Small Ruminant Nutrition pt.2

What are the essential microminerals to consider in sheep nutrition?

Cu, Mn, Se, and Zn

What livestock species is most susceptible to Copper (Cu) toxicity?

Sheep

What two key minerals will cause copper absorption to decrease?

Molybdenum (Mo) and Sulfur

What has to be done if there are elevated levels of Molybdenum or sulfur in the diet?

We have to increase the level of copper in the diet

What happens if ewes are fed copper deficient diets (maternal Cu deficiency)?

There is a negative effect on lamb survival

What does maternal Cu deficiency cause?

• neonatal ataxia

• reduced vigor at birth (less likely to get up and get colostrum)

• Reduced cold tolerance due to impaired brown fat thermogenesis

• Increased incidence of diarrhea

• Reduced neonatal survival rates

What is neonatal ataxia?

A nervous disorder. Inability to suckle, incoordination, and a stiff gait

What are the oxide forms of trace minerals known for?

Having low bioavailability

What does low bioavailability cause in sheep?

Copper deficiency

What happens when there is a maternal selenium deficiency?

There is a decrease in lamb survival

What does Maternal Selenium deficiency cause?

• white muscle disease (Stiff-lamb disease)

• Abortion and stillborn fetuses

• weak lamb syndrome

What does maternal Se supplementation of pregnant ewes result in?

• Decreased incidence of diarrhea

• Decreased neonatal mortality rates

• Increase brown-fat thermogenesis of newborn lambs (improves cold tolerance)

• increased survival rates of lambs

Rank the 5 production phases of ewes based on importance of meeting requirements: (PPEED)

1. pre-lambing (most critical)

2. Pre-breeding

3. Early lactation

4. Early gestation

5. Dry period (least critical)

Rank the 5 production phases of ewes by DE requirements: (EPPED)

1. Early lactation (highest)

2. pre-lambing

3. pre-breeding

4. early gestation

5. dry period (lowest)

What is the timeline for the 5 production phases of ewes?

1. Early gestation (16 weeks)

2. early lactation (8 weeks)

3. extended dry period (16 weeks)

4. Breeding

he wasn’t very clear about this

What is the stage prior to breeding called?

Flushing (3 to 4 weeks before breeding)

Why do we feed a lot of energy during the flushing stage?

To increase bcs and incidence of twinning

Why is pre-lambing so critical?

If we underfeed pregnant ewes we decrease growth and development resulting in lower birth weight

T/F Light birth weight lambs are very susceptible to cold stress

True

What impact does underfeeding energy to a pregnant ewe have on brown fat?

• lambs born to ewes fed low-energy diets during gestation contain less brown fat than lambs born to high-energy diets

• Twin lambs have less brown fat than single lambs

• Lambs born with less brown fat will be less cold tolerant and have higher mortality rates

What does most brown fat in a new born calf surround?

The kidney

Pre-lambing nutritional restrictions (underfeeding) can cause-

Pregnancy toxemia aka. pregnancy ketosis

What does pregnancy ketosis do?

• affects ewes during late gestation (Twin-bearing ewes are more susceptible)

• can cause death of ewes if severe enough

• glucose requirements increase rapidly during late gestation

• Rumen capacity is reduced due to fetal crowding which causes feed intake to decrease

• fat stores are mobilized

• glucose production by the liver is reduced (leads to ketosis)

What are ways to prevent pregnancy toxemia (Pregnancy ketosis)?

• good feeding management during late gestation

• Target BSC is greater than 2.5 (1 to 5 scale) at lambing

• feed single and twin-bearing ewes separately

• provide oral dose of propylene glycol

When do range ewes utilize cheap feedstuffs?

During early gestation and the dry period

When are body condition scores evaluated?

Prior to breeding and at start of 3rd trimester of gestation

When is creep feeding used?

For nursing lambs, especially beneficial in flocks with high twinning rates

What happens if we overfeed replacement ewes during a critical period?

A reduction in milk production potential

What causes white-muscle disease?

Maternal Se deficiency or vitamin E deficiency

T/F 86% of what livestock consume globally is NOT in competition with human food

TRUE

Why are ruminant animals considered super-upcyclers?

• They convert fiber CHO to VFAs

• They Convert low-quality protein into high-quality microbial protein that gets absorbed from the small intestine

• cattle can make the phosphorous in all our feeds available for absorption (Pigs excrete feces high in P while ruminants don’t)

• B-complex vitamins don’t need to be included in ruminant diets

T/F Livestock is one of the biggest contributors to greenhouse gas emission

FALSE, they contribute less than 2% of greenhouse gas emissions in the U.S

T/F Methane will stay in the atmosphere as long as CO2

False, methane is only 10 years, CO2 is thousands of years