# Feed conversion ratio

> Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Feed_conversion_ratio
> Markdown URL: https://mediated.wiki/source/Feed_conversion_ratio.md
> Source: https://en.wikipedia.org/wiki/Feed_conversion_ratio
> Source revision: 1355601389
> License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/)

Ratio of animal feed to desired product

In [animal husbandry](/source/Animal_husbandry), **feed conversion ratio** (**FCR**) or **feed conversion rate** is a [ratio](/source/Ratio) or [rate](/source/Rate_(mathematics)) measuring of the [efficiency](/source/Efficiency) with which the bodies of [livestock](/source/Livestock) convert [animal feed](/source/Animal_feed) into the desired output. For [dairy cows](/source/Dairy_cattle), for example, the output is [milk](/source/Milk), whereas in animals raised for [meat](/source/Meat) (such as [beef](/source/Beef) cows,[1] pigs, chickens, and fish) the output is the [flesh](/source/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](/source/Animal_slaughter) 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](/source/Multiplicative_inverse) of FCR), is used. These concepts are also closely related to [efficiency of conversion](/source/Efficiency_of_conversion) of ingested foods (ECI).

## Background

Feed conversion ratio (FCR) is the ratio of inputs to outputs; it is the inverse of "feed efficiency" which is the ratio of outputs to inputs.[2] FCR is widely used in hog and poultry production, while FE is used more commonly with cattle.[2] Being a ratio the FCR is [dimensionless](/source/Dimensionless), that is, it is not affected by the [units of measurement](/source/Units_of_measurement) used to determine the FCR.[3]

FCR a function of the animal's genetics[4] and age,[5] the quality and ingredients of the feed,[5] and the conditions in which the animal is kept,[1][6] and storage and use of the feed by the farmworkers.[7]

As a rule of thumb, the daily FCR is low for young animals (when relative growth is large) and increases for older animals (when relative growth tends to level out). However FCR is a poor basis to use for selecting animals to improve genetics, as that results in larger animals that cost more to feed; instead [residual feed intake](/source/Residual_feed_intake) (RFI) is used which is independent of size.[8] RFI uses for output the difference between actual intake and predicted intake based on an animal's body weight, weight gain, and composition.[8][9]

The outputs portion may be calculated based on weight gained, on the whole animal at sale, or on the dressed product; with milk it may be normalized for fat and protein content.[10]

As for the inputs portion, although FCR is commonly calculated using feed dry mass, it is sometimes calculated on an as-fed wet mass basis, (or in the case of grains and oilseeds, sometimes on a wet mass basis at standard moisture content), with feed moisture resulting in higher ratios.[11]

## Conversion ratios for livestock

Animals that have a low FCR are considered efficient users of feed. However, comparisons of FCR among different species may be of little significance unless the feeds involved are of similar quality and suitability.

### Beef cattle

As of 2013[\[update\]](https://en.wikipedia.org/w/index.php?title=Feed_conversion_ratio&action=edit) in the US, an FCR calculated on live weight gain of 4.5–7.5 was in the normal range with an FCR above 6 being typical.[8] Divided by an average carcass yield of 62.2%, the typical carcass weight FCR is above 10. As of 2013[\[update\]](https://en.wikipedia.org/w/index.php?title=Feed_conversion_ratio&action=edit), FCRs had not changed much compared to other fields in the prior 30 years, especially compared to poultry which had improved feed efficiency by about 250% over the last 50 years.[8]

### Dairy cattle

The dairy industry traditionally didn't use FCR but in response to increasing concentration in the dairy industry and other livestock operations, the [EPA](/source/United_States_Environmental_Protection_Agency) [updated its regulations in 2003](/source/Concentrated_Animal_Feeding_Operation#EPA_final_rule_(2003)) controlling manure and other waste releases produced by livestock operators.[12]: 11–11 In response, the [USDA](/source/United_States_Department_of_Agriculture) began issuing guidance to dairy farmers about how to control inputs to better minimize manure output and to minimize harmful contents, as well as optimizing milk output.[13][14]

In the US, the price of milk is based on the protein and fat content, so the FCR is often calculated to take that into account.[15] Using an FCR calculated just on the weight of protein and fat, as of 2011[\[update\]](https://en.wikipedia.org/w/index.php?title=Feed_conversion_ratio&action=edit) an FCR of 13 was poor, and an FCR of 8 was very good.[15]

Another method for dealing with pricing based on protein and fat, is using energy-corrected milk (ECM), which adds a factor to normalize assuming certain amounts of fat and protein in a final milk product; that formula is (0.327 x milk mass) + (12.95 x fat mass) + (7.2 x protein mass).[11]

In the dairy industry, feed efficiency (ECM/intake) is often used instead of FCR (intake/ECM); an FE less than 1.3 is considered problematic.[13][11]

FE based simply on the weight of milk is also used; an FE between 1.30 and 1.70 is normal.[10]

### Pigs

Pigs have been kept to produce meat for 5,000 to 9,000 years.[16] As of 2011[\[update\]](https://en.wikipedia.org/w/index.php?title=Feed_conversion_ratio&action=edit), pigs used commercially in the UK and Europe had an FCR, calculated using weight gain, of about 1 as piglets and ending about 3 at time of slaughter.[5] As of 2012[\[update\]](https://en.wikipedia.org/w/index.php?title=Feed_conversion_ratio&action=edit), in Australia and using dressed weight for the output, an FCR calculated using weight of dressed meat of 4.5 was fair, 4.0 was considered "good", and 3.8, "very good".[17]

The FCR of pigs is greatest up to the period, when pigs weigh 220 pounds. During this period, their FCR is 3.5.[16] Their FCR begins increasing gradually after this period. For instance, in the US as of 2012[\[update\]](https://en.wikipedia.org/w/index.php?title=Feed_conversion_ratio&action=edit), commercial pigs had FCR calculated using weight gain, of 3.46 for while they weighed between 240 and 250 pounds, 3.65 between 250 and 260 pounds, 3.87 between 260 and 270 lbs, and 4.09 between 280 and 270 lbs.[18]

Because FCR calculated on the basis of weight gained gets worse after pigs mature, as it takes more and more feed to drive growth, countries that have a culture of slaughtering pigs at very high weights, like Japan and Korea, have poor FCRs.[5]

### Sheep

Some data for sheep illustrate variations in FCR. An FCR (kg feed dry matter intake per kg live mass gain) for lambs is often in the range of about 4 to 5 on high-concentrate rations,[19][20][21] 5 to 6 on some forages of good quality,[22] and more than 6 on feeds of lesser quality.[23] On a diet of straw, which has a low metabolizable energy concentration, FCR of lambs may be as high as 40.[24] Other things being equal, FCR tends to be higher for older lambs (e.g. 8 months) than younger lambs (e.g. 4 months).[21]

### Poultry

As of 2011[\[update\]](https://en.wikipedia.org/w/index.php?title=Feed_conversion_ratio&action=edit), in the US, broiler chickens has an FCR of 1.6 based on body weight gain, and mature in 39 days.[25] At around the same time, the FCR based on weight gain for broilers in Brazil was 1.8.[25] The global average in 2013 is around 2.0 for weight gain (live weight) and 2.8 for slaughtered meat (carcass weight).[26]

For hens used in egg production in the US, as of 2011[\[update\]](https://en.wikipedia.org/w/index.php?title=Feed_conversion_ratio&action=edit) the FCR was about 2, with each hen laying about 330 eggs per year.[25] When slaughtered, the world average layer flock as of 2013 yields a carcass FCR of 4.2, still much better than the average backyard chicken flock (FCR 9.2 for eggs, 14.6 for carcass).[26]

From the early 1960s to 2011, in the US, broiler growth rates doubled and their FCRs halved, mostly due to improvements in genetics and rapid dissemination of the improved chickens.[25] The improvement in genetics for growing meat created challenges for farmers who breed the chickens that are raised by the broiler industry, as the genetics that cause fast growth decreased reproductive abilities.[27]

### Carnivorous fish

In [aquaculture](/source/Aquaculture), the fish feed for carnivorous fish commonly includes fish-derived products in the form of [fishmeal](/source/Fishmeal) and [fish oil](/source/Fish_oil). There are therefore two ratios to be reported:[28][29]

- The regular feed conversion ratio, i.e. output fish mass divided by total feed mass.

- The conversion ratio only taking into account the fish-based component of fish feed, called the FIFO ratio (or Fish In – Fish Out ratio). FIFO is fish in (the mass of harvested fish used to feed farmed fish) divided by fish out (mass of the resulting farmed fish).

FIFO is a way of expressing the contribution from harvested wild fish used in aquafeed compared with the amount of edible farmed fish, as a ratio. The fish used in fishmeal and fish oil production are not used for human consumption, but with their use as fishmeal and fish oil in aquafeed they contribute to global food production.

Fishmeal and fish oil inclusion rates in aquafeeds have shown a continual decline over time as aquaculture grows and more feed is produced, but with a finite annual supply of fishmeal and fish oil. Calculations have shown that the overall fed aquaculture FIFO declined from 0.63 in 2000 to 0.33 in 2010, and 0.22 in 2015. In 2015, therefore, approximately 4.55 kg of farmed fish was produced for every 1 kg of wild fish harvested and used in feed. (For Salmon & Trout, the FIFO ratios for 2000, 2010, and 2015 are: 2.57, 1.38, 0.82.)[30]

As of 2015[\[update\]](https://en.wikipedia.org/w/index.php?title=Feed_conversion_ratio&action=edit) farm-raised [Atlantic salmon](/source/Atlantic_salmon) had a commodified feed supply with four main suppliers, and an FCR of around 1.[31] [Tilapia](/source/Tilapia) is about 1.5,[32] and as of 2013[\[update\]](https://en.wikipedia.org/w/index.php?title=Feed_conversion_ratio&action=edit) farmed [catfish](/source/Catfish) had an FCR of about 1.[8]

It is possible for fish to have an FCR below 1 despite obvious energy losses in feed-to-meat conversion. Fish feed tends to be dry food with higher energy density than water-rich fish flesh.[33]

### Herbivorous and omnivorous fish

For herbivorous and omnivorous fish like [Chinese carp](https://en.wikipedia.org/w/index.php?title=Chinese_carp&action=edit&redlink=1) and [tilapia](/source/Tilapia), the plant-based feed yields much lower FCR compared to carnivorous kept on a partially fish-based diet, despite a decrease in overall resource use. The edible (fillet) FCR of tilapia is around 4.6 and the FCR of Chinese carp is around 4.9.[34]

### Rabbits

In India, rabbits raised for meat had an FCR of 2.5 to 3.0 on high grain diet and 3.5 to 4.0 on natural forage diet, without animal-feed grain.[35]

### Global averages by species and production systems

In a global study, [FAO](/source/Food_and_Agriculture_Organization) estimated various feed conversion ratios, taking into account the diversity of feed material consumed by livestock.[36][37] At global level, ruminants require 133 kg of dry matter per kg of protein while [monogastrics](/source/Monogastric) require 30 kg.[36][37] However, when considering human edible feed only, ruminants require 5.9 kg of feed to produce 1 kg of animal protein, while monogastrics require 15.8 kg.[36][37] When looking at meat only, ruminants consume an average of 2.8 kg of human edible feed per kg of meat produced, while monogastrics need 3.2 kg.[36][37] Finally, when accounting for the protein content of the feed, ruminant need an average of 0.6 kg of edible plant protein to produce 1 kg of animal protein while monogastric need 2 kg.[36][37] This means that ruminants make a positive net contribution to the supply of edible protein for humans at global level.[36][37]

## Feed conversion ratios of meat alternatives

Many alternatives to conventional animal meat sources have been proposed for higher efficiency, including insects, [meat analogues](/source/Meat_analogue), and [cultured meats](/source/Cultured_meat).[34]

### Insects

Although there are few studies of the feed conversion ratios of [edible insects](/source/Insects_as_food), the [house cricket](/source/House_cricket) (*Acheta domesticus*) has been shown to have an FCR of 0.9 - 1.1 depending on diet composition.[38] A more recent work gives an FCR of 1.9–2.4. Reasons contributing to such a low FCR include the whole body being used for food, the lack of internal temperature control (insects are [poikilothermic](/source/Poikilotherm)), high fecundity and rate of maturation.[34]

### Meat analogue

If one treats [tofu](/source/Tofu) as a meat, the FCR reaches as low as 0.29. The FCRs for less watery forms of meat analogues are unknown.[34]

### Cultured meat

Although [cultured meat](/source/Cultured_meat) has a potentially much lower land footprint required, its FCR is closer to poultry at around 4 (2-8). It has a high need for energy inputs.[34]

## See also

- [Entomophagy](/source/Entomophagy)

- [Food vs. feed](/source/Food_vs._feed)

- [Life-cycle assessment](/source/Life-cycle_assessment)

## References

1. ^ [***a***](#cite_ref-ShikeBeef_1-0) [***b***](#cite_ref-ShikeBeef_1-1) Dan Shike, University of Illinois [Beef Cattle Feed Efficiency](http://www.beefusa.org/CMDocs/BeefUSA/Resources/cc2012-Beef-Feed-Efficiency--Dan-Shike.pdf)

1. ^ [***a***](#cite_ref-Cottle_2-0) [***b***](#cite_ref-Cottle_2-1) DJ Cottle and WS Pitchford. Production Efficiency. Chapter 18 in Beef Cattle Production and Trade, Ed Lewis Kahn. Csiro Publishing, 2014 [ISBN](/source/ISBN_(identifier)) [978-0-643-10989-6](https://en.wikipedia.org/wiki/Special:BookSources/978-0-643-10989-6) [Pp 439-440](https://books.google.com/books?id=suFZAwAAQBAJ&pg=PA439)

1. **[^](#cite_ref-3)** Stickney, Robert R. (2009) [*Aquaculture: An Introductory Text*](https://books.google.com/books?id=UaT8gZaOA04C&q=%22Feed+conversion+ratio%22+dimensionless&pg=PA248), page 248, CABI, [ISBN](/source/ISBN_(identifier)) [978-1-84593-589-4](https://en.wikipedia.org/wiki/Special:BookSources/978-1-84593-589-4).

1. **[^](#cite_ref-4)** Arthur P.F. et al. 2014 [Lessons Learnt from 25 Years of Feed Efficiency Research in Australia](https://web.archive.org/web/20151109210517/https://www.asas.org/docs/default-source/wcgalp-proceedings-oral/110_paper_10178_manuscript_1215_0.pdf?sfvrsn=2). Proceedings, 10th World Congress of Genetics Applied to Livestock Production. Abstract here [\[1\]](https://asas.confex.com/asas/WCGALP14/webprogram/Paper10178.html)

1. ^ [***a***](#cite_ref-Varley_5-0) [***b***](#cite_ref-Varley_5-1) [***c***](#cite_ref-Varley_5-2) [***d***](#cite_ref-Varley_5-3) Mike Varley for Pig Progress. [Taking control of feed conversion ratio](https://web.archive.org/web/20150917051750/http://www.pigprogress.net/Breeding/Sow-Feeding/2009/4/Taking-control-of-feed-conversion-ratio-PP005927W/) Apr 1, 2009, Last update:Jan 26, 2011

1. **[^](#cite_ref-6)** National Research Council (Subcommittee on Environmental Stress). 1981. Effect of environment on nutrient requirements of domestic animals. National Academy Press, Washington. 168 pp.

1. **[^](#cite_ref-7)** Dennis DiPietre for Pig 333. April 21, 2014 [Feed Conversion Ratio: critically important but often misused](https://web.archive.org/web/20140503042415/http://www.pig333.com/swin_markets_commentaries/feed-conversion-ratio-critically-important-but-often-misused_8570/)

1. ^ [***a***](#cite_ref-Shike2013_8-0) [***b***](#cite_ref-Shike2013_8-1) [***c***](#cite_ref-Shike2013_8-2) [***d***](#cite_ref-Shike2013_8-3) [***e***](#cite_ref-Shike2013_8-4) Dan W. Shike, Ph.D., University of Illinois at Urbana-Champaign Driftless Region Beef Conference 2013 [Beef Cattle Feed Efficiency](https://web.archive.org/web/20160616072736/http://lib.dr.iastate.edu/cgi/viewcontent.cgi?article=1027&context=driftlessconference)

1. **[^](#cite_ref-9)** Travis D. Maddock, Darren D. Henry, and G. Cliff Lamb. Animal Sciences Department, UF/IFAS Extension. [AN217: The Economic Impact of Feed Efficiency in Beef Cattle](https://web.archive.org/web/20160310005835/http://edis.ifas.ufl.edu/an217) Original publication date May 2009. Revised October 2015.

1. ^ [***a***](#cite_ref-Fry_10-0) [***b***](#cite_ref-Fry_10-1) Robert C. Fry, Atlantic Dairy Management Services. [Measuring Feed Efficiency Why & How on the Back of a Napkin](http://dairy.ifas.ufl.edu/rns/2011/2fry.pdf)

1. ^ [***a***](#cite_ref-Ishler_11-0) [***b***](#cite_ref-Ishler_11-1) [***c***](#cite_ref-Ishler_11-2) Virginia Ishler for Progressive Dairyman. June 30, 2014 [Calculating feed efficiency](https://web.archive.org/web/20160616040107/http://www.progressivedairy.com/topics/feed-nutrition/calculating-feed-efficiency)

1. **[^](#cite_ref-12)** Cornell University, University of Wisconsin-Madison, USDA-Agricultural Research Service, Dairy Forage Research Center April 30, 2004 [Whole-Farm Nutrient Management on Dairy Farms to Improve Profitability and Reduce Environmental Impacts](https://web.archive.org/web/20140117181322/http://www.manuremanagement.cornell.edu/Pages/General_Docs/Reports/Whole_Farm_NM_on_Dairy_Farms_to_Improve_Profitability_and_Reduce_Env_Impacts.pdf)

1. ^ [***a***](#cite_ref-Hutiens_13-0) [***b***](#cite_ref-Hutiens_13-1) Michael F. Hutjens August 21, 2012 [Feed Efficiency and Its Impact on Feed Intake](https://web.archive.org/web/20160616043236/http://articles.extension.org/pages/11317/feed-efficiency-and-its-impact-on-feed-intake)

1. **[^](#cite_ref-14)** USDA Natural Resources Conservation Service [Conservation Practice Standard: Feed Management: (Animal Units (AUs) Affected): Code 592](https://web.archive.org/web/20121024103048/http://www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb1046856.pdf). September 2011

1. ^ [***a***](#cite_ref-Hall_15-0) [***b***](#cite_ref-Hall_15-1) Tony Hall for Eastern Dairy Business September 2011 [Define And Improve Your Herd's Feed Conversion Ratio](https://web.archive.org/web/20160616035304/http://lallemandanimalnutrition.com/wp-content/uploads/2011/10/Hal_Dairybusiness_09111.pdf)

1. ^ [***a***](#cite_ref-Jukes_1992_16-0) [***b***](#cite_ref-Jukes_1992_16-1) Jukes TH (February 1992). ["Today's non-Orwellian animal farm"](https://doi.org/10.1038%2F355582a0). *Nature*. **355** (6361): 582. [doi](/source/Doi_(identifier)):[10.1038/355582a0](https://doi.org/10.1038%2F355582a0). [PMID](/source/PMID_(identifier)) [1538742](https://pubmed.ncbi.nlm.nih.gov/1538742). [S2CID](/source/S2CID_(identifier)) [4308400](https://api.semanticscholar.org/CorpusID:4308400).

1. **[^](#cite_ref-17)** Department of Agriculture and Fisheries, Queensland Government. Managing a piggery >> Production and performance >> [Performance standards](https://web.archive.org/web/20160616102808/https://www.daf.qld.gov.au/animal-industries/pigs/managing-a-piggery/production-and-performance/performance-standards) Last updated 28 September 2012

1. **[^](#cite_ref-18)** David R. Stender, Iowa State University Extension. [IPIC 25h. Swine Feed Efficiency: Influence of Market Weight](https://web.archive.org/web/20150909053400/http://www.swinefeedefficiency.com/factsheets/IPIC25h%20SFE%20Influence%20of%20Market%20Weight.pdf) 2012

1. **[^](#cite_ref-19)** Knott, S. A., B. J. Leury, L. J. Cummins, F. D. Brien and F. R. Dunshea. 2003. Relationship between body composition, net feed intake and gross feed conversion efficiency in composite sire line sheep. In: Souffrant, W. B. and C. C. Metges (eds.). Progress in research on energy and protein metabolism. EAAP publ. no. 109. Wageningen

1. **[^](#cite_ref-20)** Brand, T. S., S. W. P. Cloete and F. Franck. 1991. Wheat-straw as roughage component in finishing diets of growing lambs. S. Afr. J. Anim. Sci 21: 184-188.

1. ^ [***a***](#cite_ref-NRC2007_21-0) [***b***](#cite_ref-NRC2007_21-1) National Research Council. 2007. Nutrient requirements of small ruminants. National Academies Press. 362 pp.

1. **[^](#cite_ref-22)** Fahmy, M. H., J. M. Boucher, L. M. Pose, R. Grégoire, G. Butler and J. E. Comeau. 1992. Feed efficiency, carcass characteristics, and sensory quality of lambs, with or without prolific ancestry, fed diets with different protein supplements. J. Anim. Sci. 70: 1365-1374

1. **[^](#cite_ref-23)** Malik, R. C., M. A. Razzaque, S. Abbas, N. Al-Khozam and S. Sahni. 1996. Feedlot growth and efficiency of three-way cross lambs as affected by genotype, age and diet. Proc. Aust. Soc. Anim. Prod. 21: 251-254.

1. **[^](#cite_ref-24)** Cronjé. P. B. and E. Weites. 1990. Live mass, carcass and wool growth responses to supplementation of a roughage diet with sources of protein and energy in South African Mutton Merino lambs. S. Afr. J. Anim. Sci. 20: 141-168

1. ^ [***a***](#cite_ref-Best2011_25-0) [***b***](#cite_ref-Best2011_25-1) [***c***](#cite_ref-Best2011_25-2) [***d***](#cite_ref-Best2011_25-3) Peter Best for WATTagnet.com November 24, 2011 [Poultry performance improves over past decades](https://web.archive.org/web/20160616092918/http://www.wattagnet.com/articles/10427-poultry-performance-improves-over-past-decades)

1. ^ [***a***](#cite_ref-fao-chi-po_26-0) [***b***](#cite_ref-fao-chi-po_26-1) MacLeod, M.; Gerber, P.; Mottet, A.; Tempio, G.; Falcucci, A.; Opio, C.; Vellinga, T.; Henderson, B.; Steinfeld, H. (2013). [*Greenhouse gas emissions from pig and chicken supply chains – a global life cycle assessment*](http://www.fao.org/3/i3460e/i3460e.pdf) (PDF). Food and Agriculture Organization of the United Nations. [ISBN](/source/ISBN_(identifier)) [978-92-5-107944-7](https://en.wikipedia.org/wiki/Special:BookSources/978-92-5-107944-7).

1. **[^](#cite_ref-27)** Mississippi State University Extension Service [Broiler Breeder Management Is No Easy Task](https://web.archive.org/web/20160616101934/http://extension.msstate.edu/sites/default/files/publications/publications/p2783.pdf), 2013

1. **[^](#cite_ref-28)** ["FIFO explanation document"](https://web.archive.org/web/20161010101003/http://www.iffo.net/cn/system/files/100.pdf) (PDF). Archived from [the original](http://www.iffo.net/cn/system/files/100.pdf) (PDF) on 2016-10-10. Retrieved 2016-06-04.

1. **[^](#cite_ref-29)** ["FIFO explained"](https://web.archive.org/web/20160701195846/http://www.feap.info/default.asp?SHORTCUT=603). Archived from [the original](http://www.feap.info/default.asp?SHORTCUT=603) on 2016-07-01. Retrieved 2016-06-04.

1. **[^](#cite_ref-30)** ["Fish in: Fish Out (FIFO) ratios for the conversion of wild feed to farmed fish, including salmon"](https://web.archive.org/web/20201031044911/https://www.iffo.com/fish-fish-out-fifo-ratios-conversion-wild-feed). *IFFO*. 2010-04-16. Archived from [the original](http://www.iffo.net/fish-fish-out-fifo-ratios-conversion-wild-feed) on 2020-10-31.

1. **[^](#cite_ref-31)** FAO [Cultured Aquatic Species Information Programme: Salmo salar (Linnaeus, 1758)](https://www.fao.org/fishery/en/culturedspecies/salmo_salar/en) 2004

1. **[^](#cite_ref-32)** Dennis P. DeLong, Thomas M. Losordo and James E. Rakocy Southern Regional Aquaculture Center [SRAC Publication No. 282: Tank Culture of Tilapia](https://web.archive.org/web/20151106233121/http://www2.ca.uky.edu/wkrec/TilapiaTankCulture.pdf) June 2009

1. **[^](#cite_ref-33)** USAID Harvest. ["Technical Bulletin #07: Feed Conversion Ratio (FCR): How to calculate it and how it is used"](https://web.archive.org/web/20170131140103/http://pdf.usaid.gov/pdf_docs/PA00K8MQ.pdf) (PDF). Archived from [the original](https://pdf.usaid.gov/pdf_docs/PA00K8MQ.pdf) (PDF) on January 31, 2017. Retrieved 22 March 2024.

1. ^ [***a***](#cite_ref-GFS_34-0) [***b***](#cite_ref-GFS_34-1) [***c***](#cite_ref-GFS_34-2) [***d***](#cite_ref-GFS_34-3) [***e***](#cite_ref-GFS_34-4) Alexander, Peter; Brown, Calum; Arneth, Almut; Dias, Clare; Finnigan, John; Moran, Dominic; Rounsevell, Mark D.A. (December 2017). ["Could consumption of insects, cultured meat or imitation meat reduce global agricultural land use?"](https://doi.org/10.1016%2Fj.gfs.2017.04.001). *Global Food Security*. **15**: 22–32. [Bibcode](/source/Bibcode_(identifier)):[2017GlFS...15...22A](https://ui.adsabs.harvard.edu/abs/2017GlFS...15...22A). [doi](/source/Doi_(identifier)):[10.1016/j.gfs.2017.04.001](https://doi.org/10.1016%2Fj.gfs.2017.04.001). [hdl](/source/Hdl_(identifier)):[20.500.11820/17f627e0-ff81-4492-87d8-97bd6f454840](https://hdl.handle.net/20.500.11820%2F17f627e0-ff81-4492-87d8-97bd6f454840).

1. **[^](#cite_ref-35)** ["Animal Husbandry: Rabbit"](https://agritech.tnau.ac.in/animal_husbandry/animhus_rabbitbreed.html). *[Tamil Nadu Agricultural University](/source/Tamil_Nadu_Agricultural_University) Agritech Portal*. Retrieved 2026-05-22.

1. ^ [***a***](#cite_ref-:0_36-0) [***b***](#cite_ref-:0_36-1) [***c***](#cite_ref-:0_36-2) [***d***](#cite_ref-:0_36-3) [***e***](#cite_ref-:0_36-4) [***f***](#cite_ref-:0_36-5) Mottet, A.; de Haan, C.; Falcucci, A.; Tempio, G.; Opio, C.; Gerber, P. (2022). [*More fuel for the food/feed debate*](https://www.fao.org/documents/card/en/c/cc3134en). Rome: FAO.

1. ^ [***a***](#cite_ref-:1_37-0) [***b***](#cite_ref-:1_37-1) [***c***](#cite_ref-:1_37-2) [***d***](#cite_ref-:1_37-3) [***e***](#cite_ref-:1_37-4) [***f***](#cite_ref-:1_37-5) Mottet, Anne; de Haan, Cees; Falcucci, Alessandra; Tempio, Giuseppe; Opio, Carolyn; Gerber, Pierre (2017-09-01). ["Livestock: On our plates or eating at our table? A new analysis of the feed/food debate"](https://www.sciencedirect.com/science/article/pii/S2211912416300013). *Global Food Security*. Food Security Governance in Latin America. **14**: 1–8. [Bibcode](/source/Bibcode_(identifier)):[2017GlFS...14....1M](https://ui.adsabs.harvard.edu/abs/2017GlFS...14....1M). [doi](/source/Doi_(identifier)):[10.1016/j.gfs.2017.01.001](https://doi.org/10.1016%2Fj.gfs.2017.01.001). [ISSN](/source/ISSN_(identifier)) [2211-9124](https://search.worldcat.org/issn/2211-9124).

1. **[^](#cite_ref-38)** [van Huis, Arnold](/source/Arnold_van_Huis) (7 January 2013). ["Potential of Insects as Food and Feed in Assuring Food Security"](https://doi.org/10.1146%2Fannurev-ento-120811-153704). *[Annual Review of Entomology](/source/Annual_Review_of_Entomology)*. **58** (1): 563–583. [doi](/source/Doi_(identifier)):[10.1146/annurev-ento-120811-153704](https://doi.org/10.1146%2Fannurev-ento-120811-153704).

v t e Meat Poultry Cassowary Chicken Duck Emu Goose Ostrich Pigeon Quail Rhea Turkey Livestock Alpaca Beef Beefalo Bison Buffalo Camel Cat Goat Dog Donkey Snails Frog Guinea pig Horse Lamb and mutton Llama Pork Veal Yak Żubroń Game Alligator Bat Bear Bushmeat Boar Crocodile Elephant Fox Iguana Kangaroo Monkey Mouse Pangolin Rat Hare Rabbit Snake Turtle Venison Dog Wolf Fish Anchovy Basa Bass Carp Catfish Cod Crappie Eel Flounder Grouper Haddock Halibut Herring Kingfish Mackerel Mahi Mahi Marlin Milkfish Orange roughy Pacific saury Perch Pike Pollock Salmon Sardine Shark Sole Swai Swordfish Tilapia Trout Tuna Wahoo Walleye Shellfish and other seafood Abalone Calamari Chiton Clam Crab Crayfish Dolphin Jellyfish Lobster Mussel Octopus Oyster Scallop Seal Shrimp/prawn Sea cucumber Sea squirt Sea urchin Whale Insects Ants Black soldier fly maggots Cicada Crickets Flour Grasshoppers (locust) Mealworm Mezcal worm Mojojoy Silkworm Mopane worm Palm grub Cuts and preparation Aged Bacon Barbecued Biltong Braised Burger Charcuterie Chop Confit Corned Cured Cutlet Dried Dum Fermented Fillet/supreme Forcemeat Cretons Pâté Fried Frozen Ground Ham Jerky Kebab Kidney Liver Luncheon meat Marinated Meatball Meatloaf Offal Pickled Pemmican Poached Potted Rillettes Roasted Salt-cured Salumi Sausage Smoked Steak Stewed Tandoor Tartare List articles Meat dishes Beef Chicken Fish Goat Lamb Pork Ham Seafood Veal Steaks Meatball Smoked foods Sausage Other Countries by meat consumption Countries by meat production Food and drink prohibitions Meat substitutes Ethics and psychology Ethics of eating meat Carnism Animal rights Psychology of eating meat Meat paradox Alternatives Vegetarianism Semi-vegetarianism Pescetarianism Pollotarianism Plant-based diet Meat alternative Veganism Meat science Beef hormone controversy Drip loss Feed conversion ratio Preservation Tenderness Water holding capacity Meat industry Broker Branch house Butcher Cutter Environmental impact Factory farming Jobber Packing Slaughter Slaughterhouse Related subjects Arachnophagy Artificial marbling Cannibalism Case-ready meat Meat diaper Cultured meat Doneness Entomophagy Mystery meat Offal Non-vegetarian food in India Pink slime Raw meat Red meat Roadkill cuisine Warmed-over flavor White meat Food portal Category: Meat

v t e Ecology: Modelling ecosystems: Trophic components General Abiotic component Abiotic stress Behaviour Biogeochemical cycle Biomass Biotic component Biotic stress Carrying capacity Competition Ecosystem Ecosystem ecology Ecosystem model Green world hypothesis Keystone species List of feeding behaviours Metabolic theory of ecology Productivity Resource Restoration Producers Autotrophs Chemosynthesis Chemotrophs Foundation species Kinetotrophs Mixotrophs Myco-heterotrophy Mycotroph Organotrophs Photoheterotrophs Photosynthesis Photosynthetic efficiency Phototrophs Primary nutritional groups Primary production Consumers Apex predator Bacterivore Carnivores Chemoorganotroph Foraging Generalist and specialist species Intraguild predation Herbivores Heterotroph Heterotrophic nutrition Insectivore Mesopredators Mesopredator release hypothesis Omnivores Optimal foraging theory Planktivore Predation Prey switching Decomposers Chemoorganoheterotrophy Decomposition Detritivores Detritus Microorganisms Archaea Bacteriophage Lithoautotroph Lithotrophy Marine Microbial cooperation Microbial ecology Microbial food web Microbial intelligence Microbial loop Mycoloop Microbial mat Microbial metabolism Phage ecology Food webs Biomagnification Ecological efficiency Ecological pyramid Energy flow Food chain Trophic level Example webs Lakes Rivers Soil Tritrophic interactions in plant defense Marine food webs cold seeps hydrothermal vents intertidal kelp forests North Pacific Gyre San Francisco Estuary tide pool Processes Ascendency Bioaccumulation Cascade effect Climax community Competitive exclusion principle Consumer–resource interactions Copiotrophs Dominance Ecological network Ecological succession Energy quality Energy systems language f-ratio Feed conversion ratio Feeding frenzy Mesotrophic soil Nutrient cycle Oligotroph Paradox of the plankton Trophic cascade Trophic mutualism Trophic state index Defense, counter Animal coloration Anti-predator adaptations Camouflage Deimatic behaviour Herbivore adaptations to plant defense Mimicry Plant defense against herbivory Predator avoidance in schooling fish

v t e Ecology: Modelling ecosystems: Other components Population ecology Abundance Allee effect Consumer-resource model Depensation Ecological yield Effective population size Intraspecific competition Logistic function Malthusian growth model Maximum sustainable yield Overpopulation Overexploitation Population cycle Population dynamics Population modeling Population size Predator–prey (Lotka–Volterra) equations Recruitment Small population size Stability Resilience Resistance Random generalized Lotka–Volterra model Species Biodiversity Density-dependent inhibition Ecological effects of biodiversity Ecological extinction Endemic species Flagship species Gradient analysis Indicator species Introduced species Invasive species / Native species Latitudinal gradients in species diversity Minimum viable population Neutral theory Occupancy–abundance relationship Population viability analysis Priority effect Rapoport's rule Relative abundance distribution Relative species abundance Species diversity Species homogeneity Species richness Species distribution Species–area curve Umbrella species Species interaction Antibiosis Biological interaction Commensalism Community ecology Ecological facilitation Interspecific competition Mutualism Parasitism Storage effect Symbiosis Spatial ecology Biogeography Cross-boundary subsidy Ecocline Ecotone Ecotype Disturbance Edge effects Foster's rule Habitat fragmentation Ideal free distribution Intermediate disturbance hypothesis Insular biogeography Land change modeling Landscape ecology Landscape epidemiology Landscape limnology Metapopulation Patch dynamics r/K selection theory Resource selection function Source–sink dynamics Niche Ecological trap Ecosystem engineer Environmental niche modelling Guild Habitat Marine Semiaquatic Terrestrial Limiting similarity Niche apportionment models Niche construction Niche differentiation Ontogenetic niche shift Other networks Assembly rules Bateman's principle Bioluminescence Ecological collapse Ecological debt Ecological deficit Ecological energetics Ecological indicator Ecological threshold Ecosystem diversity Emergence Extinction debt Kleiber's law Liebig's law of the minimum Marginal value theorem Thorson's rule Xerosere Other Allometry Alternative stable state Balance of nature Biological data visualization Ecological economics Ecological footprint Ecological forecasting Ecological humanities Ecological stoichiometry Ecopath Ecosystem based fisheries Endolith Evolutionary ecology Functional ecology Industrial ecology Macroecology Microecosystem Natural environment Regime shift Sexecology Systems ecology Urban ecology Theoretical ecology Outline of ecology

---
Adapted from the Wikipedia article [Feed conversion ratio](https://en.wikipedia.org/wiki/Feed_conversion_ratio) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Feed_conversion_ratio?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.