Beef Cow Nutrition

1
Beef Cow Nutrition

• John B. Hall, Ph.D.
• Extension Beef Cattle Specialist
• VA Tech

2
Beef Cow Production Cycle
Calving
50
110
82
123
3
Influence of Pre- and Postpartum Nutrition on
Reproduction in Cows
4
Pre-calvingPhysiological events

• Rapid fetal growth
• Cows need to gain weight
• Intake decreases
• Prepare for lactation

5
Pre-Calving Nutritional Needs

• TDN 12 lb./day
• Protein 1.7 lb./day
• Calcium 27 g/day
• Phos.21 g/day
• Vitamin A
• 27,000 IU/day

6
Pre-CalvingType of feed

• Forage needs to be good quality
• Poor quality forages need supplement
• Cold weather may require supplementing good
  forages
• Good orchardgrass hay, fescue-clover hay,
  grass-alfalfa, corn silage, grazing-vegetative

7
Heifers Must Calve in BCS 6 or Better to Rebreed
8
Effects of Energy During Late Gestation on Calf
Growth and Survival
9
PostpartumPhysiological events

• Lactation
• Repair of reproductive tract
• Start heat cycles
• Maintain body weight (grow)
• Increase activity

10
PostpartumNutritional needs

• TDN 15 lb./day (25 increase)
• Protein 2.4 lb./day (41 increase)
• Calcium 33 g/day
• Phos. 27 g/day
• Vitamin A 40,000 IU/day (48 increase)

11
PostpartumFeed needs

• Highest energy, highest protein forage available
• Low quality forages require grain supplement
• 1st calf heifers need grain
• good alfalfa/grass mix, alfalfa hay, grass hay
  and supplement, excellent pasture

12
Pregnancy Rates as Affected by Nutrition in
Postpartum Cows.Wt. Maintained, Losing, Gaining.
Selk et al., 1988
13
Lactating and PregnantPhysiological events

• Lactation - peaks then decreases
• Pregnant - little fetal growth
• Maintain or lose less than 5 weight
• Activity still high
• Continued growth in 2 and 3yr olds

14
Lactating and PregnantNutritional needs

• TDN 13 lb./day (13 decrease)
• Protein 2.2 lb./day (8 decrease)
• Calcium 30 g/day
• Phos. 23 g/day
• Vitamin A 37,000 IU/day

15
Lactating and PregnantFeed needs

• Good to average quality forage
• Abundant forage
• Poor quality forages should be supplemented
  (cow)
• High quality grazing, alfalfa-grass hay, silage,
  hay-corn-litter

16
Some Diets for Lactating Cows
17
GestationPhysiological events

• Pregnant - slow fetal growth
• Increase body condition if needed
• replacement and 1st calf heifers growing at 1 to
  1.5 lb. per day

18
GestationNutritional needs

• TDN 10 lb./day (23 decrease)
• Protein 1.4 lb./day (36 decrease)
• Calcium 18 g/day
• Phos. 18 g/day
• Vitamin A 25,000 IU/day (32 decrease)

19
GestationFeed needs

• Poorest quality feed can be used
• Good quality feeds can be limit fed
• Supplementation is rarely needed
• Overmature hay, poor quality alfalfa, stockpiled
  grazing

20
Some Diets for Late Pregnant Cows
21
Stockpiled Fescue

• Graze off field
• 80 units of N - Aug.
• Dont graze until after frost
• Grazing from Nov-Feb
• High quality -
• 60 TDN
• 10 - 12 CP
• Low Cost - High Value
• Use strip grazing

22
(No Transcript)
23
(No Transcript)
24
Replacement Heifers

• Need to grow at 1.25-1.75 lbs / day
• Target Weight
• 60-65 of mature weight (British)
• 65-70 of mature weight (exotic)
• Protein requirement may depend on muscling of
  heifer
• Dietary requirements 65 TDN, 11-12 CP

25
Using Target Weight to Plan a Feeding Program

• Weaned 500 lb. heifer on October 15
• Breeding on May 15
• 780 lb.-500 lb. 280 lb.
• 280 lb./211 days 1.31 lb./day

26
Milk vs. Growth

• Peak lactation occurs at 8 weeks
• By 5 months of age milk supplies less than 30
  of the needed nutrients for the calf

27
Some Diets for Late Pregnant Cows
28

Energy Value of Different Fields of Stockpiled
Grasses
29

Protein Content of Stockpiled Grasses
30
Some Diets for Lactating Cows
31
(No Transcript)
32
Impact of Ionophores on Replacement Heifers

• Increased growth rate and body weight
• Earlier puberty
• Improve pregnancy rates
• May have extra rumenal effect as well

33
Deficient Minerals In VA

• Deficient
• Copper
• Selenium
• Sodium
• Zinc

• Marginal
• Calcium
• Phosphorus
• Magnesium
• Iodine

34
Minerals supplement - Commercial
35
Mineral Supplements - Commercial
36
(No Transcript)