This year has been a challenging year to make hay. I was a new county agent 5 years ago when we had a similar situation (even worse that year) and we ended up having a lot of cattle starving to death with a belly full of hay that was too fibrous to digest. So, UGA Extension Forage Scientist Dr. Dennis Hancock is encouraging cattlemen and producers to sample their hay and baleage to assess the nutritive value of it. This is a little from Dr. Hancock:
Earlier this afternoon, I asked Dr. Saha at the Feed and Environmental Water Lab to summarize the samples received from this growing season so far (April 1-current). He responded quickly and provided the attached summary.
Copy of NIRStats_2018 Growing Season
If you compare the values to the means shown in the long-term summary found in Figure 11 of the “Understanding and Improving Forage Quality” Extension Bulletin, you will see that the average values from 2018 compare favorably to these long-term data. BUT (and I strongly emphasize this BUT), there is tremendous variability this year. He kindly provided the ranges in values for these forage categories, as well as the standard deviation. These summary statistics alert us to the real risks out there: There are many samples that are extremely low quality. For reference, wheat straw generally has a TDN value of ~45% or less. Note the range in the quality on some of these samples.
The final column in the attached is one that I calculated which is the coefficient of variation (standard deviation as a percent of the mean). Normally, we see a CV of ~10%. This year, the we have a LOOOOTTTTT more variability. Some categories are showing as much as 38% CV!
So, please, please, please!!! Encourage your producers to test their hay. Hay testing is almost always economical, but it may just help the producer prevent the death of some of their livestock.
How to take forage samples
We want to pay attention to how we do our sample. One of the first things I ask is where the hay is from? We want to make sure to take samples by “lots” of hay or silage. This is hay from the same cutting, field or stage of maturity. Most cattleman purchase hay, and it is more difficult to differentiate “lots” in these samples. We separate it as best we can, and not represent more than 200 tons of dry matter.
Another important procedure is bale sampling. We need to get as much from the middle or core of the bale that we can. A hollow probe is best to use for this. We have a probe here in the office you can borrow to sample. It takes some time, but getting that core sample is really good.
How much do you need? If you can fill a gallon size Ziploc bag half way, that is enough for the lab. They ask for more however. It may take 8 – 10 core samples to get that much. The best thing I can tell you is don’t grab a hand full of random hay that fell off of a bale. We need to be representative. Here is a more detailed write up of Taking a Good Forage Sample.