Written by: Lacie Dotterweich | October 24, 2019
Formulating diets for livestock and pets is no easy feat. What many people don’t know is that the making of animal food is a very scientific and specialized process. I had the opportunity to speak with Kate Jackson, Ph.D., and Trevor Faber, Ph.D., of Trouw Nutrition, on what goes into animal food and why.
How do nutritionists develop diets for animals?
Nutritionists think about what the goal of the diet is or what the diet is to accomplish. That will be the first consideration in formulating the diet. You must consider the animal species, life stage and production focus (i.e., dogs or cattle, babies or adults). Nutrient requirements vary greatly among species and even differ from young to mature animals. Production animal nutrient requirements vary based on their stage of production. For example, feeding dairy cows to maximize milk production is different from feeding a heifer getting ready to have her first calf. Feeding a mature sow for reproductive efficiency is different from feeding the family pet for health and longevity.
How do you know what the nutrient requirements are for the different life stages of animals?
Almost all animal species and life stages have defined nutrient minimums for protein, energy, vitamins and minerals. Those nutrient minimums or requirements are often codified in the National Research Council’s (NRC) publications on nutrient requirements, which includes most species such as horses, dairy, beef, swine, poultry and fish. There is also an NRC publication for dogs and cats, but state regulators instead follow the published Association of American Feed Control Officials (AAFCO) nutrient requirements for those species. Some species and/or life stages are not well researched and/or defined, such as exotic animals. This requires nutritionists to leverage our knowledge of nutrition, physiology and experience to approximate the best nutrient profile for those animals.
What feed ingredients are available to meet these nutrient demands? How do pet food ingredients differ from feed?
The livestock industry leverages basic feed commodities like corn, soybeans, certain co-products and roughages, with the addition of feed additives, to enhance the diet and meet production goals.
The pet food industry uses many of the same commodities as the feed industry, but also uses a wide array of non-traditional feed ingredients. Pet food diets are formulated to mimic those ingredients commonly found in a human diet, and may include such things as meat, grains, beans, fruits and vegetables.
How does the physical form of the animal food affect ingredient decisions?
The physical form of the diet must also be determined, whether it be coarse, pelleted, textured, block/tub, liquid, canned wet food or extruded dry kibble. Diets are created for the way they will be fed to the animal, through various kinds of feeders, while also considering the accessibility to different types of processing equipment. Livestock diets are made to fit the production system, while pet food diets are created either for convenience, such as dry kibble or canned food, or to meet a consumer preference, such as raw diets and minimally processed pet foods. The finished feed form can greatly dictate what ingredients are used, the ratios of those ingredients and if certain ingredients to help achieve the specific form are needed. Formulating a canned pet food is very different than formulating an extruded pet food, although they both may be fed to a dog.
Nutritionists make animal food healthy and nutritious, but what about taste?
Each species has ingredients they do and do not find palatable. For instance, cats do not show a preference for sweet, where most farm animals such as cattle, sheep, horses and swine do. If the desire is to increase food intake, using a preferred ingredient may increase intake. If the desire is to limit intake, such as when food is available all the time, then using an ingredient that the species does not like tends to restrict food intake and prevent overeating.
What role do feed additives and specialty products play in your formulations?
Some foods/feeds are designed to fit a particular niche market or health issue such as obese pets, animals with compromised immune systems or animals with special health considerations, (i.e. urinary calculi or scours). It is important to know and understand the science behind these additives, so you know when and where to use them and how much to feed to solve the health issue. In other instances, feed additives can be used to improve production performance and help keep the animal healthy if a stressor would occur.
Many considerations are taken into account when making pet food or feed. What life stage the animal is in, how the animal is being fed and what the goal of the feed is are just some of the questions nutritionists’ research in the process. From liquid feed to pet treats, every aspect of animal food is well-researched and analyzed.