Dairy Herd Health

1. Dairy Herd Health Animal Science I Unit 44

2. Introduction • Subject to the same diseases and parasites as beef cattle • However, dairy cattle do have some health considerations that need to be emphasized

3. Herd Health Plan • Needs to be developed for maintaining the health of the dairy herd • Effective plans put emphasis on the prevention of problems • Vet services should be used on a regular and planned basis • A regular planned program of testing and vaccination should be carried out for the herd for • Brucellosis • Infectious Bovine Rhinotracheitis (IBR) • Bovine Virus Diarrhea (BVD) • Parainfluenza-3 (PI3)

4. Herd Health Plan • Keep health records • Follow a parasite control program • Follow a planned program for mastitis control • Keep accurate reproduction records • Follow a planned calf health care plan

5. Management Practices to Reduce Herd Health Problems • Proper feeding of the herd • Good facilities with ventilation • Using dry, clean bedding • Proper cleaning and sanitation • Controlling disease carriers-flies, birds, rodents • Raising replacements needed for the herd • Requiring health records of replacement animals and isolating them for 30 days • Isolating sick animals • Using a vet • Controlling access to dairy herds • Require visitors to wear protective footwear • Do not allow visitors unlimited access to where cattle are kept • Have bulk milk and feed delivery points as far away from cows as possible

6. Dairy Quality Assurance Program • Designed to help dairy farmers produce high quality milk • Participation is voluntary • Developed by the National Milk Producers Federation and the American Veterinary Medical Association • Producers are certified by going through a 10 point check list of management practices with a Veterinarian

7. Dairy Quality Assurance Program • Program identifies critical control points that help herd owners produce a high quality product • Emphasis is placed on following a preventative health program

8. Use of Drugs for Treatment of Dairy Cows and Calves • See p. 804 and 805 for the itemized list

9. Mastitis Control • Serious economic problem • Causes losses by • Lowering milk production from infected cows • Increasing the cull rate in the herd • The cost of treatment • Loss of infected milk that must be thrown away • Increased labor cost to treat infected cows • Possible loss of permit to sell milk if infection becomes serious enough

10. Mastitis Control • Caused by bacteria that enter the udder through the teat opening • Bacteria may also enter through injury to the teat • May be acute or chronic

11. Acute Mastitis Symptoms • Inflamed udder • Swollen, hot, hard, tender quarter • Drop in milk production • Abnormal milk • Lumpy, stringy, straw-colored, contains blood, yellow clots • Cow goes off feed, shows depression, dull eyes, rough hair, chills • Death may result

12. Chronic Mastitis Symptoms • Abnormal milk-clots, flakes, watery • Slight swelling and hardness of udder that comes and goes • Sudden decrease in milk production

13. Chronic Mastitis • May not show any symptoms • Often not treated • Sometimes does not respond to treatment • More of an economic problem than the acute form • Both acute and chronic mastitis may cause permanent udder damage

14. Leukocytes • White blood cells that fight infection • Mastitis increases their presence

15. Somatic Cells and Somatic Cell Count and Mastitis • Somatic cells are leukocytes and other blood cells • All normal milk contains some somatic cells • Goal of the dairy herd should be an average of no more than 150,000-200,000 cells per milliliter • 90% of the herd should be below 200,000 cells per milliliter • Somatic cell count can vary greatly from month to month in cows that have mastitis infection

16. Problem Somatic Cell Counts • Daily per head losses increase as somatic cell counts increase • Ranging from 1.5 lbs at 72,000 cells/milliliter to 6.0 lbs at over 1 million cells/milliliter • Somatic cells counts over 500,000 usually indicated a bacteria infection, a cow in late lactation, udder injury or an old cow • Problem cows should be culled

17. Bulk Grade A Milk • Picked up at the farm it cannot have a somatic cell count exceeding 750,000 cells/milliliter • Violation results in the loss of the farms Grade A permit

18. Testing for High Somatic Cell Counts • Several test • Most common is the California Mastitis Test (CMT) • Used to test the herd for mastitis and should be used at least once a month

19. California Mastitis Test (CMT) • A small paddle with 4 cups is used • About 1 teaspoon of the first milk from each quarter is placed in each cup, each quarter must be checked separately • A chemical that reacts with the milk is placed in each cup • The presence of leukocytes is shown by the reaction • Slight precipitation show a low count • A heavy gel and purple color show a high count

20. California Mastitis Test • http://www.youtube.com/watch?v=BvbZPk5riEc&feature=related

21. Other Methods of Testing • Lab • Chemical • Electronic

22. Controlling Mastitis • The following practices should be followed for an effective mastitis control program • Maintain milking equipment in proper operating condition • Practice proper milking procedures • Identify the bacteria causing the infection and determine the extent of the infection in the herd • Promptly treat identified cases of mastitis • Treat all quarters of cows when at drying off time • Cull cows with chronic mastitis problems that do not respond treatment

23. Displaced Abomasums • Also called DA • Condition where the abomasums moves out of place in the abdominal cavity • More common in dairy cattle than beef • Majority of cases occur shortly after calving • Symptoms • Poor appetite • Reduced fecal discharge • Soft or pasty feces • Diarrhea • Drop in milk production • Dull, listless, thin appearance

24. Displaced Abomasums • Type of ration being fed appears to be involved • Too rapid an increase in grain feeding just before calving increases the chance of DA • Poor quality, moldy roughage or too much silage in the ration also increase DA • Do not over feed silage and concentrates to dry cows • Increase the amount of concentrate slowly at calving time

25. Retained Placenta • A condition in which the placenta is not discharged within 12-24 hours after calving • Normal for 10-12% of dairy cows • A higher rate indicates a problem that needs attention

26. Causes of Retained Placenta • Infection in the reproductive tract during pregnancy • Deficiencies of vitamin A or E, iodine, and selenium • Calcium to phosphorus ratio in diet out of balance • Cow too fat • Stress at calving • Breeding a cow too soon after calving • Good management is the best practice to prevent retained placenta.

27. Ketosis • Nutritional disorder in dairy cattle • Blood sugar drops to a low level • Caused by not feeding enough high energy feeds to meet the cows needs for high milk production • Usually occurs in the first 6-8 weeks after calving

28. Symptoms of Ketosis • Cows go off feed shortly after calving • Drop in milk production • Loss in body weight • Cows become dull and listless • Odor of acetone in breath, urine and milk

29. Preventing and Treating Ketosis • Feed a properly balanced ration • Common Treatments • Glucose injections into the bloodstream • Hormone injections (cortisone or adrenocorticotrophic hormone) • Oral feeding of propylene glycol or sodium propionate • Feeding molasses will not cure Ketosis

30. Metritis • Infection of the uterus • Affects cows within 1-10 days after calving • Higher rate is seen in cows that are too fat at calving

31. Symptoms of Metritis • Loss of appetite • Fever • Drop in milk production • Abnormal (thick, cloudy, grey, foul odor) discharge from the vulva • Standing with the back arched • In severe cases, rapid death

32. Prevention and Treatment of Metritis • Feed a properly balanced ration to dry cows • Keep the calving area clean and sanitary • Treat with intrauterine antibiotic drugs

33. Milk Fever • Parturient paresis • Caused by a shortage of calcium salts in the blood • More common in older, high producing cows • Usually occurs within a few days after calving

34. Symptoms of Milk Fever • Loss of appetite • Reduction in quantity of feces passed • In early stages excitement • Staggering • Depression • Cold skin, dry muzzle • Paralysis • Lies on brisket with head turned back toward side • Later stages, lies on side with head stretched out • Bloating • Death, if not treated

35. Prevention and Treatment of Milk Fever • Feed a balanced ration to dry cows with the correct calcium-phosphorus ratio • Treat by intravenous injection of calcium

36. Internal Parasites • Follow a regular program of treatment • All mature dairy cows should be treated for worms after each lactation • Replacement heifers should be wormed near the end of their pregnancy

37. External Parasites • Use care when using insecticides on the dairy • Use only insecticides approved for dairy animals and facilities • Follow label directions carefully to avoid illegal residues in the milk

38. Summary • Effective herd health plan emphasizes prevention • Good management helps prevent health problems • Mastitis is the most serious disease that affects dairy cattle • Use care when using drugs to avoid illegal residues in the milk • Good herd health plans increase net profits • Control internal and external parasites.

39. Assignment • Complete Unit 44 Review Questions—due Thursday Dec 2 • Review for Test Dec 2 • Test over units 39, 40 and 44 on Friday • Dairy Anatomy Test December 8th