Livestock Management RANCHING
Understand Limits of Fecal Egg Count Reduction Tests Knowing boundaries could save you money
M
ANY PRODUCERS RELY ON FECAL EGG COUNT REDUCTION TESTS (FECRTS) TO determine which parasites are affecting their herds or whether they might have resistant parasites on their property. Knowing
the facts about these tests can help you decide whether they are the right choice for your cattle — and your wallet. A FECRT is a fi eld-based tool that gives a qualitative estimate of internal
parasite reduction in animals treated with a parasiticide. Many producers and veterinarians use FECRTs, but because the tests have many limita- tions, they often are misused or misinterpreted. “FERCTs can be a useful tool if the producer has the right expecta-
tions of what they are looking for and are aware of the test limitations,” says Gary Sides, Ph.D., cattle nutritionist, Cattle and Equine Technical Services, Pfi zer Animal Health. “This test can help determine which adult parasite groups are present and qualitatively evaluate the effi cacy of recent deworming treatments.” Even though many producers rely on them, FECRTs may often provide
misleading results, Sides notes. “You cannot distinguish between worm species that have similar-
looking eggs,” Sides says. “And FECRTs are not able to account for larval stages since larvae do not lay eggs. Also, because of the immune system response, fecal egg counts do not correlate to abomasal or intestinal worm burdens in animals older than 6 months.” In calves less than 6 months of age, there can be a fair correlation
between egg numbers and adult worm numbers, except for the internal roundworm genus, Nematodirus. Additionally, fecal counts will produce false negative results for inhibited larvae of Ostertagia ostertagi (the brown stomach worm) — one of the most damaging parasites. “For the most accurate results, fecal samples must be taken all from
the same animal, before treatment and again about 3 weeks after treat- ment,” Sides says. “These samples also need to be taken from the rectum — not off the ground — to ensure the feces are not contaminated with soil nematode eggs. Once samples are collected and submitted, a labora- tory technician will conduct an analysis and report the fi ndings on an eggs-per-gram basis.” Sides adds that although fecal egg counts and FECRTs can be useful in
evaluating your parasite-control program, conducting yearly performance evaluations and keeping accurate performance records are much more reliable and useful than counting eggs. “To ensure that you are maximizing your parasite-control program,
animals should be dosed properly, products should be stored according to label indications, and you should work with your veterinarian to design a strategic deworming program that includes all classes of dewormers in the spring and fall,” Sides says. “This conversation with your veterinar- ian should give you a reliable, effi cient way to protect your cattle and bottom line.”
tscra.org
1990 Louisville Road, Unit 4 Bowling Green, KY 42101
305 Limestone Terrace, Suite E Jarrell, TX 76537
April 2013 The Cattleman 47
. . . For Improved Herd Health.
• Reduces morbidity from respiratory disease
• Significantly lowers disease events
For more information about BVD-PI Testing call
(800) 808-3552
BVD-PI Testing
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92 |
Page 93 |
Page 94 |
Page 95 |
Page 96 |
Page 97 |
Page 98 |
Page 99 |
Page 100 |
Page 101 |
Page 102