1. Parasite Control and Rotational Grazing Patty Scharko, DVM, MPH Extension Ruminant Veterinarian Livestock Disease Diagnostic Center

2. Parasite Control â External parasites â Internal parasites  Ostertagia – Brown stomach worm – Inhibited; arrested in stomach lining  Haemonchus- goats and sheep – Barber pole worm

7. Inhibited Ostertagia

8. Subclinical parasitism  Decreased dry matter intake  Decreased performance weight gain conception rate milk production

9. Effect of Strategic Deworming in Grazing Stocker Cattle Trial 1 Days of Gain Increase Over GrazingControls, lbs LA15567 VA, 112020 VA,213890 CA 10924 Agri-Practice, Vol 13, No. 1, Jan. 1992 11 1 Controls treated at trial initiation

11. Effect of Strategic Deworming in Grazing Cattle TrialWW over Pregnancy/ Calving Control, lbs over Controls, % FL2010 (C) GA1922.5 (C) MN,13911 (P) MN,22712 (P) Agri-Practice, Vol 13, No. 1, Jan. 1992

12. Where are the worms? â 5-10% in animal â 90-95% on pasture

14. Rotational Grazing Larval Counts â Long rotations (4-6 mo.) reduce pasture larval counts, waste forage â Intensive rotations increase larval loads

15. Worm counts in treated & control heifers under continuous or rotational grazing Am. J. Vet. Res. 49:724, 1988

16. Worm Immunity l Cattle develop immunity to internal parasites as they mature. l Calves have no immunity and show the most problems when exposed to worms. l Goal is low exposure to worms early in life by keeping pasture levels low.

17. Dewormers (Anthelmintics) Short Action Inhibited OstertagiaIntestinal Panacur/ Safeguard + + +*+ + + + Synantic + + ++ + + + Valbazen + + ++ + + + Levasole/ Tramisol ++ + + Rumatel -+ + + + * Dose at 10 mg/kg body weight

18. Dewormers Long Action/ Endectocide Inhibited OstertagiaIntestinal Cydectin + + + + + + + + Dectomax + + + + + + + + Eprinex* + + + + + + + + Ivomec + + + ++ + + +

19. EndectocideDosage Weather Proof Meat Withdrawal Time (days) Cydectin Pour-On5 ml per 110 lbs Yes0 Dectomax Pour-On5 ml per 110 lbs Yes45 Ivomec Eprinex Pour-On 5 ml per 110 lbs Yes- wet or dry 0 Ivomec Pour-On generic ivermectin PO 5 ml per 110 lbs “ No*48 Cydectin Injectable1 ml per 110 lbs -21 Dectomax Injectable1 ml per 110 lbs -35 Ivomec 1% Injection1 ml per 110 lbs -35 Need at least 4 hours before rain, best 24 hours

20. Parasite Transmission Patterns in Southern Cow /Calf Herds Eggs per gram of feces Larvae/kg forage Weaning Months

21. When to deworm? SPRING (strategic) Deworming Deworm 4 weeks after start grazing OPTIONS: Long action 1. Long action ( Ivomec, Cydectin, Dectomax, Eprinex )  2 treatments: 6 weeks apart Short action 2. Short action ( Safeguard, Synantic, Valbazen, Levamisol, Rumatel)  3 treatments: 3 weeks apart ? Stockers- deworm every 90 days

23. SPRING (strategic) Deworming Eggs per gram of feces Larvae/kg forage Weanling Months

24. SUMMER (tactical) Deworming l June 15 – July 15:  “Preventive Deworming”  Spring calving: cows & calves  Fall calving: cows l Weaning:  Spring calving- calves (FEC)  Fall calving- do calves in March l “It depends”  Weather- moisture

25. Summer (tactical) Deworming Eggs per gram of feces Larvae/kg forage Weanling Months Deworm

27. Classes of Dewormers Goats/ Sheep Benzimidazole Imidazole/ Pyrimidine Macrolide Safeguard/ Panacur Synathic/ Benzelmin Valbazen* Levasole/ Tramisol Rumatel StrongidT Ivomec Dectomax Eprinex Cydectin** *Do not use in first trimester pregnancy ** Use sparingly Trade Names Drug Class

28. Avermectin Resistance Evaluation Study in Cattle Farm 1Farm 2 Ivomec Pour-on54 %86 % Safeguard100%99 % Ivomec PO & Safeguard 92 %100% Month tested Fecal Egg Counts August 13 FEC November 240 FEC

29. Hay Fields â Hay production removes many larvae in the grass and opens up the plant to UV light and heat.

30. Dragging pastures  Do in summer  Do on NON-grazing pastures  Return on investment?  Combine with clipping?

31. When to deworm? Fecal Examination  To monitor current deworming programs thru fecal egg counts and parasite identification  Do before deworming  Can recheck after deworming to evaluate effectiveness  Caution about sampling cows- spring is best  Calves can be checked thruout the year

32. Parasite Transmission Patterns in Southern Cow /Calf Herds Eggs per gram of feces Larvae/kg forage Weaning Months

33. Oklahoma State University Stocker Cattle Deworm Control ControlControl Deworm Deworm Deworm Deworm FeedlotFeedlot Pasture ControlControl

34. Strategic Pasture Deworming with Safeguard (FBZ) and Stocker Gain TreatmentControlDeworm Head 371363 Int. Wt., lbs627632 Final Wt., lbs737790 ADG, lbs0.931.34

35. Effect of Deworming with Safeguard (FBZ) and Feedlot Health Pasture Treatment Control Deworm Feedlot ControlDewormControl Deworm Treatment Morbidity % 13.8 8.1 3.8 2.5

36. Effect of Deworming Treatment with Safeguard (FBZ) and Feedlot Health Pasture Control Deworm Feedlot ControlDewormControl Deworm ADG 3.85 4.564.224.46 DDMI 21.7523.2423.2423.91 % Ch 295244.655.2 % Std 5.90.61.90.6

37. Cattle Parasite Control “Some diseases are not easily eradicated, but can be managed to minimize their economic effects. These include internal parasites (thru deworming and monitoring.)” Ray Schultz

38. Goat Parasite Control Rotate every 3 days Consider deworming 10 days after a good rain during dry conditions Beware of coccidia if goats can get indoors Consider FAMACHA training & “smart drenching”

39. 21 days 2 days to 3 months Coccidia