Explaining Fiber and Fiber Digestion

 

In Part 1 of this series we broke down the different components of balanced animal nutrition namely carbohydrates, protein, fat, vitamins, minerals and water. Now, in part 2 of this series we will expand on what fiber is, and what effect it has.

What is fiber:

Carbohydrates can be broken down into two parts: the easily digestible starch part and the fiber part that is digested by microbial enzymes in the guts of ruminants like sheep and cows.

It is important that the size of the fiber pieces, as well as the amount of fiber that gets fed, should be taken into account. Here are a few quick notes about fiber intake:

• Long fibers in the rumen may get tangled up and be unable to pass into the lower digestive tract, which often causes a “rumen mat”.
• It is important that fiber passes from the rumen so that the rumen does not get filled; this causes the animal to feel full and will lower or stop feed intake.
• An optimum retention time should be achieved so that enough microbial digestion can take place. If fiber particles pass through the rumen too quickly, not enough microbial digestion will take place.
• Grinding fiber into particles that are too small will increase the passage rate and not enough digestion will be achieved.

Why is fiber so important for cows?

Cattle will have varying fiber requirements, depending on their physiological stage. Calves that are not yet weaned do not have a requirement for fiber, however the feeding of grains will stimulate the development of the rumen. Calves are often fed chopped hay after weaning to help improve their performance, but weaned calves also have no minimum requirement for it.

Feedlot steers can be adapted to high concentrate diets, which means that the fiber content is very low. This is suitable to the animal provided they do not develop acidosis.

Dry cows – cows not producing any milk- and lactating cows have a minimum fiber requirement in their daily diets, and this is due to the high amounts of milk that they continually produce. These cows have a daily dry matter intake that is too high for them to be fed on concentrate diets as it will lead to acidosis.

It is important to include the right amount of fiber in the ruminant diet to ensure that rumen activity stays normal and that the gut microorganism environment stays stable. The fiber content helps to maintain the pH level in the gut, preventing it from developing acidosis or other metabolic conditions, and helps to keep the animal sated.

Contact you nearest Molatek technical advisor for more information on what to feed your herd.