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Balancing Rations

With respect to balancing rations, there are really four rations that we have to deal with. One is on the paper and that is what we concentrating on in the remainder of this course. Balancing a proper ration on paper. And then we actually have the ration that is delivered to the bunk. There is some error between ration the that feeders are supposed to mix and actually the ration that gets to the bunk. Then, we have the ration that is consumed by the cow. The cows do do some sorting. And so the ration that they consume differs a bit from that that is delivered to the bunk, which differs from that that is on the paper that is done by the nutritionist. Lastly, what we have no control over, is the ration that is actually fermented and absorbed by the cow.

When we are looking up requirements in the book we always need to know what the body weight is. A good average body weights for a large breed dairy cattle, Holsteins, Brown Swiss, will be somewhere in the range of 1,350 to 1,450 pounds. A bit less for Ayrshire and Guernsey, at about 1,200 to 1,300 pounds, and Jerseys, at about 900 to 1,000 pounds. We also need to have some handle on milk production. We can get this from several ways. Some farms have meters in parlors, so we have daily-metered weights. Some farms officially test all cows once per month, so maybe we have monthly test weights. But probably the cheapest is daily tank averages. We know how much milk we are shipping each day, we can divide that by total number of cows, and we can get average production per day.

Now, beyond the scope of this class, but sometimes we want to balance for weight gains. We can also take into account weight losses in early lactation because that is going to supply some energy. We also need accurate feed analysis in order to balance rations. Ideally, forages would be tested when harvested so this would give us some lead-time on knowing what we have to deal with in the future. Also forage samples should be pulled monthly to determine analysis. We can get as simple or as elaborate as we want on analysis at labs. Minimum analysis or the bare-bones analysis of what we would need to formulate a ration, would be about $30 per sample or we could get a very sophisticated analysis that costs upwards to $60 per sample.

Forage dry matters, or particularly silages, should be determined weekly, because these can vary as much as 10% each week. For grains, in general, so for cereal grains, book values are very good to use. We do not have to test these very often. By-products have a tremendous amount of variability associated with them and so we should test these by each truckload.

With ration formulation, many times we want to formulate actually for more than the average of our herd. Now, think about a herd that has one group, or we feed one ration to all cows. We will have some cows producing high levels of milk and some cows producing low levels of milk. In order to meet the nutrient requirements of the very high yielding cows, we actually need to formulate for a higher level of milk yield than the herd average. It has been shown that we will get economical returns based on additional ration costs or by balancing a better ration for farms that feed a one group TMR. For example, if we have a herd average of 70 pounds, we can actually balance for 30% more than this or a 91-pound goal and actually meet the requirements of most of the animals on the dairy. You can see as we get more groups on the farm, we balance closer for the average of that group. If we have two groups, maybe a high yielding group and a low yielding group, and high yielding group is at 80 pounds, we would balance for 20% more than this or 96 pounds of milk would be our goal. As we move to three groups, we would balance for 10% higher in that group. When we go to four groups, the lead factor becomes almost zero and we actually balance for the average milk yield in that pen.

When doing your rations, first start with the forages, because these are the foundation of all dairy diets. Based upon the forages then we can determine our energy and protein supplement needs. Monitor intake, protein, NEL or energy and ADF as you change ingredients. These are the main components that we want to focus on.

We will look at some values of what ration densities should be. In general, ADF and the NDF, or the spread between these, will be about 10 to 12 points. And so if ADF is balanced, NDF will be balanced. However, the problem occurs when we feed many by-products and these can have a spread between ADF and NDF of 15 to 25 points. At that point, it becomes very difficult to balance both ADF and NDF. If you use lots of by-products in your feeds, it is better to focus on NDF and effective NDF. In the end, once our ration is balanced for intake, protein, energy, ADF and NDF, then we will balance for vitamins and minerals, which may either come through a commercial grain mix or a mineral-vitamin pack.

If we look at potential production and optimal productivity, it is held together by about six or seven chain links. We have to meet the first one, before we can reach the second one and also any weak link can result in a disconnect between production potential and optimal productivity. We need to know or have a good handle on the requirements of the animals. Accurate feed analysis. It’s good to have an idea of predicted intake. But we actually need to know actual intake on the farm to determine if there is a problem, if our cows should be consuming more dry matter based upon their milk yield. Then we formulate the ration cows will consume, some amount of dry matter, and this in turn will determine how much milk a cow can give based upon energy and protein.

If you look at NDF intake from mature lactating cows, they can consume about 1.2% of body weight.

Remember NDF capacity limits intake at some point. For mature dairy cows, they can consume about 1.2% of their body weight as NDF.

The next two slides show suggested ration composition of diets for four different levels of milk yield, 55, 77, 99 and 120 pounds.

I have given you what we would predict these cows should consume, what the NEL concentration of the diet should be, what the crude protein percent should be, rumen degradable and undegradable protein concentration should be and then also what the fiber concentration should be, the effective of fiber, non-fiber carbs and finally fats. You can use this for a reference when we are balancing dairy diets.

Nutrient densities are useful, especially when evaluating diets. However, the most important thing is that we meet the nutrient requirements at a given level of intake. If farms are continually having problems meeting intake levels, then we may have to deviate from densities and actually have a higher density ration, nutrient density ration, for a lower level of milk yield.

If we look at feed costs, and one of the reasons that we are so interested in balancing rations and maximizing productivity is, on dairies, feed cost makes up about 50% of the expenses. If we look at lactating cow diets, or feed cost for just lactating cows, in the Western US these will range somewhere between $6 and $7 per hundred pounds of milk. It costs the dairy farmer $6 to $7 dollars to produce 100 pounds of milk. If we look at current milk prices, which are about $11 to $12 per hundred weight, that means our income over feed costs, at this point, is about $6 for the farmer. If we look at feed costs for all cows, or we add in our dry cows, these will increase hundred weight cost by about $.50. This graph shows the relationship between feed costs and milk production.

The tan line is maintenance feed costs. It is about $1.10 per cow per day for a cow giving no pounds, or giving no milk, or zero pounds, so a cow at maintenance. It will cost all cows just slightly over a dollar to meet their maintenance requirement. The yellow line is that additional cost for milk production. If we simply look on which cows cost the most on a dairy, it would be cows that give 100 pounds of milk, it costs us well over $5 per cow per day to feed these animals. If you look at the cows that are the cheapest, it would be cows that produce no milk. Based on this rationale, it would be better to have cows on our farm that produce no milk. We know that if do not have milk, farmers cannot pay bills. So the key is efficiency and that is the red line; this is dollars per hundred pounds of milk. If we look at cows producing 10 pounds of milk, it costs almost $15 per hundred pounds of milk to produce that. As we move up to cows giving greater yields, or great amounts of milk, it costs somewhere around $5 to $6 per hundred pounds of milk. Cows that produce more milk are more efficient at converting feed to milk and mainly this is due to that $1.10 maintenance cost, we are simply spreading it over more pounds of milk.

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