| NUTRITION AND NUTRITIONALLY RELATED DISORDERS
The objective of these notes is to give you some information and ideas which you can use when planning the feeding of your animals.
We will begin with a review of the mechanics of digestion in camelids, then continue with the nutritional requirements of different classes of stock. We will look at how their various needs might be met, and mention a few cautions along the way. Finally we will look at some Digestive System related disorders to give you some ideas on how they may be best avoided.
CAMELID DIGESTION
In common with all grazing animals, alpacas need a mechanism for turning plant energy into alpaca energy. Mammals lack the enzymes need to break down the starch cellulose in plant cell walls and grazing mammals have all turned to bacteria, fungi and protozoa to help them out here. They have evolved to set up a symbiotic relationship with these micro organisms, where the alpaca provides a stable protected environment for the bugs to grow, with a constant supply of substrate (i.e. food) and in turn absorbs and uses the chemical products of the bacterial fermentation. This allows a permanent dynamic “factory” to exist, because the chemical products of fermentation would reach toxic concentrations to the microbes if not removed by the host.
Chewing and Cudding
The contractions which cause cud to come up help with the mixing of the fermentation “soup”, as well. Alpacas will chew the cud for up to 8 hours a day, usually during daylight. The more fibrous the diet, the more they chew the cud. A reduction or cessation in cudding can be a sign of pain, fever, over acidity or too much gas in the gut, or lack of calcium in the blood stream, and should start you thinking that something is amiss.
The teeth of alpacas don’t truly grow throughout adult life, but they do gradually emerge through the gums, in the expectation of being worn away by chewing forage. Chewing breaks up the plant stems and increases the area available for the enzymes of the microbes to attack, and chewing the cud aids this process further by improved grinding and by mixing the partly digested matter with more saliva. Initial chewing of the food is normally quick and incomplete, allowing the animal to graze a fairly high bulk in a short time (useful for a prey animal who may have to run off suddenly). Proper grinding and saliva mixing take place while the animal is safely relaxed out of harm’s way, through cudding.
Microbial Products
The fermentation processes going on in C1,2, and 3 produce volatile fatty acids, protein (as microbial cell protein), vitamins (especially B vitamins) and gas. The linings of the fermentation areas have pockets in them where these products collect, and from where the soluble elements are absorbed into the alpaca’s bloodstream. The efficient and rapid absorption of these products promotes the production of more by the microbes, which means that camelids can have a more productive microbial factory on poor quality forage than true ruminants. (Interestingly enough this advantage is lost on higher quality forages.)
The energy portion of the alpaca’s diet is provided from the Volatile Fatty Acids (VFA’s) and these are produced from starch in the diet. As their name implies, they are acidic and over production of them causes the whole fermentation chamber to become more acidic.
It’s also worth noting that there is correspondingly much less gas and liquid in alpaca fermentation chambers than is found in rumens. In the ruminant, the main fermentation chamber contains a gas cap, a floating mat of fibrous matter and microbes, and a lower layer of liquid and smaller particles. In camelids there is a much more dry homogeneous spongy mass. This has the practical benefit of making them very resistant to bloat, but may mean that altering the environment of this stable more solid mass is more difficult than with more liquid, fluid contents.
Other nutrients
Most of what nourishes the alpaca is either produced by the microbial flora, or is the flora themselves, when their spent cells pass into C3 and are digested as a food source. Plant protein has been turned into microbial protein and is digested, and any dietary protein which has not been degraded in fermentation is digested as well. This type of protein, which survives the fermentation process is termed Bypass protein, Undegraded Dietary Protein (UDP) or Non Degraded Dietary Protein (NDP). The protein content of the diet available from microbial sources is limited by the production capacity of the microbes themselves, so this extra protein can become very significant in certain circumstances.
Feeding implications
The population of microbes is dynamic and its make up variable to some extent. Particular food sources favour particular species. For this reason, new food sources should be introduced gradually, over 10 - 14 days, to allow the make up of the microbe population to change gradually, and to adjust to the new make up of nutrients.
Fibre
Because of the absolute reliance of the alpaca on the health of its microbial guests, they must have sufficient fibre in the diet to ensure that the microbial population is well balanced and living in the ideal environment. This means that the ration must contain a large proportion of long fibre - i.e. > 4 cm (2in) in length.
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