Strategic Parasite Control Back in the news. Backed by sound science.

Strategic Parasite Control – The Buzz Today March 2005 Drovers “Deworming calves (beginning in the spring) may be the most cost-effective management practice around: it results in healthier calves with healthier immune systems, weight gains that provide return on investment and cleaner pastures.” March 2005 JAVMA A series of 11 South Dakota trials demonstrates the value of controlling internal parasites at spring turnout and throughout the grazing season.

The Concept Has Always Been Appealing “It would seem that a new approach is being made in the control of nematode parasites. The emphasis is now on pasture hygiene, achieved by combining the intelligent use of anthelmintics with controlled grazing in such a way as to protect young animals from heavy infestations and at the same time to build up their resistance to parasitic diseases. The same principles may be applied to practically all helminth infections and as better anthelmintics become available and more knowledge of life cycles and bionomics of various parasites are acquired, there is every reason to hope that the tremendous losses due to parasitism of farm livestock will be greatly reduced.” – A. Russell, 1949 Vet Rec 61:

The Science Has Always Been Sound l Preventive approach l Multiple treatments l Reduce parasite populations below performance threshold l Reduce pasture contamination

The Benefits Have Always Been Compelling l Increased weight gains l Heavier weaning weights l Improved immune response to vaccinations l Reduced pasture contamination

l Subclinical Parasitism m Reduced weaning weight m Reduced milk production m Reduced reproductive performance m Reduced growth rate m Increased susceptibility to disease m Negative effects on immune response l Clinical Parasitism m Diarrhea m Bottle jaw m Anemia m Rough hair coat – Dr. Bert Stromberg, University of Minnesota Parasite Signs – Rarely Seen

95% in pasture – Dr. Bert Stromberg, University of Minnesota Parasite Populations – Rarely in the Host 5% in host

“The primary purpose of parasite control is not to cure sick animals…but to reduce levels of pasture contamination and consequently prevent such episodes of illness or reduced productivity.” SOURCE: Williams JC, Loyacano AF. Internal Parasites of Cattle in Louisiana and Other Southern States. LSU Research Information Sheet #104 (2001):13.

Strong Demand and Markets Make SPC Hard to Ignore l High demand and high prices raise the stakes l Every pound of production is worth more l It gets harder for all producers to ignore the value of SPC

Why Isn’t Everybody Using Strategic Parasite Control?

l Tradition (“Dad only wormed cattle once a year.”)

l Tradition l Lack of understanding of epidemiology (“What difference does it make when I treat cattle?”) Why Isn’t Everybody Using Strategic Parasite Control?

l Tradition l Lack of understanding of epidemiology l Lack of convenience (“I’ll just wait and treat them for parasites when I’ve got a good reason to handle them.”)

Economic Impact of Cattle Parasites * l GI Nematodes m 0.4 to 1.0 lb per day m 10:1 ROI l Horn Flies m 0.2 lb per day m 5:1 ROI *Derouen SM, Foil LD, Knox JW, Turpin JM, Horn Fly Control and Weight Gains of Yearling Beef Cattle, 1995 Veterinary Entomology

Why Isn’t Everybody Using Strategic Parasite Control? l Tradition l Lack of understanding of epidemiology l Lack of convenience l Subclinical infections are often overlooked l Effectiveness of today’s endectocides (“We killed a whole bunch of parasites a few weeks ago. That should hold ’em.”)

Merial Hosts Parasitologist Symposium l Leading cattle parasitologists attending l To review established benefits of Strategic Parasite Control l To identify regional differences in parasite control l To discuss the latest in Strategic Parasite Control

Treat the Cattle. Clean up the Pasture.

Where are the Parasites? - Dr. Bert Stromberg, University of Minnesota 5% to 10% In Host 90% to 95% On Pasture

Seasonal Transmission Patterns (Cool- vs. Warm-Season Parasites) (for graphical representation only) Relative transmission of nematodes and lungworms in cattle in the southeastern United States. - Dr. Thomas Craig, Texas A&M

Season Transmission Patterns – Northern US (Total Worms and Inhibited L 4 Larvae) (for graphical representation only)

Dynamics of Parasite Transmission – Northern US - Dr. Bert Stromberg, University of Minnesota Eggs per gram

Mathematics of Parasite Infection Conservative parasite load 2 eggs/gram Average fecal production 20 kg/day Daily production/animal 40,000 eggs For a 100-cow herd: 4,000,000 eggs/day

Cattle are Hosts – and Multipliers - Dr. Bert Stromberg, University of Minnesota Eggs per year (millions)

Pasture Contamination – A Vicious Cycle - Southern US (for graphical representation only) Data on file at Merial.

Does Winter Kill Off Parasites? l Infected larvae on pasture survive winter to reinfect cattle in spring m Cold and dry: reduced survivability m Cold and snow: survivability is high l Research shows that parasites can also be transmitted during cold Northern winters –Dr. Bert Stromberg, University of Minnesota

Why Spring Treatment is Important l Spring pastures will be contaminated with overwintered parasites l Rapid growth of cool-season pasture grasses encourages grazing l Spring-treated cows wean heavier calves l Spring vaccinations are more effective when cattle are parasite-free

28 days after infection, the immune system is negatively affected by the presence of parasites* Change in Mass of Draining Lymph Nodes After Infection with Ostertagia *Data on file at Merial.

Timing is Everything March 2005 Drovers “Deworming calves (beginning in the spring) may be the most cost-effective management practice around: it results in healthier calves with healthier immune systems, weight gains that provide return on investment and cleaner pastures.” 0-wk + 10-wk program32.66 lbs 3-wk + 10-wk program43.56 lbs March 2005 JAVMA Cattle receiving consistent control throughout the grazing season (using the IVOMEC ® SR Bolus) had higher average daily gains. A series of 11 South Dakota trials demonstrates the value of controlling internal parasites at spring turnout and throughout the grazing season.

The Importance of Multiple (Effective) Treatments Trial comparing multiple treatments IVOMEC ® 8x program373 lbs IVOMEC 3x program282 lbs Fenbendazole 3x program189 lbs Control group (w/salvage treatments of IVOMEC)259 lbs SOURCE: Williams JC, et al. Agri-Practice 1992

In a Perfect World… l You could provide consistent control throughout the grazing season with a single treatment l The real-world alternative is to maintain low parasite populations with multiple, well-timed treatments

Sustained Release = Optimal Gains Effect of IVOMEC ® SR Bolus on weight gains.* Mean Weight Gain – Increase ( P <0.01) *Jacobsen JA, et al. Productivity of cattle treated with the IVOMEC ® SR Bolus, Proceedings of the American Assoc. of Veterinary Parasitologists, #75, July, 1996.

IVOMEC ® SR Bolus vs. Popular Endectocides Demonstration Trials* IVOMEC Pour-On IVOMEC Plus VALBAZEN ® IVOMEC 1% Injection *Jacobsen JA, et al. Productivity of cattle treated with the IVOMEC ® SR Bolus, Proceedings of the American Assoc. of Veterinary Parasitologists, #75, July, 1996.

Maximum Cow/Calf Parasite Control l If the goal is to achieve maximum parasite control with minimal pasture contamination and reinfection, multiple treatments will be necessary l With endectocides, reinfection via eggs will resume in approximately five weeks l Re-treatment every five weeks will control the worms in the animal and continue to reduce pasture contamination (Williams et al Agri-Practice 1992 had eight treatments) Note: Trial conducted on stockers.

Optimum Cow/Calf Parasite Control l Spring treatment with an endectocide when spring grazing begins l Treat again five weeks later with an endectocide l Treat again eight weeks later with an endectocide l This treatment schedule will result in ultimate parasite control and maximum productivity benefits (Williams et al Agri-Practice 1992 had eight treatments) Note: Trial conducted on stockers.

In Your World… Regardless of timing/schedule and parasite problems (including flukes, coccidia, Ostertagia and other internal and external parasites) IVOMEC ® Brand products can combine for an effective SPC program.

Strategic Parasite Control – It Makes More Sense Than Ever l Spring treatment helps m Reduce pasture contamination m Deliver heavier weaning weights m Better vaccination response l Multiple treatments maintain low parasite levels – in cattle and in the pasture l Strategic Parasite Control pays off

Northern Cow/Calf Recommendations l Treatment 1 – Spring (April or May) Treat cows and calves over 200 pounds (2 months) with IVOMEC ® EPRINEX ® or IVOMEC Plus l Treatment 2 – Summer (July) Treat calves or cows and calves with EPRINEX l Treatment 3 – Fall (October or at weaning) Treat cows with IVOMEC Pour-On, EPRINEX or IVOMEC Plus Note: Weaned calves that are retained (stockers, replacement heifers, young bulls) will also need to be treated in the fall. See Slide #40.

Southern Cow/Calf Recommendations l Treatment 1 – Spring (February through May) Treat cows and calves over 200 pounds (2 months) with IVOMEC ® EPRINEX ® or IVOMEC Plus l Treatment 2 – Mid-Summer (July) Treat cows and calves with EPRINEX l Treatment 3 – Fall (September, October, November) Treat cows and weaned animals with IVOMEC Plus or EPRINEX* * Weaned calves that are retained (stockers, replacement heifers, young bulls) will need additional treatments. See Slide #41.

Northern Plains & South Weanling Recommendations (Stockers, Replacement Heifers, Young Bulls) l Treatment 1 – Weaning or upon receiving – Treat with IVOMEC ® Plus l Treatment 2 – Treat again six to eight weeks later (Days 45 to 60) – treat with IVOMEC EPRINEX ® or IVOMEC Plus l Treatment 3 – Treat again three months later with EPRINEX or IVOMEC Plus (Day 150), just before breeding season l Treatment 4 – Treat again three months later with EPRINEX or IVOMEC Plus (Day 240), just after breeding season for replacement heifers Note: Some herds may need additional treatments for maximum profitability.

Western Cow/Calf Recommendations (Coastal & Foothills – San Francisco Bay) l Treatment 1 – Spring (April or May) Treat cows and calves over 200 pounds (2 months) with IVOMEC ® Plus prior to movement to spring pasture l Treatment 2 – Fall (November) or weaning – Treat cows and fall calves with IVOMEC Plus l Treatment 3 – Winter (January or February) – Treat cows and fall calves with IVOMEC Plus

Western Cow/Calf Recommendations (Central Valley and Mountains) l Treatment 1 – Spring (March, April, May) – Treat cows and calves over 200 pounds (2 months) with IVOMEC ® Plus l Treatment 2 – Summer (July) or weaning – Treat cows and calves with IVOMEC EPRINEX ® l Treatment 3 – Fall/weaning (September to November) – Treat cows and weaned calves with IVOMEC Plus or IVOMEC Pour-On NOTE: Weaned calves that are retained (stockers, replacement heifers, young bulls) will need additional treatments. See Slide #44.

Western Weanling Recommendations (Stocker cattle, replacement heifers, young bulls) l Treatment 1 – Weaning or upon receiving – Treat all cattle with IVOMEC ® Plus l Treatment 2 – Treat again in six to eight weeks with IVOMEC Plus l Treatment 3 –Treat again with IVOMEC Plus when moved to spring pasture (fall weaned animals) or at the end of summer grazing (spring weaned animals) NOTE: Some herds may need additional treatments for maximum profitability.

How Much Weight Gain Do You Need to Pay for One of These Control Programs?

Cost Comparison of Parasite Control

MERIAL ® Brand Products for Strategic Parasite Control l IVOMEC ® Plus (ivermectin/clorsulon) l IVOMEC (ivermectin) Pour-On l IVOMEC 1% Injection l IVOMEC EPRINEX ® (eprinomectin) Pour-On l CORID ® (amprolium)

®MERIAL, CORID, EPRINEX and IVOMEC are registered trademarks of Merial. All other brands in capital letters are registered trademarks of their respective holders. ©2005 Merial Limited. Duluth, GA. All rights reserved. (7/05)