Epidemiology and effects of gastrointestinal nematode infection on milk productions of dairy ewes

Abstract

Summary :66 Pampinta breed ewes were studied during milking to evaluate the infection and the effect of gastrointestinal nematode on milk production sheep system. Naturally infected ewes on pasture were randomly allocated to two groups: TG, suppressively treated group every four weeks with levamisole and UG, untreated group. Faecal nematode egg counts and larval differentiation were conducted monthly. Successive groups of worm free tracer lambs were grazed with ewes and then slaughtered for worm counts. Test-day milk yield of individual ewes was recorded and ewe machine-milking period length (MPL) were estimated. Faecal egg counts and tracer nematode numbers increased towards midsummer and declined sharply toward the end of the study. TG (188.0 ± 60 liters) produced more (p < 0.066) milk liters than UG (171.9 ± 52.2) and TG had significantly more extended (p < 0.041) MPL than those of UG. The present study showed that dairy sheep were negatively affected by worms, even when exposed to short periods of high acute nematode (mainly Haemonchus contortus) infection.

Prevalence and intensity of infection with gastrointestinal nematodes in sheep in eastern Serbia

“…Being the limiting factor of sheep productivity, GI nematodes have a highly detrimental effect on the sheep industry (Coop and Holmes, 1996;Jones, 2001), resulting in significant economic losses in meat, milk and wool production, as well as in sheep reproduction (Levya et al, 1982;Urquhart et al, 1996;Hayat et al, 1996;Suarez et al, 2009). Being the limiting factor of sheep productivity, GI nematodes have a highly detrimental effect on the sheep industry (Coop and Holmes, 1996;Jones, 2001), resulting in significant economic losses in meat, milk and wool production, as well as in sheep reproduction (Levya et al, 1982;Urquhart et al, 1996;Hayat et al, 1996;Suarez et al, 2009).…”

Interactions between parasitic infections and reproductive efficiency in sheep

“…Beasley et al (2012) found that increased parasitic output from infected ewes was evident for up to 1.5 months after lambing, but, again, suggested that an association with endocrinological factors was unlikely (bar, possibly, a potential role for cortisol), concluding that some other factor(s) would be contributing to the relaxation of immunity to nematodes and the consequent increase in faecal parasitic output during the post-partum period (Beasley et al, 2012). Suarez et al (2009) andCruz-Rojo et al (2012) have documented that gastrointestinal nematode parasitism can cause 10-15% reduction in milk yield of affected ewes, as well as shorter persistency of lactation. Anthelmintic treatment has also been found to increase milk production (Rinaldi et al, 2007).…”

Epidemiology and control of human gastrointestinal parasites in children

“…However, subtle damage and dysregulation can occur in the absence of any noticeable infection. For example, it has been observed that minor levels of GI nematodes impair functions such as milk production in animals [94,95]. Summary findings of two major studies of the literature [67,96] found that in humans:

The effects of GI parasites depend on the species, the mixture of species, the duration of infection and the number of worms;

The distribution of worms among hosts is highly skewed such that a minority of individuals, almost entirely young, have moderate-to-heavy infections and are more likely to be clinically affected;

The intensity of infections depends on the size and nutritional status of the host;

Treating worms can lead to improvements in growth and nutritional status, but deworming alone does not treat any underlying nutritional deficits that have been caused or made worse by infection.

…”