Author: Susan Kerr, Washington State University
Publish Date: Spring 2009
Well, not exactly, but that is how the poem goes… Actually, February and March tend to be the cruelest months for livestock. This article will help livestock owners appreciate why this is true and how they can mitigate late winter’s impact on livestock health.
Green Does Not Always Mean GO
Livestock producers eagerly await spring pasture greenup so they can turn animals out and stop feeding hay. However, it takes several weeks after initial pasture greenup before fresh forage contains adequate concentrations of essential nutrients to meet animals’ requirements. Early forage growth is called “washy,” meaning it has high water content.2 Livestock forced to subsist exclusively on low-nutrient washy pasture become “washy,” too, and produce copious amounts of diarrhea. The moral of the story: keep feeding hay until pastures come on sufficiently, i.e. 6” to 8” in height. Supplemental hay and/or grain may be needed to meet the nutritional demands of grazing livestock in some situations. Before spring turn-out, horse owners should educate themselves about the danger of laminitis (“founder”), which can be caused by grazing.
The Pull Test
Turning livestock out to graze too early in the spring is not good for pasture health, either. Animals should not be allowed to graze until pasture forage passes the “pull test.” This involves grasping a forage plant and pulling; if a human can uproot plants by pulling, livestock can do so by grazing.3 Although there are multitudes of managerial errors that can reduce pasture performance, completely uprooting pasture plants eliminates production. Soil runoff, noxious weed invasion and water quality degradation ensue, along with increased input costs and other negative impacts on profitability.
Wet soils can be damaged and compacted by livestock activity, especially heavy animals such as horses and cattle. Ruts caused by hoof imprints can make pastures rough, uneven and dangerous when the soil dries. Compacted soils are less productive because plant roots have difficulty expanding for nutrients and water does not permeate non-compacted soils well.3
Heads Down, Stomachs Empty?
Good managers take time to observe livestock behavior. Observation helps identify problems with individual animals as well as whole-herd issues. For example, if all animals always have their heads down grazing and are never observed lying down, ruminating, sunning themselves or playing, they are probably hungry and constantly eating what little forage is available as soon as it appears. As you can imagine, this is not good for pasture health, either—hungry grazing animals re-graze what little re-growth occurs immediately, thereby reducing plant root development, vigor and longevity. Close grazing of early spring pasture growth also makes ingestion of parasite eggs and larvae more likely.
Death from Starvation
Ironically and tragically, animals can starve to death even with a full stomach. If they have not received adequate quality and quantity of nutrition throughout the winter, livestock will gradually deplete their fat stores of energy. By late winter, these stores are gone and the body must now degrade its own muscles to meet critical energy demands. If proper nutrition is not provided in time, this process is fatal.
Tremendous loss of body weight and condition can go unnoticed due to heavy winter coats/fleeces or poor monitoring by managers. Body condition scores must be monitored regularly throughout the winter to prevent the unwanted surprise of late winter starvation deaths.
Body Condition Scoring
Body Condition Scoring (BCS) is a hands-on, objective way to assess and monitor an individual animal’s fleshiness and fat stores. Muscle and fat covering of certain body landmarks are palpated and animals are assigned a score using either a five-or nine-point scale. In essence, scores equate to degrees of “thin,” “moderate” or “fat.”
Several good BCS resources are listed at the conclusion of this article. Others can be found by conducting an Internet search using the terms “body condition scoring” and the species of interest (horse, goat, sheep, cattle, etc.). BCS can be used to group animals for feeding, monitor the progress of conditioning in individual animals, assess nutritional programs and determine the impact of parasites, weather, disease and other parameters on livestock condition.
It takes about six weeks to move up or down one condition score. Noticing a BCS of 2 in a beef heifer in March means it will take three months to get her into the minimum condition she should be in time for breeding. It would have been preferable to realize she was slipping from a 5 to a 4.5 in December, increase the energy content of her ration and score her 5 in January, February, March and right up to breeding time.
Identify the Cause
What can you do if it is late winter and your animal is in poor body condition? First, ask yourself these questions to determine why body condition is low:
Is there an underlying health issue such as bad teeth, parasitism, cancer, etc.? Lice are a very common problem in late winter. A lice infestation can cause loss of livestock body condition through the lice’s parasitic actions and the host’s response—time and energy spent scratching instead of eating. A veterinarian may need to determine the cause of poor body condition.
- Is there a social or behavioral issue such as an aggressive animal taking food away from timid animals? Re-grouping, isolating or even culling certain animals may be necessary.
- Is there enough feeder space and can animals of all sizes access food in the feeder? Lack of sufficient feeder space is a very common reason for weight loss or poor performance in timid or small individuals.
- Is there enough quantity and quality of food? A feed analysis will determine if feed quality is sufficient for animals’ needs. Your Extension educator can help determine if animals have a balanced diet and are receiving enough food. Extension personnel can also advise you regarding feeding methods that result in less wasted feed.
- Have environmental conditions been particularly stressful? Chronically cold and wet conditions drain calories away from animals. Provide opportunities for them to get dry and out of mud and wind. Cold snaps can increase maintenance energy requirements three-fold, so give livestock more energy during cold spells to prevent loss of condition.
Ensure Energy In > Energy Out
After determining why body condition is low, focus on reducing energy loss by addressing its cause; it is also essential to increase nutritional energy to improve body condition. Here’s an example: an elderly but otherwise-healthy horse is in poor body condition due to worn teeth and cold weather. A concerned caretaker could carefully increase the calories in the horse’s diet through a variety of means and/or reduce calorie loss by providing shelter and or a blanket. The animal should be required to do little work and its body condition re-assessed often
Various approaches can be taken to increase the energy content of a ration. If the animal has not been receiving an energy concentrate such as grain, a high-energy feed could be added to the diet. If the animal has been receiving an energy concentrate, the amount fed could simply be increased. If the animal is already consuming the maximum amount of dry matter daily, an energy-dense portion of the diet will have to replace some of the less energy-dense portion of the diet. All changes should be made gradually to avoid digestive disruptions.
Address underlying health issues, too. If sore feet prevent an animal from moving and eating enough food, correct the foot problem. If a horse’s teeth have uneven wear, have corrective dentistry performed on the horse. If an animal is infested with lice, use an approved and effective de-lousing product on all animals of that species; follow label directions and re-treat if indicated. A quantitative fecal examination will help determine the level of internal parasite load so managers can make treatment decisions.
Although it is not intuitively obvious, late winter/early spring is when most cases of livestock starvation occur. Routine monitoring of body condition scores, understanding of animals’ nutritional requirements, attention to environmental factors, assessment of health issues and respect for pasture conditions will help prevent management-related causes of ill thrift.1. “The Waste Land” by T. S. Eliot. 2. “Sheep Production and Management,” 100B-15, by C.P. Mathis and T. Ross, http://aces.nmsu.edu/pubs/_b/100B15.html. 3. “Pasture and Hayland Renovation for Western Washington and Oregon,” EB1870, by S.C. Fransen and M. Chaney. http://cru.cahe.wsu.edu/cepublications/eb1870/eb1870.pdf.