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Newsletter of Penn Dutch Cow Care April 2013

Hi Folks,

As I write this I’m looking out the window and see our Amish neighbor plowing the field behind our house. It’s a chilly 40 F but sunny and pleasant. The horses probably like this weather to work in. We’re wondering what will be planted but will have to wait and see what starts turning green. We’re hoping the field will be pasture so the cows will be right behind our backyard.

Speaking of pastures, they are certainly later getting started this year, that’s for sure. As we soon get into the early pasture season, there are some things that come to mind for cow health. Many folks may think “what problems can there be with cows on pasture?” Well, believe it or not, there can be some. Above all, changing the diet of the herd radically by putting them all out onto lush growing pasture can cause digestive upsets. Try putting cows on grass for only a few hours a day at this point while still feeding the dry hay and/or long leaf baleage in the barn. Moving cows quickly through fields at this point is also good so they don’t trample young growth too much. Keep them in a paddock for an hour or two and move on. Transition your cows to 12 hour grazing by going from 2-3 hours per day in pleasant afternoons to both morning and afternoon grazing over a week’s time. It’s understandable that people want to get their cows out of the barn but try to do it in a way that doesn’t hamper the early growth of your pastures, otherwise you might be shooting yourself in the foot.

Once pasture is in full gear, we often notice cows with pipe stream “pasture” manure. What does this mean? Simply put: excessive rumen degradable protein. Fast growing grass in the vegetative state is simply chock full of protein – actually way too much for a cow’s rumen to remain healthy. All that protein from the pasture creates ammonia as it’s broken down. That ammonia can seep through the rumen walls. The cow’s system takes care of it by sending it to the liver, which converts the ammonia to urea. This urea is then in the blood stream and is called blood urea nitrogen (BUN). This BUN is mostly turned into urine and excreted. But the BUN also freely moves into the udder and creates milk urea nitrogen (MUN). This whole process is the cow’s way of getting rid of too much protein intake – but transforming the excessive ammonia costs the cow biological energy and lowers milk production. This is part of the reason why we often see cows on prime pasture getting lean. But we can reduce this excessive drain on their system in two simple ways, by making sure (1) that there is enough energy for them to balance out the excessive protein being taken in and (2) by slowing down the rate of passage through the rumen by feeding effective fiber.  The best effective fiber is dry hay – but cows don’t tend to like the dried feeds when they have lush green salad to enjoy in the spring time. They will eat it, though, by pouring or spraying diluted molasses on it – and the molasses will provide energy to the rumen as well. And while many farmers that are into grazing do not like the thought of corn silage (even though it’s a grass itself), corn silage actually complements grazing well because it provides energy and fiber… and cows still like it even when on pasture! Regardless, balancing intake protein, fiber and energy is critical for your cows’ sake.

While cows on pasture are athletes and very fit due to exercise, folks also need to keep in mind basic biology. By matching the amount of pasture fed to the pasture stand, it will be a win-win situation. In the 2010 study I did when taking pasture clippings to size paddocks for desired dry matter intake from pasture, I found that the best time to put cows onto a field is about when you’d make hay: for instance, when the clover is about 7-8”, the alfalfa is early bloom at 10-14” and orchard grass is 12-18” high. At this height it yielded about 250 lbs dry matter per inch per acre. At that height, it provided the best quality according to brix measurements. It also provided some effective fiber right from the pasture itself. Give it some thought. If starting to graze pasture 24” or taller, it’ll be too mature to support good levels of milk production. Draining cows of milk twice daily means feeding your cows correctly. The New Zealand method of grazing 4-8” tall grass simply doesn’t work in southeast PA due to excessive protein, lack of fiber and lack of energy.  But it sure could fit cooler areas that simply cannot grow grass any taller.

I have a couple other thoughts prior to full spring grazing. Every year I usually get at least a few calls from alarmed farmers that cows are suffering from pasture bloat. Pasture bloat is a very real problem but easily prevented by feeding your cows correctly. Pasture bloat results from putting cows (especially hungry cows) onto legume dominant pasture for a few days in a row and is most likely to happen in the cooler early or late times of the season, though it can happen mid-summer. Always feed your cows some dry hay or long leaf baleage ½ hour prior to putting out to pasture regardless of pasture species as the fiber mat in the rumen is vital for cow health. Pasture bloat is even more likely if putting cows onto frosted legume pasture – always wait 2 hours after frost is off prior to putting cows on legume dominant pasture.

Another possibility for cows on lush pasture is, believe it or not, rumen acidosis. The condition is created during lush early growth and the cows are brought inside and immediately fed grain, and then fed baleage and then out to pasture again, with the cycle repeating itself. The problem is easily prevented by NOT feeding grain first thing to cows coming in from pasture. Never feed grain to cows straight after pasture – it’s way too much highly fermentable starch for the rumen to handle after the rapidly fermentable sugars from pasture are already in there. Always put some kind of forage out first – whether it is hay, baleage or corn silage. Then feed the grain. While I have seen rumen acidosis in grazing herds, the fact that they walk on the land and not only on concrete has saved their hooves from the severe damage that rumen acidosis can cause.   

We all know that grazing is more of an art than a science. But just because cows are on green grass doesn’t necessarily mean that their rumens are healthy and happy. Perhaps one of the best and easiest ways to watch rumen health is to let your cows tell you how they are doing. Do they chew at least 60 chews per cud that they bring up? It’s easy to do - simply count the chews they chew of a cud right after they bring it up. Do it with a bunch of cows. If chewing less than 50 chews per cud they are lacking fiber for the rumen mat. That is actually vital biological information to know. Also, are at least 60% of the cows chewing cud an hour after eating? And, what does the manure look like? With good digestive health manure should not shoot out of cows like water from a hose but instead should “set up”. It also shouldn’t have any grain chips in it. That’s money going right through your cows without any benefit to you. Truly, feeding stored forage really can balance out lush green grass nicely. By some simple steps, you can make sure that your cows are healthy and happy when out on pasture this season.

 

For Bovinity Health, information on functional alternatives to antibiotics see:
www.bovinityhealth.com

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