may be improved by this new anthelmintic if maximum nutritional levels
are not provided. If maximum well balanced nutrient intakes are main-
tained then the beneficial effects of thiabendazole appear to be re-
duced. These data also suggested that responses to thiabendazole oc-
curred under low levels of parasite infestation and even after the use
of phenothiazine.


Table 1. Average Gains of Steers Being
 out Thiabendazole.


Fed on Pasture With and With-


 Concentrate Feed/Day Full 10 lbs. 5 lbs. None

 With Thiabendazole
 Number of steers 10 10 10 10
 Initial weight (Ibs.) 543 544 544 543
 Final weight (Ibs.) 849 781 712 602
 Total gain (lbs.) 306 237 168 59
 % increase 56.4 43.6 30.9 10.9
 No Thiabendazole
 Number of steers 10 10 10 10
 Initial weight (lbs.) 546 543 547 544
 Final weight (lbs.) 855 736 704 571
 Total gain (lbs.) 309 193 157 27
 % increase 56.6 35.5 28.7 5.0



 Table 2. Average EPG Counts of Steers Being Fed on Pasture With and
 Without Thiabendazole.

 Concentrate Feed/Day Full 10 lbs. 5 lbs. None

 With Thiabendazole
 Number of steers 5 5 5 5
 Initial EPG 143 260 91 78
 Final EPG 13 26 65 26
 Total Decrease 130 234 26 52
 % reduction 90.9 90.0 28.6 66.7
 No Thiabendazole
 Number of steers 5 5 5 5
 Initial EPG 273 52 299. 65
 Final EPG 156 0 78 52
 Total decrease 117 52 221 13
 % reduction 42.9 100.0 73.9 20.0

EES65-24
350 copies