Overmilking and Teat Condition

Transcription

1 Overmilking and Teat Condition Morten Dam Rasmussen

2 Summary Overmilking prolong machine-on time and may have negative effects on teat condition and udder health There is no real benefit of overmilking and we do not need overmilking in order to maximize milk yield Short-term effects are teat coloring and ringing at the base Long-term effect will be hyperkeratosis Excellent teat condition is not equal to excellent udder health

3 Evaluation of external teat condition Teat Condition Measure 1. Colour 2. Swelling at Teat Base 3. Swelling at Teat End 4. Openness 5. Vascular Damage 6. Teat End Roughness 7. Open Lesions Differential Diagnosis Short-term Responses to Machine Milking Longer Term Response to Machine Milking and/or Environment Environmental, Chemical, Viral Causes

4 Teat Condition Measures and Criteria for Further Investigation (Mein et al, 2001) Teat Condition Measure 1. Colour 2. Swelling at Teat Base 3. Swelling at Teat End 4. Openness 5. Vascular Damage 6. Teat End Roughness 7. Open Lesions Criterion > 20% visibly reddened or blue > 20% swelling or palpable rings > 20% firm, hard or swollen > 20% classified as open > 10% petechiations > 20% Rough and Very Rough > 5% open lesions or cracked skin

5 Overmilking may affect AARHUS UNIVERSITY Ringing Swelling Redness Openness Roughness

6 No ring AARHUS UNIVERSITY Rough ring Smooth ring Very rough ring

7 Score No Ring Illustration Smooth Rough Very Rough

8 Anatomy of the teat canal

9 Keratin cells are formed in the teat canal and protect against invasions

10 Teat canal lumen Epithelium Milk flushing & massage AARHUS UNIVERSITY Desquamation KERATIN Keratinocyte differentiation Keratinocyte proliferation

11 Interaction with liner and teat 0 mm 25 mm 55 mm 85 mm

12 Overmilking dis-colour teats more than wrong choice of liner, % cows (Hillerton et al., 2002) Overmilking, min Fit liner Wide bore Narrow bore

13 Wide and narrow bore liners make teats hard or firm with overmilking, % cows. (Hillerton et al., 2002) Overmilking, min Fit liner Wide bore Narrow bore

14 Pulsation Pulsation failures increase new infections The liner has to collapse around the teat end Pulsation becomes critical as vacuum increases and overmilking takes place D-phase >250 ms Pulsation rate >55 cycles per minute

15 High vacuum increases teat thickness % kpa 40 kpa 30 kpa , Min. after detach Hamann et al. 1993

16 The mouthpiece lip Seal at the teat base Keep vacuum and avoid liner slips Stiff lips occlude and cause ringing Soft flexible lips allow passage of tissue fluid

17 The mouthpiece chamber Local vacuum reserve Prevents liner slip Lack friction Too short teats = too high MPC vacuum

18 What happens inside the teat during overmilking?

19 What happens during suckling? Teat cistern Teat end = mouth

20 Breeding for high milk yield has resulted in More alveoli tissue Relatively higher cisternal capacity Cows less sensible to changes in milking routines Is it possible to under-milk without loss of milk?

21 Detachment at 200 or 400 g/min (Rasmussen, 1993) Research Center Foulum, Denmark Two groups of cows for complete lactations Total 135 cows included Switch point 200 g/min, delay time 18 s Switch point 400 g/min, delay time 12 s Stanchion barn, high pipeline milking

22 Early removal decreased machine-on time Min 10 8 Older cows First lactation Days

23 Early removal improved teat end condition % Older cows First lactation Days

24 Teat thickness was influenced in first lactation Group thickness of front, % thickness of rear, % 5.5* 1.1

25 Clinical mastitis per 100 cow days Group First lactation Older cows

26 High thresholds for 3X cows (Reid & Stewart, 1997) , 2x10 milking parlor kg/min, delay 15 3 s Machine-on time: min Hand stripping: < 0.1 L/cow Milk yield: kg/cow/day No kicking, easy to milk first lactation cows

27 Detachment at high thresholds (Stewart et al., 2002) Herd 1: 0.50 and 0.64 kg/min Herd 2-4: 0.73 and 0.84 kg/min Increased milk flow Decreased machine-on time Increased milk yield in two herds

28 Fixed machine-on time for slow milking cows (Clarke et al., 2004) Machine-on time: 34% No loss of milk yield Higher strip yield (NS)

29 Removal of the milking unit 400 g/min reduced machine-on time, no loss of milk (Rasmussen, 1993) 400 g/min and fixed machine-on time, no loss of milk in mid to late lact. (Clarke et al., 2004) 900 g/min and 3X daily milking, faster milking and no loss of milk (Reid and Stewart, 1997) 800 g/min, 2.5% loss of milk (Magliaro and Kensinger, 2005)

30 Detection of overmilking No milk in hoses or claws Restless or kicking cows Nervous first lactation cows Fluctuating mouthpiece vacuum Observe teat color and ringing Rough teat ends

31 Environment Milking Machine Operator Cows AARHUS UNIVERSITY Evaluation of milking performance, (Reinemann el al., 2005) Machine-on time High yield, Damaged teat canal, Small diameter teat canal Concerns related to milking performance. Slow Milking Milk Quality Milk Yield Teat Condition Cow Behaviour Unhappy Workers Symptoms and tests to quantify the situation Cows milked per hour High yield, Cow behaviour (see behaviour section) Somatic cell count (Bulk tank SCC) Genetic predisposition Bacterial \count / Other (Bulk tank SPC, TBC, or Bactoscan) (kg/cow/milking) (kg/cow/day) Possible Causes and Tests (see text for test numbers) Streptococcus agalactiae, Streptococcus uberis mastitis Genetics Teats rough, swollen, discoloured, or lesions Pointed teat end, Slow milking cow (see slow milking section) Stepping, kicking, urinating, defecating Breed Injuries, complaints Poor cow behaviour (see behaviour section) Late manual removal, poor preparation Work routine efficiency Pre/post milking teat sanitation, separating infected cows Pre-milking cow sanitation, unit fall-off, equipment cleaning routines Animal handling, Milking Routine unit balance Late manual unit removal teat dip coverage Cow handling in parlour and in housing area Control over work environment, level of pay, unit slips and falls ACR setting, milking vacuum level, pulsation, liner design. Maintenance Too few clusters, milking unit slips and falls, unit balance Milking vacuum level, pulsation, liner design, Effectiveness of equipment cleaning, milking unit falloffs Completeness of milking Milking vacuum level pulsation, liner design, ACR setting High milking vacuum, over milking, uncomfortable liner, pulsation Machine working properly, ease of use, educated workers, milking unit slips and falls Cow comfort in holding area and parlour Cow cleanliness, ease of cow movement, gates, lanes, etc. Clean, dry cow housing and exercise areas General level of farm sanitation Nutrition, access to water, cow stress, temperature, humidity, disease Clean dry housing environment, chemical contact, change in climate Ease of cow movement, lighting, dogs, other stresses Ergonomics and light levels in work areas, risk of injury, working hours / breaks, expectations, communication

32 The mastitis complex Correct antibiotic treatment Protection against transmission Good feeding and management Good surveillance Analysis and interaction Good milking routines Biological barrier Physical barrier Milking machines Milking Infection Teat dip/spray Mastitis Hygiene Immunity Stress Feeding Teat shape Teat skin condition Teat skin colonization Teat dip/spray Housing system Climate Minimal stress Good cow comfort Breeding for better: Teat shape, condition Mastitis resistance Good skin condition (teat dip/spray) Good hygiene and environmental protection Well functioning milking equipment Good bedding and housing K. Krogh

33 Conclusions Overmilking has negative effects on teat condition and may lead to reverse pressure gradients across the teat canal There is no real benefit of overmilking and we do not need overmilking in order to maximize milk yield Some hyperkeratosis is not detrimental to udder health Keratin must be removed from the teat canal during milking

34 Recommendations Fit the best liner for the herd Maintain the milking equipment espc. pulsators Avoid milking at 45 kpa or higher Early detachment Increase switch point in small steps Decrease delay time Monitor milk and strip yield Watch chronically infected cows Consistent milking routine well prepped cows

35 Thank you for your attention