1. Dr. Rachel J. E. Stewart BVSc, MVSc, PhD CVS, UZ COLOSTRUM MANAGEMENT IN CALVES: Is it really a matter of life or death?

4. Table 1 Heifers needed to keep herd size at 100

6. THE OBJECTIVE OF FEEDING COLOSTRUM To maximize the defence capacity of the newborn calf as soon as possible after birth. (specific and aspecific) Calves are born agammaglobulinaemic: no antibodies and no immune system due to the type of placentation (syndesmochorial)

7. COLOSTRUM COMPOSITION Enzyme inhibitors Bacteriostatic proteins Lactoferrin Lysozyme Lactoperoxidase system Leukocytes Immunoglobulins

8. COLOSTRUM COMPOSITION

9. LEVEL OF PASSIVE IMMUNITY Ig G absorbed depends on: Amount of ingested colostrum Concentration of Ig G in colostrum Absorption efficiency of calf gut Depends on the age at first feeding Method of colostrum feeding

10. Absorption of Colostrum Intestinal cells of the newborns digestive tract are able to engulf large molecules such as Ig in vesicles for a period of approximately 24 hours after birth Peak ability to engulf occurs within the first 6 hours after birth and declines until 24 hours when it stops altogether The vesicles cross the cell and release their contents into the blood circulation via the lymphatic system

11. Transport of Ig between blood and intestine After absorption of the Ig’s into blood the Ig's are released continuously from blood into the lumen of the intestine to provide local immunity to the gut High serum concentrations of serum Ig are needed to maintain this cycle to ensure adequate levels in blood and gut at time of closure

12. Serum Ig concentration Calf serum Ig concentration peaks at 24 to 36 hours after birth. Thereafter serum concentrations gradually decline to minimal between 15 and 28 days of age There is a gradual but steady increase in serum isotypes from 4 to 7 weeks

13. Mean Serum Concentrations of Ig at different ages

14. Failure of Passive Transfer A serum Ig G concentration of <1000mg/dl by 48 hours has been defined as failure of passive transfer

15. Reasons for failure of passive transfer DAM: low colostral Ig CALF: weak calves due to dystocia, premature birth, infections, suckling calves. MANAGEMENT: first feeding too late or amount too small - CONCENTRATION * VOLUME

19. Colostrum feeding 10% of birth weight within 1 hour of birth 5% of birth weight at 6 hours after birth 5% of birth weight at 12 hours after birth 5% of birth weight at 24 hours after birth

20. Colostrum Quality CHECK Dry off strategy (use of dry cow antibiotic) Disease history Length of dry period Parity Colostrum leakage Prepartum milking Premature calving Dystocia Colostrum yield

21. Risk Factors IgG intake COW FACTORS: yield >8kgs, front quarter colostrum, parity of dam, heifer calves, dystocia, diseases MANAGEMENT FACTORS: prepartum milking, milk leaking, time/ amount 1 st colostrum gift, hygiene, maternity pen, caretaker

22. Colostrometer Use first milking colostrum Test colostrum at room temp. Most effective in identifying poor quality samples Specific gravity > 1.045 indicative of IgG conc of > 50 mg/ml

23. IgG concentration in colostrum 48.2 (20 – 100) mg/ml (Pritchett et al 1991) 66 (28 – 115) mg/ml (Quigley et al 1994) 76.2 (26 – 110) mg/ml (Rajala and Castren 1995) At least 100g of pure IgG must be ingested at each of the first two colostrum feedings to achieve a blood conc of at least 1000 mg/dl to reduce the incidence of disease and death

24. Serum Ig Tests Done on calves Zinc turbidity test (Ig): Gel/ turbidity if adequate Refractometer (total protein): 5.2g/dl and above Sodium sulfite precipitation test (Ig) Latex agglutination test (Ig) NA Radio immunodiffusion test kit (Ig) NA Gluteraldehyde test (Ig and fibrinogen)

25. Storage of Colostrum Room temperature for 1 day Acidified (5 gr proprionic acid or lactic acid) at 5 C for 6 weeks Deep frozen (-20C) for more than a year Not in frost free freezers Thaw in warm water (<60C)

26. Ig and disease An overwhelming pathogen challenge or environmental conditions that are poor will overwhelm even very good passive transfer

28. 3 Zimbabwean Farms Workers and Owners knew the correct method Tested serum total protein of all calves between 2 and 14 days of age. Over 50% below 5.2 All 3 farms had problems with calf scours, pneumonia and death Instituted improved colostrum management

30. 3 Zimbabwean Farms All 3 farms calves tested on a regular basis to check on compliance 2 farms constant passes 1 farm one set of over 50% failure again one month into new regime No failures over 25% since

31. 3 Zimbabwean Farms One farm greatly reduced scours and coughing, improved weaning weights Another farm no more umbilical hernias and can’t remember the last time they treated a sick calf Last farm no more scours and greatly reduced pre weaning mortality

32. Post Calving to Weaning Disinfect umbilical cord Move to clean well ventilated pens/ hutches Colostrum for 5 days Feed good clean milk at 39C at to 15% of birth weight divided into two feeds per day

33. Post Calving to Weaning Clean water from day one all day Calf meal of good quality from day 4 Good quality hay from week 2. Move hutches or clean out pens at least every three days. Check feed intakes, can be weaned when eating more than 2.5% of birthweight per day