Member Fatima
MemberForum Replies Created
-
Organic acids (OAs) are widely used in poultry feed as an alternative to antibiotic growth promoters (AGPs) because of their significant and generally beneficial impact on the gut microflora. Their primary mechanism of action relies on their antimicrobial properties and their ability to modify the gut environment.
Here is a breakdown of how different organic acids (and their related compounds) affect the poultry gut microflora:
1. The Core Mechanism: \text{pH} and Un-dissociated Form
Organic acids are weak acids. Their effect on the microflora is primarily dependent on their ability to remain in their un-dissociated (non-ionized) form, which is lipophilic (fat-soluble).
* Lowing Gut \text{pH}: When added to feed or water, OAs immediately lower the \text{pH} of the feed and the upper gastrointestinal tract (crop, proventriculus, and gizzard). This lower \text{pH} directly inhibits the growth of many acid-intolerant pathogenic bacteria like Salmonella spp. and E. coli.
* Intracellular Pathogen Killing: In their un-dissociated form, OAs can penetrate the cell membrane of a pathogenic bacterium. Once inside the relatively neutral \text{pH} cytoplasm of the bacterium, the acid dissociates, releasing \text{H}^+ ions. This causes the bacterium’s internal \text{pH} to drop sharply, forcing the cell to expend enormous energy trying to restore \text{pH} homeostasis. This energy depletion and the disruption of cellular metabolism eventually kill the pathogenic bacteria.
* Favoring Beneficial Bacteria: Beneficial bacteria, such as lactic acid bacteria (Lactobacillus and Bidifobacteria), are generally more acid-tolerant than pathogens and thrive in the lower \text{pH} environment created by the OAs, leading to their increased population.
2. Effects of Specific Organic Acids
Organic acids are broadly categorized based on their chain length:
A. Short-Chain Fatty Acids ($\text{SCFA}$s)
These are the most common OAs used in poultry and are the primary compounds produced by beneficial gut microbes.
| Organic Acid | Primary Effects on Microflora | Other Benefits |
|—|—|—|
| Formic Acid | Strongest antibacterial activity against gram-negative pathogens (e.g., Salmonella, E. coli). Highly effective in the upper gut (low \text{pH}). | Improves protein digestion by enhancing pepsin activity; good for feed preservation. |
| Propionic Acid | Inhibits mold growth in feed; also active against E. coli and other gram-negative bacteria. | Improves feed efficiency; its salts can be used to deliver the acid deeper into the gut. |
| Butyric Acid | A critical energy source for the intestinal cells (enterocytes). While technically a SCFA, its unique action is highly beneficial for the microflora indirectly. | Enhances gut barrier function and mucosal health; stimulates villus growth (improving absorption); helps colonize butyrate-producing commensals. |
| Lactic Acid | Produced naturally by Lactobacillus and Bidifobacteria; addition can further reinforce their dominance. | Promotes a healthy, acidophilic gut environment. |
B. Medium-Chain Fatty Acids ($\text{MCFA}$s)
These are fatty acids with 6 to 12 carbon atoms (e.g., caprylic, capric, lauric acid).
| Organic Acid | Primary Effects on Microflora | Other Benefits |
|—|—|—|
| $\text{MCFA}$s | Strong bactericidal effect on pathogenic bacteria (both gram-positive and gram-negative), often acting differently than $\text{SCFA}$s to disrupt the bacterial cell membrane. | Effective at higher \text{pH} (small intestine); potent antifungal and antiviral properties. |
C. Other Common Organic Acids
| Organic Acid | Primary Effects on Microflora |
|—|—|
| Citric Acid | Lowers the gut \text{pH} to a lesser degree than $\text{SCFA}$s, but its effect is significant in the upper gut to improve mineral and protein utilization. |
| Fumaric Acid | Similar to citric acid in its function as a \text{pH} reducer and mild antimicrobial. |
Summary of Modulation Effects
The overall impact of organic acid supplementation is a shift in the microbial population:
| Gut Microbe Type | Effect of Organic Acids |
|—|—|
| Pathogens (Salmonella, E. coli, Clostridium perfringens) | Decreased population and reduced ability to colonize and produce toxins due to \text{pH} disruption and direct antimicrobial action. |
| Beneficial Bacteria (Lactobacillus, Bidifobacteria) | Increased population due to better competition in the lower \text{pH} environment. |
| Overall Gut Health | Improved intestinal barrier integrity, better nutrient digestion and absorption, and a more stable, less inflammatory gut environment. |Organic acids (OAs) are widely used in poultry feed as an alternative to antibiotic growth promoters (AGPs) because of their significant and generally beneficial impact on the gut microflora. Their primary mechanism of action relies on their antimicrobial properties and their ability to modify the gut environment.
Here is a breakdown of how different organic acids (and their related compounds) affect the poultry gut microflora:
1. The Core Mechanism: \text{pH} and Un-dissociated Form
Organic acids are weak acids. Their effect on the microflora is primarily dependent on their ability to remain in their un-dissociated (non-ionized) form, which is lipophilic (fat-soluble).
* Lowing Gut \text{pH}: When added to feed or water, OAs immediately lower the \text{pH} of the feed and the upper gastrointestinal tract (crop, proventriculus, and gizzard). This lower \text{pH} directly inhibits the growth of many acid-intolerant pathogenic bacteria like Salmonella spp. and E. coli.
* Intracellular Pathogen Killing: In their un-dissociated form, OAs can penetrate the cell membrane of a pathogenic bacterium. Once inside the relatively neutral \text{pH} cytoplasm of the bacterium, the acid dissociates, releasing \text{H}^+ ions. This causes the bacterium’s internal \text{pH} to drop sharply, forcing the cell to expend enormous energy trying to restore \text{pH} homeostasis. This energy depletion and the disruption of cellular metabolism eventually kill the pathogenic bacteria.
* Favoring Beneficial Bacteria: Beneficial bacteria, such as lactic acid bacteria (Lactobacillus and Bidifobacteria), are generally more acid-tolerant than pathogens and thrive in the lower \text{pH} environment created by the OAs, leading to their increased population.
2. Effects of Specific Organic Acids
Organic acids are broadly categorized based on their chain length:
A. Short-Chain Fatty Acids ($\text{SCFA}$s)
These are the most common OAs used in poultry and are the primary compounds produced by beneficial gut microbes.
| Organic Acid | Primary Effects on Microflora | Other Benefits |
|—|—|—|
| Formic Acid | Strongest antibacterial activity against gram-negative pathogens (e.g., Salmonella, E. coli). Highly effective in the upper gut (low \text{pH}). | Improves protein digestion by enhancing pepsin activity; good for feed preservation. |
| Propionic Acid | Inhibits mold growth in feed; also active against E. coli and other gram-negative bacteria. | Improves feed efficiency; its salts can be used to deliver the acid deeper into the gut. |
| Butyric Acid | A critical energy source for the intestinal cells (enterocytes). While technically a SCFA, its unique action is highly beneficial for the microflora indirectly. | Enhances gut barrier function and mucosal health; stimulates villus growth (improving absorption); helps colonize butyrate-producing commensals. |
| Lactic Acid | Produced naturally by Lactobacillus and Bidifobacteria; addition can further reinforce their dominance. | Promotes a healthy, acidophilic gut environment. |
B. Medium-Chain Fatty Acids ($\text{MCFA}$s)
These are fatty acids with 6 to 12 carbon atoms (e.g., caprylic, capric, lauric acid).
| Organic Acid | Primary Effects on Microflora | Other Benefits |
|—|—|—|
| $\text{MCFA}$s | Strong bactericidal effect on pathogenic bacteria (both gram-positive and gram-negative), often acting differently than $\text{SCFA}$s to disrupt the bacterial cell membrane. | Effective at higher \text{pH} (small intestine); potent antifungal and antiviral properties. |
C. Other Common Organic Acids
| Organic Acid | Primary Effects on Microflora |
|—|—|
| Citric Acid | Lowers the gut \text{pH} to a lesser degree than $\text{SCFA}$s, but its effect is significant in the upper gut to improve mineral and protein utilization. |
| Fumaric Acid | Similar to citric acid in its function as a \text{pH} reducer and mild antimicrobial. |
Summary of Modulation Effects
The overall impact of organic acid supplementation is a shift in the microbial population:
| Gut Microbe Type | Effect of Organic Acids |
|—|—|
| Pathogens (Salmonella, E. coli, Clostridium perfringens) | Decreased population and reduced ability to colonize and produce toxins due to \text{pH} disruption and direct antimicrobial action. |
| Beneficial Bacteria (Lactobacillus, Bidifobacteria) | Increased population due to better competition in the lower \text{pH} environment. |
| Overall Gut Health | Improved intestinal barrier integrity, better nutrient digestion and absorption, and a more stable, less inflammatory gut environment. | -
Phytase enzymes significantly improve phosphorus (P) availability in feed formulations by breaking down phytate, which is the primary storage form of phosphorus in plant-based feedstuffs (like grains and oilseeds) and is otherwise largely unavailable to monogastric animals like swine and poultry.
The mechanism is as follows:
Mechanism of Phytase Action
- Phytate as an Anti-Nutrient: In plant seeds, most phosphorus (50-80%) is stored as phytic acid (myo-inositol hexakisphosphate, or \text{IP}_6) and its salt, phytate. Monogastric animals lack sufficient amounts of the natural phytase enzyme in their digestive tracts to effectively break down this molecule. Consequently, most of the phytate-bound phosphorus is excreted. Furthermore, phytate acts as an anti-nutrient by strongly binding to essential minerals (like calcium, zinc, and iron) and proteins, reducing their overall digestibility and absorption.
- Hydrolysis of Phytate: When exogenous phytase (typically derived from fungi or bacteria) is added to the feed, it acts as a catalyst in the animal’s gastrointestinal tract, primarily in the acidic environment of the stomach/proventriculus.
- Release of Phosphorus: The phytase enzyme initiates the hydrolysis (breakdown) of the phosphate ester bonds on the inositol ring of the phytate molecule. This process occurs in a stepwise manner, releasing the phosphate groups one by one as inorganic phosphorus (\text{P}_{\text{i}}) and converting the phytate (\text{IP}_6) into less-phosphorylated inositol derivatives (\text{IP}_5 through \text{IP}_1) and eventually inositol.
Benefits in Feed Formulation
- Increased Bioavailability of Phosphorus: By hydrolyzing phytate, phytase makes the previously locked-up phosphorus available for absorption by the animal. This means less expensive inorganic phosphate supplementation is required in the diet, leading to cost savings.
- Reduced Anti-nutritional Effects: The breakdown of phytate mitigates its ability to chelate essential minerals and bind to proteins and amino acids. This results in improved digestibility not only of phosphorus, but also of other minerals, protein, and amino acids, ultimately boosting animal performance.
- Environmental Sustainability: Less phytate-bound phosphorus is excreted into the manure, significantly reducing the environmental pollution risk associated with phosphorus runoff from animal waste into waterways.
In essence, phytase serves as an efficient and economical tool to unlock a major nutrient (phosphorus) from the plant ingredients already present in the feed.Phytase enzymes significantly improve phosphorus (P) availability in feed formulations by breaking down phytate, which is the primary storage form of phosphorus in plant-based feedstuffs (like grains and oilseeds) and is otherwise largely unavailable to monogastric animals like swine and poultry.
The mechanism is as follows:
Mechanism of Phytase Action
Phytate as an Anti-Nutrient: In plant seeds, most phosphorus (50-80%) is stored as phytic acid (myo-inositol hexakisphosphate, or \text{IP}_6) and its salt, phytate. Monogastric animals lack sufficient amounts of the natural phytase enzyme in their digestive tracts to effectively break down this molecule. Consequently, most of the phytate-bound phosphorus is excreted. Furthermore, phytate acts as an anti-nutrient by strongly binding to essential minerals (like calcium, zinc, and iron) and proteins, reducing their overall digestibility and absorption.
Hydrolysis of Phytate: When exogenous phytase (typically derived from fungi or bacteria) is added to the feed, it acts as a catalyst in the animal’s gastrointestinal tract, primarily in the acidic environment of the stomach/proventriculus.
Release of Phosphorus: The phytase enzyme initiates the hydrolysis (breakdown) of the phosphate ester bonds on the inositol ring of the phytate molecule. This process occurs in a stepwise manner, releasing the phosphate groups one by one as inorganic phosphorus (\text{P}_{\text{i}}) and converting the phytate (\text{IP}_6) into less-phosphorylated inositol derivatives (\text{IP}_5 through \text{IP}_1) and eventually inositol.
Benefits in Feed Formulation
Increased Bioavailability of Phosphorus: By hydrolyzing phytate, phytase makes the previously locked-up phosphorus available for absorption by the animal. This means less expensive inorganic phosphate supplementation is required in the diet, leading to cost savings.
Reduced Anti-nutritional Effects: The breakdown of phytate mitigates its ability to chelate essential minerals and bind to proteins and amino acids. This results in improved digestibility not only of phosphorus, but also of other minerals, protein, and amino acids, ultimately boosting animal performance.
Environmental Sustainability: Less phytate-bound phosphorus is excreted into the manure, significantly reducing the environmental pollution risk associated with phosphorus runoff from animal waste into waterways.
In essence, phytase serves as an efficient and economical tool to unlock a major nutrient (phosphorus) from the plant ingredients already present in the feed. -
Good discussion
-
Common enzymes used to enhance non-starch polysaccharide digestibility in animal feed include xylanase, β-glucanase, and β-mannanase, which are often combined in a multi-enzyme complex to break down different types of non-starch polysaccharides (NSPs). Xylanase breaks down arabinoxylans, β-glucanase degrades β-glucans, and β-mannanase acts on β-galactomannans, improving nutrient absorption and overall feed value.
-
Yes, that is correct. Phytase enzymes improve phosphorus availability in animal feed by breaking down phytate, the indigestible, plant-based form of phosphorus, into a form that animals can absorb. This process also releases other nutrients and minerals that phytate would otherwise bind to, such as calcium, amino acids, and zinc.
-
Different organic acids affect poultry gut flora by reducing pathogenic bacteria and promoting beneficial microbes, though their specific impact varies. Generally, organic acids decrease the population of harmful bacteria like E. coli and Salmonella, partly by lowering digesta pH, which inhibits their growth and can lead to their cell membranes being penetrated by the acids. Some, like formic acid, are particularly effective against certain pathogens, while others, such as lactic and butyric acids, can support beneficial bacteria and improve gut health.
-
Great, thanks
-
Good, thanks for the information
-
Excellent, thanks
-
Good, thanks
-
Agree with “By increasing fish farms, the amount of nutrients discharged to natural sources will increase, which has a negative effect on the environmental balance”.
-
How different organic acids affect gut micro flora of the poultry?
-
Aquaculture has several environmental concerns that impact ecosystems and communities. Some of the key issues include:
– *Water Pollution*: Aquaculture can lead to water pollution through nutrient overload, excess feed, and waste accumulation, causing eutrophication, algal blooms, and oxygen depletion.
– *Habitat Destruction*: Aquaculture farms often require large areas of land and water, leading to habitat destruction, loss of biodiversity, and increased coastal vulnerability. Mangrove forests and wetlands are particularly vulnerable ecosystems.
– *Disease and Parasite Spread*: Intensive aquaculture practices can facilitate the spread of diseases and parasites among farmed and wild fish populations, posing risks to ecosystem health.
– *Genetic Disruption*: Escaped farmed fish can interbreed with wild populations, altering genetic makeup and potentially weakening wild fish populations.
– *Chemical Use and Antibiotic Resistance*: Aquaculture often involves the use of antibiotics and other chemicals, contributing to antibiotic resistance, pollution, and harm to non-target species.
– *Greenhouse Gas Emissions*: Aquaculture contributes to greenhouse gas emissions through energy consumption, feed production, and waste management.
– *Resource Overuse*: Aquaculture relies heavily on wild-caught fish for feed, contributing to overfishing and pressure on marine ecosystems.
– *Water Usage and Waste Management*: Aquaculture requires significant water resources, and poor waste management can lead to water pollution and waste accumulation.
To mitigate these concerns, sustainable aquaculture practices focus on:
– *Recirculating Aquaculture Systems (RAS)*: Closed-loop systems that minimize water usage and prevent pollution.
– *Integrated Multi-Trophic Aquaculture (IMTA)*: Combining species like fish, shellfish, and seaweed to mimic natural ecosystems and reduce waste.
– *Best Management Practices (BMPs)*: Implementing BMPs, such as optimizing feed management and biosecurity measures, to reduce environmental impact.
– *Sustainable Feed Sources*: Exploring alternative feed sources, like plant-based proteins and algae-based alternatives, to reduce reliance on wild-caught fish.
– *Regulatory Frameworks*: Strengthening regulations and monitoring systems to ensure aquaculture operations prioritize environmental sustainability.Aquaculture has several environmental concerns that impact ecosystems and communities. Some of the key issues include:
– *Water Pollution*: Aquaculture can lead to water pollution through nutrient overload, excess feed, and waste accumulation, causing eutrophication, algal blooms, and oxygen depletion.
– *Habitat Destruction*: Aquaculture farms often require large areas of land and water, leading to habitat destruction, loss of biodiversity, and increased coastal vulnerability. Mangrove forests and wetlands are particularly vulnerable ecosystems.
– *Disease and Parasite Spread*: Intensive aquaculture practices can facilitate the spread of diseases and parasites among farmed and wild fish populations, posing risks to ecosystem health.
– *Genetic Disruption*: Escaped farmed fish can interbreed with wild populations, altering genetic makeup and potentially weakening wild fish populations.
– *Chemical Use and Antibiotic Resistance*: Aquaculture often involves the use of antibiotics and other chemicals, contributing to antibiotic resistance, pollution, and harm to non-target species.
– *Greenhouse Gas Emissions*: Aquaculture contributes to greenhouse gas emissions through energy consumption, feed production, and waste management.
– *Resource Overuse*: Aquaculture relies heavily on wild-caught fish for feed, contributing to overfishing and pressure on marine ecosystems.
– *Water Usage and Waste Management*: Aquaculture requires significant water resources, and poor waste management can lead to water pollution and waste accumulation.To mitigate these concerns, sustainable aquaculture practices focus on:
– *Recirculating Aquaculture Systems (RAS)*: Closed-loop systems that minimize water usage and prevent pollution.
– *Integrated Multi-Trophic Aquaculture (IMTA)*: Combining species like fish, shellfish, and seaweed to mimic natural ecosystems and reduce waste.
– *Best Management Practices (BMPs)*: Implementing BMPs, such as optimizing feed management and biosecurity measures, to reduce environmental impact.
– *Sustainable Feed Sources*: Exploring alternative feed sources, like plant-based proteins and algae-based alternatives, to reduce reliance on wild-caught fish.
– *Regulatory Frameworks*: Strengthening regulations and monitoring systems to ensure aquaculture operations prioritize environmental sustainability. -
Acidification of soils :If a farm is land based and has to be abandoned for any reason this can leave the soils eroded and too salty to be used for other forms of farming in the future.
pollution of drinking water : Inland aquaculture has been linked to the pollution of water bodies used for human drinking water. One such study estimated that one farm producing 3 tonnes of freshwater fish would generate the equivalent waste of 240 people.
introduction of invasive species :There have been a total of 25 million reported fish escapes worldwide, usually as a result of damaged netting, which occurs in severe storms or hurricanes.
There have been a total of 25 million reported fish escapes worldwide, usually as a result of damaged netting, which occurs in severe storms or hurricanes.
Escaped fish have the potential to affect wild fish populations by outcompeting them for food and other resources. This not only directly affects wild fish populations but also forces local fisherman in the area affected to fish in other areas which might already be overexploited.
Aquaculture can have some positive impacts for the environment, especially when carried out in a sustainable and well-regulated fashion.
Reduces pressure on wildlife : Overfishing is a big environmental problem, driven by a growing global desire for fish. According to the Food and Agriculture Organization (FAO) over 70% of the worlds wild fish species are either fully exploited or depleted. This disrupts ecosystems, taking away predators or prey species from the oceans.
Other problems from industrial scale sea fishing include:
- bycatch where large nets are cast catching unwanted species which are simply discarded;
- injuring and deaths of wildlife caught in discarded fishing nets and lines (sometimes known as ghost fishing);
- trawling of nets along the sea bed causing damage and stirring up sediments.
-
thanks for the clarifications
