Fat for animal feed

Rendering is the process by which the inedible parts (Head, raw fat, hooves, bones, waste trimming, and condemned carcass) which are highly perishable Ingredients are converted into value added; stable, environmental friendly sterilized end products such As ANIMAL FAT, GEL BONES, MBM/POULTRY FEED SUPPLEMENT AND BLOOD MEAL

Raw material of <50 mm size is cooked & dried in the same steam jacketed vessel to the equivalent of 133°c for  20 min. In this method water is separated from the Protein & then Fat from the Protein. Energy required is 60% more than Wet rendering but much of the heat can be recovered as hot water.

Advantages:

Little Effluent, more MBM & lower Machinery cost.

 Problems:

Low Quality Protein, High Fat in MBM, lower Fat yield, higher FFA rise & high Expeller wear & tear.

Raw material of <16 mm size cooked with water in steam heated agitated vessel at 95°c for 5-10 min. In this method water together with fat is separated from protein & then fat from water. Protein is then dried in a direct fired rotary drier with inlet temperature of up to 800°c and outlet temperature of 130°c to achieve best Sterilization. Energy required in this method is 40% less than dry rendering.

 Advantages:

High quality Protein, low fat in MBM, high Fat yield, low FFA rise.

 Problems:

More effluent, high machinery cost.

Wet continuous Rendering Process:

Rendering is a process that separates fat from raw material by boiling in water. The process involves addition of water to the raw material and the use of steam to cook the raw material and accomplish separation of the fat. There are mainly two processes in the Continues rendering process

1.     A horizontal, steam-jacketed cylindrical vessel equipped with a mechanism that continuously moves the material horizontally & has a live steam injected during the process. Continuous cookers cook the material faster than batch cookers and typically produce a higher quality fat product. From the cooker, the material is discharged to the decanter, which serves the same function as the percolator drain pan in the batch process. The remaining operations are generally the same as the batch process operations.

2.     The another method involves the minced pieces are passed to the reactor wherein the material is boiled along with water at 90-95 Deg.C & it is passed to the decanter.

The poultry industry in the India has a long history of using rendered products in its rations. Rendered fats are generally lower in cost than

Vegetable oils such as soybean oil, Corn Oil Etc which is used substantially in other countries. This allows for higher inclusion rates of fat and thus higher energy diets. These higher energy diets provide faster growth and improved feed conversion, providing a competitive advantage to the Indian poultry industry. Rendered protein sources are also a boon to the poultry industry. A variety of high quality products are available including Meat and bone meal (MBM), Blood Meal and Animal Fat. Each of these is an excellent source of specific nutrients and generally provides a cost-effective source of protein. MBM provides an excellent source of amino acids and phosphorus. Blood meal provides an excellent source of protein, amino acids and energy. Animal Fat is very high in saturated fatty acids. Combined, these products can be used to provide a substantial cost savings to the poultry industry and use of the products is quite high by the industry. Use of these products is estimated to save the industry as much as Rs.12-15 for each ton of feed produced in the India. Strong utilization of these products by the poultry industry is the norm and is expected to continue into the future.

These products of animal origin provide nutrients needed by poultry, Aqua and pet food at reasonable prices relative to competing products, and in fact, prices tend to fluctuate based on prices of competing products. There has also been some interest in replacement of a portion of the soybean meal in poultry rations with animal products to improve performance. The oligosaccharide portion of soybean meal has been shown to produce some detrimental effects to poultry. This is thought to be due to a substance in the undigested portion of the product that irritates the footpad. The addition of animal protein sources may improve performance over standard diets. While these results may be due to high levels of limiting amino acids, it may also be explained by the reduction of poorly digested carbohydrates in the soybean meal. Previous work in the lab has suggested that up to half of the protein source can be provided with mixed by-products if one formulates correctly. While each

Product has different nutrient contents and potential values, most are excellent sources of energy or high quality protein, highly available phosphorus, and other minerals.

The goal of this write up is to provide the information needed to utilize

these products in ration formulation, methodology for their use, and limitations on their use as well as the economics of their use. Ultimately with this information in hand, proper decisions about the use of these products can be made, and money saved.

• Concentrated source of energy and the main method of increasing the energy content of diets

• Increased growth rates

• Increased feed efficiency

• Decreased feed intake

• Source of Saturated & Unsaturated Fatty acids

• Decreased dustiness of feeds and reduced dust losses

• Lubricant for equipment in feed mills

• Increased palatability of feeds

• Increased rate of gain can decrease age at market and increased  throughput of housing systems

• Lower heat increment during heat stress keeps caloric intake up.

• May slow gut transit of other feeds, resulting in increased digestibility

• May show an “extra caloric” effect

• May be more cost effective than other energy sources

• Concentrated feeds can decrease transportation costs for feed delivery

• Use of higher levels of fat may negate the effects of pelleting.

• Measurement of Metabolizable energy (ME) content can be difficult

• Potential for rancidity

• Equipment needs relative to fat additions must be adequate

• Poor digestibility of saturated fats by the young bird.

Fatty acids that are not bound to other organic components as glycerol are the so-called free fatty acids. Lipids constitute the main energetic source for animals and they have the highest caloric value among all the nutrients. Besides supplying energy, the addition of fat to animal diets improves the absorption of fat-soluble vitamins and the efficiency of utilization of the consumed energy. Furthermore, it reduces the rate of food passage through the gastrointestinal tract, which allows a better absorption of all nutrients present in the diet. The energetic value of added fats depend on the following: the length of the carbonic chain, the number of double bonds, the presence or absence of ester bonds (triglycerides or free fatty acids), the composition of the free fatty acid, the composition of the diet, the quantity and the type of the fatty acids (saturated or Unsaturated fatty acids) supplemented in the diet, the intestinal flora, the age of the birds. In birds, body fat composition is similar to the composition of the fat from the diet.

The apparent digestibility of unsaturated fats is high in the first days of life of birds,

Whereas apparent digestibility of saturated fats is low. Adding fat is desirable for many reasons; firstly energy from fats is 2.25 times as energy from CHO also, it can reflect its fatty acid composition on carcass yield. Also the birds cannot depend only on CHO energy because it is a fact that feeding broilers on a fat deficient diets led to excessive Lipogenesis (building up fats from carbohydrates). Building up fat unit costs you more than building up a protein unit. The deposition of 1 g of energy from carbohydrates or protein by an animal requires higher quantities of these nutrients in comparison to the deposition of 1 g of energy from fat. In broiler nutrition you should care for building up meat protein. Considering diets with similar nutritive value, chickens fed rations containing fat showed better performance than birds fed diets without fat inclusion. In formulating broiler diets please, do not take into consider the least cost pathway but you should consider the best cost pathway.

There are some regulations which we sometimes fail to notice it during feeding fats to broilers. These regulations are

1) linoleic acid percent.

2) The ratio between saturated and unsaturated fatty acids.

3) The acid base balance (meq/100g).

However, the linoleic acid is the only essential fatty acid whose diet requirement has been demonstrated. Many producers depend on high linoleic vegetable oil like soy and sunflower oil as the only fat source in their broiler diets and that resulting in a very high linoleic acid percent in the diet and may be duplicated in the absence of corn gluten meal. The higher percent of linoleic acid in broiler diet which off course plenty exceeds its diet requirement is never being recommended by NRC and considered an extra cost for broiler producers moreover it leads to soft carcass fat formation and that means a rapid carcass deterioration and short shelf time. Furthermore, broiler nutrition guides always recommend you to formulate a mix between saturated and unsaturated fatty acids as 0% SFA : 100% USFA in starter diet, 25% SFA : 75% USFA in grower diet and 50% SFA : 50% USFA in finisher diet. Many producers formulate their diets with only oils as a sole source of fat but economically we have to use a mix between both saturated and unsaturated fatty acids by the above mentioned ratios. Moreover those broilers do not require this higher percentage of linoleic fatty acid which in turn has a negative effect on broiler and layer performance.

In order to formulate a diet with the target level of linoleic we should depend on another fat source rather than the high linoleic vegetable oils. The acid base balance is also of great concern, we should formulate our diets to contain the required amount from Potassium(K),Sodium(Na) and Chloride(Cl) to make the acid base balance nearly around 20 meq/100g feed. In some cases we need to formulate the high energy diets with minimum amount of oils either for an economic reasons or making good quality pellet durability, in such two cases we have to use a high percent of gluten in order to decrease the amount of oil. Using a high percent of gluten especially in grower or finisher diets consequently resulting in decreasing the amount of SBM which in turn leads to a significant difference in potassium level if compared by starter diets. The difference of potassium level between starter and grower finisher diets is due to the fact that SBM is rich in potassium and gluten is very deficient in it. But you do not have a chance to select, you have to reduce oil content to avoid the lubricant action of oil during pellet compressing and on the same time you have to compensate the energy by corn gluten. Using the dry fat to substitute the half amount of added oil not only allows you to formulate finisher and grower diets with minimum amount of corn gluten to keep your broiler diet acid base balance but also gives you a better pellet durability. By selecting dry fat to be added to your broiler diet formula you a fatty acids mix with low linoleic acid which will supply your broiler diet by the ideal linoleic acid percent which required for ideal broiler performance but not the excess linoleic which has a negative effect on performance and carcass quality. By selecting dry fat to be added to your broiler diet formula you a dry concentrated energy source with no lubricant effect on die holes which in turn will improve and ensure excellent feed compressing into pellets. Being a feed ingredient, dry fat increase the scope of ingredient availability allowing us to formulate a broiler diets with a varying energy sources and enable us to make our diets without fear of fat restrictions during pellet processing nor fear of acid base imbalance.

 

Impurities are most often referred to collectively as M.I.U. (moisture, impurities and Unsaponifiables). Most of these compounds will have little nutritional value, and so obviously digestibility values must be adjusted corresponding to total fat content. During oxidation at both high and low temperatures, a vast range of unusual polymers can be produced, and Wiseman (1986) has extensively described their structure and formation and the adverse effect of feeding such polymers in oxidized fats. Wiseman (1986) cites evidence for the dramatic effect of oxidation of a fat caused by overheating on available energy where loss in digestibility can reach up to 30%. A number of naturally occurring fatty acids can also adversely affect overall fat utilization, although their mode of action is most likely via general well-being of the animal rather than through any specific mode of action related to digestion or absorption, etc. Two such components are erucic acid present in rapeseed oils and some other Brassica sp., and the cyclopropenoid fatty acids in cottonseed

Fat composition can influence overall fat digestion because different components can be digested and/or absorbed with varying efficiency. It is generally recognized that following digestion micelle formation is an important prerequisite to absorption into the portal system. Micelles are conjugations of bile salts, fatty acids, lipase, some Monoglycerides and perhaps glycerol. The conjugation of bile salts with fatty acids is an essential prerequisite for transportation to and absorption through the microvilli of the small intestine. As previously described, polar unsaturated fatty acids and Monoglycerides form this important association. However, already formed mixed micelles of unsaturates and bile salts themselves have the ability to solubilize non-polar compounds. Efficiency of fat utilization is, therefore, dependent upon there being an adequate supply of bile salts and an adequate balance of unsaturates: saturates.

The status of the intestinal lumen will obviously have an effect on the digestion and/or absorption of any nutrient. Freeman (1969) indicates that digesta pH can influence fat digestion in those acidic conditions reduces micellar solubilization. A fatty acid-albumin complex has been shown to be absorbed less efficiently than are micellar fatty acids (Sklan, 1975) and the formation of a complex of these fatty acids with undigested protein may be partly responsible for the poorer fat digestion seen when animals are fed improperly processed soybean meal. Birds infected with coccidiosis often exhibit inferior fat digestibility. Steatorrhoea occurring with intestinal coccidiosis may, therefore, result from the loss of reconstituted fat globules following the rupture of parasitized epithelial cells. Fat, per se, and Linoleic acid in particular may also affect the microbial population in the intestine. Groneuer and Hartfield (1975) indicate reduction in coliform bacterial population in layers fed corn oil. Fat digestion also seems to be adversely affected by high levels of indigestible fiber (Cherry and Jones, 1982). Increased levels of cellulose apparently result in reduced fat digestion, possibly through complexing of fiber with bile salts. Diet fat, per se, can affect rate of passage of digesta, and this can influence overall diet digestibility. Sell and co-workers at Iowa State have used this argument to account for the so-called "extra metabolic" effect of fat. Mateos et al. (1982) suggest that fats and oils likely inhibit stomach emptying and intestinal digesta movement. However, this effect is influenced by diet constituents, the rate of passage being more affected when the diet contains sucrose versus starch (Mateos and Sell, I98 1). Decreased rate of passage suggests that digesta spends more time in contact with digestive enzymes, carriers or cofactors and absorptive sites, etc. Addition of fats to the diet may, therefore, lead to increased digestion of non-fat components of the diet

The fact that young birds cannot digest fats as well as older birds , has been documented for many years, and yet this fact has rarely been incorporated in formulation matrices. The effect of age on ability to digest fats is most pronounced for the saturates (Whitehead and Fisher, 1975). This age-related phenomenon does not seem to be of significance with other nutrients (Fisher and McNab, 1987). The reason why adult birds are better able to’ digest fats, and particularly saturated fats, is not clear. Young birds recycle bile salts less efficiently, and this may be a factor as described previously. Also there is an indication that fatty acid binding protein is not produced in adequate quantities by young birds.

Both Sell et al. (1986) and Katongole and March (1980) cite evidence for up to 5x increase in FABP with chicks from hatch through 8 weeks of age.

Once fats have been digested, free-fatty acids have the opportunity to react with other

nutrients within the digesta. One such possible association is with minerals to form soaps that may or may not be soluble. If insoluble soaps are formed, there is the possibility that both the fatty acid and the mineral will be unavailable to the bird. Atteh and Leeson (1984) indicate substantial soap formation in the digesta of broiled? A chick which is most pronounced with saturated fatty acids and with high levels of diet minerals. Differences in fat digestibility were mirrored in changes in fecal soap formation. In other studies, Atteh and Leeson (1983) indicated such increased fecal soap production to be associated with reduced bone ash and bone calcium content of broilers. Soap production seems to be less of a problem with older birds. This is of importance to laying hens that are fed high levels of calcium. In addition to calcium, other minerals, such as magnesium, can form soaps with saturated fatty acids. In older birds and some other animals, there is an indication that while soaps form in the upper digestive tract, they are subsequently solubilized in the lower tract due to changes in pH. Under these conditions both the fatty acid and mineral are available to the bird. Control over digesta pH may, therefore, be an important parameter for control over soap formation.

• Generally, very cost competitive relative to vegetable protein sources

• Use will reduce total diet costs in most cases

• Source of high quality protein

• In most cases, highly digestible

• May help balance the amino acid needs

• In many cases, will provide slightly faster growth rates than vegetable

   Protein-only diets

• Excellent source of highly available phosphorus and other minerals.

• Poor quality control could result in decreased amino acid digestibility

• Proper formulation methods must be used to make most effective use

• Potential for microbial contamination if improperly handled

• Variation in product due to material mix, processing methodology