Feed Technology | Disadvantages of Animal Protein Feed

Animal protein feed is an important component of livestock and poultry diets, which largely determines the cost, utilization rate and breeding benefits of diets. Farmers can obtain maximum economic benefits only if they fully understand its characteristics and master the usage methods and precautions.

1. Fishmeal

Fishmeal is the best protein feed for chickens and pigs. The crude protein content of imported fishmeal can reach about 60%, while domestic fishmeal is 35%-55%. Fishmeal is rich in amino acids such as methionine, lysine, and tryptophan, and also contains known and unknown growth factors such as growth-promoting nucleotides, active small peptides, and taurine. Therefore, fishmeal is commonly used in aquaculture to supplement protein and adjust the balance of dietary amino acids.

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

1. The price is high. The price of fishmeal is very high, which will directly affect the cost of the diet. From an economic point of view, the amount of fishmeal must be strictly controlled, and the amount used in broiler and laying hen diets is preferably 2% to 5%.

2. Spontaneous combustion. The fat in fishmeal will release a lot of heat during the oxidation process, and the phosphorus contained in it will release elemental phosphorus after chemical decomposition. The ignition point of elemental phosphorus is very low, so it is easy to spontaneous combustion if it is not stored properly.

3. Perishable. Fishmeal contains histamine and its compounds, which can easily cause poultry gizzard erosion, especially deteriorating fishmeal, which has a higher content of histamine. The content of histamine in chicken feed reaches 0.4%, which can cause typical gizzard erosion, while the content of low-quality fishmeal histamine can be as high as more than 5%, and the harm can be imagined. The fishy, rancid, or hala smell of inferior fish meal will also affect the palatability and nutritional value of the feed.

4. Easy to pollute. If the processing method is improper or the transportation and storage are not good, fish meal is easily contaminated by various harmful microorganisms such as Escherichia coli, Salmonella, Clostridium botulinum, Bacillus cereus and Aspergillus flavus, which will endanger the health of farmed animals and even lead to death. According to regulations of relevant departments, great-grandfather chickens do not use fishmeal in their rations, and ancestral chickens do not use fishmeal or use less fishmeal. A fishmeal-free diet has been developed in China, which not only reduces feed costs, but also benefits the health of breeders, and is generally welcomed by chicken farms.

5. Easily poisoned. Fishmeal contains a certain amount of salt. Imported fishmeal has a salt content of 1.5% to 2.5%, and domestic fishmeal has a salt content of 4% to 5%. %. If the salt in the fish meal is neglected when formulating feed, it may cause the poisoning of livestock and poultry, especially the death of chicks.

6. Easy to adulterate. The price of fish meal is high and the profit is huge. Unscrupulous traders often adulterate or shoddy fish meals to obtain huge profits. The most common is the addition of cake feed and additives with a strong fishy smell. Farmers must pay attention to identifying the quality of fishmeal to prevent losses caused by adulteration and shoddy products.

7. It is easy to affect the quality of livestock and poultry products. Fishmeal has a fishy smell and should not be used to feed dairy animals, otherwise, it will affect the quality of milk and cause economic losses. In the process of raising chickens, unreasonable use of fish meals will also cause the peculiar smell of eggs and chicken, affecting people's taste.

2. Meat and bone meal

Meat and bone meal is specifically divided into meat meal and bone meal. A meat meal with a phosphorus content of less than 4.4% is a meat meal and bone meal with a phosphorus content of more than 4.4%. Meat and bone meal have the characteristics of rich nutrition, high absorption rate, and low price. It is a high-quality supplementary feed for protein, calcium, and phosphorus. It is widely used in chicken production, the dosage should not exceed 5%.

The main disadvantages of meat and bone meal:

1. The composition is unstable. The content of nutrients in meat and bone meal is closely related to the processed 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. It is easy to deteriorate. Meat and bone meal is rich in protein and fat. Under high temperatures and high humidity conditions, it is easy to oxidize and spoil, and is easily polluted by microorganisms and other chemical substances. Therefore, meat and bone meal products should not be stored for too long to avoid quality deterioration. When storage is necessary, antioxidants and preservatives should be added.

3. Restricted Use. Meat and bone meal cannot be added to ruminant feed, because meat and bone meal produced in epidemic areas may cause the spread of mad cow disease and sheep scrapie, and its palatability is relatively poor.

3. Feather powder

Feather meal is a product formed by hydrolyzing the clean feathers of poultry with steam and high pressure. Because the disulfide bond and sulfhydryl bond in the feather meal structure is broken, the protein is partially hydrolyzed, and the chemical structure of the feather fiber is changed, so the digestibility of feather meal protein can reach 75%. The biggest feature of feather meal is its high protein content, generally about 80%, which is higher than that of a fish meal. Another feature of feather meal is that the content of glycine, serine and isoleucine is also very high, reaching 6.3%, 9.3%, and 5.3% respectively, and the content of cystine reaches 4%, which is the highest among all feeds. In addition, feather meal also contains a variety of trace elements, and its selenium content is second only to fish meal and rapeseed cake. Feather meal is a better protein supplement feed. The appropriate amount of feather meal in chicken feed is 4%.

Fur animals such as mink and blue fox are prone to trichology. The practice has proved that adding feather powder to the feed, with a daily dosage of 3 to 5 grams, and adding the appropriate amount of linoleic acid, inositol, vitamin B2, etc., will obviously improve after feeding for 1 week. , can be eradicated after 3 weeks of feeding. In addition, adding feather powder to chicken feed can also treat feather pecking disease.

The main disadvantages of feather meal:

1. Poor quality. Although the protein content in feather meal is high, the quality is poor, the amino acid composition is unbalanced and lacks lysine, methionine, tryptophan, histidine, etc. Therefore, the biological value of protein in feather meal is low, plus Poor palatability, it can only be used as a protein supplement and must be used in conjunction with other animal or vegetable protein feeds to obtain good feeding effects.

2. Poor palatability. During the hydrolysis process, feather powder will decompose some small molecular polypeptides, exposing hydrophobic amino acid residues, which will stimulate the taste buds and present a bitter taste. During the chemical treatment of feathers, an odor is also produced. Both bitterness and off-flavor can affect the palatability of feather meals.

3. Restricted Use. Hydrolyzed feather meal cannot be degraded by the rumen, and the Ministry of Agriculture stipulates that feather meal cannot be used in ruminants.

4. Blood meal

The crude protein content of blood meal is as high as 80% to 93%, and the lysine content is as high as 6% to 8%. The content of iron in blood powder is also very high, up to 1 g/kg, which is an important feed for iron supplementation.

The main disadvantages of blood meal:

1. Uneven composition. The amino acids contained in the blood meal are very unbalanced, the content of lysine is high, but the content of methionine and arginine is low, the content of isoleucine is almost zero, and the content of calcium and phosphorus is very low. As a protein supplement feed, attention should be paid to the nutritional balance when using it.

2. Processing technology affects digestibility. The blood meal made by spraying method and fermentation method has higher digestibility, but the blood meal made by ordinary drying method has lower digestibility, and the palatability is not good, so the amount of chicken feed should not exceed 2%, and the amount of pig feed should not exceed 2%.

3. Difficult to preserve. Blood meal has strong hygroscopicity, and is easy to be damp, agglomerated, moldy, spoiled, and easily polluted by microorganisms. Therefore, moisture-proof, mildew-proof, and pollution-proof should be paid attention to when storing blood meal. Farmers try not to store blood meal for a long time.

5. Silkworm chrysalis powder

The crude protein content of full-fat silkworm chrysalis powder is about 54%, and the crude fat content is about 22%; the crude protein content of defatted silkworm chrysalis powder is about 64%, and the crude fat content is about 4%. Silkworm chrysalis powder contains more B vitamins (especially vitamin B2), methionine, lysine, tryptophan, leucine and isoleucine, etc. It is an ideal component for balancing amino acids in livestock and poultry diets.=

The main disadvantages of silkworm chrysalis powder:

1. Uneven composition. The content of arginine, calcium and phosphorus in silkworm chrysalis powder is relatively low, so attention must be paid to nutritional balance when preparing livestock and poultry diets.

2. The dosage is limited. Silkworm chrysalis powder has a unique smell of silkworm chrysalis, and the dosage should be limited, otherwise, it may cause a peculiar smell in livestock and poultry products. According to the amount of silkworm chrysalis powder in the diet, the feed for broilers should be 2.5% to 5%, the feed for laying hens should not exceed 2%.

3. Difficult to preserve. Silkworm chrysalis powder contains a certain amount of fat, and full-fat silkworm chrysalis powder has a higher fat content. When storing, pay attention to moisture-proof, pollution-proof, and anti-corruption to avoid foul smell.

6. Single-cell protein feed

Single-cell protein feed is a new protein feed product. Due to different biological populations, the protein content of this kind of feed has obvious differences. For example, the protein content of bacteria is 69% to 80%, the protein content of yeast is 45% to 55%, the protein content of mold is 30% to 50%, and the protein content of algae is 50%. The content is 60% to 70%. Adding single-cell protein feed to the diet can improve the feed utilization rate, enhance the body's immunity, and the lean meat rate of pigs, egg production of laying hens and milk production of dairy cows will also be improved

Disadvantages of single-cell protein feed:

1. Low digestibility. Toxic peptides in single-cell protein feed can combine with feed protein and affect protein digestion; single-cell protein also contains some indigestible substances (such as mannan), which have a certain impact on the digestion of feed dry matter. Therefore, the digestibility of protein in single-cell protein feed is 10% to 15% lower than that of conventional protein.

2. Poor palatability. The single-cell protein feed made of yeast has a bitter taste and poor palatability, especially for cattle that do not like to eat. Use single-cell protein feed, and the dosage is generally controlled at 5% to 10%.

3. Large side effects. The nucleic acid content in the single-cell protein feed is high, and the purine bases in the nucleic acid form uric acid after metabolism. If the dosage is too large, the uric acid will be formed too much, and it will precipitate or crystallize in the joints with the blood circulation, which can cause gout or rheumatism. arthritis. The amount of single-cell protein feed in the diet should not exceed 15% of the total protein.

4. Poor security. The substrates for the production of single-cell protein feed come from a wide range of sources, especially when using industrial and agricultural waste, which may cause the product to contain some toxic substances such as heavy metals, pesticide residues, and pathogenic bacteria. Therefore, the use of single-cell protein feed may have potential safety hazards, and farmers must choose qualified products produced by regular manufacturers when using single-cell protein feed.