Dairy farming in New Zealand

In 1814 the missionary Samuel Marsden introduced the first Shorthorn dairy cows (then known as Durhams) to mission stations in the Bay of Islands.

From the 1840s, most settlements had farms with some Shorthorn dairy cattle and it was common for families to have one or two cows, milked by the women and children.

In 1881, the newly arrived colonist William Bowron gave a series of lectures propounding the notion that the institution of dairy factories, for the mass production of cheese, would be greatly advantageous to the economy of New Zealand.

Dairy cattle primarily feed on grass, supplemented by silage, hay and other crops during winter and other times of slow pasture growth.

[14][13] Some farms, either wholly or partly, employ winter milking, with calving in late summer and early autumn (February and March).

Production began to be centralised in the second half of the 20th century, with facilities such as the Fonterra plants at Whareroa (near Hāwera), Edendale, Clandeboye (near Timaru), and Te Rapa being the four largest in the Southern Hemisphere.

This was declared successful in 2009[27][28] Bovine tuberculosis is currently (2012) endemic in possums across approximately 38 per cent of New Zealand (known as ‘vector risk areas’).

[29] The Biosecurity Act 1993, which established a National Pest Management Strategy, is the legislation behind control of the disease in New Zealand.

The Animal Health Board (AHB) operates a nationwide programme of cattle testing and possum control with the goal of eradicating the bacterium responsible for bovine tuberculosis (Mycobacterium bovis) from wild vector species across 2.5 million hectares – or one quarter – of New Zealand's at-risk areas by 2026 and, eventually, eradicating the disease entirely.

Terminally ill TB possums will show increasingly erratic behaviour, such as venturing out during the daytime to get enough food to eat, and seeking out buildings in which to keep warm.

[33] Mycoplasma bovis, a bacterial disease known to cause a range of serious conditions in cattle was detected in New Zealand in July 2017.

As a response to the campaign the Dairying and Clean Streams Accord was established in an attempt to reduce the level of water pollution.

Initially the family owned Crafar Farms bore the brunt of the prosecutions and were labelled the "poster boys for dirty dairying" by Environment Waikato's regulatory committee chairman Ian Balme.

[42] Farmers are penalised if they supply milk that fails to meet quality standards, for example, if there is a high somatic cell count or antibiotics are present.