What Are The Functions And Roles of Methionine in Feed Additives?

Methionine, as the "first limiting amino acid," is a crucial nutrient that animals cannot synthesize themselves during growth and development and must obtain from feed. In modern, efficient, and intensive animal husbandry, animal growth performance, meat quality, and health directly determine farming profitability. This article will comprehensively analyze the core value of methionine in the feed additive industry, focusing on its core functions, the underlying logic for its necessity in feed, and the application characteristics of different farming scenarios.

 

1. What is Methionine?

 

Methionine, also known as methionine, is a sulfur-containing essential amino acid. "Essential" means that animals cannot synthesize it themselves and must obtain it from feed or feed additives. Conventional plant-based feed ingredients, such as soybean meal, corn, and rapeseed meal, typically have very low methionine content. Failure to supplement in time will directly reduce the animal's utilization efficiency of other amino acids and proteins.

 

Methionine is the most important methyl (-CH₃) donor in animals. Through its metabolic cycle (methionine cycle), methionine provides methyl groups to participate in dozens of important biochemical reactions in the body, acting as the "engine" of life metabolism.

 

With the development of modern animal husbandry towards high efficiency and precision nutrition, methionine has become increasingly important in feed additives, becoming an indispensable core nutrient element.

 

2. Core Functions and Key Roles of Methionine

 

The functions of methionine are: promoting protein synthesis, improving growth performance, and reducing the feed conversion ratio; participating in the synthesis of key substances, ensuring the health and physiological functions of the body; providing active methyl groups, regulating fat metabolism and gene expression; and improving feed quality and animal product quality.

 

(1) Promoting Protein Synthesis, Improving Growth Performance, and Reducing the Feed Conversion Ratio

 

As the first limiting amino acid, sufficient methionine supplementation can make the amino acid ratio in feed closer to the "ideal protein model" of animals. A lack of methionine directly leads to inhibited protein synthesis, resulting in stunted growth, slow weight gain, and low feed conversion rate in animals. For example, insufficient methionine in broiler feed can lead to poor muscle development and reduced slaughter rate; piglets may experience weight stagnation after weaning, or even emaciation and decreased immunity. Using methionine as a feed additive can precisely supplement the nutrients needed for animal growth and activate protein synthesis pathways. It can significantly increase daily weight gain, promote muscle growth, improve carcass quality (increase lean meat percentage), and significantly improve breeding efficiency.

 

(2) Participating in the synthesis of key substances, ensuring bodily health and physiological function. 

Methionine metabolites participate in the biosynthesis of various key substances and have multiple functions in animals.

 

Synthesis of cystine and taurine: Methionine is a precursor to the synthesis of cystine and taurine. Cystine is an important component of hormones such as hair, feathers, hooves, and insulin. Appropriate methionine supplementation helps to: improve the quality of poultry feathers, enhance the luster of skin and coat, reduce feather loss and damage, not only improving animal health but also enhancing the appearance quality of end products. Meanwhile, taurine is crucial for the development of the retina, brain, and heart in mammalian offspring (such as piglets and calves).

 

Synthesis of glutathione: Glutathione is one of the most important antioxidants in animals, capable of scavenging free radicals in cells, reducing oxidative stress damage to cells, and protecting the functional integrity of key organs such as the liver and intestines. Meanwhile, methionine participates in the synthesis of immunoglobulins, which can increase antibody levels in animals, enhance resistance to bacteria and viruses, reduce stress responses, and prevent growth inhibition, increased disease incidence, and mortality during breeding.

 

It also participates in the synthesis of polyamines and adrenaline, contributing to cell proliferation and differentiation, intestinal mucosal repair, and neurotransmitter regulation.

 

(3) Providing active methyl groups to regulate lipid metabolism and gene expression

 

Affecting gene expression and DNA methylation: Methionine provides methyl groups through S-adenosylmethionine (SAM), acting as an important "methyl donor" in hundreds of biochemical reactions, including DNA methylation, hormone synthesis, and choline production. Methylation is a key mechanism for gene expression regulation and cell differentiation, significantly impacting animal growth, development, and reproductive performance.

 

In laying hen farming, the methyl groups provided by methionine participate in the synthesis of ovalbumin and vitellin, directly affecting egg production rate, eggshell quality, and egg nutrition. In dairy farming, methylation promotes the synthesis of milk protein and milk fat, increasing milk yield and quality.

 

Regulating lipid metabolism: Methyl groups participate in the synthesis of phospholipids (cell membrane components) and carnitine (responsible for transporting fat into mitochondria for combustion). Sufficient methionine promotes β-oxidation of fat, reducing body fat deposition, especially abdominal fat, thereby improving carcass quality. Adding methionine to feed can promote the conversion of methionine into choline, a key substance in fat metabolism. This effectively prevents fat deposition in the animal liver and reduces the risk of fatty liver disease, especially for animals under high metabolic stress such as high-producing dairy cows and fattening pigs.

 

(4) Improving Feed and Animal Product Quality

 

Balancing feed nutrition and improving feed quality: Protein raw materials in animal feed (such as soybean meal, corn, and fishmeal) often have an imbalance in amino acid ratios. Supplementing with methionine can improve the absorption and utilization rate of other amino acids. If methionine in the feed is insufficient, even if the content of other amino acids is sufficient, it will lead to incomplete protein digestion and absorption, resulting in feed waste and increased breeding costs.

 

Improving egg quality: In egg-laying poultry feed, methionine directly affects egg production rate, egg weight, and especially eggshell quality. It is an important component of eggshell matrix protein and membrane protein. Supplementing with methionine can significantly reduce the rate of broken eggs and soft-shelled eggs.

 

Improving meat quality: By promoting protein synthesis and regulating fat metabolism, it makes muscles firmer and fat distribution more even, thereby increasing the market value of meat products.

 

3. How to Scientifically Add Methionine to Feed?

 

While methionine is indispensable in feed, proper addition and scientific formulation are key to maximizing its effectiveness. The dosage must be precisely calculated based on the animal breed, growth stage, and feed composition to avoid over- or under-addition. Excessive methionine addition increases the metabolic burden on animals, leading to liver damage, increased nitrogen excretion, and higher breeding costs; insufficient addition fails to meet animal needs and affects growth performance. Currently, the industry generally uses lysine as a benchmark to determine the optimal methionine addition ratio to ensure amino acid balance.

 

The methionine requirements of poultry (broilers, laying hens), pigs (especially piglets and growing pigs), ruminants (cattle, sheep), and aquatic animals (fish, shrimp) vary. When purchasing, consult the factory or supplier, such as Polifar, for the best advice.

 

Regarding product selection, the main methionine products currently on the market include DL-methionine, methionine hydroxy analogs, and methionine chelates. DL-methionine offers high cost-effectiveness and wide application; methionine hydroxy analogues exhibit strong stability, making them suitable for high-temperature pelleting feed production; methionine chelates (such as zinc methionine and iron methionine) combine the nutritional benefits of methionine with mineral supplementation, and are increasingly used in high-end feeds.

 

Conclusion

Methionine's efficacy and role span the entire lifecycle of animal growth, reproduction, and immunity, making it a core nutrient for ensuring efficient and stable operation in large-scale farming. The multiple factors mentioned above collectively determine the irreplaceable role of methionine in feed additives. With continuous advancements in farming technology, the application of methionine will become more precise and efficient, providing solid support for the high-quality development of the farming industry. For farmers, a scientific understanding of methionine's efficacy and the rational formulation of feed are key to improving farming efficiency and reducing risks. Polifar consistently provides the best quality methionine, safeguarding your farming business!