Table 1.
Faecal egg counts (FEC) and plasma pepsinogen (PP) concentrations in positive control and targeted selective treatment (TST) suckler beef calves in their first grazing season
| Date and day (d) of study | P-values | |||||||||||
| Variable | Treatment | 28-Jun-12 | 17-Jul-12 | 8-Aug-12 | 28-Aug-12 | 18-Sep-12 | 9-Oct-12 | 30-Oct-12 | TRT | Time | TRT × Time | TRT × Time × Sex |
| (TRT) | d 0 | d 19 | d 41 | d 61 | d 82 | d 103 | d 124 | |||||
| FEC (epg) | Control | 73a,x (24.4) | 51a,x (24.3) | 66a,x (24.3) | 64a,x (24.3) | 209a,x (24.3) | 95a,x (24.3) | 64a,x (24.3) | < 0.01 | 0.05 | 0.04 | 0.61 |
| TST | 57a,x (24.3) | 102a,y (24.3) | 75a,x (24.3) | 156a,y (24.3) | 415b,x (24.3) | 258a,y (24.3) | 172a,x (24.4) | |||||
| PP (Utyr) | Control | 0.40a,x (0.03) | 0.23b,x (0.03) | 0.29a,x (0.03) | 0.29a,x (0.03) | 0.30a,x (0.03) | 0.39a,x (0.03) | 0.28a,x (0.03) | 0.53 | < 0.01 | < 0.01 | 0.50 |
| TST | 0.43a,x (0.03) | 0.25b,x (0.03) | 0.14b,y (0.03) | 0.37a,x (0.03) | 0.45a,x (0.03) | 0.45a,x (0.03) | 0.27b,x (0.03) | |||||
The values are expressed as Lsmeans (± s.e.m.). a,b, means within row and within measured variable not having a common superscript differ (P < 0.05) from day 0. x,y,means within columns and within measured variable not having a common superscript differ (P < 0.05). Eggs per gram of faeces = epg. International units of tyrosine/litre = Utyr. Control calves were treated subcutaneously with ivermectin on days 0, 41 and 82. Targeted selective treatment calves were treated with the same product when one of the following thresholds were met; 1), positive for lungworm larvae using the modified Baermann technique or 2), positive or negative for lungworm larvae using the modified Baermann technique with PP ≥ 2 Utyr and FEC ≥ 200 epg