Efficacy of pour-on dewormers on weight gain and fecal egg count in Hawaiian stocker cattle

1. Efficacy of pour-on dewormers on weight gain and fecal egg count in Hawaiian stocker cattle Jonathon Beckett1, Tim Richards2, Craig Reinemeyer3 1Animal Science Department, Cal Poly State University, Kahua Ranch2, East Tennessee Clinical Research3

2. What is a Parasite? The Random House Dictionary defines it as an organism that lives on or within a plant or animal of a different species, from which it obtains nutrients.

3. Essentially we are trying to reduce the overall effects of parasites on our cattle - this is where much of our problem starts.Essentially we are trying to reduce the overall effects of parasites on our cattle - this is where much of our problem starts.

6. Parasites of Concern

7. Parasites of Concern

8. Clinical Parasitism Diarrhea Anemia Rough hair coat �Pot bellied� appearance �Bottle jaw� Less common There are a number of warning signs to let us know animals are parasitized such as:There are a number of warning signs to let us know animals are parasitized such as:

9. Subclinical Parasitism Decreased milk production Poor performance More susceptible to disease Infertility Unthrifty Additional signs that are important but more difficult to see include: A University of Maine study demonstrated that infected calves showing no clinical signs of parasitism gained 23.2% less than non-infected animals.Additional signs that are important but more difficult to see include: A University of Maine study demonstrated that infected calves showing no clinical signs of parasitism gained 23.2% less than non-infected animals.

10. We Deworm Cattle For Only One Reason FOR THE MONEY

11. Parasitism Economics of Parasite Control Calves More efficient Less susceptible to disease Cows Increased milk production Better body condition Better breeding efficiency Less susceptible to disease Parasitism affects calves and cows differently. Ultimately the value of parasite control is measured by economics. We can focus on production parameters in cows and calves such as weight gain and disease resistance in calves and milking ability, body condition, breeding efficiency and disease resistance in cows.Parasitism affects calves and cows differently. Ultimately the value of parasite control is measured by economics. We can focus on production parameters in cows and calves such as weight gain and disease resistance in calves and milking ability, body condition, breeding efficiency and disease resistance in cows.

12. Benefits of Deworming Increased productivity Increased efficiency Better immune status Increased breeding efficiency Reduced pasture contamination There are a number of intangible gains received from deworming your cattle. All of which can be influential upon the profitability of your operation.There are a number of intangible gains received from deworming your cattle. All of which can be influential upon the profitability of your operation.

13. Importance of fecal egg counts? Most commonly used technique Usefulness depends on its precision and accuracy Requires knowledge of parasite biology in area, experience with levels that are indicative of economic impact in a given situation

14. EPGs (Eggs Per Gram) importance? An indicator, but only tell you that you have at least one female worm laying eggs Can be used to determine potential parasite transmission levels in groups of animals, but not individual animals Poor indicator of number of worms in an individual animal Should not be used to measure production losses

15. Importance of Larval Cultures Very few parasitologist are able to differentiate between different genera of the parasite eggs Nematodirus is only �easy one� Larval cultures let eggs hatch then the worms are identified

16. Macrocyclic Lactones Avermectins Ivermectin (Ivomec) Doramectin (Dectomax) Eprinomectin (Eprinex Look alikes Generic Milbemycins Moxidectin (Cydectin)

17. Macrocyclic Lactones These are the chemical structures of the current Pour-On products available. You can see that there is a difference between the moxidectin molecule and the other common avermectins. These differences allow moxidectin advantages in potency and persistency. These are the chemical structures of the current Pour-On products available. You can see that there is a difference between the moxidectin molecule and the other common avermectins. These differences allow moxidectin advantages in potency and persistency.

18. Types of Administration Injectable Advantage � Easy to administer Disadvantage � Can create problems in the meat Disadvantage � Must be re-dosed every 60 days Pour-On Advantage � Very quick to administer Advantage � Noninvasive administration Disadvantage � Must be re-dosed every 60 days Drench Advantage � Very quick to administer (not as quick as Pour-On) Disadvantage � Must be re-dosed every 60 days Disadvantage � Cow can spit out most of the product Bolus Advantage � Dosed only once in the cow�s life Disadvantage � Much longer administration time Disadvantage � Administration requires training

19. Just Some More Facts Worms die after 5-8 wks in adult stage Some products kill most of the worms present in the digestive tract at time of treatment Some control only external parasites Some control both internal & external A few also kill the inhibited stages A few offer persistence of several weeks

20. Hypothesis The effective drug in pour-on dewormers will affect growth and parasite infection throughout the grazing season in stocker cattle.

21. Protocol

22. Average Daily GainDay 0-105

23. Average Body WeightDay 105

25. Fecal Egg Counts

26. Carcass Weights

27. Yield Grade

28. Backfat

29. Ribeye Area

30. Marbling Score

31. Yield Grade 1 & 2�s

32. What does this mean? It is important to deworm Eprinex and Cydectin equally resulted in maximal growth Ivomec is the weakest against internal parasites Without adequate forage, no dewormer is fully effective

33. What does this mean? Effect of dewormer during stocker phase is not significant at slaughter but effects are visible Take advantage of cheap gain during stocker phase rather than pay more for the gain in the feedyard

34. What does this mean? Other factors must be considered when selecting a dewormer Cost Persistency of Protection Ease of Administration Rain Fastness Flame Resistance Customer Service

35. Acknowledgements Kahua Ranch � Thank you for allowing Cal Poly to conduct the trial on their cattle Bruneau Cattle Company � Accommodating the feedlot phase 2001 Swanton Pacific Stocker Enterprise group for participating in the data collection and organization of the trial Brian Wetzel � Cal Poly Alumni for initiating this line of research as his senior project