Tail painting — a simple form of oestrus detection in New Zealand dairy herds

Abstract
Tail painting could be a satisfactory, convenient, and economical aid to oestrus detection in many dairy herds in New Zealand. A strip of enamel paint 20 cm × 5 cm running posteriorly from the first coccygeal vertebra was used as a method of oestrus detection in 4 herds of lactating dairy cows during the premating period. Occurrence of oestrus activity was accurately identified in 335 of 350 cycling cows and lack of oestrus activity was identified in 40 of 49 anoestrous cows. Only 4 cows correctly identified in oestrus by the herd owners were not detected by tail painting. In contrast, 24 cows not observed in oestrus by the herd owners were correctly identified by painting. The technique was used in 4 herds as well as 2 larger herds to identify groups of cycling cows which were subsequently treated with a prostaglandin analogue as part of an oestrus synchronisation programme. The interval from treatment to behavioural oestrus and the incidence of silent oestrus were conveniently monitored by observation of the paint strip.