Portal Cattle

fertility

Pregnancy or pregnancy examination (TU)

An animal is considered to be pregnant from an evaluable insemination if:
  • no post-insemation (NB) took place and
  • there is no negative pregnancy result and
  • there is no departure due to infertility.

In central evaluations, the key figures for pregnancy are determined only from 90 days after the insinfusion in question.

When determining the non-return rate (NR90), the gestation study (pregnancy result) results are not taken into account.

In order to calculate the rates of pregnancy (TREB, TRG), the evaluable insamions must be determined.

Rest time (RZ)

The resting time is the period between the last calving and the subsequent initial infusion.
Rastzeit (RZ)=FWZ + UWZ

Guideline:

  • Stock: 60 to 85 days
  • Cows: 42 to 90 (115) days depending on performance and body condition
The expected resting time (vRZ) is an estimate for the expected resting time of the cows that have not yet been inseminated.

It is calculated on a daily basis for cows that have not yet been inseminated, which have exceeded 42 lactation days p.p. It results from their average number of days after calving plus 11 days (equivalent to half a cycle). It is assumed that all these animals are first inseminated in the current breeding cycle (on average 11 days after the current day date).

See also Physiologically Conditional Minimum Rest Time.