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Newsletter of Penn Dutch Cow Care September 2010

Hi Folks,

As the summer season draws to a close we should consider how our animals have done out on pasture this season. For milking cows, it is pretty easy to see how well they have been doing by milk production and body condition. While we see them everyday close-up at milking times, we may at times become numb to what we always see in front of us and thus lose an objective or “detached” viewpoint which sometimes can lull us into a false sense of security. Yet with younger animals, especially weaned spring calves out on pasture, we don’t see them quite as much and at times may think “gee, they don’t look quite as good as they did earlier”, but then not think much more about it until the next time they are really looked at, maybe a week or two later.

As I have written on various occasions previously, adult cows generally can withstand various environmental pressures that younger animals simply cannot. This is because younger animals don’t have the ability to adjust as well to brand new situations since their immune systems have not had previous exposure to various challenges yet. This is where vaccinating for a disease which has repeatedly occurred on a farm may be beneficial. While vaccines will prepare an animal for future challenge, they sometimes are relied upon too much and cover up (like a band-aid) some root cause of disease in the animals’ environment. Additionally, vaccines won’t work well if the animals’ nutritional plane is deficient. However, I didn’t intend here to write on vaccines; I am simply saying that young animals are more prone to show the effects of challenges they face.

In my experience, some of the most troublesome problems for dairy animals of all ages are parasites. Parasites are those organisms which make their living at the expense of others, without giving anything back in return. It’s pretty much that simple. And usually the parasitized animal will show wear and tear. A really “smart” parasite will live off the animal (or person) as much as possible without causing the death of the host – for then the parasite is out of a home. Parasites can live internally in an animal or person or externally on the animal or person’s skin. A parasite could be a single organism, such as a tick that attaches to a dog or person. In farm situations the parasite is more often a population, such as an infestation of internal worms, coccidia or flies. Of course the population is made up of individuals, but it is the effects of the combined individuals (the population) that make for the downfall of a beautiful milk-fed, spring calf into a pot bellied, diarrhea squirting, rough-haired, poorly muscled animal. This happens to purebred Holsteins and Jerseys as well as cross-bred animals. It has nothing to do with breed in this case, it has to do with the biological reality of the bovine immune system not yet being fully functional against internal parasites until the animals are about a year old.

Of course just because a disease causing organism like a parasite (or bacteria or virus) is in contact with an animal does not mean that disease will necessarily occur. It greatly depends on the plane of nutrition of the animal(s) as well as their environment. If the animals are on a robust plane of nutrition and they have been given proper shelter, bedding and access to clean water at all times, those parasites will be held in check because the animal’s immune system can rally, adjust, and win the battle. Keep in mind that in a typical day, an animal or person is exposed to thousands of challenges, and thanks to the immune system we stay healthy, at least on outward appearance. Yet in young, weaned animals the point of outward illness is sooner and they will be much, much weaker once the outward signs appear. With a constant and increasing challenge by the same exact bug – combined with possibly inadequate nutrition and perhaps not proper shelter, bedding and fresh water – the bug will win. Or at least it will make major gains against the immune system of the animal, its host. This is even though the immune system is constantly reorganizing itself and re-shaping its response to the assault. In the ongoing battle between parasite/bug and the animal, the balance tips in favor of one or the other at some point. It is all simply a matter of time. Either the animal comes through the challenge, and in my opinion will be stronger for having won the battle, or it doesn’t. What the farmer does in the mean time is the critical element. It is absolutely crucial, especially with young recently weaned animals, that they are given solid support in terms of nutrition and their environment. If not, there will be – and I have seen it countless times – a slow but steady downward demise to what were an absolutely beautiful set of milk-fed spring calves.

One of the main reasons for the demise is that weaned calves are often put on the exact same paddocks as a steady stream of previous calves. The parasites are waiting for them in those areas. It’s that simple. And with the warm, humid summer air that we have in the northeast, the conditions are excellent for those parasites (in the form of internal worms and flies) to rapidly multiply every few days. The flies you can easily see, but the worm larva you cannot. But the effects of the internal worm parasites are usually noticeable right about now (early September through early October). Additionally, if the immune system is being taxed heavily in its effort to keep things in balance to allow the basic survival of the animal, watch out when we get a spell of rainy cool days. Now the immune system has to re-double its efforts as the animal chills…..and then begins to cough….and cough and cough. This is happening while the animal is still dealing with an infestation of internal worms, which are constantly sucking blood from the stomach lining to grow and reproduce themselves. The animal becomes anemic due to blood loss. How on earth can an animal win in that situation? Sure, the animal can “make it” but hasn’t it lost an incredible amount of time and energy which it could have been putting toward growth? Sure, they are still eating, but it is a constant losing battle if the parasites are sucking the life right out of them.

OK, so I started by talking about how we can become numb to situations that we see routinely, like our milking cows (for example some being slightly lame). We let it go because there are more pressing tasks to do than lifting a cow’s hoof to examine it and deal with it. (That’s not good since putting off a problem is never smart - especially in organics). And then we go and check the group of calves occasionally (that we are not “numb” to). What do we do when we see that they aren’t looking as good as they did just a few weeks ago? Do we let it go, hoping for the best? Or do we address the situation – moving them to a different pasture, supplementing them more robustly, giving them really good quality feed? (For calves, nice looking pasture can still come with parasite larva waiting for them.) In the end it is a matter of time – do we finally reach for the medicine (like ivermectin, which is known to kill dung beetles) or the antibiotic when they are coughing with snotty noses? More importantly, what are the biological consequences to your animals and your system?  And what are the economic consequences to you at that point?  As its said: An ounce of prevention is worth a pound of cure. It all comes down to priorities, ideals and reality – not always an easy set of factors to balance. But keep trying; it’ll be worth it in the long run.

 

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

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