Effects of milking machine settings and teat liners on bovine udder health

Abstract

The purpose of milking machines is to harvest milk at an optimum speed while maintaining cow comfort and preserving teat defence mechanisms against the invasion of mastitis pathogens, thus making machine settings critical in dairy herds. The various settings and combinations for milking machines were reviewed to enable operators to optimize them to preserve teat canal integrity and minimize mastitis. All databases of Web of Science and relevant websites were used to document machine settings and teat liners. All vacuum levels in milking systems need to be monitored. In addition, liners, milk yield, and automated cluster removal switch-point settings need to be regarded as bearing a risk of teat damage. They affect milking speed and vacuum levels at total, peak, and over-milking. An equilibrium should be reached between optimal milking speed and risk of teat damage. An increased switch-point setting shortens milking time and decreases overmilking and claw vacuum to preserve teat-canal integrity. Analysis of milk flow dynamics with a VaDia instrument highlights opportunities to improve milking protocols and equipment functions that align with the physiology of the cow. This knowledge can be applied on individual farms, in which herd milk yield, parlour layout, milking machine system, parlour management, and economics should be considered to obtain a balance between milking efficiency, udder health, and cow comfort. Standards for switch-point settings were identified in this review.

Milking Machine Settings and Liner Design Are Important to Improve Milking Efficiency and Lactating Animal Welfare—Technical Note

“…The ideal milking system meets the physiological needs of lactating animals to increase milk yield, achieve better milk quality and maintain healthy udders. Therefore, the settings of the milking machine are very critical to lactating animals [5,29]. Individual quarter pulsation milking systems may prevent overmilking and improve teat-end condition [10,25,30].…”

“…Thus, vacuum pulsation and the pulsation ratio are important operating parameters that affect milking performance [5,34]. An ideal pulsation setting on the milking machine helps to maintain a high milk flow, limit animal discomfort, reduce the occurrence of new intramammary infections and stimulate the milk ejection reflex [29]. Interestingly, individual quarter-pulsation milking systems can prevent overmilking and reduce hyperkeratosis in Holstein cows [48].…”

“…This helps to avoid teat congestion when using vacuum milking machines [47]. However, post-milking teat thickness tends to increase with the pulsation ratio, whereas it decreases significantly when the pulsation rate is between 20 and 80 cycles/min [29,35,47]. It has also been found that pulsation rates below 55 cycles/min affect udder health by increasing the risk of new intramammary infections [54].…”

“…These artificial physiological and pathological changes in the circulatory system damage the teat ends, reduce the effectiveness of the udder's defense systems [53] and cause mastitis [34,55]. Thus, changes in teat condition can occur [29,34], which can be divided into short-, medium-, and longterm changes [56]. The most important short-term changes caused by circulatory disorders are discolored teats, ringing, swelling and openness of the teat canal [27,34].…”

“…The liner plays a big part in this as its movement provides continuous stimulation during milking, resulting in oxytocin release and continuous milk ejection until cluster detachment [1,64]. In all cases it has been shown that liners, milk yield and blind milking must be considered as risk factors for teat damage as they affect milking speed, overall vacuum levels, peaking and over-milking [29]. A balance should be struck between optimal milking speed and the risk of teat damage.…”