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  4. 1999
  5. August

Why Are We Supplementing our Livestock?

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Do you feed hay or protein supplements to your livestock at some time during the year? Do you have hay samples analyzed? Do you know the nutritional values of your supplements? Do you know the quantity and quality of the grass in your pasture? If you answered "yes" to all of these questions, you deserve a great deal of praise. If you answered "no" to any of the questions, then there may be an opportunity for you to save some money and become more productive at the same time.

If you don't know the answers to these questions, how do you decide how much of what supplement to feed? If we supplement because we think the cows are looking thin or because they look hungry, we may be wasting our money by supplementing more nutrients than the animals need or conversely, not meeting the animals' nutritional needs. If the animals are deficient in nutrients it can result in decreased average daily gains, longer estrus cycles, or decreased conception rates, resulting in fewer and lighter calves.

Livestock producers spend a great deal of money putting up hay and buying feeds to see their stock through the winter. What if we didn't have to haul hay and feed all winter?

We have to first consider the goals we have for our livestock. If we are wintering bred cows (last trimester) that will calve in the spring, then they only need 8% protein and 50% energy for most of the winter. If we manage our pastures with a year-round grazing perspective, leaving some standing summer forage for the livestock to come back to during the winter, we may not need as much, if any, supplemental feed.

There are cost saving incentives built into managing on a year-round basis. If we plan, and leave sufficient standing forage in the pasture to winter the livestock, then we do not have the costs associated with putting up or purchasing hay. If we monitor the nutrient quality of the forage and only supplement what is needed to meet our goals for the livestock, then we save the money that would have been spent on that unnecessary feed.

The key to all of this is deciding on our goals for the livestock and developing a plan to see it through. Once we know what the goals are and know what resources are available (forage supply), then it is important to monitor the quantity and quality of those resources. There are several techniques that can be utilized. The most effective and accurate way to determine forage quantity is to make a plot frame and clip and dry the grass. Then, with a few calculations you can get an estimate of pounds per acre. I know nobody likes to do this. It isn't near as easy as counting the number of bales you have left in the stack, but it is well worth the time and effort to get an accurate measurement of how much standing forage you have available.

Now, determining forage quality is a little more difficult. You can collect a sample of the forage and have it sent to a lab for analysis or you can collect a sample of feces from the animals and have that sent to Texas A&M's Grazing Animal Nutrition Lab for analysis. Each of these techniques has some good points and some bad ones.

The fecal sample analysis will theoretically give us a better idea of what the animals actually decided to eat, whereas, sending off a forage sample only tells us what the animals had to choose from. So, while fecal sampling is a more accurate technique, it only allows you to sample where the animals have been, not where they are going (i.e. sampling pastures prior to moving the animals in).

Typically, the information about fecal samples will be back to you in about three working days, while forage samples may take up to ten working days. This is very important during times when forage quality is changing rapidly (i.e. onset of fall and spring). No matter which technique you use, you have to get an estimate of quantity. If you choose to have the forage samples analyzed, all you have to do is send off the material you clipped to get your quantity estimate.

Once you have gathered the information on forage quantity and quality, you then need a tool to help you predict animal performance based on your available resources. We use a computer program called Nutritional Balance Analyzer (NUTBAL). This program allows you to input information on your herd, your goals for those animals and what resources you have available. With that information the program can predict animal performance and tell you if you need to supplement to meet your goals. If supplementation is necessary, the program can also calculate the "least cost" form of supplementation.

During the winter of 1998 we conducted a study to examine the effectiveness of supplementing protein and energy based on the different forms of forage quality analysis. We divided the cow herd at The Noble Research Institute's Red River Demonstration and Research Farm into three groups of 32 cows each. For one group, we collected forage quality data by clipping and sending off samples for analysis. For the second group, we collected fecal samples to get the forage quality information. And for the third group, we supplemented the same way they have traditionally supplemented at the farm based on how the animals look and how dry their feces had become.

In November the cows in all three groups averaged 1,160 pounds and a body condition score of five. Our performance goal for the cow herds was to maintain their weight and body condition through the winter months. By mid-February all three groups had gained, on average, about 70 pounds (increase due to fetal calf weight) and had maintained a condition score of 5 and there were essentially no differences in the cost of supplemental feeds. This may have been due to the mild weather conditions we had this winter. We are planning to continue this study for at least another year.

With all of that said, I also need to point out that there is a substantial difference in the cost of forage sampling and fecal sampling. To get the necessary information from a forage sample costs about $15 (we provide this service free to Noble Research Institute cooperators), while fecal sample analysis costs $21. If you have a fecal sample analyzed by A&M, you can also have them run the NUTBAL analysis for an additional $10, or you can buy a copy of the program from Texas A&M for $95 and run it yourself.

It may seem a little odd to be talking about winter feeding in the middle of summer, but this is the time to be planning ahead if we are going to have standing forage for our livestock this winter.

This is an opportunity to decrease cost and increase profit, but it does require time and effort to make it work. If implemented, Santa might bring you something more fun than a truck load of feed for Christmas this year.

Editors Note: Rob is serving a three year appointment as a post-graduate Research Assistant in forages.