Reproductive physiology

Detailed description of follicular dynamic and oestrus cycle in bos indicus can be found in Bo et al., (2003) and Sartorelli et al. (2005). The main reproduction traits are identical in bos indicus and bos Taurus, there are however some differences that should be considered in the reproduction management.

Differences in reproduction traits between Bos Taurus and Bos indicus cattle
  Bos taurusBos indicus
Maximum diameter of the dominant follicle14–20mm10–12 mm
Average corpus luteum diameter20–30 mm17–21 mm
Age at pubertyApprox. 12-14 months16-40 months
Oestrus durationApprox. 18 h mainly during the dayApprox. 11 h Mainly at night
Ovulation28-31 h after the onset of heat25-26h after the onset of heat
HierarchyCan affect the oestrus behaviourStrongly influences oestrus behaviour

Practical implications of differences in reproductive physiology between bos indicus and bos taurus
  • In bos indicus CL is more difficult to palpate during the rectal examination
  • Bos indicus females are highly sensitive to the FSH dosages currently used for superstimulation of bos taurus cattle and lower doses should be used in this species.
  • Due to high incidence of post partum anoestrus and poor body condition in the first months post partum the answer in many oestrus synchronisation programs is poor in pastured bos indicus cows in the first 100d pp.
  • Improvement of the nutrition of bos indicus cows and temporary calf removal are important tools when an oestrus synchronisation program is to be used in bos indicus suckled cows.