Attapulgite for Liquid Animal Feed Suspensions
The Need for Gelling Agents
Gelling or thickening agents are used to impart viscosity to a liquid supplement, thus reducing the tendency of the undissolved liquids or solid matter to settle, keeping insoluble particulate matter in suspension. In most liquid supplements there is not enough water to completely dissolve all the various ingredients. Liquid feed supplements generally/may contain a mixture of soluble (e.g. urea), insoluble solid (e.g. biuret), and liquid ingredients (e.g. fats and oils). The ability of the liquid feed supplement to retard settling or stratification of such ingredients as limestone, salt, feather meal, fats, and vitamins is of prime importance in a suspension liquid feed program. A most important feature for any such liquid supplement is to keep these ingredients uniformly dispersed throughout the system.
Specialty clay additives such as attapulgite gelling clay have been proven to be most effective and cost effective for thickening and preventing settling and separation of ingredients. While molasses does display some thickening qualities and can still be added for its other properties, it does not offer the gel strength required to combat sedimentation or layering of ingredients during storage.
Attapulgite clay outperforms molasses and other thickening agents because its viscosity is thixotropic; forming a gel at rest, and thinning when agitation or shear is applied. When shear is slowed or stopped, the dispersion stiffens at a controlled rate which prevents or minimizes settling or stratification. Thixotrophy is a desirable property because it is advantageous to have a liquid supplement that flows easily when pumped. Attapulgite clay is available to the liquid feed supplement producer as either a dry powder or in a pre-dispersed form (liquid clay).
Pictured above are the results of a BASF study comparing the efficiency of attapulgite powder and liquid clay to sepiolite mineral.
Pictured are the results of another BASF study, demonstrating the cost-performance advantage of using attapulgite powder with partial addition of gum.
Attapulgite products provide thixotropic viscosity modification. Gums may have some thixotropic properties but mainly function as thickeners. Thixotropic viscosity allows the gel to maintain viscosity at rest - improving suspension, and thinning under shear - allowing better pumping.
Attapulgite products are typically more economical and easier to process to use than gums, including xanthan gum. HiLoad attapulgite can be used as a full or partial replacement of gum, or reduce the difficulties of gum processing.
In particularly demanding formulas requiring stronger syneresis control, a combination of attapulgite and gum can offer an economical solution.
Note: In November 2022, Clariant Corporation acquired the attapulgite business from BASF Corporation.
The Attagel 350 product in the study above is now named Tonnegel 350. Attagel is a trademark of BASF Corporation.
Tonnegel is a trademark of Clariant Corporation. Blair Ag LLC has been the largest distributor of both Attagel and Tonnegel products for more than 20 years.
The Attaflow product in the study is equivalent to Blair Ag’s Hiload liquid clay product. Attaflow is a trademark of BASF Corporation. Hiload is a trademark of Blair Ag LLC.