Equine feeds come in many different forms, pasture, hay, grains, mixtures of grains and elements known as mash feeds. Horse feeds can also be pelleted and extruded or formed in a number of ways. My initial exposure to horse products was involved in treats for horses. They were typically larger cereal grain extruded pieces which included flavours loved by horses – beet, apple and carrot for example.
Pelleted horse feeds are much like any livestock feed, made with a pellet mill and usually with a standard heavy density associated with pelleted feeds. With regards to horse feeds, the general discussion on their formulas can be open or highly kept secrets – especially for competition racehorses. There are many different categories for competition horses, short sprint racing, long sprints, endurance racing, jumping and dressage and this does not mention the rodeo events as well as others.
I assume all have seen a few cowboy movies where horses are feed hay and a “bait of Grain” usually oats after a hard day and to prepare for the next. Oats being higher in fibre and a reasonable oil level makes it popular. Besides oats other cereal grains uses include barley, corn (usually cracked, steam roller milled or ground), wheat, wheat by products, grain sorghum, beet pulp, molasses as well as soybean products.
Horse feeds vary greatly
Current technology allows for many forms of feeds to be made and typically these prepared feeds are used to supplement roughage, grazing in pastures, hay cubes or bales. Grains or prepared feeds made from ingredient combinations are fed usually in small amounts. The goal is to figure out how to feed horses based on his needs relative to size and their level of work or activity.
Prepared horse feeds or supplements as noted above vary greatly. Oats are feed whole or rolled, slightly processed by steaming and passing through a set of rolls. Micronising is also a process where grains are heated and then rolled yielding a little better cook level then just rolled grains. It is noted the bulk of the diet should be roughage but there are horses with special needs or situations. Extruded diets or supplements allow horses with lung issues to avoid dust as in mash and pelleted feeds. Teeth issues, age and digestive issues are additional reason for looking at extruded diet supplements.
The major reason for extrusion of horse diets is the ability to include higher fat content diets for energy needs in working and competition horses. Pelleted feeds have a reduced ability for high fat levels and maintain the pellet shape. The cooked starch in extruded feeds is more easily digestible and absorbed in the small intestine allowing the large intestine to do it job on the roughage.
There are always concerns on the extrusion process reducing the vitamin content in the feed. Yes, this is true, but all extruders do not destroy vitamins equally. The level of moisture in the extruder used has a big effect on the vitamins, more water less losses. There are numerous sources for vitamin reduction levels based on the temperature and moisture used in petfood production and these numbers would be very similar when making horse feeds.
As a note, extrusion work has been done where running the equipment to not exceed 80°C resulted in pre and probiotic enzymes included not being destroyed, mentioning this as the temperature can be modulated while getting starch gelatinisation. Similarly drying feeds at low temperatures is also possibly
protecting heat sensitive ingredients.
Advancements in some areas of production
The industry is starting to look at the level of cook and how products are cooked in many cases including petfoods. Historically the view was we needed to cook more, and the results were more energy conversion from electrical inputs in the form of SME (Specific Mechanical Energy) which creates the friction in the extruder barrel, generating pressure and high temperature levels.
The goal of cooking the starch is to hold the feed together and as many animals can’t handle uncooked starch. What is the definition of a cooked starch cell? It is when it is ruptured or broken open. In general, starch cells swell in water and eventually rupture when reaching the 30- 33 percent moisture range. Improved preconditioning as well as adjustments in the extrusion process can use this as a method of cooking but controlling the cook to achieve the gelatinisation required in a gentler manner.
Advanced preconditioning use steam inputs and can in many cases achieve in the 40 percent cook range before the extruder barrel. Older preconditioner designs usually had a much lower cook level. Ok, depending on the cook going into the extruder barrel determines how much cook is needed to finish the job. Therefore, some barrel setups need to be more aggressive; hence the increased input of energy creating more friction that is needed to finish the cooking process.
Handling of the product out of the extruder can be managed if higher moistures are used. Pre-dryers to set the product and longer lower temperature finish dryers to remove the moisture are all possible. Based on the variation of market segments, the production of petfoods in all their various forms will continue as we see advancements in some areas of production being adopted for use as the knowledge of the animals needs improve.
The driving force behind production advancements are in dog and cat foods which make up the bulk of the market. Extrusion advancements for petfoods is a driving factor in many extrusion areas. For example, last month at Wenger’s Tech Center a demonstration of using high meat levels with low SME input was impressive.
Personally, always having an eye towards aquatic feeds it seems this technology could be quite useful in that industry. Fish meal, poultry meal, meat and bone meal could all be used without double processing. What additional nutrient advantage can be had without drying or heating these products twice when you can simply add them in the raw state when making the feed directly. Obviously, there are some logistics involved but I am positive some advantage, due to attractability of the aquatic feeds and efficiencies might be possible for the future.
Keeping the industry moving forward
The conclusion is that if we watch what is going on in petfood developments, we will see these techniques more than likely in other animal production processes. Is in the case of horse feeds, what
level of cook and the severity of cook is desired or needed for horses
in all of the possible situations.
The dynamic of extrusion and petfood development is a driving force behind most extrusion advancements for a wide variety of animal feeds and you have and will be part of it, as your nutritionists and animal experts develop questions and ideas advancing the thought process of equipment designers. These interactions will keep the industry moving forward.
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Article contributed by Joe Kearns, Editor of International Petfood magazine.
