Proceedings of the New Zealand Society of Animal Production.
1989, 49: 307-313
Proceedings of the New Zealand Society of Animal Production.
1989, 49: 307-313
Commencing at weaning and continuing into late winter/spring, trial animals received ivermectin subcutaneously at 200 µg/kg live weight either once (control group), or four (4x) or six times (6x) at 6-week intervals. The mean faecal egg counts in control groups varied considerably from Day 0 to trial end ranging from 183 to 271 epg on day 0, 166 to 715 epg on day 84, and 8 to 69 epg at trial end. Larval differentiation demonstrated that Ostertagia, Trichostrongyulus and Cooperia predominated, regardless of the region. Salvage treatment of varying numbers of control animals was necessary in each trial, and deaths associated with parasitism also occurred in control group animals. These confirm that beef weaners in these regions are likely to be exposed to substantial parasite challenge in their first year of life.
Average daily weight gains ranged from 0.41 to 0.50 kg for groups treated with invermectin six times, from 0.35 to 0.38 kg for groups treated four times, and from 0.23 to 0.28 kg for control treated ones. In each trial, the 6x group gained significantly (P<0.01) more weight than the 4x group which in turn gained significantly (P<0.01) more than the control group. Similarly, dollar valuations per head ranged highest to lowest from the 6x, to the control group.
In these trials treating beef weaners with ivermectin at 6-week intervals from weaning through to mid-spring was beneficial for improving weight gains, animals values and parasite control.
Keywords: NZSAPAB; Ivermectin; beef weaners; parasite control; weight gains; animal values
