Small Ruminant Nutritional Diseases

Chapter 12

When does pregnancy toxemia occur?

final 30 days of pregnancy

What is another name for pregnancy toxemia?

ketosis

True or false: Pregnancy toxemia can occur with single or multiple fetuses

true

The following describes what?

• inability of females to consume enough forage to meet energy requirements

• caused by excessive use of body fat for energy

• buildup of ketones in blood

causes of pregnancy toxemia

What percentage of fetal growth occurs in final months of gestation?

more than 60%

What is the primary nutrient needed for mammary gland and uterus?

glucose

In pregnancy toxemia, as the pregnant uterus expands what happens to the rumen?

rumen is compressed

When is there a greater risk of pregnancy toxemia?

stress from environment or illness

True or false: Ewes with pregnancy toxemia become listless with acetone smell

true

What are the end results of fat catabolism?

Inefficient at glucose production, fatty liver, hypoglycemia, hyperketonemia, uremia, and death

True or false: If the young of an ewe with pregnancy toxemia survives, they are usually weak

true

What are the clinical signs of pregnancy toxemia?

anorexic, depressed, grind teeth, ketone smell (acetone), altered behavior, neurological signs, dysoxia, recumbent, and death

True or false: pregnancy toxemia take quickly

true

How can you diagnose pregnancy toxemia?

clinical signs, ketosis, hypoglycemia, and/or urinalysis positive for ketones and protein

How can you prevent pregnancy toxemia?

good management (BCS of 2.5-3, promote adequate energy intake, consider number of offspring (ultrasound), feed high quality forages, have feed available at least 21 hours a day, minimize excess body condition, and increase grain in diet to 0.75 to 1.5 lbs per day)

What is another name for hypocalcemia?

milk fever

Hypocalcemia is a result of what?

low serum calcium

What animals can hypocalcemia occur in?

cattle, goats, sheep, and small animals

When does hypocalcemia most often occur?

shortly after parturition (can also occur in final 4 weeks of gestation)

True or false: acute onset of flaccid paralysis is common with hypocalcemia

true

What management practices are good for hypocalcemia?

low calcium diet during gestation (minimal alfalfa and high calcium grain), and increase calcium in diet AFTER parturition (strategy improves calcium absorption and from intestine and reabsorption from bones)

What is another name for hypomagnesium?

grass tetany

What animals are most susceptible of hypomagnesium?

cattle, sheep, and goats

True or false: Hypomagnesium is a problem with small ruminants grazing on lush, rapidly growing forage

true

When does hypomagnesium typically occur?

early spring (recently fertilized pastures)

What are the clinical signs of hypomagnesium?

excitable, paddling convulsions, muscle spasms (trembling), increased respiratory rate, and dead in pasture (often within 2-3 hours)

How can we check if a dead animal had grass tetany?

ocular fluid

What is the primary mineral storage organ of the body?

liver

True or false: copper excretion is inefficient

true

True or false: the ability to excrete copper is species specific

true

What disease occurs from excess accumulation of copper in liver until the liver becomes saturated?

copper toxicity

Sheep are sensitive to copper toxicosis at what?

10 mg/kg

Llamas and alpacas are sensitive to copper toxicosis at what?

20 mg/kg

Once liver storage is full, where does copper spill into?

liver and blood

Copper spilling into the liver and blood causes what?

oxidative stress (cellular damage), massive hemolysis (destruction of red blood cells), and free hemoglobin leaks into blood and urine (kidney damage)

True or false: copper toxicity is a much bigger problem in sheep rather than goats

true

Hemolytic crisis caused by copper toxicity is nearly always what?

fatal

High levels of copper are found in what?

mineral mixes for cattle or goats, copper containing footbaths, copper plumbing, and horse, hog, or chicken feeds

What are the clinical signs of copper toxicity?

weakness, dyspnea, gastroenteritis, icterus, hemoglobinuria, and death

What is tall fescue?

a cool season perennial that is grown on an estimated 35 million acres in the US (heavily concentrated here)

Why is tall fescue so popular?

easy to grow, adapts well to wide ranges of soil and climatic conditions, tolerant of poor drainage, drought resistant, and first grass to emerge and last to die off

What toxin was found in tall fescue in the mid 1970s?

an endophytic fungus

What grows between the cells of the host plant, drawing nutrients from it, but in return conferring resistance to insect pests, drought tolerance, and protection from overgrazing (symbiosis) while also producing a toxin harmful to animals?

endophyte

What are the clinical signs of fescue toxicosis in ruminants?

reduced birth weight, reduced conception rate, delayed return to cycle postpartum, hypothermia, reduced weight gain, lameness, and necrosis of the digits, ears, tail, and fat

What are the clinical signs of fescue toxicosis in mares?

gestation length was increased by 27 days, the number of stillborn foals doubled, aglactia (absence of milk secretion after birth) was 100%, retained placentas were increased more than 5 times, placental weight and thickness increased, and prolactin and progesterone decreased

How do you treat fescue toxicity in mares?

remove pregnant mares 60-90 days before foaling (30 days is absolute minimum), daily oral domperidone paste started 20 days prior to the expected foaling date if mares remain on toxic fescue up to parturition, and agalactic mares can start domperidone daily and should produce milk in 5 days

True or false: Sheep appear to be less affected by fescue toxicosis than cattle

true

When it comes to fescue toxicosis, what are sheep prone to?

"fescue foot, hypothermia, poor wool production, reproductive problems, lowered feed intake, and poor weight gains

What is the best treatment for fescue toxicosis?

good pasture management (especially at breeding facilities)

The best way to manage endophyte-infected fescue is using methods to lower its effect. This includes what?

growing a legume with tall fescue (clover is most common and cheapest) and feed hay such as Bermuda grass or sericea lespedeza

What are the fescue options?

endophyte free and endophyte infected

What are the advantages of endophyte free fescue?

cattle had less reproductive problems, gained better, and better BCS

What are the disadvantages of endophyte free fescue?

cost and did not have a high tolerance for drought, overgrazing, or high traffic