Oestrus manipulation

LO1

State oestrus detection aids for a variety of species

• rodents - vaginal flush - epithelial counts.

• dairy cows HDR (heat detection rate) / HDA

  • tail paint, mount indicator, activity monitors,

• Mares - follicle observation

  • follicles grown 3-5mm a day 

  • ovulate at 35mm 

  • follicle wall thicken 24h prior to ovulation 

  • form teardrop shape less than 24h before ov 

  • become softer less than 6-12h of ovulation 

• dogs - vaginal cytology 

  • anoestrus, parabasal cells 

  • pro-oestrus, 10% cornified cells 

  • oestrus, 100% cornified 

  • di-oestrus day 1 50% cornified 

• dogs - progesterone testing 

  • base level = 2ng/ml 

  • ovulation = 5-10ng/ml 

  • post-oestrus = rising to 40-50 ng/ml (10-90) by 20-30 days
    after ovulation
    • >25ng/ml = end of fertile period
    Parturition:
    • decline to <1ng/ml 24 hours before

    
    

LO2 - list reasons for manipulating oestrus 

• poor detection, synchronisation (economical) enable AI / ET (embryo transfer), trigger post partum resumption 

LO3 - explain effect of commonly used hormones on oestrus cycle, and chose appropriate hormone.