| T O P I C R E V I E W |
| maryjane |
Posted - Nov 16 2015 : 12:03:19 PM
Here are two good articles that talk about the logistics of milking and milk let-down. Thank you Janet!!!!
Milk let-down—an efficient routine
from AHDB.org.uk (Agriculture and Horticulture Development Board)
The process of milk ‘let-down’ in the cow is of particular interest, as the timing of let-down can be used to form an efficient routine to milk cows as quickly and efficiently as possible while minimizing any teat damage that can be caused by ‘overmilking’—when there is a high vacuum but little milk flow—and also by acknowledging that the time immediately following milking is crucial to controlling bacterial entry into the teat as the teat sphincter takes time to close post-milking.
Milk let-down is controlled by unconditioned factors, most notably the response to tactile stimuli provided by a calf rubbing the udder or teat when suckling, or a similar stimulus provided by the milker when foremilking the quarter or otherwise preparing it for being milked. Other, conditioned factors, such as the psychological stimuli provided by the sounds, smells and routine the cow experiences at or around milking time also contribute to milk let-down.
These stimuli result in the release of the hormone oxytocin from the cow's pituitary gland in the brain into the bloodstream, where it travels to the udder and causes several important processes to occur.
Oxytocin release causes the mass of interconnecting blood vessels at the base of the teat to fill with blood, making the teat more erect and allowing milk to enter it from higher in the udder and pass through the teat. Oxytocin also encourages muscles throughout the udder to act to release milk. Most importantly, the muscle cells around the milk-producing alveoli deep in the udder contract and force the milk into the various ducts in the udder, down into the udder cistern and then into the teat cistern, ready for the milk to be removed by the suckling calf or the milking equipment.
This is why during milking, for efficient let-down cows should be subjected to minimal stress, as this can cause the release of the hormone adrenalin (as a response to stress) which can counter the effect of oxytocin.
The average time between beginning to prepare the cow for milking and the resultant let-down of milk is in the order of 60 to 90 seconds. During the period between milkings, an amount of milk will have already collected in the udder and teat cisterns, and will be released almost immediately upon attachment of the milking equipment. There then follows a period known as lag time, whereupon the oxytocin released into the bloodstream causes the release of milk deep in the udder. If the time between the first stimulus of the udder by foremilking or wiping the teats occurs approximately 60 seconds after beginning the process, the release of milk from higher in the udder will be practically continuous with the first release of milk stored in the teat and udder cisterns.
Where a longer or shorter lag time occurs, the milk flow can become bimodal; there is effectively a gap where overmilking can occur, even at this early stage of the milking process. Here, the high vacuum from the milking machine combined with a low or nonexistent flow of milk can cause significant damage to the teat end, making the cow more susceptible to mastitis, and likely also to lengthen the milking time significantly.
During milking, the teat lengthens while the teat canal opens up and becomes shorter, to allow faster removal of the milk from the cistern structures above it. Following milking, the overall teat length shortens, the teat canal lengthens and the teat sphincter begins to close, as the folds of skin around the opening close around one another, creating a tight seal, and the lipidised film around the sphincter stops a column of milk forming through which bacterial entry could occur. A waxy keratin seal begins to form in the teat canal to protect against bacterial entry after milking.
However, the sphincter muscle can take in the order of 20 to 30 minutes to close, and it is during this time that the risk of bacterial entry is greatly increased. This is why post-dip treatments play an important role, and also why cows should not be permitted to lie down for a 30 minute period post-milking.
---------------
A stimulating story: Harvest milk like a calf
by Ron Robinson, ProgressiveDairy.com
Since the beginning of time, calves have been efficiently stimulating and harvesting mother’s milk. As dairy operations seek to harvest more quality milk from cows in less time, lessons can be found in nature. It comes down to training milkers to mimic the calf.
Physiology of the udder:
First, let’s examine the basic anatomy and physiology of the udder. Between each milking, milk accumulates in the alveoli, the milk ducts, the gland cistern, and the teat cistern.
Most of the milk stored in the milk ducts and cisterns—about 40 percent of the total accumulated—can be removed with very little stimulation. The rest of the milk, stored in the alveoli, can only be harvested when the myoepithelial cells (muscles) contract and force/squeeze the milk out of the alveoli.
The hormone oxytocin, which is stored in the pituitary gland, is what causes the contraction of the myoepithelial muscles. When teat stimulation begins, the nerves are activated, causing the release of oxytocin. What happens next and the timing of it all is important for milkers to understand:
• It takes one to two seconds after the nerves are activated to release the oxytocin.
• It then takes 19 to 22 seconds for the oxytocin to arrive at the receptors in the udder and cause the contraction of the myoepithelial cells.
• The myoepithelial cells contract completely in six seconds.
• It takes 20 to 30 seconds to completely fill the milk ducts and the cisterns. Teats are now flush with milk.
The oxytocin flow initiated at the beginning of this process lasts for five to six minutes. For optimal milking, the milking unit should be attached within 20 to 30 seconds after proper stimulation. That’s what a calf does—stimulates milk letdown and then nurses immediately. The entire milking process, from attachment to takeoff, should take place and be completed during the five to six minutes of oxytocin flow.
It’s important to note that more and proper stimulation in the beginning of the milking process is what gets the oxytocin flowing. Increased oxytocin flow increases pressure on the alveoli, where 60 percent of the milk is being stored. Think of it this way:
More and proper stimulation >> more oxytocin >> more contraction of the alveoli >> more pressure >> more milk squeezed out of the alveoli = faster milking.
What is “proper” stimulation?
The key to proper stimulation is emulating how a calf approaches a cow, triggers milk letdown, and completes its own milking process—all within an optimal time window for milk flow.
Proper stimulation begins with forestripping, which gets the process going. It’s the equivalent to the calf’s first nudges against the udder. It also gives the milker the opportunity to check for and remove abnormal milk. The next step is teat massage, which, like the calf’s tongue, greatly aids the stimulation process.
Because time is a critical element here, I recommend the use of an effective one-step sanitation method that can both bring the stimulation process to its peak while providing good cleaning of the teat ends. The milker should use a gentle downward circular motion, as a calf does, with focus on the teat ends. This process should continue until milk letdown, at which time the milker should attach the milking unit immediately. Research shows that optimal milk harvest happens with proper stimulation and milking unit attachment within 20 to 30 seconds of stimulation.
Benefits of a good process:
The benefits of emulating the calf come in the form of increased milk flow, a boost in milk harvest, and decreased milking time. When our technicians visit dairies, we are asked to analyze the milk process from a sanitation and milk quality perspective. In doing so, we often find shortcuts in the stimulation process.
These shortcuts, according to industry research and our own field studies, really aren’t saving milking time at all, and in fact are probably costing the dairy in milk production. Why? Think back to the physiology of the udder—it takes a certain amount of time and the right type of touch for oxytocin to do its job. Once milk is let down, peak milk flow happens during that initial oxytocin flow. Timing is important.
Another benefit of proper stimulation and on-time unit attachment is a reduction in the amount of milk remaining in the udder after milking. Even with excellent milking conditions, the amount of milk remaining in an udder is typically about 12 percent to 15 percent of the total volume of milk before milking. The amount of milk left behind is increased with improper stimulation and late unit attachment.
Other notes on milk letdown:
As you evaluate your milking process for efficiencies, alert your milking team to other physiological factors that affect milk letdown. If your prescribed stimulation process isn’t yielding the expected results, one of these factors may come into play:
• Early lactation cows stimulate faster than late-lactation cows. Therefore, later-lactation cows need more stimulation for good milk letdown.
• The receptors in the udder become less sensitive to oxytocin once the cow is pregnant. That’s because hormones (estrogen and progesterone) increase, decreasing the sensitivity of the receptors in the udder.
• Trace mineral deficiencies, such as insufficient cobalt and manganese, can decrease the sensitivity of the receptors in the udder.
• Lack of calcium in the cow’s diet can affect the contraction of the myoepithelial cells (muscles) surrounding the alveoli, causing reduced milk harvest.
Getting what you want—more quality milk faster—means being kind to the cow and treating her as nature designed. That’s why milker training is so important. Make sure milkers know the “natural” techniques behind proper stimulation. Quality milk, maximum milk production per worker-hour and profitability all depend on it.
|
| 11 L A T E S T R E P L I E S (Newest First) |
| txbikergirl |
Posted - Nov 19 2015 : 4:57:02 PM
yes charlene, if only all of life could be as calming as milking a cow! |
| CloversMum |
Posted - Nov 19 2015 : 10:48:04 AM
We did a similar thing, Cindy. During the terrible storm a few nights ago, we left Humble with Clover so he could nurse for comfort. Usually they are separated at night. But the amusing part was that Clover gave us more milk the next morning. Go figure. But we were trying hard to help lessen any stress on the cows during the storm and help them to hunker down.
I am finding that the routine is so much more important than the actual timing of everything ... it makes everyone, human and cow and goat, more relaxed. I find my own tension slipping away during milking time. I do wish the rest of my daily schedule could lighten a bit so I could enjoy the milking even more. |
| txbikergirl |
Posted - Nov 18 2015 : 5:56:09 PM
the whole cow psychological thing is fascinating. yesterday we had a big storm. HUGE. an hour before milking a huge wind came through. i then had a window of about 60 minutes before torrential rain and wind hit us, so i headed to the barn to bring sally up 30 minutes early for milking. then during prep and milking it proceeded to rain and hail - on a metal roof. so loud i couldn't hear the cow moo. so unsettling she actually KICKED when trying to hobble her; she might pick up her foot now and then, she has NEVER kicked.
all this added up to a total milking session of ONE PINT. seriously. now i normally just get 1/2 to 1 gallon since the calf is still on her. but sally's nerves were so rattled that i milked all four teats dry and got one pint. one little pint.
yep, the cows feelings and thoughts matter greatly. in order to make myself feel better after this i went ahead and put the calf in with her an hour later, just to ensure i didn't start any udder/teat issues with the lousy milking.
today we had calm. everyone was happy. it was cow and human love. and we got a nice milk supply ;> |
| txbikergirl |
Posted - Nov 17 2015 : 01:54:03 AM
ok, this makes me happy. i am soooo relaxed in my morning cow routine, no stress here at all. and sally lets down her milk so fast it is amazing to me. the moment those bottles attach the milk is streaming. so i'll keep doing exactly what i am doing and not change a thing other than educating myself to constantly ensure i am not ever moving in the wrong direction.
i did notice a HUGE difference in milking once we got into the proper parlor and once i was milking on my own, and i always attributed that to (1) a proper routine for the cow and (2) a relaxed happy human milking the cow.
|
| NellieBelle |
Posted - Nov 16 2015 : 6:43:37 PM
That sounds so wonderful MaryJane. Cows are truly so mild in temperament if given the chance. I truly believe much has to do with calm and routine. They are such gentle animals. There are always going to be times where there will be some stress but if we can keep it to a minimum as best we are able, I believe they will give us all they have to give. (milk included). Isn't that something with Fanci? Such a tender scene with Finnegan and momma. The more we can let them be natural, cow/calf life and ask for a little milk on the side, maybe they will give it willingly as a natural process too. |
| maryjane |
Posted - Nov 16 2015 : 6:28:24 PM
I read through the articles ... selectively. I'd come across the hurry-up thing years ago. I ignored it then and I'm going to ignore it now. However, being reminded again about the release of oxytocin was helpful. And I'd never come across the adrenalin idea. It was a light bulb moment for me. It ties in with what we've all been trying to say and what Janet stressed again:)
Don't stress. Keep your cow free of adrenalin.
During the last week I've had someone milking with me for training purposes; stress. I've been worried about Fanci; stress. I've been anxious about Eliza Belle; stress. I haven't gotten a good night's sleep in a while; stress. I've been applying Fanci's stinging bacteria-eating dermatitis spray in the parlor after I milked; STRESS (she hates it). Consequently, I've been hobbling both her back legs; stress. On and on. Just a whole lotta stress. So this morning, I milked Miss Daisy first. I took the time to shave her and talk to her.
Then I brought Fanci in but first I turned her and her little guy loose. He was running free as the wind. It probably made her as happy as it made me. I didn't hobble her feet. I waited to spray her stingy stuff until she was away from the parlor. I talked to her. I rubbed her head a couple of times. I decided not to care how much milk she gave me. Consequently, as I milked her (one teat at time with my EZ instead of my noisy tension-producing NuPulse), her other teats started leaking onto the ground. I patted her udder and put down a towel and let her drip her "oxytocin" all over everything.
I'm looking forward to tomorrow. |
| NellieBelle |
Posted - Nov 16 2015 : 5:16:32 PM
Love the pictures of the anatomy of the udder and teats. Now if we get the physiology in our heads and how all works it could be helpful in many cases. Thank you MaryJane. |
| maryjane |
Posted - Nov 16 2015 : 5:09:14 PM
I found it helpful to spend a little bit of time looking at the anatomy of an udder.
When I get a minute later tonight, I'll tell you what I did different with Fanci this morning that I think helped. |
| NellieBelle |
Posted - Nov 16 2015 : 4:53:25 PM
Hello Cindy. I know it sounds really quick, but I think it would be worse to stress over it, or anxious, because your cow will pick up on that. Routine is important. It takes me 3-5" to clean udder and teats, but then it's really muddy here with all the rain. Sometimes, even after I've washed Nellie, tested, she won't let her milk down until she hears the milk machine turn on, then here it comes. Each cow will be different. I even got to thinking, maybe only milk one teat, then, stimulate the next and milk etc. That's a bit impractical. I think as long as things are clean and done in a timely manner it will be fine. For me, I know that the longer (weeks after and up to weaning) the milk comes easier, the more relaxed the cow and use to the routine. |
| txbikergirl |
Posted - Nov 16 2015 : 4:22:16 PM
ok, this is really good stuff. and perhaps timely as today's milk production was less than stellar.
so, here is the question - from the moment i am starting the udder/teat cleaning i am supposed to milk within 60 second? is that what it is telling me? because i think it probably takes me 5 minutes to wipe udder to ensure clean, clean each teat separately to ensure clean, teat dip, mastitis test... then go into milking.
or are they talking from the time i take my mastitis test which is the first milking... that is when the clock starts ticking? |
| NellieBelle |
Posted - Nov 16 2015 : 2:56:55 PM
Thank you MaryJane, this is much easier to get to. |
|
|
![[flourish]](/images/flourish-txt_mobius.png)
![Heritage Jersey Organization [logo]](/images/HJO-logo.png){kind=logo}
