Types of sorbents

An important characteristic of quality feed, besides its nutritional value, is its safety. However, the constituents of the feed are a breeding ground for micro-organisms and microscopic fungi and are therefore constantly more or less susceptible to contamination. Contaminants in the feed are bacterial toxins, decomposition products, radioactive compounds and heavy metals. Mycotoxins, products of the metabolism of mould fungi that affect both raw materials for future fodder during the growing season and finished fodder, occupy a special place in the toxic contamination of fodder. Feeding animal feed contaminated with mycotoxins causes significant damage to animal production, including:

• loss of body weight of animals;
• loss of productivity;
• decreased immunity of animals;
• chronic diarrhoea;
• liver damage;
• retarded growth and development;
• reduced fertility, abortions and births of non-viable young;
• poor quality of meat and dairy products of livestock production;
• increased mortality rates, etc.

In order to prevent and treat poisoning caused by toxins in food, it is common to use sorbents - substances that bind and remove toxic compounds from the body. Sorption, i.e. the binding of harmful substances, can be of two types:

• adsorption, in which toxins are "collected" on the surface of the sorbent;
• absorption, in which the toxic substance is absorbed throughout the sorbent.

In veterinary medicine, adsorbents are most commonly used, which in turn are divided into different types of adsorbents according to their surface nature:

• sorbents with non-polar surface, they are insoluble in water and have hydrophobic properties (activated carbon, lignin)
• sorbents with polar surface, they are well wetted and mix with water (silicates).

Sorbents are classified according to their origin:

• mineral (bentonites, paligorskite)
• Organic (compounds of organic origin based on modified glucomannan of yeast cell walls and bacterial peptidoglycan, indigestible cellulose, various types of activated carbon)
• synthetic polymers (cholestyramine, polyvinylpyrrolidone).

To be most effective, the choice of sorbents should be approached wisely. Yes, these substances have low specificity, so in addition to toxic compounds, nutrients in the intestinal lumen (vitamins, amino acids) can also be sorbed. For example, hydrophobic non-polar sorbents adsorb very well the same hydrophobic compounds (fats and fat-soluble vitamins), so their prolonged use can lead to hypovitaminosis A, D, E, K. Mineral sorbents by the specific structure cannot sorb most mycotoxins, this is because the molecule size of these toxins is larger than the sorbent pore size.

The presence of vitamins, micro- and macronutrients (e.g. that have been fed as feed additives) and medicines in the intestinal lumen significantly reduces the effectiveness of the sobriety.

As a preventive measure, it is common to feed animals sorbents on a regular basis, as it is impossible to completely avoid the contamination of feed with toxins, so even in good quality feed the level of mycotoxins is at the limit of tolerance.