Beef nutrition for beginning farmers
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EmailBeef cattle can maintain body weight by digesting fibrous feeds and grow rapidly on high grain rations. Due to this versatility, beef cattle are fed a broad variety of rations to match animal performance goals with feed resources.
Ruminant animals are unique because of their digestive system, which allows them to digest forages. Beef cattle are ruminant animals with a four-compartment stomach made up of rumen, reticulum, omasum and abomasum. The rumen and reticulum are where fermentation occurs. They are full of anaerobic bacteria that utilize nitrogen compounds and carbohydrates to grow and multiply in numbers. The microbial population is made of bacteria, protozoa, yeasts and fungi.
Most of the nitrogen consumed by microbes is taken from amino acids. Amino acids are the building blocks that make up protein. They also can utilize non-protein nitrogen (NPN) which can be supplemented in the diet in a limited amount to boost the crude protein of a ration. Non-protein nitrogen as the term indicates, is nitrogen that is not part of true protein, but rather nitrogen compounds such as ammonia or urea.
Ruminants have a uniquely beneficial ability to digest various forms of carbohydrates. Monograstrics, or non-ruminants have a simple stomach digestive system meaning they have one stomach. Examples include humans, pigs and chickens. Monogastrics can digest and absorb sugars and staches but can not digest structural carbohydrates such as lignin, cellulose, and hemi-cellulose. Lignin, cellulose and hemi-cellulose make up the cell wall of plants and give them their structure.
As the ruminant microbes consume nitrogen and carbohydrates to grow in numbers, they produce volatile fatty acids (VFA) as a byproduct. The VFA are absorbed mostly through the rumen wall and to a smaller extent the lower digestive tract. The VFA are utilized as an energy source by the ruminant animal. The bacteria themselves also pass through the digestive system and serve as energy and protein for the animal.
The design of the ruminant animal allows it to survive on low-quality forages. Because of the bacteria in the rumen, they can digest low-quality fiber carbohydrates and low protein feeds. The ruminant digestive system is designed to allow animals to roam through prairies eating grasses, legumes, forbs and woody materials. These feedstuffs are sufficient to support their basic body functions including reproduction and lactation. However, as we have selected animals for higher performance of growth and milk production, low-quality forages do not contain enough nutrition to support high levels of production. While ruminants were designed to digest fibrous diets, they can be fed rations containing higher concentrations of high energy and protein feedstuffs such as grains and seed oil meals.
Michigan State University Extension specialists and educators understand the great diversity of feeding regimens that can be managed by cattle producers depending on their feed resources and the types of cattle they are feeding. Cattle can be fed fibrous feeds with lower energy and protein content to maintain body weight while lactating and raising calves or concentrate feeds with higher nutrient digestibility for rapid growth. For more information regarding beef cattle nutrition, contact Frank Wardynski, MSU Extension educator at 906-884-4386 or wardynsk@msu.edu.
