In our article in the Agroindustria Magazine, in its edition No. 147, we made a general description of the historical fibre and new forms accepted by international organisations. We also spoke about the types of fibre offered by the market, functions, virtues and where we wanted to continue seeding the field of fibre systems.
There are more and more professionals, technicians or those responsible for thinking, assembling and deciding the ingredients in pet diets. Therefore, it’s important to consider and incorporate these parameters of dietary fibre, both soluble and insoluble in their formulators. It’s important to include them, and consider how it became a market trend.
Total dietary fibre is made up of insoluble (FI) and soluble (FS) fibre.
Insoluble fibres are not insoluble in aqueous media such as intestinal and classic examples are the structures of vegetables: lignin, cellulose and some hemicelluloses.
Cereal grains are especially rich in water-insoluble fibres, found in greater amounts in wheat and corn. They have a sponge effect, as they are able to retain water in their matrix, several times their own weight, forming low viscosity mixtures. They lead to an increase in faecal mass and a greater acceleration of intestinal transit. They are not very fermentable because they resist the action of microorganisms in the intestine. This is where using fibre in the treatment or prevention of constipation, comes in.
In soluble fibres, their solubility simply refers to the fact that they dissolve in aqueous media. They are viscous fibres, which form gels naturally and their range is very varied depending on how simple or complex their chemical structure is and whether or not they have the ability to be prebiotic. For example, going to the smallest or simplest: oligosaccharides (fructooligosaccharides, galactooligosaccharides, xylooligosaccharides, and isomaltooligosaccharides), inulin. And if we go to something larger or complex, we find: pectins, hydrocolloid gums, resistant starch, polysaccharides from algae, non-digestible sugars polydextrose, methylcellulose, carboxymethylcellulose, hydroxymethylpropylcellulose and others.
If we cite some ingredients rich in soluble fibre, we find legumes, oats, barley, beets, carrots, apples and many other fruits and vegetables.
Fermentability of dietary fibre is the digestion process that takes place under anaerobic conditions in the large intestine, where bacteria, with their numerous enzymes, can digest it to a greater or lesser extent depending on its structure. This process is fundamental, since thanks to it the development of bacterial flora takes place, as well as the maintenance of the integrity of the intestinal epithelium, which is relevant for the absorption and metabolism of nutrients.
Both soluble and insoluble fibres live in a flexible balance and achieve important health benefits.
Importance of fibre
Beyond the attractiveness of packaging, the degree of fibre contribution in our food produces a visible result, as few ingredients, since it will impact on the type of faeces and presence of gases.
If we make a mistake in the formulation, in the chosen ingredients or in their balance, we may end up in diarrhoea or gas formation in the animal.
With this ingredient we will be closer to the right path: better quality faeces, easy to collect and minimal gas formation. Up to substantial improvements in digestibility and absorption. Being a great complement to prevent pilobezoars, gastric dilation and volvulus, obesity, diabetes and kidney diseases.
Pet nutrition is currently increasingly focused on the use of food (digestibility studies) and on improving human-animal interaction as much as possible. Additionally, how to reduce the number of stools per day, improve fecal characteristics, consistency, moisture and odour are all important.
This is sought out in commercial foods, not only an appreciable body condition, including fur, but also in the prevention of diseases.
Factors affecting the digestibility of the feed
Although there are multiple factors that can affect it, such as the quality of each raw material, time since harvest, process variables, temperatures, pressure, and so on; several authors agree that excesses in the inclusion rate of fibre, especially insoluble ones, will give fibre the ability to affect its own digestibility as well as that of other nutrients, such as protein and carbohydrate digestibility.
Understanding that the variable ‘fibre’ is one of the essential factors in this regard.
Different authors concluded that the inclusion of increasing levels of crude fibre in pet diets negatively affects the digestibility of dry matter. This is mainly due to an increase in the rate of passage and less contact with food enzymes.
After the inclusion of prebiotic soluble fibres, changes are observed in microbial populations that lead to greater digestibility of nutrients at the hindgut level. In vivo studies on prebiotics such as fructooligosaccharides and inulin have shown encouraging results, attributed mainly to their effect on fibre utilisation, the apparent absorption of calcium and phosphorus, and the modulation of hindgut fermentation.
The daily production of faeces has an inverse relationship with the digestibility of the food. As the digestibility of the diet increases, the stool volume decreases and solid, better-formed stools are produced.
Faeces quality: they can be evaluated quantitatively (number of daily defecations, weight, DM content, pH) and qualitatively (visual classification) considering consistency and shape, applying a numerical scale.
Fibre increases the volume and water retention of the intestinal content, is fermented by the colon microflora with the production of volatile fatty acids and lactic acid, modulates intestinal transit time and different authors suggest that it is necessary to include a certain amount of fibre to maintain the health and optimal function of the entire gastrointestinal tract, as well as for the control of body weight and the treatment of obesity, since they lead to a state of satiety of the animal.
The optimal amount of fibre inclusion occurs when the stool is soft enough to prevent constipation, but firm enough to prevent diarrhea.
Fibre size and absorption capacity
The different effects of the fibre will depend on its physical characteristics. Trials observed that different sizes of insoluble fibre particles produced different effects and that the largest size, 200 to 300 microns, was the most effective in producing better quality faeces, compared to fibers of smaller size 30 to 70 microns.
Faecal PH as the thermometer of the intestinal microbiota
It is a parameter that is directly related to the fermentative activity of the intestinal microflora. Greater fermentation, higher levels of volatile fatty acids and lactate that can be used by the animal as a source of energy, maintain the health of the intestinal epithelium, reduce the incidence of intestinal pathologies and control the proliferation of pathogenic microorganisms by reducing the pH.
The ingredients of the diet that are not digested and absorbed in the small intestine pass to the large intestine where they are fermented by the microbiota. In addition, the addition of fermentable fibre to the diet of dogs leads to an increase in the production of acetic, propionic, butyric and lactic acids, being fructooligosaccharides the ones that generate a faster production of these and together there is a decrease in fecal pH. Fecal pH values were reported that were between 6.5 to 6.8 for dry diets and 7.0 to 7.1 for semi-humid diets. Lower pH values are associated with VFA concentrations and inversely with fecal NH3 concentration.
With these parameters in mind: Digestibility (consumption – less excreta) – stool pH, volume and consistency, we decided to carry out a few short tests.
Can you jump from an economic food category to premium only by varying the type of fibre?
Organisations such as the European Pet Food Industry Federation (FEDIAF), NRC (National Research Council) and the AAFCO (Association of American Feed Control Officials), agreed on the dry matter digestibility criterion (dMS) as one of the parameters to classify food according to its nutritional adequacy in standard, premium and super premium. Qualifying as generic or standard those with dry matter digestibility close to 72 percent.
Understanding that, without being a rule, the premium and super premium are made with higher cost ingredients, of quality and more stable formula, whose dry matter digestibility is greater than 78 percent, with firm and scarce stool production.
Greater digestibility, lower stool production and better faeces consistency.
Tips for soluble fibres
They develop the intestinal microbiota and that is a process that requires a few weeks, it has no magical effect.
The smaller, 4 to 10 monosaccharides in the chain, the BETTER, the faster they will be fermented, from the first portion of the intestine, already from the ileum. The larger and more complex they are, we run the risk that they end up being fermented in the colon where there is a greater amount of methanogenic and undesirable bacteria.
Low ph in stool is a good sign!
Thermosets: check with the supplier that they are thermostable and that they withstand the temperatures of the extrusion process.
Soluble: that is, they are completely solubilized in aqueous medium as they would in the intestine. It is simple to taste, in a glass of water and simple shaking.
Prebiotics: not all soluble fibre serves as food for beneficial bacteria. And it can even feed pathogenic bacteria.
Being prebiotic opens a range of virtues to food. In the microbiota cycle – volatile fatty acids – Gut-related immunity.
Tips for insoluble fibres
Consider all the ingredients. All vegetable ingredients add up to this parameter. The value of the insoluble is riskier by excess, than by default.
Authors prefer that they absorb the greatest amount of their weight in water.
Size: the bigger the better, 200 to 300 microns.
An insoluble fiber can be moderately fermented and, as it has less water retention capacity, it can lead to better quality stool.
Trends in fibres: more and more the industry seeks the inclusion of fruits such as apple, citrus, red fruits. And vegetables like Carrot, celery and legumes. All of them associated with the value of their dietary fiber.
Industrial flexitarianism: A prebiotic fiber ensures a superior intestinal microbiota mass.
With this optimal mass of bacteria, we ensure that the modifications we make in the formulation of ingredients or even variations in quality within the same ingredient, as occurs in animal meals, if they are not digested gastrically or intestinally, then they will have a high possibility of being fermented by these bacteria.
Finally, we will compensate for digestibility and maintain the quality of excreta.
Pets are members of the family and as such, aspects of their care are increasingly being considered that bring them closer to humanization in some way. From clothing, accessories, treats and more products intended especially for dogs and cats that most often integrate them into the lifestyle of the people who care for them.
There are many examples that we can share, based on global trends. The routine contemplates, the game, the walk, the daily “mime” and the food without a doubt is a fundamental part of this routine.
It is for all this that we have expressed that we are extremely willing to explore the world of ingredients in the nutrition of our pets.
1. Gonzalo H. Garriz.
2. Hermes Villalba.
3. Valentin Braggio. Ingredion Argentina. Animal Nutrition Team
1) Veterinarian. Technical advisor in Animal Nutrition Hermes.
2) Zootechnician. Technical advisor in Nutrition.
3) Veterinarian. Technical advisor in Animal Nutrition.
For more information visit CAENA’s website, HERE.