Dietary recommendations for cattle and other ruminants: molasses, distillers grains, and benefits of fish oil

After 2 years working in the cattle feed industry, one of the most astonishing things that I have learned is how efficient the agriculture industry is with the use of byproducts.

The word byproduct is a dirty word in many people’s vocabulary, but in all reality, we could call everything a byproduct. Sugar is a byproduct of sugar cane, as is molasses. Much of the globe’s molasses supply is fed to livestock and horses. It is a palatability agent and also increases the total energy content of the diet. This dramatically reduces waste in the refining process, as the human demand for sugar far exceeds the demand for molasses. One thing I found very surprising is that molasses by itself is very bitter, yet horses and cattle just love the taste.

Ethanol (aka alcohol) is a byproduct of corn. The better we can utilize our byproducts, the less waste we create and the better we use our environment. One way that the beef industry has become increasingly more environmentally friendly is by utilizing byproducts from the ethanol industry, which is currently used as a automobile fuel source. Because a cow is a ruminant, the cow cannot get “drunk” and actually processes alcohol as though it were a carbohydrate. That said, a large portion of a cow’s diet is now currently dried distillers grains-grains (DDGs) that came from the brewing industry that would otherwise end up decaying in a landfill somewhere. In addition, it has been shown that replacing the diet in feedlot cattle with DDGs decreased methane production by 19.9% (McGinn, 2009).

Fish oil is another byproduct that has had a dramatic effect on the cattle industry. High in omega 3 fatty acids, they improve heart and circulatory function (true for all mammals) as well as meat quality. The marbling in the meat is actually high in omega 3 fatty acids! Unfortunately, the supply chain does not yet exist to separate the high omega 3 cattle from those that are not (as was done with omega 3 eggs).

In addition, cattle fed a diet containing 2% fish oil had reduced methane emissions. This is believed to occur because of a reduction in the number of methanogen, the methane producing bacteria in a cow’s gut (Science Daily, 2009).

Scientists continue to look for ways to better use agricultural byproducts to produce food. If you want to stay on top of the latest developments in animal nutrition, consider subscribing to the Animal Frontiers Journal.

S. McGinn, Y. Chung. K. Beauchemin, A. Iwasssa, and C. Grainger. “Use of corn distillers’ dried grains to reduce enteric methane loss from beef cattle”. Canadian Journal of Animal Science. (2009).

Fish Oils Reduce Green House Gas Emissions From Flatulent Cows, Science Daily. (2009).