Amino acids: A bright synthetic future

The use of synthetic amino acids, which according to a UN FAO report were first produced about 4 decades ago, continues to increase in feed for both broiler chickens and pigs for several important reasons.

Sustainability and flexibility

One is that they help support sustainable livestock production, which is a very large industry concern. The incorporation of amino acids can reduce the amount of crude protein and allow better nutrient utilisation, thereby reducing nitrogen pollution from animal waste. They also enable more flexibility in the replacement of imported soybeans (and soybean meal) from Brazil and Argentina where production of the crop has involved significant destruction of the rainforest. And nowadays, amino acids can be produced economically in large volumes.

Poultry is the largest market

According to a 2021 report from Research & Markets, poultry feed constitutes the largest market for amino acids among all of the feed categories. In 2020, poultry consumed 44% of the global volume, and that is expected to grow at an annual rate of 6.5% to 2026, reaching a projected 3.3 million metric tonnes. Swine is the second-largest category at 37%, with aquafeed coming in third.

Methionine, threonine and lysine

Dr Janet Remus, senior technical director at Danisco US, notes that, although there are differences in amino acids requirements for pigs and poultry (and the age of animals can also affect their amino acids needs), methionine, threonine and lysine are the 3 main amino acids used for both types of livestock.

Animal nutrition company, Evonik, projects a growth rate between 4 and 5% until 2030 for all 3 of these amino acids. Remus explains that expansion of amino acid incorporation in feed has been supported through the use of ileal amino acid digestibility measurements for various feed ingredients and as a base for nutrient requirements in both pig and poultry diets.

This system, she says, allows a more accurate assessment of animal needs for each amino acid. She also says that “with new added amino acid products coming onto the market, nutritionists will be able to further optimise dietary essential amino acids for pigs and poultry.”

Methionine demand and market growth

The methionine market grew substantially in 2019 and 2020, explains Dr Stefan Mack, head of service marketing for animal nutrition at Evonik.  This, says Dr Mack, is due to the unprecedented shift in China from pork to poultry meat consumption as a result of the devastating pig losses in China from widespread African Swine Fever.

Dr Mack notes that “as DL-methionine is the first limiting essential amino acid in poultry and only the third or fourth limiting amino acid in swine, the average supplementation rate of DL-methionine in broiler feed is often 4 times higher than in pig feed.” And, because lysine, threonine and tryptophan are the first, second, and third or fourth limiting essential amino acids in swine, demand for them has decreased over the last 2 years.

Dr Mack says valine demand has been steady as it is generally equally supplemented in swine and poultry feeds. One-third of the global methionine market is liquid methionine hydroxy analogue, reports Dr Mack, while the rest is DL-methionine (including L-methionine), “reflecting the clear preference of end-users for a more versatile and reliable product, especially in terms of bio-efficacy.”

”…methionine irreplaceable in modern livestock production.”

Looking ahead, Dr Mack says methionine demand will probably increase along with a growing global population and a corresponding expected increase in demand for affordable, safe and sustainable animal protein. “Sustainable in this context means the consequent reduction of ecological footprint, CO₂ emissions and nitrogen excretion via sustainable nutrition concepts,” he explains, “which makes methionine irreplaceable in modern livestock production.”

Protein reduction

A study ’Progress of amino acid nutrition for diet protein reduction in poultry’ published in April 2021 found that feed formulation with methionine and other amino acids can lead to over a 20% reduction in crude protein in broiler grower diets (reducing nitrogen consumption). It can also result in over a 50% reduction in soybean meal use. Dr Mack notes that, depending on what alternatives are chosen to replace soybean meal, “the use of supplemented amino acids can move in one direction or another.” For example, if more rapeseed meal is used, less methionine is needed.

Balancing protein levels

Olivier Gestin, broiler poultry manager at ADM Animal Nutrition, explains that in addition to sustainability concerns related to soybean meal, feed ingredient price volatility and the limited availability of non-GMO feed ingredients is also impacting demand for amino acids in broiler feeds.

Like other animal nutrition companies, ADM is “exploring alternatives to reduce protein levels without decreasing animal productivity and we are expanding our knowledge of the impacts of various amino acids,”

Gestin reports. “We measure animal performance, including average daily gain, feed intake and feed conversion rate, as well as the functional effects of amino acids, such as during heat stress or following vaccinations.”

Supply and performance increases

In pigs, ADM’s pig manager, Sylvain Lebas, explains that the use of amino acids has increased first because the supply available for purchase has grown. “Second is the impact on livestock performance,” he explains. “Amino acids can support efforts towards de-medication and antibiotic reduction, though we have to control the ratio of indigestible proteins provided by amino acids so that animal productivity is not lost. Third, the strong evolution of the feed market makes alternatives to soy protein more interesting. As a result, the outlook for amino acid demand remains high.”

In ADMs swine feed research, the company has an ongoing project on the valorisation of protein by pigs. “We are researching how to adjust the nutritional intake of protein to meet the animals’ needs at each life stage,” Lebas reports. “We are also exploring how a sow’s protein intake can influence the quality of its milk, which will help address the challenge of piglet welfare and digestive health in the first days of life.”