3.2 Foundations of Animal Health

Genetics

Supporting animal health through genetics includes the cultural practice of choosing livestock breeds specifically adapted to a region, climate, and forages. It also includes selecting animals that are genetically resistant to specific parasites. For example, researchers have found that breeding sheep with low fecal egg counts results in offspring with elevated natural immunity to parasites and reduced need for deworming. Ewes with lower fecal egg counts also have more IgGs passed to their lambs when nursing and these sheep develop more antibodies in response to vaccination. Genetics can strengthen animals’ natural immunity and improve disease resistance (Bowdridge et al., 2015). Practices related to genetics reflect good husbandry and enhance animal health, welfare, and production. Selective culling should be considered when certain individual animals are not performing like the rest of the herd. Paying attention to the herd and only breeding from the best animals results in a better herd (Coffey & Baier, 2012).

Nutrition

Good nutrition helps organic and alternatively raised livestock thrive. Good nutrition impacts fertility, milk or egg productivity, and body condition score (BCS). A healthy diet also contributes to the ability of the immune system to fight disease. Reminding O/A farmers and ranchers of the importance of good nutrition, including protein, is critical.

Nutrition can seem a complicated and overwhelming topic, but important for both animal health practitioners and farmers and ranchers who likely haven’t had any formal training on the subject. Most small O/A farms/ranches raise more than one species, complicating the picture. O/A farmers and ranchers identified knowledge of nutrition and local soil conditions as an important quality in their veterinarian (Steneroden, 2021). Ideally, small farms would have livestock nutritionists and soil scientists on their team. Until then, knowing their veterinarian recognizes the importance of nutrition and soil health, as it relates to organic and alternatively raised animals, meets an identified need.

As a place to start, knowing what nutrients are in the soil and forages and what supplements farms in the area use to make up for any deficiencies is valuable information for veterinarians to learn and pass on to farmers. Soil quality can vary within communities, and livestock nutritionists often suggest analyzing pastures and soil. That way, you know what farmers and ranchers might need to do regarding their livestock’s micronutrient supplementation (e.g., cobalt, zinc, iodine, manganese, iron, copper, and selenium). Knowledge of toxic plants in the area is also good information to share with farmers and ranchers. Some states may also regulate the addition of supplements to the soil for USDA-certified organic farmers and ranchers. A discussion with the organic certifier is essential before taking any steps to meet identified deficiencies.

Livestock need easy access to clean water. Water is often the last thing that crosses the farmer/rancher’s mind when considering nutrition, but it is a common problem. As an essential nutrient for life, animals must always have access to clean, fresh water. This may mean scrubbing tanks in the summer when algae forms or chipping ice off in the winter when it gets cold.

USDA-certified organic livestock have some overarching nutritional requirements. They must be fed a 100% organic diet and have a grazing requirement to fulfill this rule. Swine and poultry, who cannot get a complete diet simply by grazing/ranging, must be supplemented with organic grain or organic protein sources such as soybean meal, camelina, or rapeseed. Organic and alternative grazing/grass farming is a science and an art. The more you know and can learn about the big picture of nutrition, feed, micronutrients, forage, grazing, and soil—the more valuable resource you will be to O/A farmers and ranchers in your community.

Stress: Sources, reduction, and management

Providing a low-stress environment supports good health and welfare for livestock and poultry. Good husbandry and stockmanship can go a long way toward alleviating animal stress. Stressful situations increase cortisol—which stimulates the mobilization of energy to overcome the stressors (Fustini et al., 2017). Stress increases cortisol levels in most animals—including humans, increased cortisol levels change energy production and metabolism, and cause immune suppression. Stress can come from many sources, including the environment, handling, movement, transport, overcrowding, and predation (Coffey & Baier, 2012).

Explore each of the sections below to learn about different sources of stress.

Exposure

Exposure to the elements, including weather extremes of heat, cold, relative humidity, ventilation, and lighting, is a source of stress and, in extreme cases, increases mortality. Animals have adaptive mechanisms to deal with environmental stress, which can come at the cost of lowered production and performance. In addition, some breeds are better suited to regional conditions. For example, grass-fed South Polls are much better suited to heat than grass-fed Devons. Keeping livestock and poultry as healthy as possible through the other means presented in this section (genetics, nutrition, etc.) will help them face extremes in weather as best they can when they arise. Genetics can also be used to select for thermal tolerance of livestock. The CFR provides outdoor access requirements for USDA-certified organic livestock and poultry. Providing shelter, shade, or fans when needed, changing diet, and changing feeding time or frequency help animals adapt to heat and temperature change (Renadeau 2012). Farmers and ranchers are encouraged to review production guidelines for each line/breed they raise.

Early handling, temperament, and stress

Stressful handling encountered early in life can have a lasting impact on livestock temperament. Coupled with genetics, it can impact breeding and production. The science of early animal handling and stress goes back many years (Grandin 1989, 2017, 2021), and the research continues to identify new stressors and potential practical methods of mitigation, control, and prevention to improve livestock welfare and production (Orihuela 2021). Ongoing research on children suggest a wide range of poor health outcomes may be associated with adverse childhood events (Oh, 2018; Petruccelli, 2019). Much remains unknown, but it seems a hopeful avenue of research into environmental and temperament traits to improve livestock health (Friedrich 2015).

Movement and Transport Stress

Stress is also critical when moving animals on, around, and off the farm. Moving animals can expose them not only to disease but to a great deal of stress if they aren’t conditioned beforehand. We tend to think that livestock only want consistency, but the variety of experiences is also important. Varied routines lead to resilient animals. First, experiences with new things are especially important. Livestock are naturally curious, and when they are taught at a young age to tolerate some variation in vehicles, people who handle them, noises, or objects they might encounter, they end up less afraid of new experiences (Grandin 2017).

Varying on farm movements—from pasture to pasture, into chutes or corrals or pens, onto trailers traveling over roads is good practice. Walking animals through new areas helps them experience the environment and allows them to get comfortable. Calm handling is also very important. The best thing is to prepare them for novel experiences. Create a positive experience by using feed rewards. One research study found that offering tasty feed to sheep after they leave a handling chute made them more willing to enter the chute in the future (Hutson 2014). Keep the particular species in mind, as requirements may vary. For example, poultry may require feed withholding before transport to processing. The movement of poultry from indoors and outdoors should also be consistent and happen at dawn and dusk to reduce the stress of a change in lighting

Another critical concept in animal movement is the flight zone. Flight zones are when a person stands behind an animal in a certain position and moves toward the animal, which causes the animal to move forward in the opposite direction. You can think of flight zones as using figurative pressure to move animals forward and relieving figurative pressure when they are moving the way you want them to move. Applying pressure and removing pressure are equally important when using flight zones. Animal behavior is guided by past experiences but also by instinct. Handler awareness of flight zones is vital in keeping grazing animals calm when moving them. Knowing how to apply figurative pressure by approaching livestock to initiate movement, and just as importantly, when to decrease the pressure once they are moving forward, is the sign of a skilled handler using flight zones to their advantage.

Training livestock to tolerate different people, vehicles, and herding or diving methods will make them less stressed when encountering new people, places, and things. Whoever is driving a vehicle needs to do it safely, without abrupt movements that might cause animals to lose their footing. Studies have shown that acclimating livestock to handling facilities and transport vehicles reduced stress and improved conception rates after artificial insemination (Cooke et al. 2009). Farmers and ranchers protect their investments when they condition their livestock by controlling what they see, hear, and experience beforehand (Grandin 2017).

Predation Stress

The best way to manage predation is through an integrated approach of good husbandry and effective control methods. Small livestock (sheep and goats) are usually more affected by predation than larger animals like cows. Poultry facilities need to be predator-proofed as predation usually results in death, and many birds can be affected.

Overcrowding Stress

Overcrowding may be less of a problem with organic and alternative farms due to the requirements of certified organic farms and the preference for alternative farms for increased grazing/ranging and outdoor access. Much of the research on overcrowding is with dairy cows, but many of the principles apply to other livestock and poultry. One of the most significant risks of overcrowding in confined livestock is lameness and disease outbreaks (Cowles, 2017).

A vital thing to remember with overcrowding stress is that when facilities are overcrowded, it is harder to maintain good sanitation and, as a result, animal health. More animals mean more manure, more urine, more flies, etc.

Stressful situations increase cortisol, which stimulates the mobilization of energy to overcome the stressors (Fustini 2017). Overcrowding and competition can happen for feed, water, shelter, or shade. Overcrowding at feeding areas generally leads to competition and results in winners and losers. With overcrowded cows, for instance, some may decrease the time spent feeding, while others will eat faster, affecting absorption and digestibility (Durst, 2013). Overcrowding can alter rumination patterns, increase aggressive behavior at the feed bunk and reduce total feeding time—all these things lead to a greater risk for subacute rumen acidosis.

When it’s not the grazing season, organic livestock must have outdoor access to yards, feeding pads, and feed. The area should be large enough to prevent crowding and competition among the animals for the feed provided (Coffey and Baier 2012). If animals have horns, they will need more space in a pasture and on laneways coming and going from barns or other pastures.

Stocking density, the number of animals in a specific area for a specific period of time, is one of the most critical management decisions a farmer/rancher can make, regardless of whether they are conventional or alternative. For example, the NOSB has recommended ten sq feet per 220 pounds of adult dairy cow for an indoor bedded space and eight sq feet per 220 pounds of cow for an outdoor pen. See NOSB Stocking Density 2010 [PDF] for more species-specific examples, including poultry, sheep and goats, bison, and rabbits.

Exercise

Exercise positively affects human health, so why not other species? Being outdoors, free to express normal behaviors, and exercising lead to better livestock health. The ability to exercise improves muscle tone, relieves stress, and boosts the immune system. This can result in improved health outcomes and smoother deliveries for pregnant animals (Coffey & Baier, 2012) and may contribute to preventing health disorders after calving, such as ketosis and hepatic lipidosis, and improved fertility in dry cows (Goselink et al., 2011). Feedlot cattle put in an exercise pen (with low-stress handling) had better weight gain. In addition, daily exercise has been shown to help dairy cows reduce the effects of heat stress (Melgares, 2016). Improved claw health has also been found with outdoor access (Loberg et al., 2004). Ideally, O/A livestock should have the choice to be inside or outside, depending on the weather.