Feed, Forage, and Pet Food Industries
Introduction
Animal feed is food that is given to domestic animals that are raised for purposes of procuring their products, such as eggs, meat, and milk. Examples of such animals include cattle, pigs, sheep, horses, chickens, and fish.
The two basic types are known as fodder and forage. Fodder is food that is specifically given to animals for feeding. Forage is plant material that is eaten by livestock in the field or pasture. There is some crossover in the definitions with certain plants that are cut and fed to animals (such as hay and silage) but for the most part, fodder refers to compressed and pellet feeds, oils, mixed rations, and sprouted grains and legumes while forage is plants that are specifically grazed in the field, although many forms of fodder can contain forage material in pellets and mixed rations after final product manufacturing. Such mixtures are known as compound feed or feedstuffs and are often produced as pellets or crumbles.
The term “animal feed” often refers to fodder. Animal feed and forage are an extremely important input to animal agriculture and are often the main cost of raising animals. It is important for farmers to maintain the wellbeing of the animals with balanced nutrition and diets while also minimizing costs. The process known as feed formulation is often used to determine the optimal balance of meeting nutritional requirements while optimizing costs.
Feed formulation specifically refers to the exercise of determining volumes of ingredients and additives for blending that meet the known nutritional requirements for specific species while achieving production goals at an optimized cost. It is not only essential for animal feed and forage but for pet food as well and results in compound feed products.
Pet food is a form of animal feed but is specifically intended for consumption by domestic pets. It is typically sold in pet stores and supermarkets and is specific to the type of animal, such as dogs, cats, birds, different kinds of small mammals, and fish. Pet food can be formulated with many different types of products and is specifically formulated to be the single source of nutrition for a pet. Meat in pet food is usually a byproduct from human food and is not meant to be consumed by humans.
Manufacturing is strictly regulated and varies from country to country. Demand for animal feed, forage, and pet food is steadily increasing and with increased demand, farmers and manufacturers face more challenges to produce quality products with maximum cost efficiency.
Animal Feed
Animal feed is primarily made from the cereal portion of plants and is used to feed livestock, swine, poultry, and fish. Maize and soybeans are the two most important feed grains. Other types of feed grain include wheat, oats, barley, rice, and sorghum.
It is estimated that 60% to 70% of all corn grown worldwide is used for animal feed. In addition to cereal grains, sources of animal feed include human food waste and by-products of food processing such as milling and brewing. The third tier of the Food Recovery Hierarchy is the diversion of food scraps to animals, although regulations vary from state to state. The practice saves money and is environmentally preferable to food disposal in a landfill.
One example of a prominent food processing product is soybean meal, which is processed into high protein livestock and poultry feed in meal form after crushing to extract vegetable oil. Distiller’s Dried Grains With Solubles (DDGS), which is the leftover product from ethanol manufacturing for both oxygenated gasoline and alcoholic beverages, are used as a protein-rich animal feed. Production has soared significantly with nearly thirty-eight million metric tons made in 2018-19. Whole grains can vary greatly in nutrition and quality depending on environmental factors, growing conditions, moisture content, and a number of other factors.
Compound feed that is blended from different raw materials and additives helps to account for variation in natural grains, although proper testing of the initial and finished products is essential. They are blended using feed formulation to meet the nutritional requirements of specific species and animals and can be processed into meal, pellets, or crumbles.
Compound feed can also contain premixes, which can be sold separately as well. They are composed of ingredients like vitamins, minerals, preservatives, antibiotics, and fermentation products. Premixes give farmers a tool for formulating their own rations to meet the specific nutritional needs of their animals.
Proper testing is essential for ensuring the feed meets proper standards and supplements can be added if necessary to balance the nutrients. As demand continues to increase for animal feed, there is a need for fast and cost-effective testing methods for parameters of interest to ensure proper product quality.
Forage
The basic definition of forage is plant material eaten by grazing livestock in the pasture. It is composed of plant leaves and stems of herbaceous legumes, grasses, shrubs, and tree legumes. Animals that consume forage include cattle, horses, goats, and sheep.
The term forage is often used to include hay and silage, which are not consumed in the field by animals but are a product of forage and grasslands. Hay is grass that is mown and dried for feeding purposes. It is used for animal feed when there is not enough pasture for grazing, when weather conditions make grazing impractical, and when the animals are unable to access the pasture (such as horses kept in a stable or barn). Common grasses used for hay include ryegrass, timothy, brome, fescue, Bermuda grass, and orchard grass. It is particularly sensitive to weather conditions, especially moisture. Drought conditions reduce nutritional value while excessive moisture can spoil hay before baling (as can improper drying).
Similarly, straw is the agricultural by-product from harvesting and consists of stems and dead leaves. While mostly used for animal bedding, it can be fed to animals as well. Straw is a good source of dietary fiber but has an overall lower nutritional value than hay.
Silage is fodder made from green foliage crops that are preserved by acidification and achieved through fermentation. It is produced by storage under anaerobic conditions, typically in a silo. During fermentation, the activities of natural bacteria convert some of the plant sugars into organic acids that preserve nutritional qualities. Common grass species used for silage include Napier grass, sorghum, alfalfa, maize, and sugarcane tops. Ideal conditions for making silage are a moisture content between 60% and 70% and a pH below 4.2 for wet crops and below 4.8 for wilted crops. It is typically fed to cattle, sheep, and other cud-chewing animals. It is typically not fed to horses as silage is highly susceptible to molds and consumption of spoiled or moldy silage can result in upset digestion and death in horses.
Proper testing is essential for ensuring forage meets proper standards. As demand continues to increase for animal forage, there is a need for fast and cost-effective testing methods for parameters of interest to ensure proper product quality.
Pet Food
Pet food is animal feed that is intended for consumption by domestic pets. Worldwide production is dominated by dog and cat food with annual production of over five billion pounds. Other types of pet food are for fish, rabbits, guinea pigs, ferrets, and birds. Farm animals and reptiles consume food that is more similar to traditional animal feed.
Manufacturing plants exist in most developed countries. Products are specifically marketed with attractive shapes and colors to satisfy owners with flavors added to appeal to the pets. Pet food is specifically designed to have a well-balanced nutritional content and complete diet for the animal so that the animal is healthy if only the pet food is consumed. There are products that are designed to be treats that have a high flavor content and appealing chewy texture, but such products are not meant to give the animal the full necessary nutrition for good health.
Dog and cat food nutrients include protein, carbohydrates, fats, vitamins, minerals, and water. The primary ingredients consist of meat, meat byproducts, cereals, and grains with supplemental vitamins and minerals added. Meat byproducts can include liver, kidney, and lungs. Leftover poultry and fish parts are also used.
Both dog and cat food can be manufactured as dry food or wet food. Wet (or canned) food must contain 60% to 70% moisture while dry food can contain no more than 10% moisture.
Wet and dry food have distinct benefits. Wet dog food is good for hydration while dry food aids in dental health. Wet food does tend to be more expensive for both dogs and cats but also usually has higher nutritional value. In the case of cats, wet food is beneficial for lowering the risk of urinary tract disease. It also helps with constipation and can help lower weight for overweight cats.
Dry food is efficient for providing calories to cats who are thin and have food volume limitations. It is also convenient for use in food puzzles and dispensers.
Nutritional composition and proper labeling of pet food is strictly regulated by the FDA. Competition in the pet food market is strong and manufacturers often use fancy names and other techniques to attract the attention of the consumer. The 95% rule means that at least 95% of the product must be comprised of the name on the label (such as “Beef For Dogs” and “Tuna Cat Food”) on a dry matter basis. If two products are named, the first one must be of higher composition. Counting added water, the named ingredient must make up at least 70% of the product. If the product is labeled a “dinner”, the named product must make up 25% of the composition on a dry matter basis and at least 10% including added water. Any minor ingredients added using the word “With” must contain at least 3% of the ingredient. A “flavor” product does not require a specific percentage but must contain an amount appreciable enough to be detected.
Proper testing is essential for ensuring pet food meets proper standards and supplements can be added if necessary to balance the nutrients. As demand continues to increase for pet food, there is a need for fast and cost-effective testing methods for parameters of interest to ensure proper product quality.
Feed Formulation
Feed formulation refers to the process of determining volumes of ingredients and additives to create compound feeds that both meet the known nutritional requirements of a specific species and achieve necessary production while optimizing costs and minimizing resources.
Two prerequisites are required for feed formulation. The first is knowing and understanding the essential nutrients for animals. With over one billion tons of animal feed produced worldwide annually, this can be a daunting and difficult process especially when considering that the nutritional requirement of animals can greatly fluctuate due to many factors, such as changes in genetics and the physiological state of the animal. The second prerequisite is outlining the sources and materials that meet nutritional requirements and ensuring that they are suitable for feeding animals.
Based on these two prerequisites, feed formulas can be further refined in numerous ways. These include considering the effect of processing on the quality of raw materials, the functionality of ingredients, the changing of nutrient requirements at different life stages, the dynamics of production systems, and market expectations. The output and nutritional values of animal products are direct functions of nutritional intake, especially in the case of the milk of dairy cows.
The process of feed formulation has emerged from hand calculations using the crude estimated nutrient content of raw materials to advanced computer software programs using nutrient values of ingredients and additives that are determined from advanced testing. Despite these advances, the variability of natural products and the ability to implement testing on a large scale to find variability can limit the effectiveness of feed formulation in practice. Engineers who work in feed formulation are required to have an in-depth knowledge of animal nutrition as well as the nutrient composition of the ingredients. They also must know and understand how varying proportions of ingredients can have an effect on processing, manufacturing, and animal diet. Changing ingredient proportions can affect things like feed flow through the mill, pellet quality of the diet, the response of the animal diet to additives, and gut health of the animal.
There are three different types of feed formulation: maximum nutrient formulation, lowest expense formulation, and least cost formulation. Maximum nutrient formulation is a formula that most closely meets the nutrient requirements of an animal regardless of cost. Lowest expense formulation is the least expensive to make but disregards the nutrient requirements of the animal. Least cost formulation is the feed formulation that is almost always used in practice and is designed to meet animal nutrient requirements while minimizing costs. Common least cost formulation constraints include meeting nutritional requirements, minimizing excreted nutrients, meeting dry matter intake, maximizing carcass fat quality, and optimizing feed manufacturing.
Feed formulation can also be used to improve product shelf life. As demand for animal food continues to increase, further research and development of feed formulation will continue and more advanced and improved testing methods will be needed.
Market Analysis
The global animal feed market is expected to grow from $345.4 billion in 2020 to $460.3 billion in 2026 at a CAGR of 4.9%. Factors driving the growth of the animal feed market include rapid urbanization and growing consumption of meat, milk, and eggs across many regions. The market is competitive with many major players who are implementing growth strategies and reaching out to new target markets.
Livestock population is growing and there is a marked shift from unorganized livestock farming to the more organized sector. Global population is increasing and the United Nations predicts that the global demand for food is expected to grow by over 50% by the end of 2050. It is estimated over this timeframe that global meat production will grow by approximately 70%, aquaculture food by approximately 90%, and dairy production by approximately 55%.
The coronavirus pandemic did have a moderate negative impact on the animal feed market due to disruptions in the supply chain, decrease in meat consumption due to health concerns, and the closing of malls, restaurants, and other segments of the food service sector. However, a strong recovery from this is expected in coming years with the easing of COVID-19 restrictions. Other factors that may impede growth of the animal feed market include the high price of raw materials for manufacturing compound feed and a growing trend towards vegan diets.
The forage feed market is projected to grow at a CAGR of 8.1% from 2020 to 2025. Factors driving projected growth include increased urbanization, wealth, and population growth. Grazing land is shrinking and consumers have shown a preference for organic animal feed, both of which bode well for forage market growth.
The rising demand for milk and other dairy products is also projected to fuel market demand for forage. The population of livestock and particularly cattle is growing and forage is the base ingredient for providing fiber to cattle. High quality forages, silages, and hay are essential for meeting the nutritional needs of cattle and subsequently providing quality milk.
Many of the positive and negative growth factors for animal feed apply to forage as well, such as the increased global demand for food and the trend towards vegan diets.
The global pet food market was valued at approximately $83 billion in 2018 and is projected to grow at a CAGR of 4.5% from 2019 to 2025. One factor expected to drive market growth is increased consumer awareness regarding natural and organic pet food products. Manufacturers are shifting focus from synthetic to natural products as a result.
Dry pet food in particular is projected to show a rapid growth in demand because of convenience, ease of shortage, and the reduced mess when feeding pets. Dry food also helps ensure good oral health. While wet pet food is more digestible, offers urinary tract benefits, and generally has higher nutritional value, it is also more expensive and messy.
There is also a rising trend in pet adoption, particularly of dogs. Humanization of pets is increasing, resulting in increased ownership, feeding of premium food, and giving pets both snacks for improved nutritional intake and treats to induce positive behavior.
Market demand for animal feed, animal forage, and pet food will grow substantially in coming years and manufacturers will continue to face new challenges for optimizing product quality and minimizing costs as demand for products increases.
Testing Methods and Analytical Shortcomings
Proper quality control testing of animal food products is essential for proper nutrition and presents a number of inherent challenges for manufacturers. Sound sampling methods and safe storage are important when preparing samples for analysis. Animal feed, forage, and pet food are important not only to manufacturers and producers, but to regulators, policy makers, processors, and consumers of the end product.
The food chain goes as follows for animal feed and the resulting end products: raw materials, feed mill and on-farm feed production, farm, animals and animal products, processed food, and distribution. Contamination of animal food can result in epidemics that can significantly impact the health of both humans and animals. Contaminants in feed can be both inherent or naturally occurring, such as mycotoxins, pesticides, PCBs, and heavy metals. They can also be biological, chemical, or physical in nature.
Because testing for such contaminants is done on a micro level, expensive and time-consuming tests such as HPLC and GC-MS are required. Such testing is done for harm reduction but it is equally important to properly test for nutritional parameters. In the case of animal feed and forage, it has been proven that the output of the animal product is directly linked to the nutritional composition of the food consumed. In the case of pet food, pet owners want good health for the animals and proper nutrition is essential for this.
The process of feed formulation optimizes nutritional composition while minimizing cost but sound testing methods are essential for this to happen. Examples of important nutritional parameters in animal feed include dry matter, ash, crude protein, crude fat, starch, fiber, gross energy, amino acids, fatty acids, and vitamins. Forage parameters include moisture, dry matter, acid detergent fiber, and neutral detergent fiber.
Pet food parameters are similar to those of feed and forage and ultimately, both energy and digestibility parameters for animal food are calculated from the nutritional parameters.
Testing is essential not only during the manufacturing process but also in the final product for compound feed. While effective methods exist for testing these parameters, they are often expensive, impractical to implement on a large scale, require the use of toxic chemicals and skilled labor, and can only measure one parameter at once.
Examples of this include the Kjeldahl method for protein which requires conversion into ammonia and subsequent titration and fiber analysis which requires digestion of the sample in a detergent solution and filtration. Such methods are especially ill-suited when considering the variability that can exist in samples from the same field or pasture and even among the same batch. This variability can be especially pronounced in byproducts. A study at Iowa State showed that variability in samples of Distiller’s Dried Grains with Solubles (DDGS) was five times of that in corn for fat and sixteen times of that in corn for protein.
A need exists for fast, non-invasive, and cost-effective methods for testing nutritional parameters of interest in animal food. One such method that has been implemented and has shown rapid development in recent years is NIR spectroscopy.
NIR Spectroscopy and Applications
NIR spectroscopy was first used for testing of animal food parameters in the 1980s and has emerged as a promising technique for food analysis. NIR spectrometers measure absorption bands from overtones, combinations of overtones, or combinations of fundamental vibrational motions in the near-infrared spectral region. In essence, a NIR spectrum provides a “fingerprint” of the sample.
A spectrometer can operate in reflectance mode when light reflects off a sample and is collected by a detector or transmission mode where the light passes through a sample (usually a liquid). It is especially well-suited to measure moisture and organic parameters. Because there is overlap between bands in the near-infrared region, statistical analysis is required to extract the desired information of interest. This process is known as chemometrics and uses advanced mathematical techniques to correlate NIR spectra to parameters of interest.
Samples with reference values must be provided, scanned, and calibration models built using chemometrics. Once this process is complete, the benefits are enormous and NIR spectroscopy can replace expensive traditional testing methods. NIR spectroscopy is fast, non-invasive, requires little or no sample preparation, and can measure multiple parameters from a single light measurement once calibration models are constructed.
Numerous application studies have been conducted for animal feed, forage, and pet food applications that have proved the feasibility of using NIR spectroscopy for animal food analysis. The success of using NIR spectroscopy has led to its use by multiple leading manufacturers of animal feed, animal forage, and pet food to analyze their products.
Examples of animal feed studies include dry matter, ash, crude protein, fiber, gross energy, calcium, and phosphorus in mixed feed rations, chemical composition and energy value of cattle compound feeds, metabolizable energy in corn for pigs (calculated from nutritional parameters using NIR spectroscopy), and analysis of feed meal protein materials.
Examples of forage studies include crude protein, crude fat, and fiber in soybean forage, forage quality parameters in Italian ryegrass, dry matter, crude protein, ash, and fiber in natural pasture, and variability analysis as a real-time pasture management tool.
Pet food studies include energy content of commercial dog food, nutritional evaluation of dry dog food, and chemical composition and peroxide value in unground pet foods.
The results of such studies have led to the implementation of NIR spectroscopy in practice across multiple animal food industries. The benefits of using NIR spectroscopy for animal food analysis are vast. It can be used for raw material ID and component analysis, as a tool for checking variation in shipments and within batches, and to test final product composition. Online analyzers that can measure multiple points with a single instrument can be used as a process control tool in the feed mill.
NIR spectrometers can be an aid for feed formulation by giving manufacturers the ability to make mixing adjustments on the fly. As a result, economic and return of investment (ROI) benefits, improved product quality, and maximization of resources are all proven benefits of using NIR spectroscopy.
In recent years, technological advances have made NIR spectroscopy even more feasible for real-time animal food analysis. Handheld and portable instruments have enabled analysis in the field. Many companies have pre-built calibrations for parameters of interest which reduces the labor and costs required to implement NIR spectroscopy. This is important as many companies do not have the trained personnel for extensive scientific and calibration work and require the use of NIR spectrometers to be easy and simple. There are third-party programs that enable the use of web-based technology that support database management, quality control, and trend analysis to optimize processes and protocols for animal food analysis.
The largest pet food company in the United States has successfully adapted NIR spectroscopy for determining quality assurance. Material arriving on trucks is scanned and tested inside the original package before it even enters the facility and subsequent tests are performed throughout the manufacturing process. This company has had so much success with NIR spectroscopy that they even share the technology with competitors in the interest of creating safer pet food products for the entire industry, ultimately benefitting all manufacturers, customers, and pets themselves.
Advances will continue in using NIR spectroscopy as an animal food analytical tool and more trained and qualified personnel will be required for continued advancement.
Sources
- A Guide To Livestock Feed and Forage
- Silage
- Pet Foods
- The Worldwide Animal Feed Industry is Expected to Grow to $460 Billion by 2026
- Forage Feed Market – Growth, Trends, COVID-19 Impact, and Forecasts (2021-2026)
- Pet Food Market Size, Share & Trends Analysis Report By Product (Dry Food, Wet/Canned Food, Nutritious Food, Snacks/Treats, Others), By Application (Dog, Cat, Others), By Region, And Segment Forecasts, 2019 – 2025
- Feed Formulation
- Iowa State University: Production Animal Feed Formulation Module
- Some Aspects of Animal Feed Sampling and Analysis
- Forage Testing
- Does a NIR System Provide a Low-Cost Alternative to On-Farm Feed and Forage Testing? A Techno-Economic Analysis
- Near-Infrared Technology and Safety