FE or feed efficiency is a factor that has a significant bearing on the profitability of livestock farming, as it is deemed to have a huge influence within the industry. Indeed, given the projections of continued growth in feed prices up to 2026, surpassing the $500 billion mark for the feed industry globally, FE can make or break a farms profitability potential.
This brings up another pertinent issue that is why does feed efficiency trump other more established factors like growth rate or carcass weight as the measure of production achievement?
The 70% Rule:
In animal production systems, feed is not just an ordinary input, as it is the largest single cost factor, accounting for as much as 60-70 percent of total variable cost of animal production, as cited by FAO estimates up to 2025.
This is because the operating profit margins of animal proteins are low. Hence, even a small improvement in the feed conversion ratio i.e. the amount of feed required per unit of body weight gained has the ability to bring large returns. For example, as mentioned by Feed & Additive Magazine (2025), even “an improvement of just one percent in feed efficiency can save a poultry factory hundreds of thousands of dollars per year.”
The “Dilution of Maintenance” Concept:
Animals also require a base energy demand that is present to sustain their vital functions, such as breathing, circulation of blood, and regulation of their temperatures. Efficiency of the feeds is critical in regulating what is referred to as the “dilution of maintenance.”
Results published in an article by The Journal of Animal Science (2024), indicate that when an animal is more efficient, a smaller percentage of the nutrients consumed by that animal is used for basic survival processes. Inefficient animals may use half their nutrients to sustain basic bodily functions, whereas more efficient animals may devote almost 70% of nutrients to muscle development or milk synthesis.
Sustainability and the “Methane Link”:
As sustainability standards are being made more stringent, feed efficiency has emerged with a new role in addressing the issue of environmental impact in agriculture in a realistic form. There is a definite mathematical relationship that links the feed efficiency performance with the environmental impact.
Animals with higher feed efficiency have a shorter time frame to achieve weight, resulting in a decrease in the number of days they release greenhouse gas emissions into the atmosphere. Research done and documented in “MDPI Animals” (2025) proved that cattle with low residual feed intake emitted 10-15% less methane into the atmosphere compared to those with low feed efficiency. Feed efficiency also minimizes excess nitrogen and phosphorus when it comes to their excretion into the soil, thereby protecting groundwater and surface water resources.
RFI (Residual Feed Intake) vs. FCR (Feed Conversion Ratio):
While FCR has traditionally been the gold standard for measuring efficiency, residual feed intake is a measure that is becoming much more widely used in the livestock industries. One of the primary issues with FCR is that it is strongly connected with growth rate i.e. selection for animals with superior FCR often inadvertently favors those that simply consume more and grow larger.
RFI transcends that limitation since it considers how much feed an animal actually consumes compared with what it is expected to consume, given body size and production level. According to Hay and Forage Grower, RFI receives growing recognition as the preferred benchmark because it identifies animals of superior metabolic and cellular efficiency, regardless of body weight or growth potential. In 2026, Feed Efficiency is no longer just a “bonus” for the top-tier producers in fact it is a survival mechanism. It bridges the gap between economic viability and environmental stewardship, ensuring that we can feed a growing population with fewer resources.
