Influence of periparturient nutritional demand on resistance to parasites in livestock

Abstract

Periparturient relaxation of immunity (PPRI) to gastrointestinal nematode parasites may have a nutritional basis, as the increasing nutrient demand at times of nutrient scarcity during late pregnancy and subsequent lactation may result in a penalty on expression of acquired immunity to parasites. This nutritional basis implies that lowering nutritional demand, at constant nutrient supply, should reduce the degree of PPRI. Evidence to support the latter is reviewed through exploration of the effects of reproductive effort on periparturient resistance to parasites. A large body of evidence shows that a lower nutritional demand arising from rearing single rather than multiple lambs and/or kids consistently reduces the degree of PPRI in small ruminants, as manifested by reduced worm burdens and/or nematode egg excretions. Such variation in reproductive effort may also account, at least to some extent, for the often observed between-breed differences in PPRI, which may arise from differences in production potential, and thus nutritional demand. A reduction in nutrient demand can reduce the degree of PPRI in a matter of days. However, host immune responses associated with this nutritional sensitivity of host resistance remain to be elucidated, which may be achieved through a recently established periparturient rodent model.

Variação sazonal da contaminação por helmintos em matrizes ovinas e borregos submetidos a controle integrado e criados em pastagens tropicais

“…Em outro estudo, foi também observado que o OPG de ovelhas da raça Merino Australiano no periparto pode chegar a 2.891, enquanto que, em outros períodos, o grau de infecção alcança uma média de 354 OPG (AMARANTE, 1993). A maior susceptibilidade de ovelhas no periparto às infecções por nematódeos gastrintestinais tem sido atribuída também ao aumento da exigência nutricional nessa fase, e o nutriente mais limitante, relacionado a essa queda da imunidade, tem sido a energia (HOUDIJK, 2008).…”

Animal health aspects of adaptation to climate change: beating the heat and parasites in a warming Europe

“…Similarly, periods of heavy downpours have been shown to have a negative effect on herbage intake (Champion et al, 1994), although they would rarely be sufficiently prolonged to seriously affect animal production or body condition. A decreased energy and protein intake will, in turn, negatively affect the immune system (Sargison et al, 2002;Houdijk, 2008).…”

The effects of anthelmintic treatments against gastrointestinal nematodes on the performance of breeding ewes and lambs on pasture in semi-arid Kenya

“…Breeding ewes are particularly susceptible to the effects of parasitism during pregnancy and lactation, an effect that is attributed to a temporary loss of acquired immunity to nematode parasites at around this time. The loss of immunity typically involves a periparturient rise in faecal egg output in late pregnancy and in lactating animals (Houdijk 2008). Whereas the increased burdens of parasites in lactating ewes may result in clinical or sub-clinical disease, its greatest significance is its association with decreased milk production with resultant negative effect on the growth of lambs (Fthenakis et al 2005;Cringoli et al 2008).…”