IV. Feeding Guidelines
A. Requirements vary with phase of lactation and gestation
1. Early Lactation
a. Milk production increases rapidly, peaking at 6 to 8 wks (45-60 d) after calving
b. Increase grain intake to meet energy requirements, but avoid excessive levels (< 65% of total DM)
c. Extra dietary protein allows more efficient use of body fat for milk production since cows are usually loosing BW
d. Limit urea to .4 to .5 lb/day
2. Peak Lactation
a. Maximum intake is reached at ~12 to 14 wks and cows should be kept at peak milk production as long as possible.
b. Grain intake may reach 2.5 % BW, forage intake should be at least 1- 1.25% BW to maintain rumen function
c. Feed several times daily
3. Mid- to Late Lactation
a. Milk production is declining, cow is pregnant
b. Match grain intake to milk production; avoid wasteful grain feeding to low producers
c. Avoid over conditioning
4. Dry Period
a. Forage quality not as critical
b. DM intake ~2% of BW
c. ~2 wk before calving increase grain feeding (~1% of BW); helps ¯ ketosis
d. Feed low Ca ration to help prevent milk fever at calving
e. 4 to 8 wk dry period, depending on age & physical condition
5. Consideration
a. Ketosis
- High blood and urine ketone levels
- Low blood sugar
- Depleted glycogen reserve
- Lack of appetite
Just giving glucose will not work in ruminants
Propylene glycol is best, use steroids
High Producing cow ---> Needs glucose for milk --> begins using body fat--> acetoacetic acid,
b -hydroxybutyrate, and acetone --> KETOSIS
Cattle prone can be fed high quality before calving & increase substantially after parturition
b. Milk Fever
1. Correlated with number of lactation’s
(50 X greater in cows with more than 6 compared to those in first lactation)
2. 75% of cases occur at or within 24 hour of parturition
3. Symptoms
drowsy, head turns into flank
4. Decreased blood Ca
5. Treatment
- IV Ca
- prevent with low Ca diet 2 to 3 wks before calving (difficult to find this kind of diet)
- Vit. D before calving, but toxic so must know exact calving date!!
- Decrease DCAD (ratio of cations to anions in the diet)