A farrow-to-finish farm went from 10% to 50% of returns to oestrus, and almost 90% of them were regular.
Returns increase in a PRRS-positive farm in the middle of a census increase plus a change of management in the batch farrowing system, from 3 weeks to 1.
The owner contacted us because he has seen a reduction in performance in recent months, although no decline has been identified in any particular parameter. He says that, overall, “the sows are doing worse".
The farm reports a problem of low prolificacy (mean annual live births of 11.91) and low fertility in summer, with a marked increase in acyclic returns.
The veterinarian is called from a new established herd in Brittany because some clinical signs appear on gilts from the two first deliveries introduced in the farm.
There is an unusual increase of the returns-to-oestrus at 31-39 days. The majority are due to sows previously negative to the pregnancy ultrasound testing, and the returns-to-oestrus happened before 42 days.
There was an increase of repetitions in females (at 17-28 days, cyclic and acyclic, with a repeat rate of 22%) and mucous-like, white to brown (chocolate) vulvovaginal discharge hours after artificial insemination.
The farm, with an elevated number of animals, had been experiencing for several days an increased number of births in gestation on the weekend before moving the sows to the farrowing pens. Mortality in these births was 100%.