In animal husbandry, feed conversion ratio (FCR) is a measure of an animal’s efficiency in converting feed into increased body mass. Specifically, FCR may be defined as weight gain divided by feed intake. Two additional terms are used by the farmer, the biological FCR and the economics FCR. Biological FCR is the net amount of feed used to produce one kg of broiler, while the economics FCR takes into account all the feed used including the effect of feed losses and mortalities. FCR is most important parameter affecting the economics and ratio of 1:1 seems to be most efficient one.

Apparently it seems impossible that feeding one kilogram feed will fetch one kilogram of broiler meat because 100% retention of nutrients is not possible because there are some losses which are unavoidable in a biological system like heat increment, incomplete amino acids, environmental losses, etc. On detail analysis of the fact it is realized that 1 kg feed has 11% moisture (i.e having 90% dry matter) while the live weight of broiler is in kg of “wet” weight (i.e having 39% dry matter). Broiler meat with skin contains 69% water according to United States Department of Agriculture Food Safety and Inspection Service, meaning that 1 kg live weight will have approximately 300 gm dry matter in it. It implies that to achieve 1 kg live weight in broiler (300 gm dry matter) only 40% of nutrients from 1kg feed (900 gm dry matter) should get deposited to give 1 kg live broiler weight.

Feed conversion ratio (FCR) is a measure of how efficient an animal converts feed mass to desired output. The desired output may be eggs for laying birds, milk for dairy cows and goat, meat for meat animals such as broilers, pigs, rabbits etc, wool for animals like sheep, goats, rabbits etc. FCR is the mass of feed eaten divided by the output over a given period of time.

FCR = Feed Eaten/Output

Farmers desire a low FCR because it means that more output is produced with less feed. Therefore a low FCR means lower feed cost. A FCR of 2 means that to produce 1kg output (live weight gain, milk), the animal will consume 2kg of feed.

Factors Affecting FCR

1. Genetics

Some animals have the natural ability to produce more output from less feed than other animals of the same species. For example, dairy goat breeds can produce much more milk than the non-dairy breeds. Commercial egg laying hens can produce far more eggs than the local breeds.

2. Age

Young animals grow faster than adult animals, so they have lower FCR. A farmer can use this knowledge to increase profit by selling or processing his animals before they reach adult age. This is common with broilers which are sold or processed in just 6 weeks. Some catfish farmers will raise their fish for 3-3.5 months and then sell or smoke them. This way, they benefit from the fast growth rate and less feed cost.

3. Feed Quality

Animals that are fed a diet that meet their nutritional requirement will have lower FCR. Nutritional requirement varies with the age of the animal in question. For broilers, there are chick starter and broiler finisher. For layers there are chick starter, grower and then layers mash. More complex feeding for layers can also include developer and pre-lay rations. All these feed were formulated to satisfy nutrient requirements at different stages of growth.

4. Management Method

This has to do with the welfare of the animals. Are the animals well protected from high temperature, cold, rain etc? Do you feed them well? Do you have measures in place to protect the animals from infection? Animals under cold weather will eat more feed to keep warm and this will lead to higher FCR than when the weather is fair. All these and more can affect the FCR.

FCR of Different Farm Animals

The values given below are general values. For specific values you may have to conduct further research.

  1. Cattle: It rangers from 5-20
  2. Pigs: Ranges from 3-3.2
  3. Sheep: For lambs (4 months), FCR is 4-5 on high concentrate rations, 5-6 on good quality forage and more than 6 on low quality forage. On straw ration, it can be as high as 40. FCR for older sheep (8 months) is higher than those for lamb
  4. Poultry: Ranges from 1-2
  5. Crickets: About 1.7.
  6. Fish: Tilapia has 1.6-1.8. Catfish is 1.5-5
  7. Rabbits: 5-3 on high grain diet, 3.5-4 on forage without grain.

How to Improve FCR and Reduce Feed Cost in Poultry?

The feed conversion ratio (FCR) is the amount of feed ingested by an animal which can be converted into one kilo of live weight. This definition also applies to a single-age poultry flock held in an enclosed house. It is important that this house contains an indication of the amount of feed that has been eaten. The end of a rearing cycle is a good opportunity to undertake the technical-economic balance sheet of the cycle taking account of the following parameters.

  • The technical FCR is the total amount of ingested feed divided by the number of animals that have exited the house.
  • The economic FCR is the total amount of feed ingested divided by the weight of poultry animals that can be accepted at the slaughterhouse. That is to say that the weight of seized meat is deducted from the total weight of goods.
  • The corrected FCR at fixed weight is the average ratio of different flocks considering that they have all been slaughtered at the same weight. In other words, these animals are all brought down to the same weight through calculations.
  • The corrected FCR at fixed age is determined by estimating the weight that these chickens might have reached at the same age, depending on what they have consumed.

    The FCR and hence, the amount of feed ingested, are the major variables that can help to set the cost of a poultry animal. Depending on the species and countries considered, the share of feed makes up 40 to 70% of cost production. Poultry, including broiler, remain the species whose FCR is the lowest (it can be as low as 1.5). Unlike other species, poultry are not religiously banned; this is why their consumption has no impediment and their yearly growth rate averages 3%.

    Improving poultry FCR and reducing feed costs

    Poultry’s FCR are first determined by the chosen genetic selection mode and the rearing conditions applied, as follows:

    • A red label chicken of slow-growing strain reared outdoors and slaughtered at 81 days will have an average FCR value ranging between 2.8 to 3.2
    • A standard broiler chicken reared in an enclosed house will have an FCR between 1.3 to 1.6.

    By comparing these two chickens of different strains that have been fed with raw materials of same origin, it turns out that the first chicken will end up costing twice as much as the second.

    Despite these differences, FCR calculations are very relevant.

    Evolving from an initial FCR of 3.2 to 2.8 in the case red label chicken implies that 800 grams of feed have been saved. Besides the type of farming and genetic selection applied, the improvement of FCRs lies on various factors:

      • On the suitable transformation of raw materials, on the nutritional standards and physical presentation of feed, on the chosen genetics and the type of farming used.
      • On the rearing conditions applied, animals’ comfort and their access to water and feed.
      • Any element likely to cause discomfort, difficulties in accessing water and feed, as well as the animals’ aversion for specific types of feed, could lead to heterogeneous growth, health issues and to seizures at the slaughterhouse.

       The eventual impact may lead to significant drops in FCRs.

      5 ways to improve broiler feed efficiency beyond nutrition

      After the feed arrives at the farm, there are five pointers that will help improve feed efficiency in broilers. Improving feed efficiency is usually associated with improved profitability. Most measures to improve this useful index of productivity are by balancing the ratio between energy and amino acids, and (or) by improving nutrient digestibility by a number of different means. But, the feed efficiency rate can be improved even after the feed is mixed and delivered at the farm. Here are five tips to ensure broilers take the most out of the feed they are given on any farm.

      1. Avoid hot spots in feed silos

      Molds consume valuable nutrients and produce mycotoxins. Moldy feed is not only unpalatable, but also toxic as well. Quite often, feed is delivered into silos that are never cleaned. In humid and warm climates, mold growth is easy to occur, and even in apparently empty silos, there are hot spots (patches of old moldy feed adhering to the inside surfaces of silos) that can serve as the leaven for the next batch of fresh feed. Adding a mycotoxin binder and a mold inhibitor is not enough. Silos must be periodically inspected and cleaned thoroughly. Usual dosage rates recommended for mycotoxins in feed do not take into account this issue, which can be quite serious under unfavorable conditions.

      A factor that greatly enhances feed efficiency is the correct placement of drinkers close to the feeders, but not so close as to cause feed spoilage.

      2. Use feeders that don’t waste feed

      It might appear obvious to buy feeders that minimize feed wastage, but low-cost is always an alluring factor that quite often makes us buy something less efficient in the long-run. Feeders should also be managed (cleaning, placement, distances, number of birds per feeder, etc.) so that feed consumption is neither an opportunity to beat boredom nor a hurried fight to eat. Quite often a factor that greatly enhances feed efficiency is the correct placement of drinkers close to the feeders, but not so close as to cause feed spoilage.

      3. Lights on and off

      It has been suggested that a constant lighting program (such as 23 hours light and 1 hour darkness) might not be the best in terms of feed digestibility. Under constant lighting, birds tend to overconsume feed, which tends to increase feed rate passage. Given that birds are fed at or near maximum genetic potential levels, this extra feed they consume has limited time to interact with digestive enzymes, resulting in reduced feed digestibility. In contrast, a lights-on, lights-off program (for example, 1 hour light, 1 hour darkness, and so on) allows birds to fully digest their feed while resting (which also improves feed efficiency as birds do not walk aimlessly all day), and gives them enough time to “refill” during light hours. The only problem with this system is that there should be enough feeding spaces for all birds to eat simultaneously, something that requires careful pre-placement feeder management.

      4. Avoid heavy body weight at market age

      If you need to attain a certain market age or market weight, then you should probably follow the guidelines of your contracting partner. But, if you sell on the open market, it pays to keep in mind that feed efficiency becomes a bit worse with each day the birds age. This is mostly due to the fact that birds have a greater body mass to maintain each day — and maintenance requires both energy and amino acids. So, finding the minimum weight per bird that is acceptable will also minimize feed efficiency. Of course, this does not necessarily mean maximal profitability, and to this end, other parameters should be consulted: cost per weight gain, or weight gain per given floor surface, etc.

      5. Keep birds healthy

      One more obvious observation, but it is always worth repeating: sick birds do not grow, and if they do not grow, feed efficiency is never ideal. Sick or subclinical affected birds don’t eat as much as healthy birds, and what they eat usually goes to fighting off the disease. In addition, they might even break down muscle proteins, which reduces their body weight, making feed efficiency the worst possible. In contrast, healthy birds, especially those with a very healthy digestive system, will utilize nutrients in the feed at maximal efficiency. Perhaps subclinical diseases are the worst “robbers” of feed efficiency points, if only because they go unnoticed, whereas we investigate anything else that might have caused this drop in performance.


      Feed conversion ratio (FCR) measures the feed intake per unit output (eggs, meat, milk). The lower the FCR the lesser the feed cost. Animals with low FCR are efficient in converting feed to output. If you want to reduce your cost of production, always think of ways you can reduce the FCR.

      Obviously, not all of the above pointers are applicable in every single farm. But, even if one point is taken into consideration and feed efficiency improves by a bit, it means increased profitability, especially since all of the above are routine management measures.

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