Barry Whitworth, DVM, MPH | Senior Extension Specialist | Department of Animal & Food Sciences | Ferguson College of Agriculture | Oklahoma State University

Foot issues are a common finding in sheep and goat operations. According to a 2011 Sheep Study conducted by the United States Department of Agriculture, footrot was found in 37.3% sheep operations. In the 2009 Goat Study, “symptoms of sores on hoof area with foul odor” were found in 6.6% of all the operations. Some studies indicate the issue increases with herd size.  

Several factors contribute to the disease, but the main bacterium involved is Dichelobacter nodosus. The bacterium is contagious and does not survive long outside the host. However, the bacterium will live for years in the feet of sheep and goats. The bacterium has many strains. In general, they can be classified as benign or virulent. Virulent strains are able to destroy the horn. Benign strains do little or no damage to the horn.

Two other bacteria may play a role in footrot. Fusobacterium necrophorum, which causes foot scald, is a common inhabitant of the digestive tract of ruminants. It does not appear to be contagious. This bacterium usually contributes to the development of footrot. Some experts believe that foot scald is a precursor to footrot. One other bacterium that may contribute to the development of footrot or footscald is Trueperella pyogenes. This bacterium may increase the susceptibility of the hoof to the other two bacteria. This bacterium is found in the environment and is associated with foot abscesses. 

The first sign of foot scald is usually lameness. In foot scald, the space between the claws may appear red, hairless, swollen, and moist. No odor is present, and the condition tends to improve with dry weather.  

In comparison, footrot will have the same clinical signs as foot scald but the signs will be more severe. The space between the claws will be necrotic and the hoof will be affected. The foot will have a foul odor. In severe infection, the hoof wall will separate from the pedal bone. The condition is highly contagious and will spread rapidly through the flock.

Both footrot and foot scald are usually diagnosed on clinical signs. The presence of a foul odor is important to separate footrot from foot scald. A definitive diagnosis is based on culturing the bacteria from the foot.

Several management tools need to be used when dealing with footrot. Studies show a significant improvement in overall herd lameness when lame animals were separated from the flock. Sheep infected with Dichelobacter nodosus that causes footrot continue to shed the organism for a period of time after treatment. If left in the herd, these animals contaminate pastures and facilities which contribute to the spread of bacteria. Lame animals need to be isolated until they are healed.

Research has demonstrated that there is a benefit to early identification and prompt treatment of lame sheep. Sheep need to be observed daily for health issues. Studies show that treatment should be initiated within 3 days of lameness. Any animal found to be lame needs to be treated promptly with a long-acting antibiotic and topical antibiotic. Their feet should not be trimmed at this time. Trimming infected feet delays healing.

Another management tool is the use of foot baths. Using a foot bath during a footrot outbreak has been found to reduce lameness. Copper sulfate, formalin, and zinc sulfate may be used in foot baths, but a 10% zinc sulfate solution is preferred. 

Lastly, significant improvement in a flock can be made by culling lame sheep. Sheep requiring 2 or more treatments should be culled. Removing chronically infected sheep from the flock reduces a significant source of the bacteria which should lower the spread of the disease. Culling will improve the economics of the flock by decreasing labor time and money associated with treating footrot. It is also recommended not to keep lambs from culled ewes with footrot for replacement ewes.

Preventing footrot begins with proper nutrition. Hoof health is influenced by minerals and vitamins. Special emphasis should be placed on ensuring adequate amounts of selenium, biotin, zinc, Vitamin A, and Vitamin E. Hooves should not be allowed to over grow. Routine trimming and examination will ensure a healthy foot. Facility and pasture management play an important role in controlling lameness as well. It was found in a study conducted in the United Kingdom that allowing pastures to rest 2 or more weeks had a high impact in reducing lameness in sheep. Facilities need to be kept clean and dry. Lambing pens need to be cleaned and disinfected between uses. Fences need to be maintained. This prevents neighboring animals from entering the farm which could contaminate the pasture with unwanted bacteria.

Footrot can be a frustrating disease. However, following the above practices should improve foot health. For more information about footrot in sheep and goat enterprises, producers should consult with their veterinarian or the Oklahoma State University County Cooperative Extension Service Agriculture Educator.

References

Reilly, L. A., Baird, A. N., & Pugh D., G. (2002). Diseases of the foot. In D.G. Pugh(Ed.), Sheep & Goat Medicine (pp. 225-227). W.B. Saunders Company

Witt J, Green L. Development and assessment of management practices in a flock-specific lameness control plan: A stepped-wedge trial on 44 English sheep flocks. Prev Vet Med. 2018;157:125-133.

By Marty New

Body condition scores of beef cows at the time of calving have the greatest impact on subsequent rebreeding performance.

One of the major constraints in the improvement of reproductive efficiency is the duration of the post-calving anestrous period. If cows are to maintain a calving interval of one year, they must conceive within 80 days to 85 days after calving. Calving intervals in excess of 12 months are often caused by nutritional stress at some point, which results in thin body condition and poor reproductive performance.

Research has shown mature and young cows that maintain body weight have ample energy reserves before parturition, exhibited estrus sooner than cows that lost considerable body weight and consequently had poor energy reserves. Body weight change during pregnancy is confounded with embryo and placenta growth. Therefore, the estimation of body fat by use of body condition scores is more useful in quantifying the energy status of beef cows. The system of body condition scoring is an excellent estimator of percentage of body fat in beef cows.

The processes of fetal development, delivering a calf, milk production and repair of the reproductive tract are all physiological stresses. These stresses require availability and utilization of large quantities of energy to enable cows to be rebred in the required 85 days.

Added to physiological stresses are the environmental stresses of cold, wet weather on spring calving cows. In normal cow diets, energy intake will be below the amount needed to maintain body weight and condition. As the intake falls short of the energy utilized, the cow compensates by mobilizing stored energy and over a period of several weeks, a noticeable change in the outward appearance of the cow takes place.

Cows that have a thin body condition at calving return to estrus slowly. Postpartum increases in energy intake can modify the length of the postpartum interval. However, increases in the quality and quantity of feed to increase postpartum body condition can be very expensive. Improvement in reproductive performance achieved by expensive postpartum feeding to thin cows may not be adequate to justify the cost of the additional nutrients.

The influence of nutrition before calving is a major factor that controls the length of time between calving and the return to estrus. Thin cows with a BCS score of four or less at calving produce less colostrum as well as give birth to less vigorous calves that are slower to stand.

The impact of quality and quantity of colostrum will effect these calves’ immunoglobulin levels, thus harming their ability to overcome early calf-hood disease challenges. It is much easier to increase condition in cows before rather than after they calve. High nutrition after calving is directed first toward milk production. Feeding cows to gain condition early in lactation therefore leads to increased milk production but has little effect on body condition.

Cows prior to calving and through breeding should have a BCS of five or higher to have good reproductive performance. First-calf heifers should have a BCS of six. Spring-calving cows are still consuming harvested forages and lactating will generally lose one BCS following calving.

Over-stocking pastures is a common cause of poor body condition and reproductive failure. Proper stocking, year-round mineral supplementation and timely use of protein supplement offer potential for economically improving body condition score and reproductive performance.

An efficient way to utilize BCS involves sorting cows by condition 90 to 100 days prior to calving. Feed each group to have condition scores of five to six at calving. These would be logical scores for achieving maximum reproductive performance while holding supplemental feed costs to a minimum.

Body condition scoring has allowed cattlemen to continually evaluate their nutritional program. By evaluating cow condition at strategic times of the year, it is possible to coordinate use of the forage resource with nutritional needs of the cow herd so supplemental feed and hay needs are reduced to a minimum.

This article originally appeared in the February 2016 issue of Oklahoma Farm & Ranch. 

Many ranchers across North Texas have discovered an easy, natural way to keep water troughs cleaner: add a few fish. It might sound like something from a backyard pond hobby, but keeping hardy fish such as goldfish or small koi in livestock troughs can help reduce algae, control insects, and even provide a little entertainment during daily chores.

The main benefit of adding fish is algae control. When sunlight hits the water and nutrients from dust, hay, or manure accumulate, algae blooms can appear quickly, especially in warm weather. Fish feed on the small organisms that make up the base of that algae growth. Goldfish, minnows, and koi are particularly effective at grazing on microscopic material and keeping buildup manageable.

Another advantage is mosquito control. In summer, stagnant water attracts mosquitoes, which lay eggs along the edges of the trough. A few small fish will eat the larvae before they hatch, breaking the cycle before it starts.

There’s also an element of simple enjoyment. Watching fish dart around beneath the water adds a bit of life to the barnyard, and they’re surprisingly hardy if cared for properly. Many livestock owners say once they’ve added fish, they never go back to fishless troughs.

Despite the practical benefits, there are some important considerations before stocking your trough. The success of fish in small water containers depends on size, sunlight, and maintenance.

Smaller troughs heat and cool quickly, so temperature swings can stress fish. Metal troughs exposed to full sun get hotter than shaded plastic or concrete ones. When possible, locate the trough where it gets partial shade and is deep enough for fish to retreat from temperature extremes.

Choosing and Caring for Fish

Goldfish are the most common choice because they tolerate temperature changes, low oxygen levels, and variable water conditions better than most species. They’re inexpensive, easy to find, and don’t require a filtration system if the water is changed regularly.

A few general guidelines make the difference between a thriving setup and a short-lived one:

Begin with only two or three fish per 100 gallons of water. Overcrowding leads to oxygen depletion, which is the main reason fish die in troughs.

Feed stores and local pet shops often sell small feeder goldfish or minnows at low cost. Avoid releasing fish from ornamental ponds or unknown sources, since they may introduce disease or parasites.

Fish should adjust slowly to temperature differences between the water they came in and the trough. Float the transport bag in the trough for 15–20 minutes, then add small amounts of trough water before releasing them.

Most fish will find enough to eat naturally — algae, insects, and organic debris. Supplementing food isn’t necessary and can actually foul the water.

While fish help limit algae, they don’t eliminate it. Every few weeks, scrub the sides of the trough lightly and refill it completely to maintain water quality. When cleaning, move the fish temporarily to a bucket with some of their old water to minimize stress.

If you use bleach, copper sulfate, or any algaecide in your tanks, the fish will not survive. Once fish are introduced, rely on natural cleaning and partial water changes instead of additives.

Most animals quickly get used to fish in their tanks and don’t bother them. If a horse or cow tends to stir the water excessively or dump feed in the trough, install a section of wire mesh or a large rock area for the fish to hide under.

Winter Care and Cold-Weather Survival

A common question is what to do when temperatures drop. In most of North Texas, you can leave the fish in the trough all winter. They tolerate cold far better than people expect.

When the water temperature falls, fish become sluggish and sink to the bottom where the water remains slightly warmer. Even when ice forms on top, they usually survive without issue as long as the trough isn’t completely frozen solid.

If your tanks regularly freeze over, here are a few tips:

Keep a small opening in the ice to allow oxygen exchange. You can gently pour a small pot of warm (not boiling) water on one spot or set in a floating object so the ice forms around it and leaves a gap.

Avoid breaking thick ice with force. The shock and vibration can stress or kill fish.

Don’t move the fish indoors unless the tank will freeze solid. Sudden temperature changes are more harmful than cold water itself.

Fish can overwinter outside just fine if there’s some depth — at least 18 to 24 inches — and no complete freeze-through. In fact, many people report their fish living for several years in the same trough, even through occasional hard freezes.

If you use a stock tank heater for livestock, that’s perfectly fine for the fish too, as long as it doesn’t raise the water temperature dramatically. They’ll appreciate the small patch of open water and the stable oxygen exchange.

During cold months, fish won’t need food. Their metabolism slows, and uneaten feed can decay and foul the water. Once temperatures climb again in spring, they’ll become more active.

Even with the best care, fish sometimes die suddenly due to poor water quality or low oxygen. Murky water, slimy buildup, or a sulfur-like smell are warning signs. Dumping and refilling the tank usually fixes the problem. If losses are frequent, check for contamination from feed, manure, or chemicals.

It’s also worth knowing that goldfish reproduce quickly. If your trough has a gravel bottom or lots of algae, you might end up with more fish than you started with by midsummer. A few extra can be rehomed in a garden pond or given away, but be careful not to release them into creeks or natural ponds — that can harm native species.

Adding fish to water troughs isn’t new, but more landowners are rediscovering its usefulness. It’s a low-maintenance, inexpensive, and surprisingly effective way to help keep tanks clearer, reduce insects, and add a little charm to daily chores.

For the most part, the system takes care of itself. A handful of goldfish or minnows, a little common sense, and routine cleaning are all it takes. Come winter, just leave them be — odds are they’ll be waiting under the ice when spring rolls around, ready to start another season of quiet work in your stock tank.

References

Texas A&M AgriLife Extension – Managing Water Quality for Livestock and Wildlife.

Oklahoma State University Extension – Farm Pond Ecology and Fish Care Basics.

Texas Parks & Wildlife Department – Small Pond and Trough Fish Management Guidelines.

North Central Texas Council of Governments – Water Conservation for Rural Landowners.

Oklahoma Department of Agriculture, Food & Forestry – Livestock Water Tank Maintenance Resources.