B10: Clinical Dietetics Of Beef Cattle

Question 1

Clinical dietetics of beef cattle. Key points

Answer 1

• focus on prevention because treatment is difficult as these animals are kept in pastures
• antiparasitic treatment! - anemia, malnutrition, reduced BW gain

Question 2

Most important nutritional disorders of beef cattle

Answer 2

1. “Washy pastures”
2. Nutritional deficiencies
3. Urea toxicity
4. Nitrate/nitrite toxicity
5. Heat stress
6. Urolithiasis
7. Sand impaction
8. Bloat
9. Acidosis, rumenitis, liver abscesses
10. Hardwarre disease
11. Hydrocyanic acid toxicity
12. Others (phytoestrogens, poisonous plants)

Question 3

“Washy pasture”

Answer 3

• early spring
• grasses: high moisture and protein content —> diarrhea
• prevention: transition period for 2 weeks, increasing DMI by feeding hays and straw

Question 4

Nutritional deficiencies. Vitamin A deficiency

Answer 4

• antioxidant —> in their deficiency protection of skin and MMs decreases —> higher chance of infections, decreased absorption of nutrients
• reproduction is negatively affected: decreased quality of sperm and eggs, decreased progesterone production
• deceased calf’s growth and bone development (should be supplemented in late pregnancy)
• vitamin A deficiency is really rare in pastures! but excess of sun can destroy vit A
• to prevent deficiency: carrots as supplementation

Question 5

Nutritional deficiencies. Magnesium deficiency = grass tetany

Answer 5

• lactating cattle !!
• early spring: lush perennial grasses are low in magnesium
• clinical signs: hyper-excitability, muscle twitching, muscle spasms, collapse, death
• grass-legume mixed pasture should be grazed first!
• ## salt blocks !, as salt can support magnesiumtransport into the cells and its uptake

Question 6

Nutritional deficiencies. Vitamin E and Selenium deficiency = white muscle disease

Answer 6

• in calves: muscular dystrophy. If cardiac muscle affected -> sudden death. If skeletal -> slow onset, difficulty swallowing (tongue)
• in adults: impaired immune responses
• muscles are pale

Question 7

Nutritional deficiencies. Calcium and vitamin D

Answer 7

• quite rare
• happens in intensive fattening animals because excess grains are fed with low calcium content
• breaking down the heel bone (os calcaneus) together with Achilles tendon
• lameness

Question 8

Nutritional deficiencies. Thiamine (vit B1) deficiency

Answer 8

• CCN: corticocerebral necrosis (=polyencephalomalacia, PEM)
• in intensive fattening
• more grains are fed -> higher demand of B1 (Krebs cycle)
• also more grains in diet decrease rumen pH -> proliferation of thiaminase producing bacteria
• molasses, corn gluten -> increase of phosphate content -> decrease thiamine utilisation
• clinical signs: circling head, convulsion

Question 9

Nutritional deficiencies. Copper deficiency

Answer 9

• rare: either soil is low in copper or other minerals inhibit copper utilisation (Mo, Fe, S)
• hair coat will be pale

Question 10

Urea toxicity

Answer 10

• urea supplementation (often in beef cattle) (protein balance!)
• urea supplementation can be done when protein balance is NEGATIVE
• recently is rare because usually urea is supplied together with molasses for good utilisation
• in case of urea toxicity -> ammonia toxicity (salivation, convulsion, in coordination, death)
• treatment: adding vinegar

Question 11

Nitrate/nitrite toxicity

Answer 11

• after fertilisation of soil -> water contamination
• in rumen nitrate is converted to nitrite (more toxic)
• in case of drought fertilisers are not utilised by plants, they stay on plants -> consumption
• clinical symptoms: DMI decreases, abortion, methaemoglobinaemia in calves

Question 12

Heat stress

Answer 12

• clinical signs: DMI significantly lower