Millet as a cost-effective and nutritious option for feeding livestock and poultry

Author: Hossein Shirzad, CEO of the National Livestock Support Company.

The world is facing challenges in water, agriculture, and nutrition at both national and regional levels, and food demand will increase proportionally with global population growth. Furthermore, climate change has accelerated farmers' vulnerability to reduced crop production. Drylands constitute over 40% of the Earth's surface and accommodate around one-third of the world's population. It is predicted that the productivity of these less fertile soils will increase by an average of 50 to 56% by 2100, unfortunately, with 78% of the expansion of drylands occurring in developing countries. For half a century, irrigated agricultural lands have been maximally utilized, thus the focus should shift to rainfed lands to increase grain production. Due to low fertility, utilizing drylands for producing sufficiently high-quality grains poses a significant challenge. Currently, about 50% of the world's total calorie intake comes directly from grains. Among these, rice, wheat, and maize have been the primary grains, but recently, sorghum and millet have also emerged, albeit with lesser quantities. The United Nations designated the year 2023 as the International Year of Millet. FAO has emphasized the potential of millet for both human well-being and environmental sustainability, urging further efforts in millet production due to its nutritional properties for livestock and poultry and their adaptability to climate change. Millet, as a climate-resilient crop with high nutritional value and adaptability to various growth conditions, scores higher compared to other grains like wheat and rice. Cultivating millet can be a solution to these challenges, as it can grow in shallow and less fertile soils with pH ranging from acidic (pH 4.5) to alkaline (pH 8.0) soils. Millet can thrive in both low and high altitudes, over a wide latitudinal range, in dry lands, in non-irrigated conditions, and in low rainfall regimes, with a low water footprint. Millet requires less water compared to rice and wheat. Millet varieties are highly resistant to heat (up to 64 degrees Celsius), drought, and floods, making this crop a clear choice for farmers in the era of climate change and diminishing natural resources. Millet can serve as a good alternative to wheat, especially in acidic soils.

On the other hand, millets such as pearl millet (Pennisetum glaucum) and finger millet can thrive in high soil salinity conditions. Millets, especially pearl millet and proso millet (Panicum miliaceum), have relatively low water requirements both in terms of their growth period and overall water needs during growth. Most millets mature within 60 to 90 days after planting, making them an efficient water-consuming crop. Millets belong to the C4 group of grains. C4 grains assimilate more carbon dioxide from the atmosphere and convert it into oxygen, have high water use efficiency, require minimal inputs, and are therefore environmentally friendly. Thus, millets can contribute to gradually mitigating climate uncertainties, reducing atmospheric carbon dioxide, and aiding in climate change mitigation. Millet has been cultivated as a staple food for hundreds of millions of people in Africa and Asia (especially in India, China, the Middle East, Russia, and Nigeria) for 7000 years and is now grown worldwide for feeding livestock and poultry. Estimates show that over 90 million people in Africa and Asia rely on millet in their diet. These nutritious grains contain vitamins, minerals, essential fatty acids, phytochemicals, and antioxidants that can help alleviate numerous diseases caused by nutritional deficiencies. Cultivating millet can sustainably utilize drylands and ensure future food security and nutrition. Millet is nutritionally similar to or superior to traditional cereal grains.

Additional benefits of millets such as gluten-free proteins, high fiber content, low glycemic index, and richness in bioactive compounds make them a suitable healthy food option. The average carbohydrate content of millet varies from 56.88 to 72.97 grams per 100 grams. The protein content of all millets is comparable, with an average protein content of 10 to 11 percent, except for finger millet, which has been reported to contain protein in the range of 4.76 to 11.70 grams per 100 grams in various studies. Finger millet protein is rich in essential amino acids such as methionine, valine, and lysine, with 44.7% of its amino acids being essential amino acids. The protein in proso millet is comparable to wheat, but the levels of essential amino acids such as leucine, isoleucine, and thiamine are much higher in millet. The fat content of millet, compared to wheat (2.0%) and rice (2.7%), is comparable and varies from 1.43 to 6 grams per 100 grams. Among millets, the lowest fat content is reported in finger millet, while the highest fat content is reported in pearl millet. Millet is the richest source of fiber, both in terms of crude fiber and dietary fiber, with an average content of 12.8 grams per 100 grams. Laboratory studies have shown that soluble polysaccharides in finger millet (primarily arabinoxylan and xylose) are potent prebiotics and also have wound healing potential. Resistant starch in millet aids in the production of beneficial metabolites such as short-chain fatty acids in the large intestine, especially butyrate, which helps in the proliferation of colonic cells, serving as a preventive mechanism against colon cancer. The mineral content in millet ranges from 1.7 to 4.3 grams per 100 grams, which is several times higher than main grains like wheat (1.5%) and rice (0.6%).The calcium content of finger millet is approximately eight times higher than wheat and, as the richest source of calcium (348 milligrams per 100 grams), it has the potential to prevent osteoporosis. Pearl millet is a rich source of iron, and its consumption can fulfill the iron needs of pregnant women suffering from anemia. Millet is also a good source of beta-carotene and B vitamins, especially riboflavin, niacin, and folic acid. The thiamine and niacin content of millet is comparable to rice and wheat. The highest amount of thiamine in millet, namely 0.60 milligrams per 100 grams, is found in foxtail millet. The riboflavin content of millet is several times higher than that of main grains. It has been reported that millet phenolics have antioxidant, antimutagenic, antiestrogenic, anti-inflammatory, antiviral, and antiplatelet aggregation inhibitory activities. The total antioxidant capacity of finger millet, little millet, and foxtail millet is higher due to their high carotenoid and tocopherol content, which varies from 78 to 366 and 1.3 to 4.0 milligrams per 100 grams in different millet varieties, and the beneficial effects of phenolics in diabetes due to the relative inhibition of amylase and α-glucosidase during the enzymatic hydrolysis of complex carbohydrates and delayed glucose absorption, ultimately controlling postprandial blood glucose levels. With the onslaught of detrimental consequences of extreme climate change on addressing global hunger (demand for grains) and improving farmers' income, there is a need for more sustainable alternatives in cropping patterns. Therefore, the role of millets cannot be overlooked in achieving sustainable tools for food security. Today, the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) is focusing on increasing the productivity of millets, considering finger millet (Eleusine coracana) as the sixth crop in its research agenda. Among grains, millets possess vital nutrients, and the protein content of millet grains is considered equal to or superior to wheat (Triticum aestivum), rice (Oryza sativa), maize (Zea mays), and sorghum (Sorghum bicolor).

Since 2010, scientific interventions involving the use of molecular biological markers, sequence information, establishment of mapping populations, and mutant development have led to the development and dissemination of various high-yielding millet varieties worldwide. Newly developed hybrids are resistant to diseases and have increased yield per hectare compared to their parental varieties. Millets exhibit abundant natural diversity, and the dissemination of new hybrids significantly increases this diversity. For example, pearl millet has nearly 140 species or subspecies belonging to the genus Pennisetum, and further maintenance efforts in gene bank collections have increased this number to 65,400 accessions. The largest gene pool for finger millet, comprising approximately 27% of the total 35,400 hybrids worldwide, is maintained by the Plant Genetic Resources Office in India. The Chinese Institute of Crop Germplasm Resources (ICGR) holds 56% of the germplasm resources of foxtail millet (Setaria italica), while the National Institute of Agrobiological Sciences in Japan, with 33% of approximately 17,600 gene bank accessions worldwide, possesses the largest collection of foxtail millet reserves. 

Africa accounts for over 55% of global millet production, followed by Asia with nearly 40%, while Europe constitutes about three percent of the global market. In recent years, their production has gradually declined due to market distortions, pressures and impositions from large multinational companies, neglect of the benefits of millets, and policies favoring the so-called "big three cereals" - rice, wheat, and maize. Farmers have turned to cultivating higher-income crops produced for sale for profit. They have distanced themselves from subsistence agriculture, which did not respond to changes in consumer preferences and market institutions. In addition to improving varieties, advancements in post-harvest operations have facilitated millet processing. In the past, traditional methods such as pounding were used for millet grains due to the lack of appropriate machinery, limiting the production of millet-based food. Today, modern threshing and polishing machines for millet, designed with the intervention of government organizations as well as private companies, have made post-harvest processing of millets easier, paving the way for the use of millets in developing food products. Millet cultivation can offer a comprehensive solution to current agricultural challenges and be a turning point in achieving the United Nations' commitment to ending all forms of malnutrition by 2030. The world is grappling with several health disorders and chronic diseases. According to the Global Nutrition Report in 2016, 44% of the population in 129 countries (countries with available data) experience serious levels of malnutrition, adult overweight, and obesity. An imbalanced and malnourished diet is responsible for most of these diseases. According to estimates by the United Nations Food and Agriculture Organization, approximately 795 million people (10.9% of the world's population in 2017) suffer from malnutrition. On the other hand, more than 1.9 billion adults (39% of the world's population) over 18 years old were overweight, and another 13% were reported to be obese. Obesity-related complications such as cardiovascular diseases and diabetes have been previously declared by the World Health Organization as epidemic. Therefore, the role of millets in designing modern foods such as multi-grain and gluten-free products is well recognized. Millets, due to their richness in polyphenols and other bioactive compounds, play a crucial role in slowing down fat absorption, releasing carbohydrates slowly (low glycemic index), and consequently reducing the risk of heart disease, diabetes, and high blood pressure. Millets rank sixth in global cereal production in agriculture and are still a staple food in many parts of the world. Various millet varieties are a rich source of many vital nutrients.

In essence, millets are among the earliest domesticated plants and are considered part of the "nutritious grains" group due to their high nutritional content. They are rich in vitamins and minerals such as iron and calcium. They are abundant in protein, antioxidants, resistant starch, and have a low glycemic index, which can help in preventing or managing diabetes. Millets are also gluten-free. As whole grains, millets provide various amounts of fiber. Dietary fiber plays a role in regulating bowel function, blood sugar, and cholesterol levels, as well as promoting satiety. Therefore, they offer an additional advantage in combating nutritional deficiencies in less developed countries. Including millets in the diet can help address nutritional deficiencies at their roots. In a country like Iran, millets are an ideal solution for increasing self-sufficiency and reducing dependence on imported grains. Millets require minimal inputs, are resistant to diseases and pests, and have less dependence on artificial fertilizers and pesticides. They are beneficial in livestock and poultry feed as well as aquaculture feeds, and they are more resilient to climate change compared to other grains. As global agricultural systems face challenges in feeding the growing population, flexible grains like millets provide a cost-effective and nutritious option, and efforts to promote their cultivation should be increased. This excerpt is from the opening message of the International Year of Millets 2023 (IYM) ceremony at the headquarters of the Food and Agriculture Organization of the United Nations (FAO). In addition to diversifying the food system, millets can help increase the livelihoods of smallholder farmers, including women, at the national and regional levels. Refocusing on strengthening millet production and highlighting its benefits is essential for reducing excessive reliance on conventional crops, enhancing diversified diets to address climate and global food security challenges.