Latest figures show a total of 6.4 million dairy cattle at the end of June 2015.
"We have 300,000 fewer dairy cattle than in 2014, which is a reversal of the trend of increases in the last 10 years," business indicators senior manager Neil Kelly says.
"Both the national dairy milking herd and the replacement herd have declined. This comes at a time of falling international prices and lower milk solid payouts."
In the same one-year period, sheep, beef, and deer numbers also fell. The number of sheep declined by 300,000, to a total of 29.5 million as at June 2015.
These provisional figures are from the 2015 Agricultural Production Survey, which Statistics NZ conducted in partnership with the Ministry for Primary Industries.
