Talk:Feed conversion ratio

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Feed Conversion Ratio of Ruminants[edit]

Citing an FAO publication, the article states "Ruminants can convert 7 kg of grain to one kilogram of meat." This reflects a misunderstanding of the statement in the original source (Rosegrant et al. 1999), cited in the FAO document. Also, Rosegrant et al. (who cite no evidence in support of their statement) used problematic wording when they wrote: "In developed countries, ... production of beef in feedlots utilizes as much as 7 kg grain/kg meat production." That is, the magnitude is too low for this to be realistic, as is evident, for example, on comparison with data of National Research Council (2000), adjusted for grain content of feedlot rations using data of USDA (2000), and converting NRC live gain data to a retail meat basis using data such as those of Realini et al. (2001) or USDA (1992; 2012). The magnitude strongly suggests that what Rosegrant et al. actually meant was that as much as 7 kg of grain might be fed per kg of meat recovered from a feedlot-finished beef animal (i.e. the kg of meat includes meat produced before entering the feedlot as well as in the feedlot). Cattle feedlot rations include more than grain (USDA 2000), and roughages are also consumed before weaning and during backgrounding, so not only the 7 kg of grain but also an unspecified mass of other feed (roughages and perhaps some oilseed product, e.g. soybean meal, and other constituents) are converted to 1 kg of meat. Clearly, the 7 kg/kg figure is not a FCR, and thus not germane to the article topic. As the quoted statement is erroneous, misleading and irrelevant to the article topic, it should be deleted.

  • National Research Council. 2000. Nutrient requirements of beef cattle. National Academy Press. 232 pp.
  • Realini , C. E., R. E. Williams, T. D. Pringle and J. K. Bertrand. 2001. Gluteus medius and rump fat depths as additional live animal utrasound measurements for predicting retail product and trimmable fat in beef carcasses. J. Anim. Sci. 79: 1378-1385.
  • Rosegrant, M. W., N. Leach and R. V. Gerpacio. 1999. Meat or wheat for the next millenium? Plenary lecture. Proc. Nutr. Soc. 58: 219-234.
  • USDA. 1992. Weights, measures and conversion factors for agricultural commodities and their products. United States Department of Agriculture, Economic Research Service. Agriculture Handbook 697. 71 pp. [cited for retail beef yield from carcass]
  • USDA. 2000. Feedlot 99. Part 1. Baseline reference of feedlot management practices, 1999. USDA NAHMS, APHIS. 66 pp.
  • USDA. 2012. National daily cattle and beef summary. Tuesday, May 29, 2012. [cited for dressing percentages]. Schafhirt (talk) 22:10, 30 May 2012 (UTC)

The Wikipedia article also states "Sheep and cattle need more than 8 kg of feed to put on 1 kg of live weight." No reference is cited in support of this. Moreover, the statement is clearly erroneous, as there are numerous peer-reviewed research papers showing some FCR magnitudes less than 8 for both cattle and sheep; similarly, one finds some lower FCR magnitudes based on cattle and sheep data in the US National Research Council's "Nutrient Requirements of Beef Cattle" and "Nutrient Requirements of Small Ruminants", respectively.Schafhirt (talk) 22:10, 30 May 2012 (UTC)

The article states "This value is an underestimation of the FCR, for it does not take in account that normally the feed is in kg of 'dry' weight and the live weight is in kg of 'wet' weight. When both factors are transformed to either dry or wet weight the FCR increases 4 to 5-fold, depending on the feeding practice and species; mammal body weight is typically mostly water ." No reference is cited to support this. In fact, FCR is not necessarily underestimated where feed dry mass and animal live (wet) mass are used, because calculation in this manner corresponds to a FCR definition commonly used. Moreover, the "4 to 5-fold" range is inappropriate. For example, water content of hay is often about 0.12 kg/kg; water content of a ruminant animal might be about 0.55 kg/kg.(Faichney and Boston 1985), although higher or lower water contents might be found, depending on fatness (Houpt 2004). In this case, FCR in kg DMI (dry matter intake) per kg live body mass gain would be increased only 1.14-fold if feed mass were converted to a wet mass basis; it would be increased only about 2.22-fold if not only feed mass, but also body mass, were expressed on a dry mass basis. Cool-season forage grasses before early boot stage often have water contents of 80 percent or more (Jones 1991; Collins and Scheaffer 1996). With a FCR in kg DMI per kg live mass gain, if FCR were converted so that not only body mass, but also feed mass, were expressed on a wet mass basis, FCR for grass at 80 percent moisture content would be increased 5-fold, but with both expressed on a dry mass basis, the increase would be only 2.22-fold, where body water content is 55 percent. Although FCR is usually calculated with feed mass on a dry mass basis, feed mass is sometimes on an as-fed basis, i.e. wet mass at the actual moisture content of the feed, or in the case of grain and oilseed, sometimes with feed mass as wet mass at standard moisture contents of the constituents. In careful presentations, the nature of the FCR (or FCE) calculation used is explicitly stated with regard to dry vs. wet mass of the feed (except in some applications where a specific usage is conventional and widely understood). The implication that it might be appropriate to calculate FCR with animal live mass expressed on a dry mass basis is unsupported by any citation, and is inconsistent with conventional usage and common definitions of FCR. The unsupported, erroneous and unnecessary content should be deleted.

  • Collins, M. and C. C. Sheaffer. 1996. Harvesting and storage of cool-season grass hay and silage. In: Moser, L. E., D. R. Buxton and M. D. Casler (eds.). Cool-Season Forage Grasses. No. 34 in the Agronomy series. American Society of Agronomy, Madison, Wisconsin. pp. 297-319.
  • Faichney, G. J. and R. C. Boston. 1985. Movement of water within the body of sheep fed at maintenance under thermoneutral conditions. Aust J. Biol. Sci. 38: 85-94.
  • Jones, L. 1991. Laboratory studies on the effect of potassium carbonate solution on the drying of cut forage. Grass and Forage Sci. 46: 153-158.
  • Houpt, T. R. 2004. Water and electrolytes. In: Reece, W. O. (ed.) Dukes’ physiology of domestic animals. 12th Ed., Cornell Univ. Press, Ithaca. pp. 12-25. Schafhirt (talk) 22:10, 30 May 2012 (UTC)

Provided citation removed conflicting sentence[edit]

I provided an online citation for the salmon FCR.

I removed a sentence because it had no citation and is OPPOSITE to every other statement in this and other articles in Wikipedia. I have NO IDEA what "TRUE" FCR is referring to nor is the concept of "true" defined anywhere that I could find. If it does exist (and I'm not saying it does not) would that make the rest of this article "untrue"? Here, then, is the sentence that was removed: "Presently, technological advances in feed research are enabling salmon farmers to lower the “true” FCR to less than 4 (i.e. by substituting fish meal and fish oil with plant products such as soy and derivatives) which in consequence lowers the Salmon’s average trophic level[citation needed]."

As an aside, in aeronautics, True Air Speed (TAS) is differentiated from Indicated Air Speed (IAS) by technical definitions. Similarly, two technical definitions need to be provided here, or the reference needs to remain deleted. N0w8st8s (talk) 06:26, 30 November 2012 (UTC)n0w8st8s

External links modified[edit]

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I've reviewed this archived source. The citation itself seemed to be in the wrong place, so I've moved it as well, and I've added a 'citation needed' to the appropriate place. CheCheDaWaff (talk) 11:57, 9 April 2016 (UTC)

Broken Citation[edit]

The link for Citation 10 (Quick Facts - The Pork Industry at a Glance) doesn't lead anywhere, and doesn't itself describe a source. Should it be removed? CheCheDaWaff (talk) 17:20, 15 March 2016 (UTC)

Citation 3 (Pork Production) seems to be suffering the exact same issue. CheCheDaWaff (talk) 17:53, 15 March 2016 (UTC)

I have taken the decision to remove the offending citations. For reference, the citations linked to the following URLs: http://www.uky.edu/Ag/AnimalSciences/pubs/asc104.pdf (previously citation 3)

http://viewer.zmags.com/publication/5bb6aa6d#/5bb6aa6d/46 (previously citation 10) CheCheDaWaff (talk) 21:55, 10 April 2016 (UTC)

Does a primary human consumable caloric/protein conversion ratio exist?[edit]

(Known articles: Feed conversion ratio (FCR), Efficiency of food conversion (ECI))

The definitions given there either explicitly refer to mass (FCR, with the discussion noting that substantial problems exist with respect to dry/wet mass) or seem to be undefined (ECI). I am looking for conversion ratios that allow an understandable comparison for human food production. An example would be human consumable calories and human consumable protein (2 different values). The sum of the caloric input fed during the raising of an animal would be divided by the sum of all calories of products generated from the animal. Thus, the weight of bones and skin etc. would not go into the equation, neither would fodder not consumable by humans (grass) enter the equation. The desire for a "primary" conversion ratio relates to the case, where the fodder itself has a feed conversion ratio (raising fish from plant matter to be fed to other fish). Here the fodder would be accounted with the primary calories used to produce it. Do this or similar definitions exist? Do data for this or similar parameters exist? --Vigilius (talk) 13:36, 29 April 2017 (UTC)

Your question is a little scary. :) But it a question for the WP:Reference desk. This page is for discussing improvements to this article. Jytdog (talk) 23:01, 29 April 2017 (UTC)
Will also ask at reference desk, but I think this is about the improvement of this article. It would be a kind of feed conversion ratio / efficiency, and would fit in the variants already discussed or linked to. Measuring in wet or dry mass is not very logical; different feed has different energy or protein content. See also Efficiency of conversion already linked. My question is thus: is there already an article, do we need an addition here (or a new article to be linked to), or is that something science does not discuss (I feel the latter is unlikely). --Vigilius (talk) 08:35, 30 April 2017 (UTC)
This is not a reference desk. Really - the place to ask your question is WP:Reference desk. And I see you have asked there. Done here. Jytdog (talk) 20:01, 30 April 2017 (UTC)