Effects of Three Anthelmintic Regimes on Milk Yield of Ewes and Growth of Lambs

Abstract

Forty ewes were allocated into one of four groups (n = 10) and were treated with albendazole (ALB) (3.8 mg kg(-1)) before lambing (group A), with ALB before and after lambing (group B), with moxidectin (MXD) (0.2 mg kg(-1)) before lambing (group C) or were untreated controls (group D). Counts of nematode eggs in faeces and coprocultures were carried out during the study, as well as ewes' milk yield measurements and lamb weighings. Pre-treatment mean eggs per gram (epg) counts were 640, 715, 625 and 630 for groups A, B, C and D, respectively (P > 0.05); respective counts 21 days after treatment were 5, 0, 0 and 690 epg, whilst 70 days after treatment they were 380, 145, 40 and 1120 epg. Mean lactation milk yield was 3527.5, 3893.5, 3786.4 and 3285.9 ml for groups A, B, C and D, respectively; no significant difference was evident among the four groups in milk yield collected during the suckling period, although subsequently, group B or C ewes yielded significantly more milk than controls (P < 0.05). Mean birthweight of lambs were 3.56, 3.45, 3.59 and 3.26 kg for groups A, B, C and D, respectively (P = 0.045); subsequently, lambs from treated ewes were significantly heavier than lambs from control animals (P < 0.001). We conclude that anti-parasitic treatment during the last month of pregnancy contributed to an increased birthweight of lambs of treated ewes, whilst the cumulative effect of two doses of ALB or the long persistent efficacy of MXD provided a longer protection of animals against new parasitic infections and contributed to a lactation persistence.

Effects of strategic anthelmintic treatments on the milk production of dairy sheep naturally infected by gastrointestinal strongyles

“…These results are in general agreement with studies in dairy sheep (Restani, 1965;Fthenakis et al, 2005) that have used lamb liveweights to provide an indirect measure of milk production, and have reported milk yield to be increased by 15% following anthelmintic treatment with moxidectin towards the end of the gestation. The magnitude of the increase in milk production in the current study is perhaps surprising as the cross-contamination as a result of the co-grazing of both treated and untreated groups would be expected to limit the epidemiological advantage of treatment to the period of persistent activity of the chemical, which should not have been greater than 5 weeks.…”

“…The beneficial impact of anthelmintic treatment on milk production have been extensively documented in dairy cows (e.g. Ploeger et al, 1990;Corwin, 1997;Nodtvedt et al, 2002;Forbes et al, 2004); however, few studies have been conducted on the impact in dairy goats and sheep (Jordan and Perez, 1991;Fthenakis et al, 2005).…”

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

“…The milk production response to treatment suggests that, irrespectively of the genetic production level or number of parities of the ewes, under the design conditions in the trial, treatment mostly improved the milk production by means of the length of the milking period. Fthenakis et al (2005), also concluded that antiparasitic treatments provided a longer protection of animals against new parasitic infections and contributed to lactation persistence. In dairy cows many studies with controversial results have been carried out to assess whether anthelmintic treatment have a beneficial effect.…”

“…There is little information worldwide on the epidemiology (Papadopoulos et al, 2003) and risk factors (Hoste et al, 2006) of GIN in dairy sheep, even though gastrointestinal parasites are a major cause of sheep production losses in the world and Argentina (Armour, 1980;Suarez, 2007), including losses that may amount to 5 %, 24 % and 25 % for wool, meat and mortality respectively (Suarez et al, 1990) in the Semiarid Pampeana Region. A small number of investigations show the detrimental effects of nematode experimental infections in lactating ewes on both woolled and meat breeds (Leyva et al, 1982;Thomas & Ali, 1983;Sykes & Juma, 1984) and on dairy sheep systems of Europe (Fthenakis et al, 2005;Cringoli et al, 2008). Milk production systems in the Pampeana region are different of those of Europe and also predominant sheep GIN species have differences, in view of the fact that Haemonchus contortus is the most dangerous nematode for sheep production (Suarez & Busetti, 1995).…”

Patterns of maternal-offspring behaviour of dairy sheep and potential association with mammary health

“…Milk yield measurements were carried out on day 13 and subsequently at weekly intervals using an established technique (Fthenakis and Jones 1990;Saratsis et al 1999;Fthenakis et al 2005). Ewes were separated from their lambs, given an intramuscular injection of oxytocin (10 IU) and 5 min later completely milked-out by hand.…”