Forage Focus: Using Low Quality Hay

Producing high quality hay depends upon cutting the forage plant at a vegetative stage and then getting enough dry sunny days to allow the plants to dry, ideally, to 15 to 18 percent moisture content before baling, writes Extension Educator Rory Lewandowski, for the Ohio State University Beef Team Newsletter, issue #601.
calendar icon 11 September 2008
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While the frequent rainfalls we received earlier this year was good for forage growth, it also hindered quality hay production. Many hayfields were cut at a full bloom or later stage of development. Remember that for any grass or legume plant quality as measured by crude protein, energy and digestibility declines as the plant matures. It looks like hay supplies in terms of quantity are in good shape this year, but quality, particularly of first cutting hay, is generally low.

One management decision cattlemen should give more thought to this year is the timing of when poor quality hay is used. In the past, when corn and soybean meal were relatively inexpensive, they were used to plug the gap between the cow's nutritional need and what the low quality hay failed to provide in terms of energy and/or protein. In today's economic reality, that practice can quickly eat away potential profitability. Ideally the cattleman should strive to match hay quality to the nutritional needs of the cow while minimizing or eliminating expensive supplemental grain. Let's take a look at the nutritional needs of the spring calving cow at this time of year, along with some expected low quality hay values.

What kind of nutrient values might be expected in low quality hay? I found a reference to some research work in Virginia that analyzed orchardgrass hay harvested at various maturity stages. Full bloom orchardgrass hay was listed at 7.5 -8.0 % CP, and about 50% TDN. I would expect similar results for tall fescue hay at a comparable maturity stage. This year I have seen hayfields harvested where maturity went beyond full bloom and into seed production. Nutrient levels will be lower for that type of hay. I have seen hay analysis results here in Athens County in past years come back with crude protein levels below 6% and TDN levels around 45%. While book values can provide some approximate ballpark figures, the only way to gain more reliable information about the nutrient value of your hay is to do a good job of sampling it and then have it analyzed.

The following table lists the daily nutrient requirements as defined by total digestible nutrients (TDN) and crude protein (CP) for a 1200 lb cow at the end of lactation and continuing after weaning into mid-gestation. (Adapted from the 1996 NRC for beef cattle)

Months Since Calving* CP (%DM) CP (lbs) TDN (%DM) TDN (lbs)
6 9.0 1.88 52.5 13.3
7 6.5 1.45 47.0 10.5
8 6.5 1.49 47.3 10.8
9 6.7 1.56 48.0 11.2
* Month 6 is the final lactation month.

Notice that after the calf is weaned from the cow, the nutrient requirements of the cow decrease by about 20%. This represents an opportunity to use a poor quality hay to meet the cow's nutritional needs without having to spend money for additional supplementation.

Using our example of full bloom orchardgrass hay, it can be seen that this hay will meet and exceed the nutrient requirements of a dry cow in mid-gestation. It is likely that hay harvested after full bloom will be adequate in this situation. However, if this hay is fed beyond mid-gestation it is not likely to meet the cow's nutritional needs without supplementation. In addition, the NRC requirements are minimal requirements. As weather conditions deteriorate in the winter, nutritional needs increase above these minimal levels, causing a larger deficit between the nutrients supplied by poor quality hay and what the cow actually needs. All of this adds up to say that August and September and in to October may be good months for the cattle producer to feed poor quality hay rather than waiting for winter use.

Feeding some of that low quality first cutting hay now in August through October offers another advantage to the cattle producer. It provides a window of opportunity to stockpile some pastures for winter grazing (see the article in this newsletter on stockpiling for more information). In most cases that stockpiled forage will be higher quality than mature first cutting grass hay. Feeding hay now can also provide any pasture paddocks that may have been overgrazed an adequate rest period to recover and recharge root reserves.

Matching forage quality to a cow's nutritional needs takes some management skills. In a year when there is plenty of low quality hay and high grain prices, feeding that hay at a non-traditional time of year can make dollars and cents.

August 2008

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