February 2014
For What It's Worth

Feed Conversion Efficiencies

Everyone has the preferred form of livestock production for their farm; there is no well-defined protocol to determine which is best for everyone. A lot of it depends on personal choice and resources (land and financial). There are some technical aspects such as feed conversion ratios, average daily gains, stocking rates, etc., most of which have to do with production efficiencies. A lot of this has to do with breeds, genetics, stage of development, and quality of nutritional resources. This article will look at feed conversion ratios and save average daily gains for another issue.

No matter what type of livestock you prefer, all animals have basic nutrient requirements, so trying to provide anything beyond fundamental requirements is a waste of nutrients and money. Protein is the most expensive component of commercial rations; therefore, it stands to reason goat feed is more expensive than cattle feed. Some general numbers to know are 10, 12 and 14; these are relevant protein requirements for cattle, sheep and goats. All this will range +/- 2 percent depending on the stage of production including maintenance, lactating and developing animals. Maintenance animals have the lower nutritional requirements such as adult animals not breeding or lactating. Lactating and developing animals have the higher nutrient needs. Lactating animals are nursing young. Young animals tend to include lactating, weanling or not fully developed animals.

Some basic components of nutrients include protein, carbohydrates, fiber, fat and minerals. Some animals process nutrients more efficiently than others; there are many variables. That is why you need to understand the term "feed conversion ratios" to better understand processing efficiencies of each species. Wikipedia defines Feed Conversion Ratios as "a measure of an animal’s efficiency in converting feed mass into increased body mass." We measure in pounds, as in pounds of feed (forages, hay or grain-based) consumed and converted into body mass (pounds). Numbers found tend to vary depending on sources of information, breeds, stage of production (maintenance, lactating, developing), age (younger more efficient, older less efficient), etc. Lower ratios indicate greater efficiencies. The following numbers are simple ranges or average of pounds of feed per pound of expected weight gain: cattle, 4.5-7.5:1; sheep, 4-8:1 and goats, 6-8:1. The higher the number, the less efficient the animal is. To put this in perspective consider the following critters: hogs, 3-3.2:1; poultry, 2:1 and fish: 1:1. All of these are much more efficient than ruminants.

How can we improve feed conversion ratios? The key is quality; quantity does not compensate. There are two primary sources of nutritional resources, forages and supplemental. (1) One is found in a natural environment or habitat such as grazing or browsing for cattle, goats and sheep. Year-round quality forage for grazing and browsing is the most efficient and healthy source of nutrition for livestock. (2) Three supplemental sources of nutrition include: commercially formulated feeds (loose and pelleted), hay (round or square bales) and silage (much of it is vegetation based). Hay and grain-based rations are ideal for supplemental feeding of lactating or developing animals. Silage works for cattle, but requires extra preparation equipment and storage facilities. Extra pounds of poor or low-quality protein/forages/hay/grains are no substitute for quality sources of nutrition. Quality contributes to an efficient feed conversion ratio and production efficiencies.

Robert Spencer is an Urban Regional Extension Specialist with the Alabama Cooperative Extension System.