Lynn Dickman

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Beef Cattle and Timing Delivery of Calves for Sale

• Lynn Dickman
• Amber Carlson
• Shi Lurvey
• Rachel Knight

2
Case 2 Summary

• 6 truckloads of calves to a feedlot
• Paid premium for approximately the same weight
  and genetics
• 410 cows-cycling and non-cycling
• Use Eazi-Breed inserts with prostaglandin
• Will need to use A.I.

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Timed A.I. at 48-54 hours
4

• Prostaglandin-Lutalyse
• Response on during diestrus, when a CL is present
• Causes rapid regression of CL and lowers level of
  progesterone
• Drop in progesterone causes ovulation to occur
  and estrus to be expressed

Hormones

• Progesterone
• Maintain pregnancy, mammary development
• Negative feedback on gonadotropin secretion

5
Effects

• Induces Cycling in estrus and anestrous suckling
  cows
• Advanced puberty in heifers

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Is it Efficient?

• Higher PR
• Easier and more accurate heat detection
• Higher genetic gain-using more A.I
• More focused heat detection and easier A.I
  breeding since groups come into heat and can be
  bred around the same time
• Heifers freshening at a younger age
• More cows becoming pregnant in the first two
  cycles
• Accurate breeding and calving dates
• Improved efficiencies in labor management

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Labor Needs

• Running cows through a chute several times
• Breeding
• Calving

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Table 1. Effects of EAZI-BREED CIDR or PGF alone
on reproductive performance of cycling and
non-cycling beef cows and heifers
(Adapted from Lucy, et al. 2001)