Abstract:
Animal Production in Australia Vol. 15 VALBAZEN (ALBENDAZOLE) TREATMENT OF BRAHMAN CROSS WE TOP END OF THE NORTHERN TERRITORY ANERS IN T HE A.R. EGGINGTON*, T.H. McCOSKER** and M.H. BAINBRIDGE Low growth rates and high mortality of weaners on Mount Bundey Station (McCosker et al 1984), together with the knowledge that a heavy Haemonchus placei burden had contributed to deaths in 1978, led to an investigation of internal parasite control in weaners. Brahman cross calves weaned at 5 to 7 months old were treated with 12 ml Valbazen at branding (April 1980), or at weaning (July 1980), or at both branding and weaning and compared to a non-drenched group. The groups were run in the same native pasture paddock at a SR of 1 to 2.6 ha with access to supplements. TABLE 1 Numbers of animals, liveweights and faecal egg counts of weaner calves , drenched with Valbazen +EPG = eggs per gram of faeces Liveweight was not significantly (P70.05) affected at any stage by drenching regime. Egg numbers at weaning were significantly lower (PLO.05) in the groups drenched at branding. Low egg numbers in November indicate a low dry season worm burden in all groups with the mean counts below the 300 epg considered by Leland et al (1973) to indicate clinical infection. Drenching at branding and weaning significantly (PdO.05) reduced post weaning dry season losses from either the weaning or the control group. The effect of early drenching (at branding) was greater than for a late drenching (at weaning) in reducing losses, but this was not statistically significant. Sixty nine percent of all losses occurred during the dry season which was influenced by the weaning weights of individuals (McCosker et al 1984). Wet season losses were similar for all groups. It is suggested that an early drench be followed by a second drench at weaning for the effect of reducing mortality, possibly from sub-clinical worm burdens. This is economically justifiable on the grounds that a 1% reduction in mortality would compensate for drenching expenses. LELAND, SE., CALEY, H.K. and RIDLEY, R.K. (1973). Am.J.Vet.Res. 34:581. McCOSKER, T-H., EGGINGTON, A-R. and DOYLE, F.W. (1984). Proc.Austmc.Anim.Prod. 15: Z * ** *** Department of Primary Production, Adelaide River, N.T. 5783. Mount Bundey Station, Adelaide River, N.T. 5783. Department of Primary Production, Katherine, N.T. 5780. 674