Fishmeal is too expensive and you want to use small peptides as a substitute? First, understand what small peptides are
Fishmeal is too expensive, you want to use small peptides - what are small peptides?
Fishmeal has become too expensive, we can't afford to use it anymore, and we don't want users to say anything. We want to add a substitute. I heard small peptides are good, so I wanted to use them, but when I asked, the standard for small peptides is just CP - how can that be? I want to ask how we can know the small peptide content, and where do these small peptides come from? Let some expert share their views.
--------------------------------------
Believe it or not, so many people are using them. If you don't use them, you worry others who do will run faster than you. It's hard. Has anyone used them or done experiments who can help? I don't have a test farm.
--------------------------------------
Fishmeal is too expensive, you want to use small peptides, but fishmeal and small peptides are two different things - they are not the same
--------------------------------------
Absorption Mechanisms of Small Peptides and Advances in Nutrition Research
Li Lusheng (College of Agriculture, Liaocheng University, Liaocheng, Shandong 252000)
Feng Dingyuan (College of Animal Science, South China Agricultural University, Guangzhou 510640)
Abstract Research trials in recent years have proven that small peptides are the main digestion products of protein and play a very important role in the digestion, absorption and metabolism of amino acids. This paper reviews the absorption mechanisms of small peptides in monogastric animals and ruminants, the nutritional effects of small peptides and the factors affecting small peptide absorption, as well as the role of small peptides in protein metabolism.
Keywords small peptides, free amino acids, absorption mechanism
Protein is one of the most important nutrients in animal nutrition, and there has been a great deal of research on its absorption mechanism. The past view held that the animal digestive tract can only absorb free amino acids, that is, protein must be broken down into free amino acids before it can be absorbed. However, in recent years, experiments have shown that when animals are fed purified diets formulated according to the ideal amino acid pattern or low-protein amino acid-balanced diets, optimal production performance and feed efficiency cannot be achieved. Therefore, some scholars believe that in addition to absorbing free amino acids, the animal digestive tract also has special requirements for protein itself or peptides. Neway and Smith first proposed in 1960 that small peptides can be transported and absorbed intact. Since then, most of the final hydrolysis products of protein in the digestive tract are small peptides composed of 2 or 3 amino acid residues, which can be absorbed intact into the circulatory system and then utilized by tissues. The type I carrier[1] and type II carrier[2] of small peptides have been cloned respectively. In recent years, great progress has been made in research on the absorption mechanisms of small peptides in animals, the characteristics of carriers, and physiological characteristics. The view that small peptides can be absorbed intact in animals has been further confirmed and developed.
1 Absorption mechanisms of small peptides
1.1 Absorption mechanisms of small peptides in monogastric animals
The absorption mechanism of small peptides is completely different from that of free amino acids. The absorption of free amino acids involves 4 systems: neutral, acidic, basic amino acids and imino acids. The driving force for transport against concentration gradients in these 4 systems mainly depends on different Na+ pumps, and it is an active transport process[3]. As for the transport mechanism of small peptides, it is not yet very clear. There may be three forms: (1) An active transport process that requires ATP consumption[4], conducting electricity depending on hydrogen ion concentration and calcium ion concentration. This transport mode is inhibited under hypoxic conditions or when metabolic inhibitors are added. (2) The second is a pH-dependent H+/Na+ exchange transport system that does not consume ATP[5]. Daniel et al. (1994) found that the driving force for small peptide transport comes from the proton electrochemical gradient; the driving force for proton movement is generated by the activity of H+/Na+ exchange channels in the apical cells of the brush border: the driving force generated by proton transport into the cell drives small peptides to move into the cell. In this way, small peptides enter the cell in the form of facilitated diffusion, causing the pH value in the cytoplasm to decrease; thereby activating the Na+/H+ channel, H+ is released from the cell, and the intracellular pH returns to its original level. (3) The third is the glutathione (GSH) transport system[6]. Since glutathione has an antioxidant effect within biological membranes, the GSH transport system may have special physiological significance, but its mechanism is not yet very clear. Vincerzini (1989) reported that the transmembrane transport of GSH is related to the concentration gradients of Na+, K+, Li+, Ca+ and Mn+, but not to the concentration of H+.
1.2 Absorption mechanisms in ruminants
The absorption of small peptides in ruminants differs from that in monogastric animals. According to research findings, there are two absorption systems in ruminants: the mesenteric system and the non-mesenteric system[7]. Under normal circumstances, the absorption of small peptides in the digestive tract occurs via the non-mesenteric system in the rumen, reticulum, omasum, abomasum and duodenum; and via the mesenteric system in the jejunum, colon, ileum and cecum. Dirienzo (1990) measured amino acid and peptide absorption in sheep separately. The free amino acids absorbed from the mesenteric system were 36.74 g/d, amino acids absorbed in peptide form were 52.01 g/d, and the amounts absorbed from the non-mesenteric system were 4.51 g/d and 308.40 g/d respectively. This shows that the non-mesenteric system is the main pathway for peptide absorption. Matthews (1991), using isolated rumen epithelial cells and omasum epithelial cells to study small peptide absorption, found that the absorption of small peptides by rumen epithelial cells and omasum epithelial cells is an unsaturated passive diffusion process, and the ability of omasum epithelial cells to absorb small peptides is stronger than that of rumen epithelial cells.
1.3 Characteristics of small peptide absorption mechanisms
Compared with free amino acids, the transport system for small peptides has the characteristics of low energy consumption, fast transport speed and being not easily saturated[8], while the transport of free amino acids is slow, energy-consuming and the carriers are easily saturated. A large number of experiments have confirmed that for peptides formed in the intestine, most of their amino acid residues are absorbed more rapidly and effectively than individual amino acids. Rerat et al. (1988), in experiments with pigs, observed that when a peptide mixture was infused into the duodenum, except for methionine, amino acids appearing in the portal vein appeared earlier than when the corresponding amino acid mixture was infused, and the absorption peaks were higher, indicating that the absorption rate of the small peptide mixture was high. Yue Guowei et al. (1997) reported that when CSP (enzymatic hydrolysate of casein mainly composed of small peptides) and a correspondingly composed free amino acid mixture were infused into the duodenum of chickens respectively, 10 minutes later the amount of some small peptides and the total peptide amount in the portal vein blood circulation of the CSP group were significantly higher than those of the FAA group. Daneil et al. (1994) believed that the absorption capacity of peptide carriers may be higher than the sum of the absorption capacities of various amino acid carriers. The reason why amino acid residues in small peptides are rapidly absorbed, apart from the small peptide absorption mechanism itself, may be that small peptides themselves promote the absorption of amino acids or their residues. As absorption substrates in the intestinal lumen, small peptides can not only increase the activity of brush border aminopeptidases and dipeptidases, but also increase the number of small peptide carriers[9].
2 Nutritional effects of small peptides
2.1 Improving the utilization rate of dietary amino acids
Free amino acids compete for absorption in the digestive tract, while the absorption mechanism of small peptides is completely different from that of free amino acids. Many experiments have shown that the addition of small peptides can increase the absorption speed of amino acids and promote the utilization of dietary amino acids. The inhibition of lysine absorption by arginine is evident in the free and partial small peptide forms; when small peptides are supplied, the absorption speed of lysine is not affected by arginine. Pharagyn and Barley (1987) reported that when lysine and arginine exist in free form, the two compete for absorption sites, and free arginine tends to reduce the lysine level in the hepatic portal vein; when lysine exists in peptide form, arginine has no effect on its absorption. Shi Yonghui et al. (1996), studying the effects of different ratios of small peptides and free amino acids on amino acid absorption in chickens, observed that an increase in the proportion of small peptides could significantly increase the absorption speed of amino acids, while increasing the proportion or concentration of free amino acids in the infusion fluid could not accelerate the absorption of most amino acids.
2.2 Increasing the deposition rate of protein in the body
The state in which amino acids exist in the diet affects protein metabolism in animals. Some animal nutrition trials have observed the role of small peptides in animal protein deposition. Infante et al. (1992) reported that when nitrogen was supplied in the form of small peptides or free amino acids as well as complete protein, rats in the di- and tripeptide diet group had the highest nitrogen deposition, the free amino acid group was poorer, and the complete protein group was in between. Yue Guowei (1996) observed that when casein hydrolysate small peptides were infused, the tissue protein synthesis rate of chicks was significantly higher than that of the group infused with the corresponding free amino acid mixture. Funabiki (1992) also observed that the body protein synthesis rate of mice in the peptide diet group was 26% higher than that of the corresponding amino acid diet group. Rerat et al. (1988) reported that after infusing small peptides into the duodenum of pigs, the plasma insulin concentration was higher than in the group infused with free amino acids; and one of the physiological functions of insulin is to participate in the extension of peptide chains during protein synthesis, increasing protein synthesis.
2.3 Promoting the absorption and utilization of mineral elements
Some small peptides have the property of binding with metals, thereby promoting the passive transport process of metal elements and their storage in the body. In the hydrolysates of casein, there exists a class of phosphorylated serine residues that can bind with calcium ions and ferrous ions, which can improve their solubility. Meiser et al. (1980), while isolating opioid peptides, obtained a phosphopeptide from bovine casein, referred to as casein phosphopeptide, whose serine hydroxyl groups are almost all phosphorylated. These phosphopeptides concentrate a large amount of negative charge, can prevent further proteolysis, and can bind free calcium, iron, copper, zinc and other metal ions to form soluble salts to increase their concentration in the intestinal lumen and promote the passive transport process of these ions. Shi Yonghui et al. (1996) reported that after adding small peptide products to laying hen diets, the plasma iron and zinc ion contents were significantly higher than those of the control group, and eggshell strength was improved.
2.4 Nutritional effects of small peptides on rumen microorganisms
Ha (1996) reported that 1 h after feeding sheep rice straw and concentrate at a 1:1 ratio, the peptide concentration in the rumen increased 2.5 times, and then decreased linearly. This result indicates that after feed protein is rapidly decomposed into peptides, most of them are utilized by microorganisms. Arggde (1989) found that about 2/3 of the ammonia required for rumen microbial protein synthesis comes from peptides and amino acids. That is, peptides are important substrates for protein synthesis by rumen microorganisms. The main effect of peptides on the growth of rumen microorganisms is to accelerate the reproduction speed of microorganisms and shorten the cell division cycle[10]. In particular, small peptides can stimulate the growth of microorganisms that ferment sugars and starch. CruzSoto et al. (1994), using pure cultures of rumen microorganisms, showed that when soluble sugars such as glucose and cellobiose were used as energy sources, small peptides promoted the growth speed of soluble sugar-decomposing bacteria by 70% more than amino acids, while cellulolytic bacteria grew at the same speed under the three nitrogen sources of ammonium chloride, mixed amino acids and peptides.
Although the mechanism by which rumen microorganisms transport and utilize small peptides is not yet clear, it has been proven that small peptides are key factors for rumen microorganisms to achieve maximum growth efficiency. However, whether small peptides can promote microbial growth mainly depends on the fermentation speed of the carbohydrate used as an energy source. For rapidly fermented soluble sugars, small peptides can promote microbial growth, while for slowly fermented cellulosic substances, small peptides cannot promote microbial growth. This is also the core of the currently established rumen microbial peptide nutrition system[11].
2.5 Improving animal growth performance
Some proteins are degraded under the action of digestive enzymes to produce many small peptides with certain peptide chain structures and amino acid residue sequences. These small peptides may have special physiological activities, can be directly absorbed by animals, participate in the body's physiological activities and metabolic regulation, thereby improving their production performance. Parisini et al. (1989), after adding a small amount of peptides to growing pig diets, significantly improved the daily weight gain, protein utilization rate and feed conversion rate of pigs. Shi Yonghui et al. (1996) reported that after adding peptide products to the basal diet of laying hens, the laying rate and feed conversion rate were significantly improved, and eggshell strength also showed an increasing trend. Pocius et al. (1981) observed that glutathione (a tripeptide) in the blood can be utilized by mammary tissue, and cysteine from glutathione can meet the needs of milk production. Other studies have shown that free cysteine in the blood cannot be used to synthesize milk protein[12].
3 Other physiological activities of small peptides
In addition to promoting the absorption of amino acids and providing amino acids themselves, small peptides also have many important physiological functions. There is also a great deal of research in this area, especially on tyrosine hydrolysates. Brantl et al. (1979) proved that bovine milk protein enzymatic hydrolysis products have opioid peptide activity. Through extensive research, people have discovered many small peptides with special physiological functions, called bioactive peptides, including antiviral and anticancer polypeptides, antibacterial polypeptides, growth-promoting peptides, immunomodulatory peptides, flavor peptides, antioxidant peptides and environmentally friendly peptides, etc. These bioactive peptides play important roles in animals such as antiviral and antibacterial action, promoting growth, immune regulation, improving palatability and protecting the environment.
4 Summary
The nutritional effects of small peptides have been confirmed by many experiments, but how small peptides participate in nitrogen metabolism, and what the requirements of livestock and poultry are, and under the current theory that animals need complete protein to meet oligopeptide requirements, how to re-evaluate the ideal protein model previously established on the basis of available amino acids - these still need further discussion.
--------------------------------------
"Small peptides are 2 or 3 amino acid residues" - are the feeding effects of residues composed of leucine and residues composed of lysine the same? After adding hydrogen ions to residues, are they complete amino acid molecules? What is the nutritional essence of small peptides? Is there a connection between the nutrition of small peptides and amino acids? During the digestion and absorption of protein feed, is part of it also utilized in the form of small peptides?
How are small peptides used in formulas? Are they added at a certain ratio, or used by calculation according to the required amount? ......
It seems there is still a certain distance before small peptides reach widespread use. Their entire metabolic process has not yet been fully clarified. Good things should be approached steadily; premature development often has negative effects, just like nano feed.
Small peptides have been studied a lot at home and abroad, and there is no shortage of literature. It has been several years since they were called a new thing, and I have discussed them with peers, but we are all not very clear and cannot figure it out.
--------------------------------------
Actually, small peptides really are a good thing - fast digestion and absorption, high utilization rate, and some special small peptides also have their unique functions. This is definitely a future development direction.
But the most important thing is that current understanding of them is still too superficial, and they have not yet reached the practical stage. The production method and production process cannot be controlled. Testing seems impossible too. Anyway, if someone says this is a small peptide, you still don't know what it specifically is.
--------------------------------------
As far as I know, Nestle is using products from Harbin Leneng. You can visit the Leneng Peptide website and take a look!!!
--------------------------------------
Actually, small peptides really are a good thing - fast digestion and absorption, high utilization rate, and some special small peptides also have their unique functions. This is definitely a future development direction.
That's right, it may be a good thing. In theory, the absorption process has been explained clearly, and the actual effects have been described even more clearly (including various livestock products), but as for the protein recombination process after absorption, whether for meat, milk or eggs, it seems no one has yet provided a theoretical basis. This is the essence of small peptide nutrition. Without this, we can only use them blindly. Domestic products include those produced by hydrolysis of fish protein and those produced by hydrolysis of soybean protein - are the effects the same? If small peptides are used as an additive, it is still relatively easy to understand, but if they are used as a main protein raw material, then how should they be calculated?
We really know too little. Who can explain it clearly?
--------------------------------------
Small peptides are a good thing. The problem is whether what is on the market is truly small peptides. Before it is fully understood, it is better to be cautious and use raw materials with a clear understanding!
--------------------------------------
Yes, in theory small peptides are very good, but when it comes to promoting their use, it always feels hard to accept. People doing small peptide business talk about a concept, but we cannot see how much of the small peptide should actually be used, and it always feels a bit vague. It is better to use fishmeal honestly. It is a bit expensive, but at least it is better than harming the hardworking farmer brothers below who are struggling with farming.
--------------------------------------
Believe it or not, so many people are using them. If you don't use them, you worry others who do will run faster than you. It's hard. Has anyone used them or done experiments who can help? I don't have a test farm.
--------------------------------------
Fishmeal is too expensive, you want to use small peptides, but fishmeal and small peptides are two different things - they are not the same
--------------------------------------
Absorption Mechanisms of Small Peptides and Advances in Nutrition Research
Li Lusheng (College of Agriculture, Liaocheng University, Liaocheng, Shandong 252000)
Feng Dingyuan (College of Animal Science, South China Agricultural University, Guangzhou 510640)
Abstract Research trials in recent years have proven that small peptides are the main digestion products of protein and play a very important role in the digestion, absorption and metabolism of amino acids. This paper reviews the absorption mechanisms of small peptides in monogastric animals and ruminants, the nutritional effects of small peptides and the factors affecting small peptide absorption, as well as the role of small peptides in protein metabolism.
Keywords small peptides, free amino acids, absorption mechanism
Protein is one of the most important nutrients in animal nutrition, and there has been a great deal of research on its absorption mechanism. The past view held that the animal digestive tract can only absorb free amino acids, that is, protein must be broken down into free amino acids before it can be absorbed. However, in recent years, experiments have shown that when animals are fed purified diets formulated according to the ideal amino acid pattern or low-protein amino acid-balanced diets, optimal production performance and feed efficiency cannot be achieved. Therefore, some scholars believe that in addition to absorbing free amino acids, the animal digestive tract also has special requirements for protein itself or peptides. Neway and Smith first proposed in 1960 that small peptides can be transported and absorbed intact. Since then, most of the final hydrolysis products of protein in the digestive tract are small peptides composed of 2 or 3 amino acid residues, which can be absorbed intact into the circulatory system and then utilized by tissues. The type I carrier[1] and type II carrier[2] of small peptides have been cloned respectively. In recent years, great progress has been made in research on the absorption mechanisms of small peptides in animals, the characteristics of carriers, and physiological characteristics. The view that small peptides can be absorbed intact in animals has been further confirmed and developed.
1 Absorption mechanisms of small peptides
1.1 Absorption mechanisms of small peptides in monogastric animals
The absorption mechanism of small peptides is completely different from that of free amino acids. The absorption of free amino acids involves 4 systems: neutral, acidic, basic amino acids and imino acids. The driving force for transport against concentration gradients in these 4 systems mainly depends on different Na+ pumps, and it is an active transport process[3]. As for the transport mechanism of small peptides, it is not yet very clear. There may be three forms: (1) An active transport process that requires ATP consumption[4], conducting electricity depending on hydrogen ion concentration and calcium ion concentration. This transport mode is inhibited under hypoxic conditions or when metabolic inhibitors are added. (2) The second is a pH-dependent H+/Na+ exchange transport system that does not consume ATP[5]. Daniel et al. (1994) found that the driving force for small peptide transport comes from the proton electrochemical gradient; the driving force for proton movement is generated by the activity of H+/Na+ exchange channels in the apical cells of the brush border: the driving force generated by proton transport into the cell drives small peptides to move into the cell. In this way, small peptides enter the cell in the form of facilitated diffusion, causing the pH value in the cytoplasm to decrease; thereby activating the Na+/H+ channel, H+ is released from the cell, and the intracellular pH returns to its original level. (3) The third is the glutathione (GSH) transport system[6]. Since glutathione has an antioxidant effect within biological membranes, the GSH transport system may have special physiological significance, but its mechanism is not yet very clear. Vincerzini (1989) reported that the transmembrane transport of GSH is related to the concentration gradients of Na+, K+, Li+, Ca+ and Mn+, but not to the concentration of H+.
1.2 Absorption mechanisms in ruminants
The absorption of small peptides in ruminants differs from that in monogastric animals. According to research findings, there are two absorption systems in ruminants: the mesenteric system and the non-mesenteric system[7]. Under normal circumstances, the absorption of small peptides in the digestive tract occurs via the non-mesenteric system in the rumen, reticulum, omasum, abomasum and duodenum; and via the mesenteric system in the jejunum, colon, ileum and cecum. Dirienzo (1990) measured amino acid and peptide absorption in sheep separately. The free amino acids absorbed from the mesenteric system were 36.74 g/d, amino acids absorbed in peptide form were 52.01 g/d, and the amounts absorbed from the non-mesenteric system were 4.51 g/d and 308.40 g/d respectively. This shows that the non-mesenteric system is the main pathway for peptide absorption. Matthews (1991), using isolated rumen epithelial cells and omasum epithelial cells to study small peptide absorption, found that the absorption of small peptides by rumen epithelial cells and omasum epithelial cells is an unsaturated passive diffusion process, and the ability of omasum epithelial cells to absorb small peptides is stronger than that of rumen epithelial cells.
1.3 Characteristics of small peptide absorption mechanisms
Compared with free amino acids, the transport system for small peptides has the characteristics of low energy consumption, fast transport speed and being not easily saturated[8], while the transport of free amino acids is slow, energy-consuming and the carriers are easily saturated. A large number of experiments have confirmed that for peptides formed in the intestine, most of their amino acid residues are absorbed more rapidly and effectively than individual amino acids. Rerat et al. (1988), in experiments with pigs, observed that when a peptide mixture was infused into the duodenum, except for methionine, amino acids appearing in the portal vein appeared earlier than when the corresponding amino acid mixture was infused, and the absorption peaks were higher, indicating that the absorption rate of the small peptide mixture was high. Yue Guowei et al. (1997) reported that when CSP (enzymatic hydrolysate of casein mainly composed of small peptides) and a correspondingly composed free amino acid mixture were infused into the duodenum of chickens respectively, 10 minutes later the amount of some small peptides and the total peptide amount in the portal vein blood circulation of the CSP group were significantly higher than those of the FAA group. Daneil et al. (1994) believed that the absorption capacity of peptide carriers may be higher than the sum of the absorption capacities of various amino acid carriers. The reason why amino acid residues in small peptides are rapidly absorbed, apart from the small peptide absorption mechanism itself, may be that small peptides themselves promote the absorption of amino acids or their residues. As absorption substrates in the intestinal lumen, small peptides can not only increase the activity of brush border aminopeptidases and dipeptidases, but also increase the number of small peptide carriers[9].
2 Nutritional effects of small peptides
2.1 Improving the utilization rate of dietary amino acids
Free amino acids compete for absorption in the digestive tract, while the absorption mechanism of small peptides is completely different from that of free amino acids. Many experiments have shown that the addition of small peptides can increase the absorption speed of amino acids and promote the utilization of dietary amino acids. The inhibition of lysine absorption by arginine is evident in the free and partial small peptide forms; when small peptides are supplied, the absorption speed of lysine is not affected by arginine. Pharagyn and Barley (1987) reported that when lysine and arginine exist in free form, the two compete for absorption sites, and free arginine tends to reduce the lysine level in the hepatic portal vein; when lysine exists in peptide form, arginine has no effect on its absorption. Shi Yonghui et al. (1996), studying the effects of different ratios of small peptides and free amino acids on amino acid absorption in chickens, observed that an increase in the proportion of small peptides could significantly increase the absorption speed of amino acids, while increasing the proportion or concentration of free amino acids in the infusion fluid could not accelerate the absorption of most amino acids.
2.2 Increasing the deposition rate of protein in the body
The state in which amino acids exist in the diet affects protein metabolism in animals. Some animal nutrition trials have observed the role of small peptides in animal protein deposition. Infante et al. (1992) reported that when nitrogen was supplied in the form of small peptides or free amino acids as well as complete protein, rats in the di- and tripeptide diet group had the highest nitrogen deposition, the free amino acid group was poorer, and the complete protein group was in between. Yue Guowei (1996) observed that when casein hydrolysate small peptides were infused, the tissue protein synthesis rate of chicks was significantly higher than that of the group infused with the corresponding free amino acid mixture. Funabiki (1992) also observed that the body protein synthesis rate of mice in the peptide diet group was 26% higher than that of the corresponding amino acid diet group. Rerat et al. (1988) reported that after infusing small peptides into the duodenum of pigs, the plasma insulin concentration was higher than in the group infused with free amino acids; and one of the physiological functions of insulin is to participate in the extension of peptide chains during protein synthesis, increasing protein synthesis.
2.3 Promoting the absorption and utilization of mineral elements
Some small peptides have the property of binding with metals, thereby promoting the passive transport process of metal elements and their storage in the body. In the hydrolysates of casein, there exists a class of phosphorylated serine residues that can bind with calcium ions and ferrous ions, which can improve their solubility. Meiser et al. (1980), while isolating opioid peptides, obtained a phosphopeptide from bovine casein, referred to as casein phosphopeptide, whose serine hydroxyl groups are almost all phosphorylated. These phosphopeptides concentrate a large amount of negative charge, can prevent further proteolysis, and can bind free calcium, iron, copper, zinc and other metal ions to form soluble salts to increase their concentration in the intestinal lumen and promote the passive transport process of these ions. Shi Yonghui et al. (1996) reported that after adding small peptide products to laying hen diets, the plasma iron and zinc ion contents were significantly higher than those of the control group, and eggshell strength was improved.
2.4 Nutritional effects of small peptides on rumen microorganisms
Ha (1996) reported that 1 h after feeding sheep rice straw and concentrate at a 1:1 ratio, the peptide concentration in the rumen increased 2.5 times, and then decreased linearly. This result indicates that after feed protein is rapidly decomposed into peptides, most of them are utilized by microorganisms. Arggde (1989) found that about 2/3 of the ammonia required for rumen microbial protein synthesis comes from peptides and amino acids. That is, peptides are important substrates for protein synthesis by rumen microorganisms. The main effect of peptides on the growth of rumen microorganisms is to accelerate the reproduction speed of microorganisms and shorten the cell division cycle[10]. In particular, small peptides can stimulate the growth of microorganisms that ferment sugars and starch. CruzSoto et al. (1994), using pure cultures of rumen microorganisms, showed that when soluble sugars such as glucose and cellobiose were used as energy sources, small peptides promoted the growth speed of soluble sugar-decomposing bacteria by 70% more than amino acids, while cellulolytic bacteria grew at the same speed under the three nitrogen sources of ammonium chloride, mixed amino acids and peptides.
Although the mechanism by which rumen microorganisms transport and utilize small peptides is not yet clear, it has been proven that small peptides are key factors for rumen microorganisms to achieve maximum growth efficiency. However, whether small peptides can promote microbial growth mainly depends on the fermentation speed of the carbohydrate used as an energy source. For rapidly fermented soluble sugars, small peptides can promote microbial growth, while for slowly fermented cellulosic substances, small peptides cannot promote microbial growth. This is also the core of the currently established rumen microbial peptide nutrition system[11].
2.5 Improving animal growth performance
Some proteins are degraded under the action of digestive enzymes to produce many small peptides with certain peptide chain structures and amino acid residue sequences. These small peptides may have special physiological activities, can be directly absorbed by animals, participate in the body's physiological activities and metabolic regulation, thereby improving their production performance. Parisini et al. (1989), after adding a small amount of peptides to growing pig diets, significantly improved the daily weight gain, protein utilization rate and feed conversion rate of pigs. Shi Yonghui et al. (1996) reported that after adding peptide products to the basal diet of laying hens, the laying rate and feed conversion rate were significantly improved, and eggshell strength also showed an increasing trend. Pocius et al. (1981) observed that glutathione (a tripeptide) in the blood can be utilized by mammary tissue, and cysteine from glutathione can meet the needs of milk production. Other studies have shown that free cysteine in the blood cannot be used to synthesize milk protein[12].
3 Other physiological activities of small peptides
In addition to promoting the absorption of amino acids and providing amino acids themselves, small peptides also have many important physiological functions. There is also a great deal of research in this area, especially on tyrosine hydrolysates. Brantl et al. (1979) proved that bovine milk protein enzymatic hydrolysis products have opioid peptide activity. Through extensive research, people have discovered many small peptides with special physiological functions, called bioactive peptides, including antiviral and anticancer polypeptides, antibacterial polypeptides, growth-promoting peptides, immunomodulatory peptides, flavor peptides, antioxidant peptides and environmentally friendly peptides, etc. These bioactive peptides play important roles in animals such as antiviral and antibacterial action, promoting growth, immune regulation, improving palatability and protecting the environment.
4 Summary
The nutritional effects of small peptides have been confirmed by many experiments, but how small peptides participate in nitrogen metabolism, and what the requirements of livestock and poultry are, and under the current theory that animals need complete protein to meet oligopeptide requirements, how to re-evaluate the ideal protein model previously established on the basis of available amino acids - these still need further discussion.
--------------------------------------
"Small peptides are 2 or 3 amino acid residues" - are the feeding effects of residues composed of leucine and residues composed of lysine the same? After adding hydrogen ions to residues, are they complete amino acid molecules? What is the nutritional essence of small peptides? Is there a connection between the nutrition of small peptides and amino acids? During the digestion and absorption of protein feed, is part of it also utilized in the form of small peptides?
How are small peptides used in formulas? Are they added at a certain ratio, or used by calculation according to the required amount? ......
It seems there is still a certain distance before small peptides reach widespread use. Their entire metabolic process has not yet been fully clarified. Good things should be approached steadily; premature development often has negative effects, just like nano feed.
Small peptides have been studied a lot at home and abroad, and there is no shortage of literature. It has been several years since they were called a new thing, and I have discussed them with peers, but we are all not very clear and cannot figure it out.
--------------------------------------
Actually, small peptides really are a good thing - fast digestion and absorption, high utilization rate, and some special small peptides also have their unique functions. This is definitely a future development direction.
But the most important thing is that current understanding of them is still too superficial, and they have not yet reached the practical stage. The production method and production process cannot be controlled. Testing seems impossible too. Anyway, if someone says this is a small peptide, you still don't know what it specifically is.
--------------------------------------
As far as I know, Nestle is using products from Harbin Leneng. You can visit the Leneng Peptide website and take a look!!!
--------------------------------------
Actually, small peptides really are a good thing - fast digestion and absorption, high utilization rate, and some special small peptides also have their unique functions. This is definitely a future development direction.
That's right, it may be a good thing. In theory, the absorption process has been explained clearly, and the actual effects have been described even more clearly (including various livestock products), but as for the protein recombination process after absorption, whether for meat, milk or eggs, it seems no one has yet provided a theoretical basis. This is the essence of small peptide nutrition. Without this, we can only use them blindly. Domestic products include those produced by hydrolysis of fish protein and those produced by hydrolysis of soybean protein - are the effects the same? If small peptides are used as an additive, it is still relatively easy to understand, but if they are used as a main protein raw material, then how should they be calculated?
We really know too little. Who can explain it clearly?
--------------------------------------
Small peptides are a good thing. The problem is whether what is on the market is truly small peptides. Before it is fully understood, it is better to be cautious and use raw materials with a clear understanding!
--------------------------------------
Yes, in theory small peptides are very good, but when it comes to promoting their use, it always feels hard to accept. People doing small peptide business talk about a concept, but we cannot see how much of the small peptide should actually be used, and it always feels a bit vague. It is better to use fishmeal honestly. It is a bit expensive, but at least it is better than harming the hardworking farmer brothers below who are struggling with farming.