**Livestock Feed Conversion Ratios:**
– **Beef Cattle:**
– Normal FCR range for live weight gain in the US: 4.5–7.5
– Average carcass weight FCR: above 10
– Limited improvement in FCR compared to poultry
– **Dairy Cattle:**
– EPA regulations in 2003 led to FCR calculations in the dairy industry
– FCR based on protein and fat content for milk pricing
– Energy-corrected milk (ECM) used for normalization
– **Pigs:**
– Commercial pigs in the UK had FCRs ranging from 1 to 3
– FCR peaks at 220 pounds and worsens as pigs mature
– Countries with high slaughter weights have poor FCRs
– **Sheep:**
– FCR varies based on diet quality for lambs
– Older lambs have higher FCR than younger ones
– Straw-based diets can result in high FCRs
– **Poultry:**
– Broiler chickens in the US had an FCR of 1.6 for body weight gain in 2011
– Significant improvement in FCR from the 1960s to 2011
– FCR for egg-laying hens in the US was around 2 in 2011
**Aquaculture Feed Conversion Ratios:**
– **Carnivorous Fish:**
– FIFO ratio measures wild fish contribution in fish feed
– Decline in fishmeal and fish oil inclusion rates over time
– Decrease in fed aquaculture FIFO ratio from 0.63 in 2000 to 0.22 in 2015
– **Herbivorous and Omnivorous Fish:**
– Plant-based feed yields lower FCR for Chinese carp and tilapia
– Resource use decreases with plant-based feed
– Tilapia’s fillet FCR: around 4.6; Chinese carp’s FCR: around 4.9
– **Farm-raised Atlantic Salmon:**
– Commodified feed supply with four main suppliers in 2015
**Rabbit Feed Conversion Ratios:**
– FCR for rabbits in India:
– High grain diet: 2.5-3.0
– Natural forage diet without animal-feed grain: 3.5-4.0
– Diet affects FCR efficiency differently
**Global Feed Conversion Ratios:**
– Ruminants vs. Monogastrics:
– Ruminants require 133 kg of dry matter per kg of protein
– Monogastrics need 30 kg of dry matter per kg of protein
– Ruminants consume 2.8 kg of human-edible feed per kg of meat
**Meat Alternatives Feed Conversion Ratios:**
– Insects, Meat Analogues, and Cultured Meats:
– Edible insects like house crickets have FCR of 0.9-1.1
– Tofu as a meat analogue has an FCR as low as 0.29
– Cultured meat has an FCR around 4, similar to poultry
– Insects have low FCR due to whole body use and high fecundity
In animal husbandry, feed conversion ratio (FCR) or feed conversion rate is a ratio or rate measuring of the efficiency with which the bodies of livestock convert animal feed into the desired output. For dairy cows, for example, the output is milk, whereas in animals raised for meat (such as beef cows, pigs, chickens, and fish) the output is the flesh, that is, the body mass gained by the animal, represented either in the final mass of the animal or the mass of the dressed output. FCR is the mass of the input divided by the output (thus mass of feed per mass of milk or meat). In some sectors, feed efficiency, which is the output divided by the input (i.e. the inverse of FCR), is used. These concepts are also closely related to efficiency of conversion of ingested foods (ECI).