FeedingBeefCowHerdL2

• What are the roles of beef breeding cows in extensive hill country pasture?

  Reproduction, environment, profitability, finishing performance, calf performance
• Reproduction includes:


  Heifer age at puberty, maintain 365 day calving interval, early conception, gestation length
• Environment includes


  Pasture management/quality control, feed requirements to annual pasture growth curve, graze with other livestock classes
• Profitability includes:


  Wean a calf at high weaning weights over multiple years, combination of genetic merit of cow, environment conditions, and management strategies
• Finishing Performance includes: 


  Impact on post-weaning growth performance, carcass merit (carcass weight/quality)
• Calf Performance includes:


  Produce live healthy calf/year, raise calf to high weaning weights, provide nutrient resources for calves to reach its genetic potential
• What are the objectives for a beef cow herd?

  Rear to weaning 90 calves/100 cows bred, wean calves ~220+ kg LW, maintain a low death rate (2%) in the herd, leverage the breeding cows to support and sustain pastures for sheep grazing
• What do average performing cows produce?

  Weans 82 calves/100 cows, grows calves ~0.8 kg/day from birth to weaning, produces 0.3 kg/calf per kg cow LW
• What do high performing cows produce?

  Weans in excess of 92 calves/100 cows, grow calves ~1-1.2/kg/head/day from birth to weaning, produce 0.48 kg calf weaned/kg cow weaning weight, provide pasture control mechanism on hill country
• What should a farmer consider with cow LW as a proxy for intake?

  Large cows eat more but will they produce larger calves, need to ensure larger calves outweighs cost of extra feed
• How much feed for a beef system rearing steers to slaughter at 300 kg carcass weight does the beef herd need to eat?

  70% of feed which is used to maintain the breeding cows
• What percentage of total feed is required to get steer to average carcass weight for maintenance of beef cow?

  49% of total feed
• Metabolizable Energy


  Daily requirements for maintenance of beef cows based on liveweight and hill country type
• For every 100 kg increase in cow LW requires an additional 11 MJME/day
• Pregnancy requirements


  Factors influencing requirements include days from conception, number of offspring, and fetus size
• Lactation requirements


  Total milk yield, milk composition, milk production ~5 to 8 liters/day
• What is milk composition?

  Milk varies concentration of fat, protein and lactose, the total energy concentration per liter will vary too
• When animals lose weight, energy is produced by mobiliazation of body tissue.In lactating animals, this energy can be used to maintain milk yield.
• How much is substituted for 1 kg of LW loss in mature cows?

  ~30 MJ ME
• One condition score change on the 1-10 scale = 30 kg LW. It will vary depending on condition score more for fatter cows than thinner cows.