Please help with hay analysis


epersh@...
 


 

Ed,
There is nothing that particularly concerns me about this hay and it can easily be balanced.  However, you ran the #601 instead of the #603. The difference is the lab uses NIR technology to only estimate the ESC and starch instead of an actual calculation using wet chemistry.  If you want the actual ESC and starch, call the lab and ask them to run a #644 on the sample they already have.  Then you'll have the equivalent of a #603 test.

Carol Broyles 
Spring Valley,  Ohio 
August 2007


Sherry Morse
 

Hi Ed,

If this was done via NIR testing the numbers for ESC+starch can be off by as much as 30%.  With that in mind, I wouldn't feed this hay without soaking.  I would also contact EA and see if they could at least run the carb pack (on the hay so you have accurate ESC and Starch numbers)




epersh@...
 

Hi Carol,
Hi Sherry,

Thanks for the responses! I'm soaking this (and any other) hay for an hour before feeding. I talked with the lab and they said that NIR has all checks and balances in place and that the tests are pretty much equivalent. I'm not knowledgeable in this so I took their word for it. This is the first cutting from the field that I will continue buying from if the hay is good. The previous sample was from the same field, but the third cutting of last year. To an untrained eye they look comparable - I'm not sure if that's accurate, of if this is even relevant. I can certainly call them and try to get them to run #644 if they still have the remainder of the sample. Should I?

Thanks!
--
Ed P in TX 2022
https://ecir.groups.io/g/CaseHistory/files/Edward%20and%20Atticus
https://ecir.groups.io/g/CaseHistory/album?id=273196


Sherry Morse
 

Hi Ed,

If it were my horse I would call and ask them to confirm that 644 is done via Wet Chem and if they still have your sample and can run it.




gypsylassie
 

Hi Ed, I don't know why, but several labs I've worked with seem to push the NIR as very accurate, when we know how far off it can be.  A lab not too far from me here in N IL, which has a good rating and I thought would be convenient and fast, actually started telling me their wet chem machine for measuring sugar and starch was down and I'd have to make do with NIR.  I went back to Equi Analytical.   They also seem to tout NIR, but at least they're happy to do wet chem when we request it.   FWIW
Laura K.  Chappie & Beau over the bridge
2011 N IL



 

Yes, Ed, follow Carol’s advice. 
--
Cass, Sonoma Co., CA 2012
ECIR Group Moderator
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Kirsten Rasmussen
 

Hi Ed,

Many members here have had NIR and wet chem run on the same samples.  The NIR results seem to consistently underestimate the ESC and possibly starch.  The lab refuses to admit to the large discrepancis we see.  I'm sorry you were talked in to doing NIR.  It's not actually an analysis where the sample goes through traditional wet chemistry techniques.  It's a comparison of reflected infrared light wavelengths coming off the sample. 
In NIR spectroscopy, the unknown substance is illuminated with a broad-spectrum (many wavelengths or frequencies) of near infrared light, which can be absorbed, transmitted, reflected or scattered by the sample of interest. The illumination is typically in the wavelength range of 0.8 to 2.5 microns (800 to 2500nm). The light intensity as a function of wavelength is measured before and after interacting with the sample, and the diffuse reflectance, a combination of absorbance and scattering, caused by the sample is calculated.
The lab runs standards/duplicates to check their accuracy, but the problem is their standards and duplicates may not encompass the range of hays they recieve from customers.  There is lots of room for results to be totally wrong. 
Generally, a quantitative NIR analysis is accomplished by selecting a group of calibration samples, for which the concentration of the analyte of interest has been determined by a reference method, and fining a correlation between various spectral features and those concentrations using a chemometric tool. The calibration is then validated by using it to predict the analyte values for samples in a validation set, whose values have been determined by the reference method but have not been included in the calibration. A validated calibration is then used to predict the values of samples.
It's a prediction of what the sample is likely to be.  NIR is ok as a first pass method to screen multiple hays cheaply, but the values reported by NIR should be confirmed by wet chemistry analysis.

You can request the 644 package, but it may be cheaper to ask them to upgrade your analysis to the 603 package since they will only charge you for 603 (and not 601) if you upgrade.

--
Kirsten and Shaku (IR + PPID) - 2019
Kitimat, BC, Canada
ECIR Group Moderator
 
Shaku's Case History
Shaku's Photo Album


Lavinia Fiscaletti
 

HI Ed,

Also worth noting is that the National Forage Testing Association, which provides accreditation for forage testing labs, does NOT accept NIR results as valid for sugar and starch.

--
Lavinia, George Too, Calvin (PPID) and Dinky (PPID/IR)
Nappi, George and Dante Over the Bridge
Jan 05, RI
Moderator ECIR


epersh@...
 

Thank you for all the replies! I'll definitely call the lab on Monday and see what they can do to re-test properly. It's easy for an inexperienced person to get mislead. I'll post the new results in this thread, when available.

Thank you again!
--
Ed P in TX 2022
https://ecir.groups.io/g/CaseHistory/files/Edward%20and%20Atticus
https://ecir.groups.io/g/CaseHistory/album?id=273196


epersh@...
 

Just talked to the lab. They were happy to do 644 on the remainder of the sample. They reiterated that even though they didn't know about other labs, their (Equi-Analytical) calibration is based on tens of thousands of results and their NIR and wet chemistry rarely differ by more than one point. I insisted that they did it anyway so it'll be interesting to compare the results once they send them to me. In any case it's better to run a more accurate test. Thanks!
--
Ed P in TX 2022
https://ecir.groups.io/g/CaseHistory/files/Edward%20and%20Atticus
https://ecir.groups.io/g/CaseHistory/album?id=273196


 

Hi, Ed. I generally core 25-40% of the bales in any load of hay I buy. That produces more than enough of a sample to check NIR vs wet chemistry of ESC. If I do Equi-Analytical the favor of running the 603/wet chemistry test first, a subsequent NIR can produce results for ESC that EA touts. Note that *I* supplied the perfect match for the NIR database by paying for a 603 analysis first.

But if I run the 601 first, the results can definitely vary by more than one percentage point. I uploaded one such example in my Hay Analysis folder that you can see. 
https://ecir.groups.io/g/CaseHistory/files/Cass%20and%20Satra%20-%20Cayuse%20-%20Diamond/Hay&%20Pasture%20Analysis/2021%20WFC%20Sept%20Blue%20String%20NIR%20vs%20WetChem.png.pdf 

For some hays, the discrepancy between 601 and 603 isn't critical because the hay is appropriate for an EMS equine at either percentage. But as ESC edges toward 7% and above, the discrepancy can mean the difference between a safe hay and one that leaves a sensitive horse footsore or worse. You don't want a barn load of that with a horse in a laminitic crisis.
--
Cass, Sonoma Co., CA 2012
ECIR Group Moderator
Cayuse and Diamond Case History Folder                
Cayuse Photos                Diamond Photos


epersh@...
 

I just uploaded the wet chemistry carb analysis results: https://ecir.groups.io/g/CaseHistory/files/Edward%20and%20Atticus/EQ148649.pdf. Lo and behold, all numbers are higher than NIR. Thank you everyone for your comments. I learned my lesson.
Could you please help me interpret the results?

Thank you!
--
Ed P in TX 2022
https://ecir.groups.io/g/CaseHistory/files/Edward%20and%20Atticus
https://ecir.groups.io/g/CaseHistory/album?id=273196


Eleanor Kellon, VMD
 
Edited

At 9.3 you will likely have to soak it.
--
Eleanor in PA

www.drkellon.com 
EC Owner 2001