Effect of Protein and Amino Acids on Fat Deposition in Poultry

Effect of Protein and Amino Acids on Fat Deposition in Poultry - Vinayak IngredientsThe abdominal fat tissue is very important in chickens due to its rapid growth as compared with other fat tissues. Most fatty acids are produced in the liver and stored as triglycerides in adipose tissues. Thus, the abdominal fat is a reliable parameter for estimating total body fat content as it directly correlates with the total lipid content in avian species. Nutritional factors play a key role in regulating body fat deposition. Therefore, this article discusses the effect of two such nutritional factors viz., protein and amino acids on the abdominal fat content and the mechanism of regulating abdominal fat deposition in poultry in a beneficial manner.

Protein is the most expensive component of poultry diets. The increase in the dietary protein content improves the daily weight gain, carcass yield, and meat quality by reducing body fat deposition and increasing protein content. A report shows that reducing dietary protein level during the starter, grower, and finisher phase, and compared with normal-protein diets as recommended by NRC, 1994 led to a significant increase in the abdominal fat content. An analogous study where increasing dietary protein level in the diets of broiler chickens in all three phases led to a significant reduction abdominal fat deposition compared with diets formulated according to NRC (1994) causing lean broiler chickens. Therefore, dietary protein content must play a direct or indirect role in the regulation of lipid metabolism. In 2002, it was found that reducing dietary protein content upregulates malic enzyme mRNA expression increases malic enzyme activity in the liver of broilers compared with the control, and vice versa. Further study also showed that increasing dietary protein content caused a significant reduction in hepatic enzyme mRNA expression in the livers of broiler chickens. Therefore, dietary protein level directly affects body fat deposition. Thus, it is important to suffice the protein requirements of birds to produce high-quality meat with low-fat deposition.

At present, only methionine, lysine, and arginine are known to beneficially regulate body fat deposition in poultry. Therefore, the addition of these amino acids in poultry diets should be ensured to prevent unnecessary fat deposition. Among these, methionine is the first limiting amino acid in poultry diet. It is essential amino acid as it directly affects on growth performance and helps in producing lean meat. A report shows that inclusion of L-methionine in poultry diet leads to a significant reduction in body fat content. The effect of dietary L-methionine in reducing the fat deposition may be associated with changes in lipolysis and lipogenesis. Lysine also has a prominent role in meat quality by increasing protein deposition, reducing the water-holding capacity, and enhancing muscle pH. The lysine supplementation in poultry diets significantly enhances lean meat production. A meat-type ducks fed with lysine-deficient diet gave significant high abdominal fat percentage while the inclusion of lysine eliminated this effect. Hence, addition of lysine in poultry diets promotes lean meat production by reducing carcass fatness via lipogenesis inhibition.

Another essential amino acid is the arginine which plays multiple roles in poultry production, implicated in reduction of carcass fat deposition. A study reports a significant reduction in the abdominal fat content in Japanese quails at 42 day of age 2.0% arginine supplementation at day zero of incubation. A corresponding study reported that providing 1.0% more arginine in addition to the NRC (1994) recommendations reduces the abdominal fat content by decreasing the activities of enzymes involved lipogenesis. In avian species, therefore, dietary L-arginine supplementation inhibits certain hepatic enzymes, which causes a reduction in the abdominal fat content by reducing the size of abdominal adipose cells.

Hence, the fat-reducing effects of protein and certain amino acids have not been fully clear. Thus this article makes an effort to elucidate our current understanding of the mechanism related to the effects of protein and amino acids that beneficially regulate abdominal fat deposition in poultry.

7 Main Nutrition Requirements in Egg Layers

7 Main Nutrition Requirements in Egg Layers - Vinayak IngredientsPoultry diets are a mixture of several feed stuffs such as soybean meal, cereal grains, fats, animal by-product meals, and vitamin and mineral premixes. Here are the few main nutrients which producer must not ignore when planning the feed diet.

ENERGY

The main source of energy for poultry is dietary carbohydrates. Corn, grain sorghum, wheat, and barley are important carbohydrates to poultry diets. These adversely affect the digestive processes of poultry when present in sufficient dietary concentrations. For example, pentosan and beta glucans of rye and barley respectively increase the viscosity of digesta and helps in nutrient absorption of poultry. Supplementation of rye or barley with dietary enzyme improves nutrient utilisation and growth of young poultry.

PROTEIN

Dietary requirements for protein are actually requirements for the amino acids contained in the dietary protein. They are main constituents of structural and protective tissues, such as feathers, bone matrix, skin, and ligaments, including organs and muscles. The individual amino acids and short peptides after digestion-absorption may serve a variety of metabolic functions and precursor to biochemical pathways. Insufficient dietary protein leads to slow growth or less productivity.

MINERAL

Minerals are the inorganic part of feeds or tissues. Calcium and phosphorus are essential for the formation and maintenance of the skeleton and eggshell formation. Sodium, potassium, magnesium, and chloride function with phosphates and bicarbonate to maintain homeostasis of osmotic relationships and pH throughout the body. The forms of phosphorus, such as ATP and phospholipids if present in plants, can be digested by poultry; however, such digestible forms usually account for only 30 to 40 percent of the total phosphorus. The remaining phosphorus is present as phytate phosphorus and is poorly digested. Trace elements, including copper, iodine, iron, manganese, selenium, and zinc are required in small amounts in the diet. Trace elements function as part of larger organic molecules. Iron is a part of haemoglobin and cytochromes, and iodine is a part of thyroxine.

VITAMINS

Vitamin C is synthesised by poultry and is, accordingly, not considered a required dietary nutrient. The dietary requirement for vitamin E is highly variable and depends on the concentration and type of fat in the diet, the concentration of selenium, and the presence of prooxidants and antioxidants. Vitamin K activity is exhibited by a number of naturally occurring and synthetic compounds with varying solubilities in fat and water.

WATER

Water must be regarded as an essential nutrient, although it is not possible to state precise requirements. The amount needed depends on environmental temperature and relative humidity, the composition of the diet, rate of growth or egg production, and efficiency of kidney resorption of water in individual birds.

XANTHOPHYLLS

The carotenoid pigments not only provide yellow-orange coloration of egg yolks and poultry fat but also contribute to coloration of the skin, feet, and beak. Alfalfa meal contains lutein which provides a yellow colour, whereas corn and corn gluten meal contain primarily zeaxanthin which impart as orange-red colour. Synthetic carotenoids are also used approved by the regulatory agencies used in poultry diets as the concentration of the desired pigments in natural feed stuff is not always constant.

ANTIMICROBIALS

Antimicrobial agents are nutritional feed additives/growth promoters and are not nutrients as they are essential to poultry. They are included in diets to improve growth, efficiency of feed utilisation and livability. They are added at relatively low concentrations (1 to 50 mg/kg), depending on the agent and stage of development of poultry.

Poultry diets are a mixture of several feed stuffs such as soybean meal, cereal grains, fats, animal by-product meals, and vitamin and mineral premixes. Here are the few main nutrients which producer must not ignore when planning the feed diet.

All We Need To Know About Methionine Requirements in Chickens

All We Need To Know About Methionine Requirements in Chickens - Vinayak Ingredients

We all know amino acids are building blocks of life. The application of amino acids in feed industry has been since four decades. Amino acids for feed now play key role in improving the efficiency of protein utilisation in animal feeding. Among others, let’s discuss DL-Methionine since it’s the first limiting amino acid, followed by L-Lysine and L-Threonine.

Methionine is an essential amino acid required by poultry in sufficient amount for optimum body weight gain or egg production. Deficiency of methionine therefore causes retarded growth in broilers and reduced egg production in layers. On the other hand, surplus of methionine has been associated with atherosclerosis. Methionine is also a major constituent in feather formation. Its deficiency leads to poor feather growth and rise in the feather pecking in order to obtain adequate methionine. This behaviour can lead to cannibalism among the flocks. This could be the worst nightmare ever possible to farmers. To our rescue, synthetic DL-Methionine began finding its way into poultry industry since late 1950s. Till now broiler requirements are been met by the use of synthetic methionine since it’s affordable to the farmers. By now we can sense that how adverse effect can DL-methionine have on chickens.

The question that comes to our mind is- How safe is synthetic Methionine to poultry?

To answer this, we first need to know little background chemistry about DL-Methionine. DL-methionine contains two isomers L-form and its mirror image D-form in equal ratios. However, only L-methionine can be utilized to synthesizer protein. The second half D-methionine first needs to be converted to L form and then it’s available to use. To our surprise, D-methionine is not converted completely but around 90% in chickens. So what happens to the rest of the 10%? So if you learnt what happens in calves, it seems that it may result in elevated plasma methionine, then it could be evident that traces of DL-methionine can be found in the carcasses of Methionine fed broilers. (J. P. Felix D’Mello, Amino acids in animal nutrition, CABI publishing, UK).

Poultry methionine requirements have always been into controversies. It has been heavily criticized for the use of synthetic amino acid in the feed to increase the bird growth rather than its health. Moreover, synthetic methionine disturbs the whole system of nitrogen cycle in the poultry. This has led to the prohibition on the use of synthetic methionine in animal feed formulation by United States Department of Agriculture (USDA), 2000.

But not forgetting that a well balanced dietary protein and amino acids for poultry is a high priority issue among nutritionists for various reasons. First, cost of proteins and individual amino acids can be expensive nutrients in feed per unit weight. The price fluctuation of DL-Methionine and supply chain discrepancies result is massive shift of feed prices and reduces your profit. Therefore, selecting the appropriate level of amino acids becomes your critical economic decision. You will reach this goal only if you are dosing your methionine correctly. Inconsistency can never be avoided in an industry where raw materials are heavily applied. Therefore whatever you add in your feed diet, will surely affect your main objective. Therefore, addition of supplemental methionine in feed formulation requires precision. Second, the environmental pollution issues about nitrogen excretion from the poultry farming which can cause pollution of soil, air and water. A study shows that one percent reduction of crude protein in a diet can yield 8 to 10% reduction of nitrogen excretion. Hence it can be said that 3 to 4% reduction of crude protein with supplementation of first, second and third limiting amino acids can yield same growth performance with 30 to 40% reduction of nitrogen emission. And third, poor quality dietary proteins and amino acids can have major negative impact in heat stress conditions which is because of inefficient amino acid digestibility.

Well, many of the scientists are in constant discovery or invention to combat these hurdles. Moritz along with its colleagues in its article explains the use of feed restriction to increase commercial broiler forage intake. Thus, the plant material consumed along with any insects if available can be sufficient to obtain methionine. To read more see (Moritz, J. S., A. S. Parsons, N. P. Buchanan, N. J. Baker, J. Jaczynski, O. J. Gekara and W. B. Bryan. 2005. Synthetic methionine and feed restriction effects on performance and meat quality of organically reared broiler chickens. Journal of Applied Poultry Research 14:521–535). However, the availability of the methionine solely depends on the forage composition and its management. Also providing large scale flocks with quality pasture would be difficult. In addition, the forage quality and quantity will differ significantly time to time.

Halder and Roy have compared the performance of broilers between no added methionine group, synthetic methionine fed group and herbal derived methionine group (Halder, G. and B. Roy, 2007. Effect of herbal or synthetic methionine on performance, cost benefit ratio, meat and feather quality of broiler chicken. Int. J. Agric. Res., 2: 987-996). The results show that liver triglycerides in methionine fed group were evidently high in contrast to herbal derived methionine group. Overall performance in both methionine-supplemented groups was found similar (higher than the methionine deficient group). However, the quality of the protein makes it difficult in digestibility in the intestine.

To summarise, there is still no proper way out to this crisis. Remember, Science is never done, it’s always changing. The goal of science is to devise framework, to describe how things works together, to study things are right now so that we can predict how things will be in the future. And so if we learn to trust science in all its fuzziness and incompleteness, it can prove to be best tool to find solution to these problems. After all, animal welfare, managing food safety and environmental issues are our major concerns.

Ileal Amino Acid Digestibility

Ileal Amino Acid Digestibility - Vinayak IngredientsKifay, the natural amino acid optimiser is the product to watch as it has the capability to enhance the ileal amino acid digestibility due to the specific natural ingredients in its composition.

Amino acid supplementation in poultry is considered as an essential part of poultry nutrition. Methionine is the first limiting amino acid in poultry important for optimum growth, feed conversion and immunity. The protein nutrition is directly related to the illeal amino acid digestibility; this term can be divided further into apparent illeal amino acid digestibility or true amino acid digestibility.

The debate is already on as to what type of digestibility is to be considered while making a feed formulation; although it is undeniable that digestibility of protein is utmost important and all digestible amino acid systems are superior to use of total amino acid system in feed formulation.

The amino acids contained in feed-stuffs are not fully available to animal. It is therefore more efficient to formulate diets using values for digestible amino acids rather than total amino acids. The optimisation of amino acid supply leads to increased animal performance and, because the ingested protein is better balanced for animal’s requirements, nitrogen excretion is reduced.