Worms...

Okay, not just any worms but rather internal parasite worms. Pretty fun subject huh? Well, yesterday I received my December issue of "The Stockman Grassfarmer" in the mail and somehow after flipping through the pages the first article I read was about worms a.k.a. internal parasites. The article is by Allan Nation and talks about pasture-rotation system that was started on research farms in New Zealand back in the early 1940's. It is part informational article about the benefits of pasture rotation for controlling parasites in young calves and part, "this is how management intensive grazing really got started," article.

Research at the Ruarkura Animal Research Station in Hamilton, New Zealand led to a rotational leader/follower system in order to help control the parasites that were killing many of the countries dairy calves. Despite the use of wormers the calves were having problems both in the short term, and in the long term because they were not building resistance to the worms. One of the researchers, Dr. C.P. McMeekan, says that internal parasites are a normal part of a pastured animal's life and that they can develop resistance to them if they are constantly challenged by them. The problem was that either the calves were dying because of overload or the were having problems in the future as the parasites became resistant to the wormers and the cattle hadn't built up the strength to combat them.

Their dairy calves were allowed access to pasture early and could even be weaned on to grass as early as eight weeks according to Mr. Nation's article. Once on the grass the rotational system began. The researchers found that parasites live on the bottom two inches of the plants in the pasture so the obvious solution to them was to not let the calves graze at that level. In order to accomplish this they divided the pasture in to paddocks (here is the history part) so that the baby calves could graze ahead of the cows. Once they had that separation accomplished the next step was the rotation. To keep the calves from hitting that bottom two inches they would rotate them daily ... and daily or at most every other day ... is the key.

They found out that their research and system worked. The calves still had a parasite load, but they could deal with it partly because they system fought them and partly because they were eating such high quality forages. Thus, rotational grazing was born ... or something like that.

The pasture rotations will also combat parasites if you are running different types of livestock through the pastures because that helps break the cycle also. It is a pretty fascinating topic because really what it all goes back to is how the animals were created to function. Now we are just trying to capture what they did on their own and do it in a controlled environment.