Abstract
Extract
In order to maintain the concentrated seasonal calving pattern which is a feature of dairying in New Zealand, herd owners must successfully mate or inseminate a high percentage of their cows within a limited mating period. That this does not always occur is indicated by the report of CitationFielden et al. (1973) who found that, among 14 Manawatu and Wairarapa dairy herds, 21% of the 2-year-old cows were not inseminated during the first 4 weeks of mating even though most of thesecows had calved at least 60 days priorto examination. Over 90% of these unmated 2-year-old cows exhibited an anoestrous syndrome associated with small inactive ovaries.