-2):56-66. doi: 10.1016/j.vetpar.2014.12.017. Epub 2014 Dec 23.
This review article summarises the many reports in the literature, confirming that, in sheep, parasitic infections can adversely affect reproductive efficiency; examples, which refer to all parts of the reproductive cycle of sheep, are as follows: trichostrongylosis in ewe-lambs (which can lead to delayed attainment of puberty), myiosis of the prepuce (which can cause impediment of mating), chorioptic mange or trypanosomosis in rams (which can lead to testicular degeneration or azoospermia, respectively), trypanosomosis or sarcoptic mange in pre-conceptual ewes (which can lead to poor conception rates or reduced number of ovulations, respectively), toxoplasmosis or neosporosis in pregnant ewes (which are causes of abortion), trichostrongylosis or trematode infections in lactating ewes (which can cause reduction of milk yield and can be a risk factor for mastitis, respectively), cryptosporidiosis in newborn lambs (which can be a cause of deaths), coccidiosis in growing pre-weaned lambs (which can cause suboptimal growth rate). In other cases, the reproductive status of the animal can influence the parasitic infection; examples are as follows: the increase in faecal parasitic output during the peri-parturient period (as a consequence of the peri-parturient relaxation of immunity), the heavier trichostrongylid infections of twin lambs compared to lambs from single parities (as a consequence of developmental origin issues in twin lambs). All the above examples support the idea of presence of interactions between parasitic infections and reproductive efficiency in sheep.
这篇综述文章总结了文献中的众多报告，证实了在绵羊中，寄生虫感染会对繁殖效率产生不利影响；以下是涉及绵羊繁殖周期各个阶段的例子：母羊羔的毛圆线虫病（可导致青春期延迟到来）、包皮肌阵挛（可导致交配障碍）、公羊的绒毛虱病或锥虫病（分别可导致睾丸退化或无精子症）、配种前母羊的锥虫病或疥螨病（分别可导致受孕率低或排卵数减少）、怀孕母羊的弓形虫病或新孢子虫病（可导致流产）、哺乳母羊的毛圆线虫病或吸虫感染（分别可导致产奶量减少，且可能是乳腺炎的危险因素）、新生羔羊的隐孢子虫病（可导致死亡）、断奶前生长羔羊的球虫病（可导致生长速度不理想）。在其他情况下，动物的繁殖状态会影响寄生虫感染；例子如下：围产期粪便中寄生虫排出量增加（由于围产期免疫力下降）、双胞胎羔羊比单胎羔羊感染毛圆线虫更严重（由于双胞胎羔羊的发育起源问题）。上述所有例子都支持了绵羊寄生虫感染与繁殖效率之间存在相互作用这一观点。
