Vacuum levels and milk-flow-dependent vacuum drops affect machine milking performance and teat condition in dairy cows
Open Access
- 1 April 2016
- journal article
- Published by American Dairy Science Association in Journal of Dairy Science
- Vol. 99 (4), 3096-3102
- https://doi.org/10.3168/jds.2015-10340
Abstract
Different levels of claw vacuum during machine milking may influence milking performance and teat condition. The claw vacuum acts on the teat and is responsible for removal and transport of milk but is also causing potential effects on the teat tissue. In the absence of milk flow, the claw vacuum is similar as the system vacuum. During milk flow, the claw vacuum drops to lower levels depending on lifting height and tube length and diameter, which may influence milking performance and the mechanical load on the teat tissue. The goal of the present study was to investigate the effects of high system vacuum and extremely low claw vacuum during milk flow on milking performance and teat condition after milking recorded by ultrasound. Treatments were control (treatment 1) with a system vacuum of 42 and a minimum claw vacuum during milk flow of 33 kPa; treatment 2 representing a system vacuum of 50 kPa, with a minimum claw vacuum almost similar as treatment 1 (34 kPa); and treatment 3 with the same system vacuum as treatment 1 but a claw vacuum drop during milk flow down to 24 kPa. Total milk yield was similar in all treatments, but strip yield was lower in treatment 3 than in the other treatments. Milk flow was similar in treatment 1 and treatment 2, but was reduced in treatment 3, thus causing a prolonged milking time in treatment 3. Teat wall thickness was increased and teat cistern diameter was decreased in treatment 2 as compared with the other treatments. The results demonstrate that the minimum claw vacuum had the main influence on milking performance independent of the level of the system vacuum and related vacuum drops and a low minimum claw vacuum caused low milk flow and long milking times. Teat condition at the end of milking, however, was mainly dependent on the system vacuum, and the load on the teat tissue was obviously increased at a system vacuum of 50 kPa. This effect was obviously occurring toward the end of milking when milk flow decreased and hence the milk flow dependent vacuum drop disappeared. Therefore, an early cluster detachment should be considered to avoid an increased effect on the teat tissue. Estimates of simulated early detachment levels in the present study of up to 1,000 g/min lead to the assumption of minimal milk loss at simultaneously shorter machine-on time through the avoidance of lowest milk flow at the end of milking.Keywords
This publication has 21 references indexed in Scilit:
- Dynamics of teat-end vacuum during machine milking: types, causes and impacts on teat condition and udder health – a literature reviewJournal of Applied Animal Research, 2015
- Milk flow-dependent vacuum loss in high-line milking systems: Effects on milking characteristics and teat tissue conditionJournal of Dairy Science, 2010
- Oxytocin Release and Milk Removal in RuminantsJournal of Dairy Science, 1998
- Simultaneous recording of oxytocin release, milk ejection and milk flow during milking of dairy cows with and without prestimulationJournal of Dairy Research, 1996
- Teat Tissue Reactions to Milking: Effects of Vacuum LevelJournal of Dairy Science, 1993
- Teat Reactions in Cows Associated With Machine Milking*Journal of Veterinary Medicine Series A, 1992
- Effects of α- and β-adrenergic agonists on intramammary pressure and milk flow in dairy cowsJournal of Dairy Research, 1991
- Responses of the bovine teat to machine milking: measurement of changes in thickness of the teat apexJournal of Dairy Research, 1988
- Milking Vacuum Influencing Indicators of Udder HealthJournal of Dairy Science, 1981
- 415. Factors affecting the rate of machine milkingJournal of Dairy Research, 1950