CompactBeefCalvingSeasonL4

• What are the factors that influence number of calves weaned?


  Percentage of cows pregnant, abortion rate, perinatal calf mortality, calf losses to weaning
• Compact Calving 


  Define by the day when the first calf is born to when the last is born
• Calving Pattern Importance


  Significance of the number of cows calved in each 21-day period for efficient calving
• Advantages of Compact Calving

  Benefits include fewer anestrus cows, more uniform calf sizes at weaning, and efficient feed budgeting
• Whatʻs is essential with compact calving?

  Match calving dates with spring grass growth
• Pregnancy Rate


  Percentage of cows pregnant per 100 cows joined to the bull
• Calving Rate


  Number of cows calving per 100 cows joined with the bull
• Calf Weaning Percentage


  Number of calves weaned per 100 cows joined with the bull
• Gestation Length

  Duration of pregnancy, normally 282 days
• Post-Partum Oestrus Interval


  Approximately 60 days interval after calving for cows to cycle again
• Conception Rates


  Around 60% for a bull mating, indicating the likelihood of successful impregnation
• Calving Interval


  Mean time between calvings, ideally 12 months
• Mating Period


  Duration for cows to mate, normally 63 days (3 cycles) (sometimes 49 days)
• Mating heifers


  Duration for heifers to mate, only 42-45 days (2 cycles) with an 85% in-calf rate
• What percentage of cows and heifers calve during the first 21 day mating period (the calving pattern)?

  70%
• Pregnancy Rate percentage


  % cows mated that are pregnant/scanned in calf, Target = 95%
• Reproductive Efficiency


  Product of pregnancy rate and calving percentage, aiming for 90% or higher
• Reproductive Problems


  Issues like poor pregnancy rates, weaning percentages, and abortion may hinder herd performance
• Preferred Calving Patter 


  Optimal calving schedule for maximizing weaning weights and profitability
• Conception Rate Calculation


  Method to calculate conception rate in natural mating scenarios
• Compact Calving Season


  Recommended period for concentrated calving to optimize reproductive performance
• What factors might influence Calculated Conception Rate (CCR)?

  Fertility of bulls/cows, venereal diseases in herd, nutrition, topography, heifers at target weights, Bull:Cow ratio
• Spread-out Calving Correction


  Pregnancy test and fetal age, decrease herd size by culling late calvers replace with early calvers, mate heifers for only 42 days, delay mating ensuring cows are cycling
• How can herd fertility be improved in the bull?

  By increasing the proportion of cows conceiving in a heat (the conception rate per heat)
• What contributes to concentrating the calving pattern (fertility) in the cow?

  Increasing the proportion of cows that show heat or oestrus in the first three weeks of mating (increasing oestrous activity)
• How can you increase estrous activity at first mating in heifer?

  Aim for 70% of heifers calving in the first 3 weeks of calving, breed at 15 months (at a min. of 300 kg), mate to bull for 6 weeks, fetal age to identify pregnant heifers in first 3 weeks - retain these heifers, breed subsequently for 49 days for entire lifetime
• How can increased oestrous activity benefit the cow herd?

  Shorten the breeding period in adult cow herd by 2 weeks in year 1
• When should foetal age in cows be scanned for pregnancy diagnosis?

  6 weeks after the end of breeding
• How should late calvers be managed for optimal results?

  Preferentially manage them to calve in good condition (CS6+) and continue to feed well after calving to ensure as many as possible are cycling when the bull goes out
• Artificial Breeding (AB)


  Use of assisted reproductive technologies for genetic improvement in cattle herds
• Fixed Time AI


  Controlled synchronization of estrus cycles for timed artificial insemination
• GnRH Injection

  Gonadotropin-releasing hormone used to induce ovulation in cattle
• PG Injection

  Prostaglandin injection for estrus synchronization in cattle
• Post Partum Oestrous Interval


  Time between calving and the first estrus cycle in female cattle
• Replacement Heifer Management


  Effective care and breeding management for young female cattle entering the herd
• Bull Soundness


  Health and reproductive fitness assessment of male cattle for successful breeding
• Whatʻs the ideal pregnancy rate in an adult beef cow herd?

  90%
• Whatʻs an appropriate mating period for adult beef cow herd?

  42-45 days in first calving heifers, under 63 days
• How many heifers should calve in the first 21 days of calving in a well managed herd

  First calving heifers get up to 70%, adult cows 60%
• How long is the post partum estrous interval in an adult cow?

  60 days