Drawbacks Analysis of 6 Common Animal Protein Raw Materials

Fish Meal

The crude protein content of fish meal can reach about 60% for imported fish meal and 35% to 55% for domestic fish meal. Fish meal is rich in amino acids such as methionine, lysine, and tryptophan, as well as known and unknown growth factors such as nucleotides, active peptides, and taurine that promote growth.

Although fish meal has many advantages, its disadvantages are also obvious:

1. The price is high. The selling price of fish meal is very high, which will directly affect the cost of rations.

2. It is prone to spontaneous combustion. The fat in fishmeal will release a lot of heat during oxidation, and the phosphorus contained in it can release simple phosphorus after chemical decomposition. The ignition point of simple phosphorus is very low, so it is easy to spontaneously ignite if it is not well preserved.

3. Easy to deteriorate. Fish meal contains histamine and its compounds, especially spoiled fish meal, which has a higher content of histamine. When the content of histamine in chicken feed reaches 0.4%, it can cause typical muscle stomach erosion, while the content of histamine in low-quality fish meal can reach over 5%. The foul odor, putrid odor, or hala odor of inferior fish meal can also affect the palatability and nutritional value of feed.

4. Easy to pollute. If the processing method is improper or the transportation and storage are not good, the fish meal is easy to be polluted by many harmful microorganisms, such as Escherichia coli, Salmonella, Clostridium botulinum, Bacillus cereus, Aspergillus flavus, etc., endangering animal health and even causing death.

5. It is prone to poisoning. Fish meal contains a certain amount of salt. Imported fish meal has a salt content of 1.5% to 2.5%, while domestic fish meal has a salt content of 4% to 5%. However, due to factors such as raw materials and processing technology, some fish meal has a salt content as high as 15% to 20%.

6. Easy to adulterate. Fish meal prices are high and profits are high, and illegal vendors often adulterate or substitute inferior fish meal for high profits. The most common ones are additives that are mixed with cake feed and have a strong fishy smell.

Meat and Bone Meal

Meat and bone meal is specifically divided into meat meal and bone meal. Meat meal with phosphorus content below 4.4% is meat meal, and bone meal with phosphorus content above 4.4% is bone meal. Meat and bone meal has the characteristics of rich nutrition, high absorption rate and low price. It is a high-quality supplementary feed for protein, calcium and phosphorus.

Main disadvantages of meat and bone meal:

1. Unstable composition. The content of nutritional components in meat and bone meal is closely related to the processing raw materials, while the composition of leftovers from food processing plants is complex and unstable, which makes the composition of meat and bone meal products unstable, and quality inspection must be carried out before use.

2. Easy to deteriorate. Meat and bone meal is rich in protein and fat. Under high temperature and high humidity conditions, it is easy to be oxidized and corrupted, and easily polluted by microorganisms and other chemicals. Therefore, meat and bone meal products cannot be stored for too long to avoid quality degradation. When forced to store, antioxidants and preservatives should be added.

3. The use is limited, and its palatability is also relatively poor.

Feather Powder

Feather powder is a product formed by hydrolyzing the clean feathers of poultry under high steam pressure. Due to the breaking of the disulfide and sulfur-hydrogen bonds in the structure of feather powder, the protein undergoes local hydrolysis, resulting in changes in the chemical structure of feather fibers. Therefore, the digestibility of feather powder protein can reach 75%. The biggest characteristic of feather meal is its high protein content, usually around 80%, which is higher than the protein content of fish meal. Another characteristic of feather powder is that the content of glycine, serine, and isoleucine is also high, reaching 6.3%, 9.3%, and 5.3% respectively. The content of cystine reaches 4%, which is the highest among all feed sources. In addition, feather meal also contains various trace elements, with selenium content second only to fish meal and rapeseed cake.

The main drawbacks of feather powder:

1. Poor quality. Although the protein content in feather powder is high, its quality is poor, with an unbalanced amino acid composition and a lack of lysine, methionine, tryptophan, histidine, etc. Therefore, the biological value of feather powder protein is low, and coupled with poor palatability, it can only be used as a protein supplement.

2. Poor palatability. During the hydrolysis process of feather powder, some small molecule peptides are decomposed, exposing hydrophobic amino acid residues that stimulate the taste buds and present a bitter taste. During the chemical treatment of feathers, a foul odor can also be generated. Bitter and foul odors can both affect the palatability of feather powder.

3. Restricted use. Hydrolyzed feather powder cannot be degraded by the rumen, and the Ministry of Agriculture stipulates that feather powder cannot be applied to ruminants.

Blood Powder

The crude protein content of blood powder is as high as 80% to 93%, and the lysine content is as high as 6% to 8%. Blood powder also has a high iron content, up to 1 gram/kilogram, making it an important feed for iron supplementation.

The main drawbacks of blood powder:

1. Uneven composition. The amino acids in blood powder are very uneven, with high lysine content, but low methionine and arginine content, almost zero isoleucine content, and very low calcium and phosphorus content.

2. Processing technology affects digestion rate. The digestibility of blood powder prepared by spray method and fermentation method is higher, but that by ordinary drying method is lower.

3. It is difficult to preserve. Blood powder has strong hygroscopicity, is prone to moisture, clumping, mold, spoilage, and is also easily contaminated by microorganisms. Therefore, when storing blood powder, attention should be paid to moisture, mold, and pollution prevention.

Silkworm Pupa Powder

The crude protein content of whole fat silkworm pupa powder is about 54%, and the crude fat content is about 22%; The crude protein content of defatted silkworm pupa powder is about 64%, and the crude fat content is about 4%. Silkworm pupa powder contains a large amount of B vitamins (especially vitamin B2), methionine, lysine, tryptophan, leucine, and isoleucine.

The main drawbacks of silkworm pupa powder:

1. Uneven composition. The content of arginine, calcium, and phosphorus in silkworm pupa powder is relatively low.

2. The dosage is limited. Silkworm pupa powder has a unique odor of silkworm pupa, and the dosage should be limited, otherwise the product may have a peculiar odor.

3. It is difficult to preserve. Silkworm pupa powder contains a certain amount of fat, while whole fat silkworm pupa powder has a higher fat content. When storing, attention should be paid to moisture prevention, pollution prevention, and spoilage prevention to avoid the generation of foul odor.

Single Cell Protein Feed

Single cell protein feed is an emerging protein feed product. Due to different biological populations, the protein content of this type of feed varies significantly, such as bacterial protein content ranging from 69% to 80%, yeast protein content ranging from 45% to 55%, mold protein content ranging from 30% to 50%, and algae protein content ranging from 60% to 70%.

Disadvantages of single cell protein feed:

1. Low digestion rate. The toxic bacterial peptides in single-cell protein feed can bind to feed proteins and affect protein digestion; Single cell proteins also contain substances that cannot be digested, such as mannan, which has a certain impact on the digestion of feed dry matter.

2. Poor palatability. Single cell protein feed made from yeast has a bitter taste and poor palatability. Using single-cell protein feed, the dosage is generally controlled between 5% and 10%.

3. Significant side effects. The nucleic acid content in single-cell protein feed is relatively high, and the purine bases in the nucleic acid form uric acid after metabolism. If the dosage is too large, uric acid forms too much, and precipitates or crystallizes at the joints with blood circulation, which can cause gout or rheumatoid arthritis.

4. Poor safety. The substrate sources for producing single-cell protein feed are extensive, especially when using industrial and agricultural waste, which may cause the product to contain certain toxic substances such as heavy metals, pesticide residues, and pathogenic bacteria. Therefore, using single-cell protein feed may pose safety hazards.