Introduction:
Achieving 1:1 FCR in broiler production may appear to be a myth to a layman, but to scientists it is just the matter of time and advancement of our knowledge of nutrition and genetics and its application thereafter. To prove the point strong evidences and facts are discussed below in its support.
Feed Conversion Ratio:
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. Thus we can conclude that FCR of 1:1 is not only possible but there is margin of error also.
Few decades ago FCR in broiler industry was around 1:2.4 and the concept of 1:1 FCR seemed like a myth or mere a dream. With knowledge advancement of nutrition and intensive research in breeding, broiler production has resulted in lowering this ratio presently to 1:1.4 and still exploration continues.
Solution to get 1:1 FCR:
With the advancement of research we can precisely estimate the amino acid requirement of broiler which can be practically incorporated into the feed, resulting in maximum retention of protein in body. If such a high precision in the supply of dietary amino acids is achieved it is practically possible that all the protein present in the feed can be converted into body tissue. Under this situation 230 gm of protein (23% crude protein in ration) will be deposited in the body which will result in a weight gain of above 1 kg because the broiler live weight of 1 kg contains only 200 gm crude protein. As discussed above feed contains about 90% dry matter which means that out 900 gm dry matter in feed only 400 gm should be retained in the animal body to achieve 1 kg live weight. Broiler feeds come from plant origins which are not rich in essential amino acids required to build body protein, resulting in deamination of excessive amino acids with extra use of energy to fix the nitrogen. Synthetic amino acids are available but are expensive. With the advent of knowledge of Nutrition we will not only know the precise limiting amino acids but also their exact amount which may be deficit. Lot more is to be done in field of synthetic amino acids, so that they become cheap and economical. Once incorporated in the diet in proper proportion, these could result in maximum retention of protein in the body. Interactions between the amino acids with each other and with other nutrients are to be studied in more details by conducting more research in this area.
Other nutrients except protein like minerals, vitamins, enzymes and other feed additives have important role to play in FCR as well as feed cost. Feeding organic minerals in place of inorganic sources have benefits in FCR in young broilers. Organic minerals can be included at much lower levels in the diet than the current recommendations for inorganic minerals, without any negative effect on broiler performance.
Broiler performance has improved enormously in recent decades. As a result, nutrition patterns have also changed. Based on the genetic progress of the birds, proper vitamin supplementation levels are needed. The Optimum Vitamin Nutrition (OVN) concept is a useful tool for supplying the correct amount of vitamins to broiler diets. When compared to other nutrients, there have been few studies carried out in recent years to estimate the optimum levels of vitamins for broilers, and there is a huge variation in the levels used commercially. Most levels recommended by the NRC (1994) have been based on old studies, performed under controlled conditions, and using the minimum levels to avoid signs of deficiency, not evaluating the best performance under the challenge conditions found in the field. Moreover, modern breeds have a higher growth and production rate, and obviously have higher nutritional requirements to express their genetic potential. Supplementation with higher levels according to the stage of broiler, rather than the minimum recommendation will result in better FCR.
Supplementation of anti oxidants has helped in reducing FCR and improved meat quality. Reports of improved FCR, growth response and immunity with Vitamin C and Vitamin E supplementation are also available. Over the past 2 decades, the use of enzymes in animal feeds has received much attention by the animal industry. Early studies indicated that supplementation of proteases, -amylases, -glucanases and mixed enzymes might have a positive influence on animal growth. These enzymes have enabled the use of barley and wheat in poultry up to 50-60% which was not possible before due to presence of β-gulcans. Recently, enzymes including endoxylanase and endomannanases have produced significant improvement in FCR of poultry when supplemented to the diets high in wheat and soybean meal. Thus day by day every nutrient is brought to its highest limit and we reach nearer and nearer to goal of narrowing the feed conversion ratio.
As a personal opinion whatever man has created till date are discoveries not inventions. For example aeroplane, which is a creation of man but as a matter of fact all its components from which it is made are already present in Mother Nature in one form or other, even the birds from which man got inspired. It appears that human brain is only arranging the information which is already present in Mother Nature just like solving a puzzle box and she keeps us up by giving us hints to inspire us to explore her. Pertaining to the topic hint and inspiration are salmons, trout and salmonid fish. These fishes have feed conversion ration close to 1:1 and some are reported to have FCR lower than 1 i.e. 0.8.
In the end it can be concluded that Mother Nature is herself saying ‘It can be done and will not remain a myth.’
by Dr. Zulfqar ul haq, Dr. Suraj A. Amrutkar, Dr. Ankur Rastogi, and Dr. Nazim Khan
