VTS257: Lg Animal Diseases & Nursing

1. Cattle Nutrition

2. Ruminant Herbivores
• Calf: young animal
• Heifer: female calf that hasn’t given birth and
is less than 30 months old
• Cow: > 30 months or has given birth
• Bull: intact male
• Steer: castrated male up to 4 yrs old
• Ox: castrated male over 4 yrs of age

3. Dairy Cattle
• Main objective: increase dry matter intake to
produce higher levels of milk production
• Key factors: ration digestibility, rumen fill,
body weight (BCS), palatability, environment,
frequency of feeding and water

4. Phase Feeding Program
• Phase feeding: changing the nutrient
concentration in a series of diets formulated
to meet an animals nutrient requirements
more precisely at a particular stage of growth
or production
• Based on lactation and gestation cycle

5. Phase one
• First 10 weeks of lactation
• Peak milk production occurs during this phase
• Negative energy balance develops so cow uses
body stores to make up difference ( can
borrow fat, but cannot borrow protein)

6. What to Feed in Phase 1
• Increased grain for energy ( corn, wheat,
soybeans)
• Protein supplementation to meet AA
requirements ( dried brewers grain, distillers
grain, corn gluten meal)
• Increased concentrates and fats to increase
energy density of feed ( soybeans, sunflower
seeds)
• Sodium bicarbonate “buffer” to reduce acidosis
and maintain ruminal ph

7. Phase 2
• Begins 10 weeks post calving and can continue
to 20th week
• Highest dry matter intake happens here
• Nutrient intake is finally in balance with
nutrient needs

8. What to feed in Phase 2
• Lower protein levels because requirement is
met by supplementation in phase 1
• Adequate fiber
• Limited grain intake
• Frequent feeding ( minimize digestive upset)

9. Phase 3
• “late lactation period”, cow is pregnant again
• Nutrient intake exceeds requirements for
production
• Main period for restoring body reserves for
next lactation

10. What to feed in Phase
• Easiest phase to manage because cow is
pregnant and milk production is declining
• Increased amount of forage instead of
concentrates
• Lower protein

11. Phase 4
• Most of the “dry” period
• Final regaining of any lost body weight
happens here
• Goal is to get cow in good condition for
parturition, but not excessively fat BCS of 3.5
out of 5.0

12. What to feed in Phase 4
• High protein, energy, Ca and P needs
• Combination of legume-grass hay and corn
silage ( with added vitamins and P)
• Long stem grass hay ( length of hay matters)
• Limit grain to energy and protein needs

13. Phase 5
• Last 1-3 weeks of “dry” period, just before
calving
• Referred to as “transition period”
• Increase grain intake to prepare rumen for
high energy diets that will be needed post
partum

14. What to feed in Phase 5
• Gradual increase in grains
• Small amounts of all ingredients used in
lactation ration
• Maybe decrease Ca in “milk fever” prone cows

15. Body condition scoring
• A numeric system to subjectively assess and
animal’s degree of fatness
Fat Cow Syndrome
- High blood lipids and fatty liver from eating
excess energy from grain or corn silage
- Can lead to calving difficulties, displaced
abomassum and ketosis

16. Beef cattle nutrition
• Most critical factor influencing performance of
cattle on forage diet is the amount of Dry
Matter Intake
• Young, growing grass and pasture crops
usually have ample nutrients
• Old pastures, crop residues and harvesting
methods cause reduction in nutrients

17. Biological Cycle
• Goal: optimal nutrition at each stage, not
maximum nutrition
• Cycle is made up of 4 periods that span 1 year
• Cycle includes 3 trimesters and 1 postpartum
period

18. First trimester ( 95 days)
• Begins the 1st day of conception
• Nutrient needs are for maintenance and
lactation if the cow has a calf with her
• Milk production is declining at this stage

19. Second trimester ( 95 days)
• Calf is weaned, lactation requirement ends
• Lowest nutrient requirements at this point
• Feed minimally
• Easiest and most economical time to increase
a thin cow’s BCS

20. Third trimester (95 days)
• Rapid fetal growth causes rapidly increasing
nutrient needs
• Watch BCS carefully, cow gains 1 lb per day
• Too thin cows experience dystocias, weak
calves and decreased milk production

21. Post partum period ( 80 days)
• High lactation requirements
• Feed intake is 35-50% higher than non-
lactation cow
• Nutrition stress at this point causes problems
during the cow’s next breeding, ( next
breeding is usually 80 days post partum)

22. Energy requirements for beef cattle
• Energy is considered first in balancing diet for
beef cattle, it’s the largest portion of the
ration
• Energy utilization determines cow’s ability to
use other nutrients
• Good quality forage satisfies adult energy
requirements
• Poor quality forages need to be supplemented
with concentrates

23. Protein requirements
• 50% of all protein and AA needs are met by
microbial protein synthesis
• Protein deficiency is common when cows
consume straw and low quality hay
• Urea is commonly used as a protein
supplement

24. Water requirements
• Need abundant supply at least once daily
• Range cows consume 2 ½ gallons daily in
winter and up to 12 gallons per head in
summer
• When salt is added, water need is increased
• Fresh succulent feeds or silage helps reduce
need

25. Mineral requirements
• Salt: need more when eating succulent forage
• Ca: depends on conc. in soil, higher needs in
growing and lactating cows
• P: low in roughages, offered free choice in
mineral mix
• Co: rumen microorganisms need for B12 syn.
• Cu: simental and charlois need more
• I: def in northwest and great lake soil, use iodized
salt

26. Vitamin requirements
• Vitamins CDEK and Bcomplex: no need to
supplement, rumen microflora syn B vit, Vit C
is synthesized in tissues, sun dried forages
contain D and E
• Vitamin A: roughage and grains low A, cattle
on pasture can store A for 2 months in liver,
(slow to show symptoms) deficiency results in
rough coat, diarrhea, excessive lacrimation

27. Grazing systems and management
1. Continuous grazing
- Most common type of grazing scheme
- Cow grazes 1 area for the entire season up to
1 year
- Low maintenance, but production often
suffers

28. 2. Deferred rotational grazing
- 4 pasture system
- 1 pasture would not be grazed from spring to
mid-summer in order to allow desirable plants
to flower and reach seed maturity
- The following year another pasture would not
be grazed
- After 4 years all pastures would have rested

29. 3. Rest rotation
- Uses 3-5 pastures
- 1 pasture is not grazed for an entire
year, while herd uses other pastures

30. 4. Short duration grazing
- Developed in France
- 8-40 pastures grazed intensively for 2-3 days,
then not grazed for several weeks

31. Nutritional disorders in Cattle
Pasture bloat:
- Comes from consuming lush legumes ( alfalfa,
red clover)
- Relieve bloat by inserting stomach tube into
rumen and giving anti-foam material ( ex
vegetable oil)
- A trocar is used in extreme cases to relieve
pressure

32. Grass Tetany:
- Low Mg levels in blood from grazing lush
green grass pastures
- Common in cows nursing calves under 2
months of age
- Symptoms: excitability, cow acts blind
- Fix by feeding free choice mineral
supplements containing Mg in early grazing
season

33. Nitrite Toxicity:
- Caused when intake of nitrite is in excess of
the rumen’s ability to convert it to ammonia
- Causes hemoglobin in blood to change into a
form that cannot transport oxygen
- Cow dies from asphyxiation
- Treat with injection of IV Methylene Blue

34. Fescue toxicity:
- Caused by grazing or consuming harvested
hay from tall fescue pastures
- Cow eats endophytic fungus that grows
between fescue cells
- Signs; soreness in hind limbs, “fescue foot”
hooves and tail slough off, hypersalivation and
polyuria

35. Acute Pulmonary Emphysema “ Asthma”
- Occurs in western Us when cattle are moved
from dry rangelands to lush meadow pastures
abruptly
- Signs in 4-5 days after diet change
- Symp: labored breathing, extended neck,
open mouth breathing, grunting
- Prevention ( no TX) slowly introduce cattle to
new pasture and supplement with monensin