Effect of cattle grazing strategies and pasture species on internal parasites of sheep

Abstract

The results of a three-year study in New Zealand undertaken to compare the effect of alternating sheep and cattle grazing and of different pasture species on internal parasitism in lambs is reported. Despite the commonly held belief that the use of cattle in sheep production systems improves sheep health by reducing nematode burdens, this did not occur. Cattle substantially reduced pasture larval numbers. However, this failed to reduce parasite burdens in lambs as those managed in the absence of cattle apparently developed increased immunity to parasites in response to the greater larval availability. Varying the number of successive grazings by sheep or cattle from 1 to 4 did not change this result. Lamb carcass weights were improved by the presence of cattle, primarily because of improvements in pasture quality. Substituting 30% of the ryegrass area with lucerne or replacing ryegrass with a multi-species mix A 96082 Received 3 December 1996; accepted 24 June 1998 consisting predominantly of bromes, tall fescue, phalaris, timothy, and red and white clover, had no effect on lamb faecal egg counts or worm burdens. Lamb liveweight was not affected by herbage species. Both lucerne and the multi-species mix increased the requirement for conserved feed during winter compared with ryegrass-based systems.

The effect of rotational grazing by either calves, cows, lambs or ewes on the removal of herbage contaminated with gastro‐intestinal parasite larvae around cattle faecal pats

“…Boom & Sheath (2008) found one herbage harvest removed 72% of L 3 , and two harvests reduced L 3 presence to less than 3% of the original population. Moss et al (1998) also found that alternating sheep and cattle grazing reduced sheep pasture L 3 by 82%, with no consistent difference in using 1, 2, 3 or 4 cattle grazings, indicating a large proportion were eliminated after one grazing. We found a similar L 3 reduction for our autumn pats.…”

“…al. 1996;Moss et al 1998). These management practices have had varying success and have often been confounded by pasture quality and supply differences.…”

Os parasitas de ovinos

“…Na Nova Zelândia, Moss et al (1998) observaram redução na contaminação de piquetes pastajados alternadamente por ovinos e bovinos. Curiosamente, a carga parasitária dos cordeiros que pastejaram os piquetes descontaminados foi similar à dos cordeiros que não compartilharam pastagens com bovinos.…”

The effect of pasture species on pasture and animal performances in irrigated systems

“…The Improved system required more conserved feed than did the Control resulting in the Improved system having an annual feed deficit, emulating the experience of Moss et al (1998), when comparing "improved" swards with perennial ryegrass in irrigated systems. Averaged over the 3 years, there was no feed deficit on Proceedings of the New Zealand Grassland Association 62: 59-66 (2000) as the study progressed, and was particularly marked in the Improved grass-based swards.…”