When formulating a diet for pigs, diarrhea remains a major concern for the nutritionist. In fact, the younger the animal that will receive the designed diet, the greater the risk of diarrhea. This is why some nutritionists avoid formulating diets for piglets, while they feel quite comfortable formulating diets for older pigs. No matter the cost, or the marketing hype, if a piglet diet leads to diarrhea, then all is lost: business, credibility, even your job.
In fact, controlling or preventing piglet diarrhea remains a hot topic among nutritionists and nutrition suppliers — more so now that we no longer have old, trusty antibiotics to keep gut microbiota under strict control. It's not that back then we had absolutely no diarrheas; to the contrary, diarrheas were often. However, let us admit it, without antibiotics life has become "more interesting" for all of us — except for the piglets, of course!
In reality, nutritionists always had, and continue to have, a plethora of good, alternative products that they use to control diarrhea. Indeed, so big has the business around these products grown in the wake of the antibiotic ban that whole industries have made a living out of it, and continue to rightly do so. Examples of the most common additives of this nature include organic acids, zinc and copper inorganic compounds, specialty fibers, probiotics and immunoglobulins. The list is long, and if one could use them all there would be no space — let alone cost — for normal ingredients like corn and soy. But, nutritionists know better than that, and they choose the right blend of additives for each diet they design.
Apart from the more common additives or compounds that control diarrhea, there is a smaller and lesser-known group of products that can also be used toward the same goal. Perhaps their use should not be considered as a replacement for other more powerful compounds, but rather as an auxiliary solution that complements the right additives mix/profile. The following list is based more on (my) experience rather than extensive (public) research because, as you will realize, commercial interest has been scant. This is often because margins are tight, suppliers do not know how to market their products for the right purpose and because we are unaware how to handle some really common ingredients — and who is going to pay for research on negative feedback now that public funded university trials are but a reminiscent of old times?
Betaine has many functions, one of which is to keep water inside the cells; in other words, it helps avoid dehydration, a phenomenon very common during heat-stress periods or after an outbreak of diarrhea. Its osmoregulating properties work with the electrolytes to ensure cells do not lose excessive water when stressed by external factors. As such, having some betaine has been proven a sound practice in some feeds for piglets prone to diarrheas. The exact amount differs according to each nutritionist, but in reality, there are no real dose-titration studies, whereas betaine is rather expensive, so normal dosages are rather low to be truly effective.
2. Sugar beet pulp
Betaine took its name from the ingredient where it was first discovered: sugar beets. So, sugar beep pulp (dried), a byproduct of the table sugar extraction process, is a rich source of betaine. It also contains a very interesting and currently undervalued fiber profile, in which pectins abound. Sugar beet pulp is characterized by its great water-holding capacity, acting as a natural gut sponge. A moderate amount of dried beet pulp can control gut moisture, but too much of this good ingredient will cause pigs to feel satiated fast, and thus it reduces actual nutrient ingestion.
An interesting clay, under several names, bentonite has a perplexing chemical and scientific background that has caused wars among chemists. Whatever product/brand/name you choose to use, make sure it is the variety that has the greatest possible holding capacity. This clay also acts as a sponge, but it does not cause satiety. Instead, it binds some useful vitamins, minerals and other such interesting and expensive nutrients, so it is not without its own problems. Moderation is rather uneventful with this ingredient, so one has to weigh the benefits of using the full dosage against all possible negatives. What is a “full dosage” is a matter of discussion, as nutritionists have agreed to disagree once more.
This is an unlikely ally in controlling diarrhea because potassium causes water excretion, and excessive potassium will even cause dehydration. On the other hand, too much sodium (salt) will cause water retention (these two work against each other) and also cause thirst, excessive water intake and liquid fecal matter. Sodium is an element added in summer packages to keep pigs drinking (hydrated), and almost all piglet diets contain high levels of sodium because it helps piglets eat more feed. So, some controlled levels of potassium should be added to ensure a balance for proper kidney functioning. Balance is the key word here, but while we know how much sodium to add, potassium levels remain a trade secret — and rightly so because no public funding has been expended to investigate this otherwise ungraceful (read, no commercial margin) nutrient.
Few recognize that sugars are hydroscopic — that is, they attract water. Yet, we all know how easily table sugar is dissolved in a glass of water. Adding sugars in piglet diets causes a mild laxative effect (soft feces) that is not pathogenic, but it is rather unacceptable. Lactose is also a sugar, and as such also a laxative, albeit a milder one than table sugar. Piglet diets rich in table sugar, glucose and lactose are prone to cause water leakage in the gut. If this is combined with other summer-related issues, we can have an osmotic diarrhea that looks like a big problem. Thus, keeping an eye on lactose (and equivalents) levels is always a good idea. A single sugar product exists that actually works the opposite direction from all other sugars, but this is beyond advanced level.
6. Glycinin and beta-conglycinin
We would not normally discuss these compounds if they were not causing an inflammation reaction to naive piglets akin to a peanut allergy. It is an autoimmune reaction leading to gut inflammation, destruction of gut surface and mayhem in general, leading to diarrhea that can become rapidly pathogenic. Now, where do we encounter these exotically named compounds to justify their inclusion in our discussion? Why, they are the major proteins in all soybeans! So, we feed them anyway every time we feed soybeans to our pigs. Piglets develop immunity quickly, but not before they suffer from it. The extent of the damage is a matter of discussion as it verges from nil, to subclinical and all the way up to a severe, acute, clinical, call-the-vet situation. Luckily, there are certain soybean products that bypass this issue, but for that we need another time to discuss it in more depth.
Proper nutrition utilizing modern knowledge
Summer formulas are not as easy as dropping fiber and protein levels, adding some salts and being done with it. This might have worked in the past, but with modern animals, we need to consider even the finer details to ensure maximal productivity and efficiency. And, we have not even discussed vitamins and their role in highly stressed animals. All in all, it is very interesting times to be a nutritionist, but never a good time to be a badly nourished, weaned piglet — so let’s give them some proper nutrition through feed and water utilizing all modern knowledge.