Beef Cow Nutrition

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Beef Cow Nutrition

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

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

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

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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

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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

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

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

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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)

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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

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Pregnancy Rates as Affected by Nutrition in
Postpartum Cows
Selk et al., 1988
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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

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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

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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

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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

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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

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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

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Stage of Forage Maturity Vs Cow Needs
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Forage growth vs. Cow needs
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Forage growth vs. Cow needs
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Forage growth vs. Cow needs
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Forage growth vs. Cow needs
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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

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Some Diets for Late Pregnant Cows
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Some Diets for Late Pregnant Cows
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Stockpiled Fescue

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

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Energy Value of Stockpiled Grasses
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Protein Content of Stockpiled Grasses
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Some Diets for Lactating Cows
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Some Diets for Lactating Cows
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Energy Value of Manufactured Feeds

• TDN 84 - ( CF - 1) 1.5
• Feed is 11 CF (max)
• TDN 84 - (11 - 1) 1.5
• 84 - (10)1.5
• 84 - 15 69 TDN as fed
• 69 / .90 76.6 TDN

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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

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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

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Impact of Ionophores on Replacement Heifers

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

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Deficient Minerals In VA

• Deficient
• Copper
• Selenium
• Sodium
• Zinc

• Marginal
• Calcium
• Phosphorus
• Magnesium
• Iodine

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Minerals supplement - Commercial
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Mineral Supplements - Commercial
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