The extended period of drought has led to feed and water shortages for livestock. Sheep and goats may have difficulty meeting their nutritional needs, which can lead to weight loss as body reserves are depleted. During this period, most of the animals are predisposed to diseases and some die, leading to great economic loss for producers. It is therefore important to prepare animals for strategies that will help them cope and maintain body condition.
During the drought period, the demand for forage and/or water can be greater than the supply. The producer is then faced with a decision to either increase the supply of forage by purchasing hay or other feedstuffs, or to reduce forage demand by reducing the number of animals that depend on the forage. This is a tough decision to make.
Management strategies consideration during drought
Selling — There has been discussion for producers to sell off their animals. However, proactiveness and early planning could increase the options for culling animals from your flock. It is important for producers to make adequate plans to sell before animals lose body condition and market prices drop. Early sale will command higher prices before the market is overcrowded. The following factors should be considered before the producer decides to sell: the timing of the sale; condition of the stock; present value of stock; quality of stock; capacity to carry stock through; likely market demand of the stock at the end of the drought; likely length of the drought. It is advisable to first sell the aged stock particularly those with poor reproductive performance. Healthy stock should be kept for breeding purposes when the drought subsides.
Relocation — The purpose of destocking is to reduce browsing pressure on pasture. Unmanaged pasture during drought might cause long-term damage and increased recovery time due to overgrazing and overstocking. Options to minimize grazing pressures on drought-stressed pastures include relocating the animals to new grazing land with available forage or moving them to terminal markets for slaughtering, thereby providing cash for the producers to support other animals.
Early weaning and parasite control — Nursing does/ewes require higher energy and protein than dry does/ewes. Early weaning reduces nutritional demands of the doe/ewe and helps them regain body condition faster. Early weaning prepares the doe/ewe for the next breeding season leading to higher conception rates. Additionally, there is reduction in grazing pressure on pastures, and the existing forages may maintain the ewe flock. Lambs and kids should be creep fed and weaned when they reach 6 weeks of age. Nutritionally stressed animals are prone to internal parasite infestation, and it takes 10 to 12 months for many lambs to develop parasite immunity. Strategic deworming is very crucial, and producers should adopt integrated parasite management approaches during drought periods. Consult your veterinarian or your local extension office if you need further information on this approach. Producers should not allow intestinal parasites to add further stress to their sheep and goat operations during drought.
Herd grouping — Producers should consider grouping livestock based on their physiological status. Young and pregnant animals require a high plane of nutrition and should be given higher priority than the mature animals. Producers should be mindful of the high cost of feed during drought. Feeding animals based on their nutritional requirements saves money. The older, dry, and early to mid-gestation animals can be relocated to less desirable pastures with little or no supplemental feeding. Protein, mineral and vitamin supplements can be formulated for sheep or goats on medium to low quality pasture, and hay or forage should be provided free choice.
Drought feeding — The main goal of drought feeding is for survival or maintenance. The producer should employ a body condition scoring system (BCS) to determine the animals that require supplemental feeding during the drought period. Supplemental feeding is required before animals lose more than 15% of their body weight. Animals should be fed rations sufficient to maintain their weight in a condition of at least 2 to 2.5 on a five-point scale until the drought ends. The animals should be monitored closely to ensure they are not losing condition or being overfed. Controlled grazing should be employed during drought while continuous grazing should be avoided. Controlled grazing stretches forage availability and allows a better utilization of the forage.
Protein
The following steps will guide producers for drought feeding — determining the total energy and protein requirements for each group of animals; how much nutrition can the available pasture supply; select the cheapest feeds based on availability; ration adjustment monitoring to save feed cost. Sheep and goats should be allowed to scavenge low quality forage from sparse pasture if available, but care should be taken to avoid overgrazing. Supplemental protein should be provided to animals grazing low quality forage or hay or when BCS drops below 2. It is advisable for producers to perform nutritional tests on their hay. Protein concentration below 7% will have an adverse effect on the animal as the diet is unsuitable for rumen microorganisms. Animals fed low protein levels will lose weight.
Energy
In drought conditions, energy is typically the most limiting nutrient in the pasture. If this is the case, producers should feed lowest cost energy supplements to the animals. High energy grain should be introduced slowly to the flock to prevent nutritional disorders like acidosis, enterotoxemia, ketosis and urinary calculi. Feeding of 0.5 to 1.0 lb. per head per day is recommended and will reduce the grazing pressure on limited pasture. In dire situations where the pasture is depleted, animals may have to be maintained solely on supplemental feed. This will allow the pasture to recover and regrow when the rain starts. However, roughage should be provided at 3-5% of their body weight for optimal rumen function.
Minerals and vitamins
The lack of green fodder during drought may result in a deficiency of vitamins A and E. Supplementing these vitamins should be considered by supplying vitamin A-containing mineral mixture. Sodium and calcium may be needed as additional supplements in drought-stressed forages, particularly when diets consist mainly of cereal grain. Salt and mineral mixes should be provided to the animals to offset the mineral deficiency.
Monitor poisonous plants
Producers should be wary of poisonous weeds in their pasture during drought which may lead to high mortality rate. Plants that contain prussic acid (hydrocyanic acid), found in the leaves of wild cherries, peaches, plums, and other stone fruits, should be avoided. Other toxic plants include milkweed, horsenettle, black nightshade, water hemlock, mayapple, sudan grass, bermudagrass, johnsongrass, pigweed and ragweed. Consult your county extension office if unsure of weeds and wild shrubs in your pasture.
Producers should follow the local, regional, and national drought advisories for drought early warning systems. For additional information on drought mitigation strategies, please contact University of Missouri county extension offices across the state.
Heat Stress
As the summer months set in, sheep and goat producers should watch their animals for heat stress. Although sheep and goats can tolerate heat better than other livestock species, long-term exposure might have devastating effects on the health and performance of the animals.
Reduced dry matter intake during heat stress can lead to a range of negative effects on animal performance, including decreased energy intake (energy deficit), decreased body condition and potential weight loss, nutrient imbalance and reduced milk production in lactating ewes/does.
Heat stress occurs when the animals are unable to regulate their body temperatures. Animals may reach a point where they cannot dissipate enough heat to maintain body thermal balance.
Temperature humidity index (THI) is the best measure of livestock environmental stress, as it gives a more accurate measure of heat stress, Brown says. Heat stress is considered severe in sheep and goats when the THI is between 84 and 86 F. A THI above 86 F is considered extreme. The National Weather Service has forecast THI of 95-100 F within the coming weeks.
Open-mouth panting is an important visual indicator of severe heat stress in sheep and goats. Producers may employ a panting assessment to determine the level of discomfort in the flock/herd as follows:
- Mild heat stress. Animals may show mild to fast panting, but with a closed mouth. Rapid chest movements will be easily observable.
- Moderate heat stress. Animals show fast panting, progressing to mouth slightly open, but the tongue is not extended beyond the lips. Rapid chest movements will be easily observable.
- Severe heat stress. Rapid, open-mouth panting will be seen, with the neck extended, head held up and tongue extended.
- Extreme heat stress. Open-mouth panting will be seen, with the tongue fully extended and the head often lowered. Deeper breathing will occur, with a reduction in the panting rate for short periods.
Other signs to look for are crowding at water source, shade seeking, increased respiratory rate, immobility or staggering, and drooling.
Producers should adopt a multidisciplinary approach to lessen the impact of high heat and humidity. Consider these strategies:
- Access to plenty of clean, cool water is extremely important during hot weather. On average, sheep or goats will drink 1-2 gallons of water per day. Lactating animals will drink more. A research report from University of Maryland Extension showed that sheep drink 12 times more water when it is dry and the temperature exceeds 100 F.
- Sheep should not be sheared in extreme heat. A thick fleece acts as insulation against temperature changes. It has been documented that sheep with a 1-inch fleece tolerated higher temperatures than sheep with less wool.
- Livestock should not graze during the heat of the day. Encourage early morning or late evening grazing to maintain normal feed intake.
- Provide nutrient-dense diets during periods of high heat and/or humidity. Less body heat is produced when livestock are fed grain rather than poor-quality forages. Feed additives such as live yeast and vitamins C and E are essential to offset the impact of heat stress.
- Provide shade in the form of Quonset huts, polydomes or carports. Mature trees are a low-cost option and provide excellent shade and shelter for grazing animals. When livestock are housed in barns, an evaporative cooling system with water in the form of mist or sprinkling is recommended, but do not let these areas become wet and muddy.
- Monitor for signs of distress. Clinical signs of heat stress include continual panting, rapid breathing, weakness, inability to stand and rectal temperature over 105 F. Death may occur with a rectal temperature over 107 F as the animal’s cells begin to degenerate.
References
- Drought Feeding and Management of Sheep. A guide for farmers and land managers. Published by the Victorian Government Department of Primary Industries Catchment and Agriculture Services RMB 1145, Chiltern Valley Road Rutherglen, Victoria 3685 Australia.
- Drought Management Strategies for Sheep and Goats. Alabama A&M & Auburn Universities Extension. UNP-2112.
- Meat Goat Production Handbook. American Institute for Goat Research. Langston University.
- Mulisa Faji Dida. Strategies for Goat Feeding and Management during Drought. Goat Science – Environment, Health, and Economy. IntechOpen. Ethiopian Institute of Agricultural Research, Holetta Agricultural Research Center, Holetta, Ethiopia.
- Signs and management of heat stress in sheep. Agriculture Victoria, May 2021.
- Jaelyn Whaley (2024). Heat stress in small ruminants. SDSU Extension.