Nutrition preparing and food borne disease treatment of sheep

13/10/2022

TREATMENT of Rumen acidosis
If acidosis is suspected, then high concentrate diets should be changed to increase intake of roughage of an adequate fibre length. On ships this involves replacing pellets with hay or chaff. Animals should be encouraged to maintain adequate fluid intake. Animals with mild to moderate acidosis will often recover within a few days following dietary change.
Infusion of alkalinising agents (magnesium hydroxide, sodium bicarbonate) into the rumen might be considered in early cases. Administration of antibiotics may provide protection against secondary infection. Transfer of >3 L, preferably 8 to 16 L, of rumen fluid from a healthy donor may be beneficial to reactivate the rumen and stimulate digestion and eating. Development of mycotic infection of the rumen wall may cause relapse over coming weeks and then the prognosis is grave.
Affected animals may also benefit from administration of antibiotic (procaine penicillin) to minimise the risk of complications associated with proliferation of gram-positive bacteria.
If feeding restricted fodder in a shipboard environment, consider feeding smaller feeds more frequently across the day.
If acidosis is suspected, then high concentrate diets should be changed to increase intake of roughage of an adequate fibre length. On ships this involves replacing pellets with hay or chaff. Animals should be encouraged to maintain adequate fluid intake. Animals with mild to moderate acidosis will often recover within a few days following dietary change.
Infusion of alkalinising agents (magnesium hydroxide, sodium bicarbonate) into the rumen might be considered in early cases. Administration of antibiotics may provide protection against secondary infection. Transfer of >3 L, preferably 8 to 16 L, of rumen fluid from a healthy donor may be beneficial to reactivate the rumen and stimulate digestion and eating. Development of mycotic infection of the rumen wall may cause relapse over coming weeks and then the prognosis is grave.
Affected animals may also benefit from administration of antibiotic (procaine penicillin) to minimise the risk of complications associated with proliferation of gram-positive bacteria.
If feeding restricted fodder in a shipboard environment, consider feeding smaller feeds more frequently across the day.

13/10/2022

CLINICAL SIGNS AND DIAGNOSIS of Rumen acidosis
Clinical findings and examination of feeding history and feed should raise suspicions. Bubbly diarrhoea can indicate acidosis, as it is a sign that feed is passing through undigested and there is fermentation occurring in the faeces.
Clinical findings and examination of feeding history and feed should raise suspicions.
Mild acidosis is associated with watery faeces accompanied by temporary inappetence. Increasing severity is evident by depression, dehydration, absence of ruminal movements, weak pulse, slow capillary refill, subnormal temperature, diarrhoea, and colic. Some animals may later develop laminitis or liver abscess.
Animals that survive the acute illness may still die within days due to kidney failure, fungal rumenitis or peritonitis.
At necropsy, the rumen is distended with pellets and fluid. Note that sloughing of the rumen mucosa is a normal post-mortem change occurring within an hour of death and should not be regarded as evidence of rumenitis or excessive grain feeding unless associated with inflammatory change.
Urine test strips or specific test strips may be used to test pH of rumen fluid. Normal rumen pH is >5.9 and acidosis should be suspected if the pH is less than5.5

13/10/2022

Rumen acidosis is most likely to occur shortly after animals consume excessive amounts of grain starch. This is most likely to occur soon after animals are introduced to pellets, or when pellet feeding is re-commenced following an interruption. Limited or no access to roughage of an effective fibre length means that stock will spend less time chewing and will produce less saliva, which results in reduced ingestion of bicarbonate and phosphate buffers normally supplied to the rumen in salivary secretions. Rapid fermentation of starch causes high levels of lactic acid to form quickly in the rumen, killing essential gut microflora, damaging the mucosal lining, and drawing in body fluid. This leads to rumen stasis, dehydration, and diarrhoea. Severely affected animals may develop systemic acidosis, abdominal or systemic infections, and laminitis. Animals may die either acutely due to overwhelming acidosis or as a result of secondary complications.
Large, strong, young animals with excellent appetites are more at risk. Rapid engorgement of a ration due to hunger or competitive feeding will predispose stock to rumen acidosis. If a single animal is showing clinical signs of acidosis it will indicate a high probability of subclinical acidosis in the rest of the herd.

13/10/2022

Control and Prevention of Ruminal Acidosis
Fresh, clean water should be provided at all times and changes in feeding must be introduced gradually to allow the rumen papillae to adapt. Home rations should be mixed thoroughly to prevent selection by the animals. Grains should be matured before inclusion and should preferably be fed in the whole grain form to sheep.
Tannins may be effective for slowing ruminal disappearance of barley to improve starch utilization by ruminants (Martínez et al., 2005, 2006). The addition of live yeast may also be effective in reducing acidosis

13/10/2022

Ruminal Acidosis is often caused by sudden changes of diet, such as the introduction of concentrates in late pregnancy, altering the composition of micro-organisms in the rumen . In North America ruminal acidosis is frequently seen in feedlot lambs and lactating or pregnant ewes that have experienced rapid changes in their ration (Wolf, 2007), but it is unlikely to be seen in extensive grass-fed systems. In Mediterranean countries concentrate-based diets lead to cases of sub-acute acidosis (Blanco et al., 2015)
The rumen becomes more acidic than it should because concentrate-based diets increase volatile fatty acids production in the rumen, increasing the fraction of propionate and lactate which lowers the rumen pH (Enemark, 2008). An acidic rumen leads to inflammation or rumenitis (Patra et al., 1993; Piercy and Kemp, 1990). This in turn causes diarrhea, dehydration and sometimes death. The energy metabolism in the liver of the animal may also be altered due to a limited availability of carbohydrate substrate
Clinical signs of mild sub-acute cases are diarrhea, but with continued appetite. In more severe cases animals are depressed, they stop eating and are often found standing or lying with ears down and grinding their teeth, which is indicative of abdominal pain. Temperature is low, with rapid heart and respiratory rates and shallow breathing
If animal health is threatened by a disease, as in the case of rumen acidosis, the risk of associated disorders increases for example, parakeratosis-rumenitis, liver abscesses, laminitis (Penner et al., 2011) and blood cell counts, especially leucocyte counts, and their response to stimuli (lipopolysaccharide (LPS), endotoxins) can be modified, thereby compromising the animal’s immune response

13/10/2022

Grain overload is also known as acidosis or grain poisoning. It occurs when cattle, sheep or goats eat large amounts of grain, and can result in acidosis, slowing of the gut, dehydration and often death. Veterinary treatment is required for severe cases.
What is grain overload?
Grain overload (acidosis, grain poisoning) occurs when cattle, sheep or goats eat large amounts of grain. The grain releases carbohydrate into the animal's rumen and this rapidly ferments rather than being digested normally. Bacteria in the rumen produce lactic acid, resulting in acidosis, slowing of the gut, dehydration and often death.
What causes grain overload?
Wheat and barley are the most common causes of grain overload, but it occasionally occurs with oats and lupins. Crushing or cracking of grain by a hammermill increases the likelihood of grain overload, because these processes result in quicker release of carbohydrates.
Cases are often seen when:
stock are suddenly grain fed without being gradually introduced to the grain or pellets
there is a sudden change in feeding regimen or in the grains being fed
stock graze newly harvested paddocks (where there may be spilled grain or unharvested areas)
stock get unplanned access to grain or pellets, such as around silosWhich classes of stock are affected?
Cattle sheep and goats of any age can be affected if they eat more grain than they can digest normally.
Signs of grain overload:
depressed appearance
lying down
diarrhoea
dehydration and thirst
bloating (of the left side of the abdomen)
staggery or tender gait and 'sawhorse' stance
deaths.
What are the treatments for grain overload?
Consult a veterinarian for a treatment plan, as treatment will vary according to the severity of the disease. Treatments include intravenous fluids, drenching with bicarbonate solution or milk of magnesia, intraruminal antibiotic injections, thiamine or steroid injections, and surgery for very valuable animals.
Following grain overload, the rumen lining takes up to six weeks to repair, so recovering animals will show poor growth rates during this time.
Some animals may develop secondary infections, including abscesses in the liver and other organs. These animals tend to become long-term poor doers and may need to be culled.
Welfare
Animals that appear very depressed after getting sudden access to bulk grain, and which are not immediately treated, will usually die. It is advisable to discuss individual animals affected like this with your private veterinarian or your local Department of Primary Industries and Regional Development, Western Australia (DPIRD) Field Veterinary Officer as many of these should be euthanased.
How can I prevent grain overload?
Grain overload can be prevented by gradually introducing animals to grain or pellets. The amount of grain and the time taken to adapt sheep or cattle to grain depends on:

availability of hay and other feed
time of year
type of grain being fed
aims of feeding (such as for weaners for sale or for lactating ewes).
Specific antibiotic products that selectively reduce the numbers of acid-producing bacteria in the gut are available on prescription from veterinarians. These make it safe to introduce grain more rapidly without a long conditioning process.

Some useful guidelines for preventing grain overload in stock are:

Use oats and lupins in preference to, or before transitioning to, wheat or barley.
During the introduction phase, feed grain daily.
Introduce oats to sheep by starting with 50 grams on the first day, followed by increases of 50g per head per day until the required ration is reached.
Ensure sheep always have access to roughage as well as fed grain.
Introduce oats to cattle by starting with 500g per head per day, followed by increases of 500g per head every fourth day until the required ration is reached.
When feeding grain to cattle for production ensure a good quality source of hay or silage is always available and that it makes up at least 20% of the ration (unless feeding a complete ration where the roughage and grain are mixed).
To transition to wheat or barley from oats, increase the wheat or barley portion by 25% of the oat ration every five days over 16 days. For example, if the current oat ration is 500g, start by adding 125g of wheat or barley to every 375g of oats.
Monitor your herd or flock for signs of scouring, depression, lethargy and lameness, which will indicate that the amount of grain being fed is being increased too fast.
Check pulpy kidney vaccinations are up to date and vaccinate if necessary before grain feeding.

13/10/2022

Processing' means milling or rolling grain. It is also inferred by cracking, grinding, hammer-milling and so on. Generally, it can be assumed that processing adds about $10 per tonne to the diet cost, due to labour, power use and machinery upkeep.
Sheep are ruminant animals; they are designed to eat forages, fermenting them in the first of four stomach compartments known as the rumen. The rumen is not an acidic stomach as is ours. It uses bacterial fermentation and requires a neutral pH, or a balance between acidity and alkalinity. To accomplish this, sheep excrete a buffer, (bicarbonate) from the salivary glands while chewing their cud. Thus, cud-chewing (rumination) promotes saliva production and rumen health. Chewing is good! So, coarser grains are better in most cases, as this promotes rumination and extends the amount of starch available over a longer period. This helps prevent acidosis - a condition to be avoided, where the rumen becomes acidic. In sheep, whole grains are sufficiently large to be ruminated and chewed, so they do not require processing, except in the following cases;
In small lambs(creep feed). Processing grains stimulates intake, as the smaller particle size is more palatable to lambs. For lambs less than 20 lbs. live weight, process all grains. For lambs less than 50-60 lbs, corn should be processed. Once they exceed this weight, all grains can be feed whole without compromising intake, and reaping the benefits of whole grain.
When energy When energy needs to be available quickly in the rumen. For the rumen to use the soluble nitrogen in silages (especially alfalfa haylage), grains can be processed to speed the availability of energy to the rumen microbes so that they might utilize the silage nitrogen for protein production. There is debate as to whether this is necessary, but the approach has been used 'successfully' by dairy farmers in the past, and by some shepherds. Consult with your flock nutritionist before proceeding with this approach, as it is intentionally contrary to the above guidelines, and useful only in specific cases!
Recent research from University of British Columbia (Dr. Steve Mason, Livestock Nutritionist) indicates that growth rate and feed efficiency were improved when whole grain was fed to lambs compared to pelleted or mash feeds.

Much of the advantages came from higher dry matter intake and overall feed "acceptance" by the lambs. Feeding whole grain offers the following advantages:
Feed intake may increase by 25% while feed utilization remains similar for whole and pelleted grain.
Growth rate is up to 20% faster with whole grain.
Feed conversion is improved by up to 10%.
Whole grain produced a firmer and more desirable fat finish on the carcass.
Whole grain does not cause damage to the rumen.
When feeding whole grain, there is less probability of off feed problems caused by acidosis.
When forage is fed with the grain, additional evidence shows that whole grain is preferable to pellets. Feed intake is again higher, and the utilization of the forage is improved. The choice of grain will vary by location and in most northern regions, mixed grain or barley is probably the best for lamb feeding.
As always, review your feeding program with a nutritionist and make feed changes slowly. Evaluation of the protein content and quality is also important.
What's the Bottom line?
Avoid processing unless required. For most cases, this means processing only lamb rations. You don't need a mill to feed sheep, and feeding whole grains actually improves rumen health in your flock as compared to processed feeds.

13/10/2022

Lamb creep feeds need to contain something to help control or prevent coccidiosis in lambs. Both Decoquinate (trade name, Deccox) and lasalocid (trade name, Bovatec) are approved for prevention of coccidia in sheep. A Veterinary Feed Directive (VFD) is not required for these products.
A smaller pellet is currently the most popular choice for creep feeding lambs. The smaller pellet is preferred by the younger lambs and prevents the sorting that is often found in a texturized or mixed feed. Some producers will make their own lamb creep feed rations on farm. The correct sheep feed pellets, maintaining consistent particle size and too many fines are all challenges with on-farm mixing.

13/10/2022

Choosing the best creep feed for lambsA trough of Purina lamb creep feed starter hangs on a fence in a pen.
A lamb creep feed ration should be between 15-20 percent crude protein, 2-5.5 percent fat and a 2:1 calcium-to-phosphorus ratio. The specific feed that works best will be determined by the genetic make-up of the sheep and the intended market. For example, purebred breeders may like a 20 percent creep pellet for added growth. Club Lamb producers like added fat to produce bloomier lambs at sale time. Some producers like the consistency of feeding a 16 percent to both the ewes and lambs and through the lambs’ grower phase.

13/10/2022

Food-producing animals are the major reservoirs for many foodborne pathogens such as Campylobacter species, non-Typhi serotypes of Salmonella enterica, Shiga toxin-producing strains of Escherichia coli, and Listeria monocytogenes. The zoonotic potential of foodborne pathogens and their ability to produce toxins causing diseases or even death are sufficient to recognize the seriousness of the situation. This manuscript reviews the evidence that links animals as vehicles of the foodborne pathogens Salmonella, Campylobacter, Shiga toxigenic E. coli, and L. monocytogenes, their impact, and their current status. We conclude that these pathogenic bacteria will continue causing outbreaks and deaths throughout the world, because no effective interventions have eliminated them from animals and food.

28/07/2022

Thin ewes, with body condition scores of less than 3, should gain weight to maintain their pregnancy and target a body condition score of 3 to 4 by the time they lamb. This can be accomplished with high-quality forage or by supplementing their diet with concentrates (i.e. grains). More information about body condition scoring sheep can be found at the Penn State Extension fact sheet: Body Condition One More Evaluation Tool .
During early gestation, defined as the first 15 weeks of pregnancy, fetal lamb growth is minimal and a ewe’s nutritional requirements are similar to her maintenance requirements. Thus, during early gestation, ewes can consume average quality pasture or stored forages. However, nutrition does play a critical role in ensuring embryonic survival. Therefore, a ewe’s diet must at least meet requirements in order to ensure adequate nutrients to support placental development. Drawing from the previous example of body condition, a ewe in early gestation should be maintaining body condition, not losing condition. Monitor ewes every two weeks to ensure condition remains adequate.
Much of the fetal growth occurs during the last third of gestation, the four to six-week period at the end of the pregnancy. During this time, the ewe should be supplemented to meet the increased nutrition demands for the added fetal growth and to allow her to produce adequate quality and quantity of colostrum, the antibody rich milk consumed by the lamb in the first twenty-four hours after birth. Energy consumption during the last third of pregnancy will affect the size and vigor of newborn lambs as well as ewe milk production. Increasing energy consumption will also prevent pregnancy toxemia. Pregnancy toxemia is a condition that occurs when pregnant ewes are using more nutrients than they are consuming, thus they are drawing heavily on body reserves. In general, energy requirements for a ewe carrying a single lamb increase approximately 50% over her maintenance requirements, while energy requirements for a ewe carrying twins increase 75%. Therefore, during the last four weeks of gestation, ewes should consume 59 to 65% TDN, 10.5 To 11.5% crude protein and approximately 3.5 to 4.5 lbs. dry matter.
Due to the increased nutrient requirements during the last four to six weeks of gestation, ewes may not be able to consume a large enough quantity of forage, particularly when carrying more than one lamb. Body capacity becomes an issue as the lambs increase in size and there is less room for the stomach to expand for forage consumption. Therefore, most sheep producers supplement ewes with some type of grain in the last trimester to increase energy consumption and sometimes protein concentrations in the daily ration. The rate at which producers supplement grain varies from one half to one pound per ewe each day, depending on ewe size and genetics. In colder climates and with ewes that often produce triplets, the supplemental feed should be started four to six weeks prior to parturition (birth of the lambs). Always remember that any ration changes should occur gradually over a period of several days.
During the winter months, producers should increase the amount of feed offered to all sheep, regardless of pregnancy status, to compensate for the additional energy the animal needs to keep warm in cold temperatures. The lower critical temperature at which rations should be adjusted varies based on fleece length. The lower critical temperature for a freshly shorn sheep is 50 degrees F, while the lower critical temperature for a sheep with a 2 ½ inch fleece is 28 degrees F. (Source: Sheep Production Handbook). Wind chills also contribute to additional energy needs and should be accounted for when making feeding adjustments.
Fleeced animals can perform very well in cold temperatures. However, energy requirements increase greatly with cold rains (temperatures in the 30’s and 40’s) and ice. A wet fleece can drain nutrient reserves of an animal. Thus, if possible, bring animals indoors or provide additional shelter in the event of cold rain or ice storms.

28/07/2022

Pasture height is critical for sheep health to prevent infections with internal parasites. Most parasite larva can be found in the first two inches of forage growth. Therefore, pasture forages should be maintained at four inches or higher to prevent infection. Pastures can also be rotated every four to six days, or less, to allow grazing sheep to stay ahead of a parasite's life cycle. For fall grazing, sheep can be rotated through crop residues or through hay fields. This will provide a "clean" pasture area with no parasite larva present while still providing adequate nutrition. For crop residue fields, be sure to subdivide the fields, using temporary fencing, so that sheep better use all of the residues without wasting them by trampling and f***l contamination.
During the fall of the year, the grazing season can also be extended with stockpiled forages. These pastures have basically been saved for fall grazing by keeping animals off these fields for several months and allowing forages to regrow. Begin stockpiling forages around the middle of August to the first of September to be grazed in November and December. The quality of fall forage should meet the nutritional needs of sheep during early and mid-gestation. Keep in mind that although tall fescue is the most common plant species used for stockpiling, this plant species is not very palatable for sheep until after a hard frost. Other grass species can work well for stockpiling but will not retain their nutrient concentrations as far into the winter season as tall fescue.
Regardless of when and where you graze, the forage quality must meet the nutrient requirements of the sheep. Forages in a growing vegetative state, without any seed heads, are better quality and contain more protein and carbohydrates to supply energy. Producers should clip seed heads to keep the forages in this vegetative state throughout the grazing season, as forage growth will slow when maturity is reached, and seed heads develop.
If adequate quantity and quality of forage is not available to graze, average quality to high quality hay should meet the nutritional needs of pregnant ewes. The table below outlines the changing nutrient requirements for protein, energy, and dry matter intake through various production stages for a 150 lb. ewe pregnant with a single or twin lambs. Dry matter intake is the amount of feed an animal consumes with all water removed.

28/07/2022

Feeding the sheep flock is a critical aspect of sheep production and management. Good nutrition influences the overall health status of the entire flock, as well as the growth performance of lambs. This is particularly important throughout the breeding season and pregnancy. Sheep need to eat a balanced diet in order to be healthy and productive.
Proper nutrition starts with the six classes of nutrients. These six classes of nutrients include water, carbohydrates, lipids (fats), protein, vitamins, and minerals. The proper balance of these nutrients can be achieved with a wide range of feed ingredients. A well-balanced diet during pregnancy will help ensure embryo survival and can also lead to healthy and vigorous lambs at birth.
Water is by far the most essential "nutrient" in a sheep diet. Fresh, clean water should always be available. Stale or dirty water will lead to decreased water intake, which ultimately will decrease feed intake. Decreased feed intake will decrease lamb growth and could impact pregnancy status of ewes. Water tests should be conducted periodically. Water can impact the absorption of another essential class of nutrients, minerals. Water concentrations of sulfur and other potentially toxic minerals should be evaluated. Inadequate water intake can cause dehydration and impact an animal's ability to excrete waste. Be sure to plan for increased water intake when the temperature is above 70 degrees F and during very cold temperatures. Sheep normally consume between one half to one and a half gallons of water per day depending on the temperature and humidity, and their body size and production status.
The other five nutrients, carbohydrates, fat, protein, minerals, and vitamins, as stated previously are met through a variety of feed stuffs. The most common feed stuffs to meet the nutrient requirements of sheep for these essential nutrients are discussed mainly as ingredients. However, it is important to bear in mind that the daily requirements of sheep are only for the nutrients, not necessarily every ingredient discussed.
Pasture is an excellent source of nutrients for the sheep flock and is often one of the cheapest sources of feed for most operations. When grazing sheep, there are fundamental objectives that producers should keep in mind to maintain pregnant ewe health and meet her nutritional needs. Good quality pastures often meet the nutritional needs of a pregnant ewe, but she may need supplemented with concentrates as she enters late gestation.

26/04/2022

22/11/2021

22/11/2021

How to make up the difference

Determine how much nutrition the ewe lamb is getting from the forage:
Assumed dry matter intake = 2.88 lb
Total energy intake (TDN) = 2.88 × 0.45 (% from forage) = 1.3 lb
Determine the potential nutrient deficiency:
Ewe lamb requirement (from Table 2) − nutrient provided by forage
1.91 lb of TDN − 1.3 lb from forage
Deficiency = 0.61 lb TDN

Find/use a feedstuff that will help make up the deficiency. Corn can be an efficient and cheap way to meet the need for additional energy. If using straight corn, however, limit it to less than 1% of the animal’s body weight because it can impact forage digestion.

Deficiency / nutrient content of supplement

0.61 lb / 0.90 (% TDN of corn) = 0.67 lb of corn

Corn is also slightly higher (%10) in protein than fall forage, so it can also help meet those deficiencies as well. Once the breeding season is over, however, it is recommended that you provide a protein supplement instead of straight corn since protein becomes very limited in the forage over the winter months.

From a practicality standpoint, feeding 0.75 lb per day of corn to ewe lambs approximately 30 days prior to breeding should result in increased body condition and ovulation rates. Feed the corn gradually. Offer 0.25 lb for a couple of days, then 0.5 lb, and finally 0.75 lb. This allows the rumen to adjust and prevents bloat or digestive upset.

Summary
Grazing sheep have a few more challenges than captive flocks as it relates to nutrition because the nutritional requirements of the ewe change throughout the course of the year. At times, the ewe’s requirements are not met by what the forage is providing, and supplementation may therefore be needed. Understanding what those requirements are and how to make up the deficiencies can result in optimal health and performance of the flock. Monitoring body condition will help ensure proper nutrition is being provided.

22/11/2021

Factors Affecting Nutritional Status
Water
Though there is no specific requirement for water, it is fundamental for life, health, and production. Stage of production (growing, lactating, dry, etc.), air temperature, and water quality all affect water intake. It is imperative that fresh, clean, reliable water sources are made available at all times. Drought and also excessive moisture can greatly impact water quality. It is therefore important to monitor water quality through regular testing.

Age
Yearling energy and protein requirements are on average 15% higher than for adult sheep due to yearlings’ growth. These requirements generally cannot be met by forage alone. Older ewes may need additional nutrition since their ability to digest and absorb nutrients decreases with age.

Exercise
Grazing sheep will use more energy than sheep in confinement. Though specific requirements are not fully understood, the additional energy needed for movement should be considered. Pasture size, topography, and distance between water sources are all contributing factors to nutritional needs.

Climate
The more extreme the weather, the more nutrition the animal will require for maintenance. Using wind breaks and providing dry ground helps minimize reduced performance due to weather.

The length and density of the fleece also affects energy requirements. Wool plays an important role in protecting sheep from both heat and cold; the insulating properties of wool help to cool the sheep in the heat of summer and keep body temperatures warmer in winter. Without wool, a sheep’s energy requirements would be higher. Finer wool breeds, for example, tend to be more adaptable to hotter, dryer climates.

Impact of twins and multiples on lactation and body condition of the ewe
It can be difficult for a ewe raising more than one lamb to maintain her body condition. If forage is not abundant, additional supplementation may be warranted to prevent ewes from getting too thin. Creep feeding lambs is also recommended to reduce the demand on ewes.

Body condition
In most sheep production situations, ewes naturally go through body condition changes due to increased or decreased nutrient demand. It is typically most economical to increase body condition after weaning and before the next breeding season.

It takes more feed to maintain a fat sheep at a constant weight than a properly conditioned sheep. Keeping the sheep excessively fat is not only expensive because of feed costs but also detrimental to the ewe’s reproductive capabilities and overall production efficiency.

A ewe can lose up to 6% of her body weight during lactation. She will then likely recover this weight loss during the dry period.

Weight gain during gestation should consist primarily of fetal growth. If ewes become over-conditioned during this time, it may become problematic, causing increased dystocia (difficult lambing) and metabolic problems.

Nutrition-related Diseases and Problems
Sheep are prone to several nutrition-related diseases. With proper management, however, most of these diseases can be avoided.

Ketosis (pregnancy toxemia)
Ketosis is most common in ewes carrying twins. The ewe cannot physically eat enough to meet the nutritional demands of the growing fetuses in the last trimester of gestation. As a result, the ewe will start to utilize her fat stores as a source of energy. Symptoms typically are not obvious until birth, or shortly before. She will go off feed, which accelerates the condition. The ewe will not have the physical energy to stand. Her breath will also have the smell of acetone. Treatment requires an infusion (preferably via IV, or orally) of glucose. A 4- to 6-oz dose of propylene glycol can then be administered orally 2 to 3 times per day until she recovers. If she goes down before birth, it is recommended to induce labor with dexamethasone (5 mL subcutaneously) provided she is only within days of lambing. Ketosis can be prevented by maintaining moderate body condition throughout gestation. Excessively fat and excessively thin ewes are more prone to ketosis.

Milk fever (hypocalcemia or low blood calcium)
As with ketosis, milk fever is more common in ewes carrying twins or multiples. Blood calcium levels drop below normal levels due to the increased demand of the growing fetuses and milk production just before lambing. Symptoms are very similar to ketosis as well. The ewe becomes depressed, but may also show signs of sickness, such as a runny nose. Hypocalcemia can be lethal if not treated when the onset of symptoms arises. An intravenous infusion of calcium gluconate will result in a fairly rapid recovery. This may also treat a ketotic condition if it is also present. A properly balanced mineral program can help prevent milk fever prior to lambing; however, additional dietary calcium is recommended after lambing. Forages such as alfalfa or clover can easily meet the increased requirement.

Enterotoxemia (overeaters disease)
Toxins produced by bacteria in the hind gut are the primary cause of this disease. Too much high-starch feeds such as corn can also contribute to the disease. Enterotoxemia develops very rapidly and often causes death before antibiotic treatment can be administered. With proper annual vaccination with a Clostridium perfringens Types C and D vaccine, the disease is very manageable. Most 7- and 8-way Clostridial vaccines contain protection against enterotoxemia.

Copper toxicity
Sheep can accumulate copper in the liver much more efficiently than other animals, and some breeds of sheep (British breeds for example) are even more efficient at accumulating copper in the liver than others. As a result, sheep are vulnerable to copper toxicity. Dietary copper levels over 5 ppm can result in toxicosis. Most cattle and horse feeds exceed these levels. Unless feeding equipment is cleaned between uses, simply mixing sheep feed in the same equipment as a ration for another species (cattle for example) can result in toxic levels of copper for sheep. Always verify with your feed supplier that the rations have appropriate levels of copper for sheep.

Polio (sulfur toxicity) from water source and feed
Dietary sulfur levels exceeding 0.3% of the diet can result in polio. Symptoms include incoordination, head pressing, and death. Excess sulfur can come from either water or feed sources naturally high in sulfur.

Urinary calculi (water belly) from feed sources high in silica (i.e., wheat and wheat byproducts), a calcium:phosphorus imbalance, and dehydration
Occurs in rams and wethers and presents itself as edema fluid buildup behind the sheath, caused by a blockage due to phosphate salt accumulation in the urinary tract. The condition is more common in wethers or rams on a high-grain, low-forage ration.

Nutritional muscular dystrophy (white muscle disease) mostly for grazing ewes
White muscle disease is caused by a deficiency in selenium. It is important to always have a sheep mineral available free choice to prevent selenium deficiency.

Supplementation strategies when forage is not enough
The nutritional quality of forages changes throughout the course of a year, and forage alone will not meet the nutritional requirements of sheep at certain stages of production. The questions are what to feed, when to feed it, and how much to feed. Nutritional requirement tables generally refer to pounds of intake of a nutrient needed to meet requirements. When reading a forage analysis or feed tag, however, the nutritional information is a percentage. Table 4 is an example of how to quickly determine supplementation needs of an animal.