Novembre 2016
Mentre io,Leonardo de Curtis e Michela Parduzzi da qualche anno durante i corsi, con i conoscenti ed i clienti parliamo di nutrizione, di analisi del fieno e della integrazione della dieta del cavallo e dell’asino, negli USA e mondo anglosassone in genere la pratica è consolidata. La rivista The Horse (da non confondere con The Horse’s Hoof edita da Yvonne Welz) non lascia passare un mese senza pubblicare un articolo sul fieno, sull’erba. La cosiddetta sindrome metabolica trova la sua origine nelle erbe e di conseguenza nei fieni con esse prodotti. Le erbe sono state “migliorate” nei decenni per massimizzare la produzione degli animali da reddito. Un settore dove l’obiettivo non è quello della performance del cavallo atleta o dell’animale che deve vivere a lungo. Senza una analisi del fieno non è possibile correggere la dieta o decidere di cambiare fornitore. Se per un animale apparentemente in buona salute la analisi del fieno è cautelativa e preventiva, nel caso di un laminitico o prono alla laminite si tratta del passo necessario per affrontare con determinazione e efficacia il cambio di gestione.
In questo articolo una alimentarista spiega semplicemente la procedura di campionamento e analisi al proprietario.
Americani, australiani, sudafricani e popoli di lingua inglese in genere inviano i campioni di fieno per l’analisi ad un laboratorio nello stato di NY. Non solo i proprietari di cavalli ma soprattutto gli allevatori di bovini e i produttori di latte. Altri laboratori lavorano in USA, ad esempio quello associato all’Università del Kentucky. Purtroppo in Europa la pratica non è ancora diffusa, i costi di analisi sono estremamente più elevati, le unità di misura per l’energia adatte all’erbivoro ruminante, di alcuni minerali ad esempio il rame non viene determinato il contenuto. Infatti, come gli australiani o i tedeschi per esempio, affrontando una pratica burocratica extra io e Leonardo de Curtis preferiamo inviare i nostri campioni in USA. Riceviamo il profilo alimentare in 15-25 giorni.
Leggete gli altri articoli di presentazione dell’argomento in questa sezione, l’alimentazione è uno dei più importanti aspetti della vita. Il vostro pareggiatore NON è un vero professionista se non è sensibile all’argomento e non è capace di aiutarvi e sostituirsi a voi almeno nel campionamento del fieno. Una pratica che è semplificativa della gestione e quindi economica.
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The Horse, 7 novembre 2016
Hay analysis is the most accurate way to determine your hay’s chemical composition and nutrient value. The data you get back is useful in deciding whether a particular hay is a good choice for you horse. Ideally, hay growers should analyze it prior to purchase, but unfortunately fewer growers and brokers fully test hay they sell to horse owners prior. Therefore, you’re often left analyzing the hay post-purchase. If you have a horse with special dietary needs, such as low nonstructural carbohydrate (NSC) levels due to equine metabolic syndrome, purchasing hay before it is tested is a gamble.
Get a Good Sample
The data provided on a hay analysis is only as good as the submitted samples, so getting a representative sample is very important. While you might feel tempted to take a grab handful from a bale to submit to your chosen lab for analysis, this won’t result in data that’s representative. You’ll need to collect samples from multiple haybales. According to the National Forage Testing Association, the first step is to identify a single lot of hay. If testing hay prior to purchase, make sure the sample is from a single cutting, from the same field, and of the same type of hay.
If possible, avoid testing hay that has just been baled. Hay just off the field may might have high moisture levels, which can impact results. It’s better to take a sample at the time of sale or just shortly before feeding it. This way the results more closely match the hay you are actually feeding.
Next, you will need a hay corer or probe. This is typically a hollow stainless steel tube with a sharpened end that’s about two feet long and 3/8- to ¾-inch in diameter. Smaller diameter cylinders result in a sample that does not adequately represent the stem-to-leaf ratio of the hay and might result in inaccurate data. The market offers several commercial hay probes, a common one being the Penn State Sampler. This corer is attached to a battery or electric drill for easy sample collection. The National Forage Testing Association (NFTA) offers a list of hay-testing probes and where to purchase them. Shafts made of metals other than stainless steel should be avoided as they could contaminate the sample. Some analysis labs sell probes and include the cost of a test in your purchase.
You’ll also need something to place your samples in as you core a minimum of 20 bales. I recommend having a sealable storage bag on hand for collecting the samples.
Collecting and Shipping Your Sample
With hay probe and bag in hand you are now ready to walk around your haystack selecting random bales to sample. It is important that you don’t avoid or select any particular bale. Rather, walk five steps and sample a bale. Walk 10 steps and sample another bale, regardless of what the bale looks like.
Take the sample from the short end of the bale, so when you insert the probe it cuts through a cross section of several flakes. Draw imaginary lines from corner to corner of the short end making an X and insert the probe where the lines cross. The probe must be inserted into the bale straight for about 12 to 24 inches. After removing the probe from the bale, empty the contents into your bag before moving to the next bale. Repeat about 20 times randomly around the stack.
Knowing how much forage to collect for your sample is important. The lab needs to grind the whole sample for accurate testing, and if you send too much they might just grind a subsample, which defeats all your efforts of collecting samples from multiple random bales. Ask your lab contact in advance whether the lab will grind the entire sample and how much sample is needed. Most require about a pound of hay.
Once collected, seal the bag and mail it as soon as possible. Avoid leaving on the seat of your car or other potentially hot areas, because this could cause some nutrient deterioration. My preference is to send the sample in a two-day flat-rate envelope.
Use the Right Lab
Choose a lab that participates in the NFTA proficiency certification program. Labs participating in this program are sent blind samples by NFTA to test and the results must match the true mean within a certain accepted range of accuracy.
Note that most labs are analyzing feeds for ruminants and not horses, so an important question to ask is whether the lab does a specialized analysis for horses. Labs that do analysis of hay solely for ruminants will not be able to provide an estimated energy content of the hay for horses. Additionally, they might not perform all the nutrient analysis desired, such as starch and trace minerals. I recommend at a minimum having energy, protein, calcium, phosphorus,magnesio, iron, copper, zinc, and manganese tested, along with the breakdown of carbohydrate fractions acid detergent fiber, neutral detergent fiber, starch, water soluble carbohydrate, and ether soluble carbohydrates. Some feed companies offer hay analysis services to their customers, so you might want to check with your chosen feed company’s representative to see if this service is available.
Hay Analysis Cost
The cost from lab to lab and will depend on the types of analysis methodology used and how many nutrients you would like tested. It’s possible to get a very thorough range of nutrients tested for approximately $30 using what is known as near infrared reflectance, or NIR. E’ necessario aggiungere il costo di campionamento,spedizione e autorizzazioni per chi non vive in USA. Using this methodology the sample is ground and subjected to light. The spectrometer that measures this has been calibrated to samples of known nutrient content and therefore the amount of infrared light reflectance is used to determine the nutrient content.
Some labs might also use wet chemistry. These techniques are more expensive due to the fact that they are more labor intensive and time consuming. With this technique, the ground sample is subjected to treatment with a number of reagents often under heat. Some believe that these techniques give more accurate results, because you’re not reliant on calibration of the NIR equipment. However there’s always the possibility of error with the wet chemistry techniques, as well.
I generally recommend NIR testing methods for carbohydrates and protein analysis. Minerals don’t utilize NIR and by making use of the slightly cheaper NIR tests it often allows for the testing of minerals not typically included in standard testing packages such as selenium. However, when testing hay suitability for horses with metabolic issues where the NSC percentage is significant, it might be of benefit to utilize the wet chemistry analysis.
Take-Home Message
Hay testing can be an important step in better understanding exactly what your horse is eating. It can help you to make choices about whether additional feeds and supplements are necessary as well as determining whether a specific hay is even appropriate for your horse. While I would argue that some data is better than no data, because an accurate and representative sample is needed for good results, if you buy hay in small quantities or go through your hay supply rapidly it might not be worth conducting an analysis.
ABOUT THE AUTHOR
Clair Thunes, PhD
Clair Thunes, PhD, is an independent equine nutrition consultant who owns Summit Equine Nutrition, based in Sacramento, California. She works with owners/trainers and veterinarians across the United States and globally to take the guesswork out of feeding horses. Born in England, she earned her undergraduate degree at Edinburgh University, in Scotland, and her master’s and doctorate in nutrition at the University of California, Davis. Growing up, she competed in a wide array of disciplines and was an active member of the United Kingdom Pony Club. Today, she serves as the regional supervisor for the Sierra Pacific region of the United States Pony Clubs. As a nutritionist she works with all horses, from WEG competitors to Miniature Donkeys and everything in between.