Getting the Cream
Enlightened house cow keepers will know that some of the most vital nutrients in milk are found in the cream.
For many a primary reason for keeping a family cow is to ensure she is fed and looked after in a way that maximises that nutrient quality and quantity.
Getting the cream, however, is a challenge that many new to milking face, as most cows will hold back at milking time and preferentially give the cream to their calves. Although the channel island breeds, Jersey and Guernsey, are known for their high butterfats, practicing a harmonious milking technique will encourage every cow give her creamiest and most nutritious milk, as well as raise her calf.
Understanding both the physiological process of milk production and the key role that the hormone oxytocin plays in the psychological process in triggering a cow to let down her milk is key to getting the cream.
MILK SYNTHESIS
Milk is synthesised in small goblet-shaped cells called alveoli. There are many thousands of these within the udder tissue. Like leaves on a tree, each has a narrow duct (stem) leading to the equivalent of a twig, then a branch and on down to the main trunk, which in an udder is a small milk reservoir called the cistern.
Each of the four quarters of the udder has its own cistern that is just above where the teat joins the udder. Each quarter is an independent unit, which is why a cow can lose (usually from infection) or dry up in one quarter but still have three fully functioning quarters.
As milk is continuously synthesised and the alveoli swell, milk leaks out of each alveolus via the network of ducts and into the cistern. However, the cistern is small relative to the size of the udder, and different components of milk leak at different rates.
When a sample of whole milk is viewed under a microscope it can be seen that the molecules of fat globules are at least 100 times larger than the next largest molecules in milk, the water-soluble proteins. The fat globules are not only the largest particles in milk, they are also the lightest, which is why fat rises to the surface when milk is left to stand.
FORMILK AND HINDMILK
Fat globules also tend to stick together which, along with their large size and light weight, means they accumulate in the alveoli in much higher proportion relative to the other components of milk, which, being smaller and heavier, leak more readily. Thus, prior to milking, the cistern, and ducts leading to it, will contain a higher proportion of more watery, mineral and protein-rich ‘semi-skimmed’ milk, called the foremilk. While the alveoli will contain a relatively high proportion of the butterfats and associated fat-soluble nutrients, called the hindmilk.
There is only one way to get this creamy hindmilk and that is by the action of oxytocin. Oxytocin triggers the contraction of the smooth muscle cells that surround each alveolus and literally squeeze the contents out of the milk-production cells and down into the cistern.
Without the action of oxytocin only the small amount of watery milk held in the cistern will be forthcoming at milking and any form of stress will counteract the action of oxytocin.
Thus, understanding both the physiological process of milk production, and the psychological process of its release, is key to getting the cream. Whilst developing a trusting relationship with your cow is the first step, share-milking with the calf is a technique that can be used to manifest harmony on a daily basis.
SHARE-MILKING WITH THE CALF
Whether a freshly-calved heifer, or an older cow who perhaps had not been allowed to keep her calf before, milking a cow at the same time as her calf is suckling is a tried and tested method for getting the cream.
Mother Nature is on our side when we work in harmony with our cows. Oxytocin is not just the hormone for milk release, and getting the cream, it is the maternal hormone of bonding and contentment.
Oxytocin is produced in large quantities at calving and, thus, when a cow calves her natural instinct to mother her calf is incredibly strong, and she will enthusiastically lick her calf clean and nudge and encourage them to stand to suckle.
With share-milking the aim is to piggy-back this natural instinct to feed her calf. It works most effectively if started within the first few days after calving to take advantage of the fairly brief window of opportunity when it is relatively easy to ‘hard wire’ a connection in the cow’s mind that triggers the oxytocin release when milked as well as when her calf is nursing. Although it can be started later in the lactation, it may just take a little more finesse and time to achieve.
Prepare for a successful milking by bringing the cow and calf inside in the evening so that her calf can be penned next to her overnight. The calf pen should enable the cow to see and lick her calf, so she does not get distressed, but does not allow the calf to suckle.
Last thing at night, the calf should be encouraged to nurse by putting him up to his mum’s teat and squeezing a little milk onto his nose. Then, with a full belly, he can go in his pen next to mum for the night. Provide hay and water for the calf, even if only a few days old.
Early next morning, so the overnight parting is no more than 8hrs for very young calves, prepare your cow for milking and then let her calf out of the pen. The calf will, of course, be hungry. Guide him to a front teat. As soon as he is latched on and sucking well, attach the cluster and milk the other three quarters while the calf is suckling. The milk should gush out and a nice head of froth in the milk bucket is a sure sign of a good let down.
This might sound easier said than done but if the groundwork has been put in place and the first harmonious technique of building a trusting relationship with your cow has been mastered, then really it is quite straightforward to start share-milking.
A cow is usually quite happy while her calf is suckling and will soon associate the cleaning of her udder and the noise of the milking machine with that all-important oxytocin release and let down reflex. After morning milking the cow and calf stay together for the rest of the day.
This process should be followed until it is clear the cow is totally at ease with being milked and is routinely giving you the cream with a good let down. When training a heifer this might take up to two or three weeks but, once learned, the next time she calves it will likely only take a week to ten days of following this routine again to remake the connection.
Once that association is made, then the cow and her calf can stay together 24hrs a day if desired. All cows are different and occasionally one will lose the association of letting down at milking time. If that happens, simply re-train her using the same process for a couple of nights.
THINK KINDLY OF YOUR COW
Getting the cream involves understanding both the physiology and psychology of cows, and working with their natural instincts. Whatever milking routine and calf-management system is used, the health, welfare and contentedness of a cow and her calf is the responsibility of their keeper and should always take priority over milk production volumes. Thinking kindly of your cow, however, usually results in getting the cream, and creamy milk is a good indicator of a content and relaxed cow.