Blood meal, blood flour, fresh blood [English], farine de sang, sang frais [French], harina de sangre [Spanish]
Blood can be collected during the slaughter of various livestock species (cattle, pigs, chickens, etc.) under a wide range of conditions. It is usually dried and made into blood meal so that it can be handled and incorporated into rations more easily. Other feed products derived from blood include fresh blood, haemoglobin and plasma. Blood meal contains mostly protein and is used to supplement diets based on cereal grains, plant by-products and forages. It has been shown to be a satisfactory replacement for other protein sources in various animal production diets for dairy cattle, beef cattle, sheep, pigs, poultry, various fish species and silkworms.
Blood meal is a by-product of the slaughtering industry and is used as a protein source in the diets of livestock. The drying of whole blood from slaughtered animals derives blood meal. The method of drying does affect the nutritional quality of the protein in the meal. The three methods of processing whole blood are batch dry rendering, ring dried rendering and spray died rendering. Batch dry rendering involves the cooking of whole blood in a jacketed cylindrical cooker that is indirectly heated by steam at a pressure of about 500 kPa. Ring dried rendering involves coagulating the blood by steam heating; the coagulum is centrifuged and dried with hot gas in a ring drier. The process of manufacturing spray dried blood meal is similar to that of skim milk powder in which liquid is sprayed inside the warm chamber and then becomes fine powder instantly.
The ring-dried and spray dried blood meal has a greater content of total and available amino acids and is of better nutritional quality. For example, the availability of lysine as a percentage of the total lysine is 84% to 89% for ring-dried blood meal, as compared to batch-dried meal in which lysine is 62% to 77% available.
Blood meal is available worldwide, but like other animal products its sale and utilization are regulated in some countries for certain species for safety reasons.
Blood is a highly perishable product and must be processed as soon as possible after slaughter. Blood meal can be prepared by a small-scale operation. Blood meal is hydroscopic and needs to be dried to less than 10-12 % moisture and stored in a dry place in order for it not to deteriorate. There are different ways to prepare blood meal: solar drying, oven drying, drum drying, flash drying, spray drying. The drying method is important because there is an inverse relationship between the amount of heat applied and protein digestibility. Particularly, lysine content and lysine availability decrease when the amount of heat increases (Batterham et al., 1986). Overcooked blood meals are darker, due to destruction of the haemoglobin, and less palatable.
Solar and oven drying
Solar drying is well suited for small-scale operations or when advanced technical equipment is not affordable. Blood is collected in large pans and slowly boiled while stirring constantly. When moisture is sufficiently reduced (10-12 %), blood meal is spread on a clean cemented surface and then sun-dried. It can also be oven-dried. The blood may be spread on milling offal’s, rice bran or other plant products for better drying and that results in a complete feed.
For large scale operations the 3 processes detailed below are used.
The raw blood is finely comminuted to form a free-flowing slurry that is then deposited onto the descending side of the top of a heated drier drum and formed into a film by one or more spreader rolls. The film is rapidly dried and scraped in the form of a dried sheet which can either be flaked or pulverized to provide a high grade blood meal product. Vapours above the drying cylinder are scrubbed before being released to the atmosphere and represent the only effluents from the process (Overton, 1976).
Ring and flash drying
The blood is dispersed into the high velocity venturi section of the system. The blood first comes into contact with the hot drying airstream and the bulk of the evaporation occurs. The product is then dried as it is conveyed up through the drying column. The presence of a "manifold" or "internal classifier" in the ring drying system is what differentiates it from the flash dryer (GEA, 2009a;GEA, 2009b).
The blood is spray dried as whole blood, or after-separation into plasma and red albumin (GEA, 2010). Blood products have to be dried at low temperatures in order to prevent heat coagulation (GEA, 2009a; GEA, 2009b). Spray dried blood meals are also called spray dried blood powder or blood floor (Dipanjali Konwar et al., 2005).
Spray-dried porcine plasma is prepared as follows: the blood from slaughtered pigs is added to an anticoagulant (generally sodium citrate) and then centrifuged to remove erythrocytes. The plasma obtained is subsequently spray-dried and used for production of animal feeds (van Dijk et al., 2001).
Products resulting from the 3 processes have an overall higher quality than sun-dried blood meals since the duration of the heating period is lower than with cooking. Proteins and amino acids are better preserved and lysine content is higher (Cromwell, 2009).
Blood can be coagulated to aid in the removal of water by adding 1 % unslaked or 3 % slaked lime. However, this method of water removal increases the amount of dry matter losses by 10–15 %, which includes many of the minerals.
In some situations, blood needs to be stored prior to being processed and dried. Raw blood can be stabilized and stored for one week by adding 0.7 % sulphuric acid or an equivalent amount of another acid. A method for preparing blood meal by adding 3 % sulphuric acid and storing for 72 h before sun-drying has been described (Divakaran, 1987; Divakaran et al., 1988).
Processing blood into feed removes potentially contaminating slaughter wastes from the environment. Modern drying techniques require high amounts of energy but solar drying is an interesting option in warm climates.
For safety reasons, blood must be heated to be used in animal feeding: a minimal temperature of 100°C for 15 min is necessary in order to destroy potentials pathogens (salmonella, mycotoxins, prions) (Göhl, 1982). It is recommended to avoid feeding a species with blood meal from the same species.
In the European Union, blood meal has been banned from feeding to animals since 2000 (Council Decision 2000/766/EC), though since 2006 blood products from non-ruminants are now authorized for use in aquaculture (Médale et al., 2009).
Blood meal contains mostly protein (about 90-95 % DM) and small amounts of fat (less than 1% DM) and ash (less than 5% DM), though non-industrial blood meals may include other materials and thus be richer in ash. Unlike other animal protein sources, blood meal has a poor amino acid balance. Its lysine content is relatively high (7-10 % DM) which makes it an excellent supplementary protein to use with plant-derived feed ingredients that are low in lysine. However, its isoleucine content is very low (about 1 % DM), so diets for monogastric animals must be formulated to contain enough isoleucine for the level of performance desired (Piepenbrink et al., 1998 ; Maiga et al., 1996). Pepsin digestibility has been shown to be a good test for assessing the availability of the protein fraction of blood meal (Hegedüs et al., 1989). Blood meal is rich in iron (more than 1500 mg/kg DM).
Blood meal is generally unpalatable, particularly if overcooked, so care needs to be taken to not add more than 5 to 6 % blood meal to a ration, especially if high feed consumption and performance are desired. Often an adaptation period is required to get animals used to eating blood meal.
Blood meal is valuable for ruminants due to its high protein content and rumen-resistant amino acids. Rumen undegradable protein is up to 78 % in blood meal and increases with the heating temperature used in its processing. Blood meal contains more essential amino acids than soybean meal (Klemesrud et al., 2000; Piepenbrink et al., 1998), but it is deficient in sulphur amino acids (Klemesrud et al., 2000) and isoleucine (Maiga et al., 1996). It should be supplemented with other protein sources (Maiga et al., 1996).
In steers and in calves, 3 % dietary inclusion of blood meal increased daily weight gain, dry matter intake and energy intake (Knaus et al., 1998; Tartari et al., 1989). In dairy cows, it improved milk production and milk protein yield (Schor et al., 2001).
In sheep, blood meal can be used as a by-pass protein (Kamalak et al., 2005), which allows a reduction in the overall dietary protein content of the diet (from 16-18 % to 13 %) (Antongiovanni et al., 1998). The nutritional status of pregnant ewes fed at or near maintenance while consuming low-quality roughages was enhanced by supplementation with additional crude protein in the form of blood meal (Hoaglund et al., 1992).
Blood meal is a good source of protein in pigs. Recommended dietary levels vary from 4% of DM (Cunha, 1977; Wahlstrom et al., 1977), to 6-8% of DM (Seerley, 1991, cited by Lewis et al., 2001).
During post-weaning phase I (day 0-14), dry skimmed milk can be replaced by animal by-products, such as porcine blood meal, porcine plasma, extracted meat protein, bovine plasma protein, spray-dried blood meal or soybean protein concentrate. Spray-dried porcine plasma (SDPP) is superior to every other protein sources (Hansen et al., 1991; Tokach et al., 1991; Rantanen et al., 1994). Recommended inclusion rate is 7.5 % spray-dried plasma (Bergstrom et al., 1994; Owen et al., 1994). However, spray-dried blood meal at 2.5% of the dietary DM could replace 67% of spray-dried plasma from day 7 to 14 (Kats et al., 1992b; Dritz et al., 1993).
During post-weaning phase II (day 14-28), spray-dried blood meal will be preferred to SDPP or fish by-products as it increases both animal performance (Tokach et al., 1991) and economic performance (Kats et al., 1992a; Dritz et al., 1992). Inclusion rates should be no more than 2-2.5 % of DM (Kats et al., 1992a; Kats et al., 1992b).
During post-weaning phase III (day 28-42), spray-dried blood meal can be included at 2-2.5 % of DM and supplemented with 0.4-0.44 % methionine (Owen et al., 1993).
In growing pigs, blood meal can partially replace soybean meal in maize-soybean based diets: it is then included at 3 to 4 % of DM (flash dried blood meal) or at 6 % (Ilori et al., 1984; Rerat et al., 1975). It can supplement cottonseed meal to counterbalance the negative effects of gossypol in pigs diet (Fombad et al., 2004).
Feeding growing pigs with fermented blood meal (dried or not) in combination with molasses allows the same feed intake, growth and feed conversion efficiency as soybean meal. Utilization of N is also high (M'ncene et al., 1999; King'ori et al., 1998). A 10 % fermented blood meal inclusion in pigs diet is recommended (Tuitoek et al., 1992).
Blood meal can be used successfully in poultry.
For broilers, blood meal is a good protein source. It can replace 50 to 100 % of fish meal (Rao et al., 2009; Seifdavati et al., 2008;Nabizadeh et al., 2005), 50 % of soybean meal (Onyimonyi et al., 2007; Tyus et al., 2008), and also copra meal or groundnut meal (Donkoh et al., 2001; Donkoh et al., 1999) resulting in improved performance and greater profit. The amounts of blood meal are equivalent to 3 to 9 % of the dietary DM (Tabinda Khawaja et al., 2007; Matserushka, 1996; Quarantelli et al., 1987).
Blood meal has a high tryptophan digestibility coefficient which is valuable as tryptophan is the third limiting amino acid in broilers (Ravindran et al., 2006). It is necessary to supplement blood meal with lysine and isoleucine (Elamin et al., 1990; Tyus et al., 2008) to ensure better animal performance.
In laying hens, blood meal is as palatable as other rendered animal products. Sun-dried blood meal given at 4.5 % of the diet has a positive effect on layer performance (feed intake, live-weight gain, egg weight and yolk colour) (Donkoh et al., 2001). Blood meal improves Fe content in yolks (Revell et al., 2009). One case of cannibalism related to blood meal feeding has been reported (Atteh et al., 1993).
Fermented cattle blood gives comparable egg production to fish meal when these products are used to replace soybean meal. However, rendered animal products can cause undesirable flavour in eggs and it is not recommended that they fully replace soybean meal in layers diets (Tuitoek et al., 1994).
Feeding turkeys with rendered animal products does not alter performance (Boling et al., 1997).
Combining blood meal with other supplementary proteins has been shown to increase performance in ducks (Sucheep Suksupath, 1980).
Rabbits fed on blood meal had the lowest feed intake, live weight gain and feed efficiency compared to other protein sources such as fish meal, shrimp meal, hatchery by-product meal or poultry by-product meal (Fanimo et al., 2002).
Blood meal is a good quality ingredient for fish and has been tested succesfully in many fish species. Spray-dried blood meal can be used as a binder in fish feeds.
In gibel carp (Carassius auratus gibelio) (Yang et al., 2004), African catfish (Clarias gariepinus) (Goda et al., 2007) and tilapia, spray-dried blood meal can replace 50 to 75 % of the fish meal, and in rainbow trout (Onchorhynchus mykiss)up to 100 % (Watanabe et al., 1998; Médale et al., 2009). However, it was found to lower performance in tilapia when replacing fish meal (El-Sayed, 1998). Blood meal is well digested by the humpback grouper (Chromileptes altivelis) (Laining et al., 2003) and its gross energy is well digested by the rohu (Labeo rohita) (Noreen et al., 2008). A maximum 5 % blood meal in the diet is recommended for sea bream (Sparus aurata) as sensorial alterations may occur at a 10 % inclusion rate (Martinez-Llorens et al., 2008).
Recent Report – August 2014
Sachin Labade- Age-35, Feed Cons.3364-Wt.2050-F.C.R.1.64-Mort%-2.43
Ashok Kale-Age.35,Feed Cons.3339-Wt.2050-F.C.R.-1.62-Mort% 5.54