Thanksgiving is behind us now, along with all of those large endless choice meals. It is kind of hard to not over eat, or eat what you should be eating, when temptations are surrounding you. Our grazing livestock actually does a better job of balancing out their perfect diet than we usually do and they don't need any food labels or scales to do it.
Ruminants have the ability, through what I will call biological feedback, to instinctly know what they should be eating and how much. Their biggest problem is usually availability. We see this easily in the spring when cows are eating the lush watery high-nitrogen forage; they need dry matter to balance it out so they search and consume whatever they can find to help maintain that mat in their rumen. That may mean dry forage left from some other period, hay, or about anything dry and consumable.
You can also see the same thing happening with other macro and micro nutrients. If they are deficient in something, they seek it out and if available in some form it is consumed. Certain plants have particular elements concentrated in them and they are often consumed by the grazing livestock to meet that nutrient need. Some advocates and graziers take this to the next level as far as the minerals are concerned and provide a "cafeteria style" mineral box for the livestock which contains twelve or more individual elements and let the livestock eat or consume the ones that they want or need. Interestingly enough, what they consume under such management tends to vary some from month to month which may in turn indicate the availability of those nutrients or more likely the deficiency of those consumed nutrients in the forage or sward being grazed.
Minerals are generally fed because they are lacking in the soil and thus the plants being consumed. It is easier to provide mineral than to try and apply all of them to the pasture in ideal amounts. The exceptions are phosphorus and potassium, both macro nutrients, which are still probably best applied directly to the field. Nitrogen may also be needed if not met by an adequate amount of legume plants which is generally at least thirty percent by dry weight. Thirty percent by dry weight would appear visually to be more like fifty percent of the stand. Micro nutrients are also needed by the plants and animals, and include calcium, magnesium, sulphur, boron, chlorine, copper, iron, manganese, molybdenum and zinc. Calcium and magnesium can be added to the field in such forms as Ag lime or dolomite lime; the dolomite containing magnesium. It is important to get a soil test to prior to application to insure appropriate amounts are being applied. Too much potassium can tie up magnesium and raise the risk of grass tetany.
We should consider the nutritional requirements of what the grazing livestock are consuming now; stockpiled forage, winter annuals, or hay.
A good forage test, for what is being grazed, is probably ideal. You are testing exactly what the livestock is consuming and then you know what needs to be supplemented. Most mineral mixes sold are shotgun type mixes of nutrients generally deficient in the area being sold; this may or may not meet what is needed on your farm or a particular field. Are the needs being met? That is the real question. I am a real believer that the nutritional health of the animal is pretty well dictated by the diet it is consuming. (Oh dear, thoughts of what all I ate for Thanksgiving comes to mind!)
Hay; it is advisable to test fed feeds to make sure it will meet the nutritional requirements of the animals consuming it. With a battery powered drill, a forage probe and then testing, you will know what you have to work with and how to supplement; it is well worth the time and money. Test different cuttings so that the nutritional plane is known for each group. Spring calving cows for example will have an increasing quality requirement; ideally they should be fed lower quality first and the best last. Even the cow's temperament will be better if she is moving toward better quality feed rather than the opposite. Like I've said before, feed me the broccoli first and then I get the ice cream for dessert.
If you are lacking ideal amounts of legumes, now is a good time to buy some clover seed to be ready to put on in the near future. I still prefer that timeframe - between Christmas and Valentine's Day. There may be an adequate seed bank present but just lacking some essential nutrients. Legumes are very particular when it comes to pH and prefer more potassium than grasses. As Henry David Thoreau said, "Though I do not believe that a plant will spring up where no seed has been, I have great faith in a seed. Convince me that you have a seed there, and I am prepared to expect wonders."
Just around the corner, in early 2014, Indiana's two grazing conferences will be going strong again. Both conferences will have outstanding speakers and I would strongly encourage you to attend either or both. Normally you would have to travel a long ways to hear some of these speakers and with a lot more expense. Each conference has its own agenda with different speakers so there will be little duplication. The Heart of America Grazing Conference is back in Indiana in January and is also sure to have a good lineup of speakers.
Keep on grazing!