Effect of herbage species and feeding level on internal parasites and production performance of grazing lambs

Abstract

The effect of internal parasites on the performance of lambs grazing different forage species was examined in two experiments.

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

“…Lucerne has been shown to give higher lamb growth rates than grass-based pastures (Nicol & McLean 1970;Scales et al 1995). However, in the present experiment its use did not improve ewe or lamb liveweights, nor did it assist in reducing lamb worm burdens.…”

“…Moss & Vlassoff (1993) found that ryegrass-and prairie grass-based swards contained more nematode larvae than did lucerne, which in turn contained more than chicory. A similar observation was made by Scales et al (1995) in a lamb grazing experiment which compared a pasture with low endophyte ryegrass, cocksfoot, and tall fescue with a pasture containing lucerne and chicory.…”

“…However, in the present experiment its use did not improve ewe or lamb liveweights, nor did it assist in reducing lamb worm burdens. In the work of Scales et al (1995), lucerne was grazed continuously for over 7 weeks, whereas in the present experiment there was only sufficient for approximately eight days' continuous grazing. This may have been a less than optimum time for the rumen microflora to adapt to the new diet and consequently for maximum lamb performance.…”

“…Although only 30% lucerne may have been insufficient to have a measurable impact on lamb performance, increasing this area would have exacerbated the associated winter feed deficiency. When comparing commonly used grass pastures, Scales et al (1995) found fewer larvae were recovered from lucerne when overall numbers were relatively high (1857 kg" 1 DM) but not when numbers were low (38 kg" 1 DM). Moss & Vlassoff (1993) also recovered fewer larvae from lucerne than from ryegrass or prairie grass pastures identically seeded with strongylid eggs, and concluded that this was caused by a micro-climate less conducive to nematode development and survival in the lucerne swards.…”

Effect of sward density and size of faecal deposit on the development and persistence of third‐stage Trichostrongylid larvae of sheep

“…Using different pasture species offers a means of influencing the microclimate within the sward and therefore the larval population (Moss & Vlassoff 1993;Niezen et al 1998), and the number ingested by grazers (Knapp 1964;Scales et al 1995).…”