Milkability

The dairy industry is swiftly changing. Dairies are becoming larger, more productive, and more intensively managed. High-quality labour may be difficult to attract and retain. The recent low milk prices have presented an all too obvious challenge. Consumers are increasingly demanding higher quality and safer products. Legitimate somatic cell count levels will likely be reduced in the next few years.

 

 

These changes require technical advances in milking systems to milk cows efficiently in a manner consistent with highest product quality and animal health. On most commercial dairies, the parlour is a major capital investment. It is also where the primary income source is reaped, where much of the labour is employed, and where the quality of the product is largely determined. For these reasons, parlour performance and efficiency discussions are common in today’s dairy industry. The goal of most dairies is to milk as many high-producing cows during each milking while still allowing time for adequate cleaning of the equipment. Several studies have shown teat condition and teat sanitation prior to unit attachment are key factors in reducing the new mastitis infection rate. Poor teat skin condition decreases the primary protective mechanism from mastitis. Roughened teat end conditions can cause difficulty in cleaning teat ends effectively. These factors can lead to higher new infection rates. Many herds in the United Kingdom have problems with good “milk ability”. Cows may be more reluctant to enter the parlour in these herds. In a parlour, poor milk ability can be spotted early in the milking process when cows move and step excessively during udder preparation practices. Stepping may also be seen soon after the units are attached and/or near the end of milking, often leading to a significant number of units being kicked off during milking. Excellent milk ability is present when cows have excellent milk flow as soon as the last teat cup is attached to the cow, with a steady, visible increase in flow until peak levels are reached. Peak flow should last 60 to 120 seconds, depending on the production of the cow. With excellent milk ability, milk flow will drop off rather quickly after peak milk flow is over. As the end of milking nears, milk flow should suddenly drop to very low levels. If equipment settings are proper, the unit will then be promptly removed. There should be minimal stepping and kicking throughout the entire milking process. Good milk ability requires adequate oxytocin prior to units being attached to cows. However, this creates a major dilemma in the industry. To achieve better performance from a parlour, the goal often becomes focused only on milking more cows. When more cows are milked, there may not be enough time allowed to properly prep cows for effective cleanliness and maximum oxytocin let-down. Unit on time (duration) is a key factor of parlour performance that has been largely ignored until recently. Unit on time is dependent on the amount of milk and the average claw vacuum under peak milk flow conditions. Adjusting systems to achieve average claw vacuum levels between 40 to 42 kpa under peak milk flow conditions will decrease the unit on time. Adjusting take off settings to remove units promptly upon completion of the milking will also significantly reduce the unit on time.

 

Research in both Europe and the United States has shown the key factor to reducing teat end hyperkeratosis is unit on time. To appreciate how unit on time contributes to reduced teat end hyperkeratosis, it is important to understand the normal pattern of milk flow from cattle during each milking. Immediately after the unit is attached to properly stimulated cows, milk flow increases rather rapidly until it reaches a peak milk flow rate. This peak flow rate is variable and depends to a great extent on the amount of milk actually given during a milking. After a period of peak milk flow, milk flow drops rather quickly. Depending on how the milking equipment is set, there can be a long period of extremely low flow and relatively higher vacuum exposure of the cows’ teats. The longer the period of relatively low flow, the longer high vacuum and increased pulsation cycles will be applied to the teat ends. This will lead to increased hyperkeratosis and a reduction in skin condition teat scores. Adjusting take-offs to remove units sooner will simply shorten the low flow/high vacuum phase at the end of milking. Removing units sooner and at a more appropriate time is important to improve teat end condition and teat end scores. However, earlier removal of units is in opposition to one of the oldest doctrines of the dairy industry: Under-milking the cow
Will cause new mastitis infections. This urban myth in fact is not true, but this perception is very difficult to overcome on some dairies… Proper udder preparation allows cows to milk quickly, completely and evenly, all of which are key factors to improving milk ability in the herd. Improved milk ability will improve the attitude of operators because fewer units will require readjustment or reattachment. Clearly, reducing unit on time offers distinct advantages to any dairy farm.