August 26, 2009

Agricultural history: New Zealand's 1948 milking revolution

Agricultural history. Dr W. E Petersen's 1948 visit to New Zealand.

By Dr Clive Dalton

Pan Am has landed

In1948, a quiet revolution hit New Zealand dairy farming. It arrived with the landing of a Pan American World Airways airliner at Auckland Airport, carrying Dr W.E. and Mrs Peterson from Minnesota University in the USA. New Zealand cows and dairy farming were never the same again.

Before 1948
The milking machine became popular in New Zealand in the early 1900s and caused another quiet revolution, mainly because it freed people from the time-consuming chore of hand milking. The result was increased herd size (to even up over 100), and increased farm income and more export income for the nation.

From hand to machine
However, much of the old hand-milking attitudes were just transferred from the three-legged stool to the milking machine, as 'the mechanical milker' wasn't trusted by many dairy farmers to get all the milk out of the cow. After the machine came off, the standard routine was to 'strip' the cow by hand to get the last drop of milk from the udder. Remember that in these times, the entire family was expected to turn out to milk the cows.

Why strip?
Stripping was done for two main reasons. The last milk from the udder always had the highest fat content, and in those days farmers were paid for 'pounds of butter fat' produced. So the strippings could help boost the income - at least that was the firm belief.

Also, if you left any residual milk in the udder, it was an ideal medium for bacteria to multiply and cause mastitis, and in the days before antibiotics, this disease was difficult to cure with old remedies.

Retired dairy engineer Tom Clancy told me that on the family farm in the 1950s, he had to milk with his mother and father and they all kept to their own bails in the walkthrough shed. Tom said his mother set that standards, both before and after they got a milking machine, and tried to keep an eagle eye on them. She took ages to strip her cows after the machine came off, and expected them to do the same. But Tom and his father managed to do a 'quick strip' when she wasn't looking to get their cows out and finish milking.

Double stripping
Many Herd Testers from the 1950s in their circuits around farms weighing and testing the milk from each cow for official recording told me that they often tested on farms where 'double stripping' was carried out. Here you stripped the cow once after the machines came off, and then waited a while and stripped again before releasing her from the bail. The Herd Testers hated these farms (and their owners who inevitably were tight with money) as double stripping extended milking by hours.

A long-retired farmer still has vivid memories of how things changed on their family farm. As a small boy helping to milk their very large herd for the times of 120 cows, he remembers his father changing the milking routine overnight. He wasn't sure whether his father went to a Petersen meeting, but the message and change was rampant in the district. It was massaging udders for the magic 30 seconds after they were washed that he remembers most. Many herds in his area he said were 10-15 cows from which the family could make a living.

The Petersen revolution

What happened in 1948 is documented in a small book of 79 pages with the title of 'Dairy Cow Wisdom - What Dr Petersen Told N.Z.Dairy Farmers. Despite being widely distributed at the time, the book is now very hard to find.

It was published by the "N.Z. Dairy Exporter" and printed by Hutcheson, Bowman & Stewart, 15-19 Tory Street, Wellington with the foreword is by C.W. Burnard, Editor 'Dairy Exporter'.

Introductory paragraph
This states - 'This book has been produced because many farmers at different meetings addressed by Dr Petersen asked whether it would be possible to have all the questions he was asked throughout his New Zealand tour made easily available in one publication. It has been produced also because those of us who have been to a number of his meetings know that Dr Petersen had the answers to all the farmers' milking problems'.

Mr Burnard pays tribute to Mr Arthur Ward (pictured on cover with Dr Petersen) who was Director of Herd Improvement for the NZ Dairy Board and who made the visit possible. Peterson had taken a great interest in Ward's work and clearly they had a lot of contact before the visit.

Burnard also says in his introduction that the information Petersen brought with him about 'the elevated milking bail' would have lasting effects on New Zealand dairying. He certainly was right about that.

Petersen's tour
Petersen toured the whole of New Zealand to packed audiences wherever he went. A picture caption in the book shows such a farmers' welcome and states:

'At Ruatoki, Dr Petersen was given a royal welcome by the Maori farmers of the district, who turned out in large numbers to learn more about better milking practice'.

Psychology of the dairy cow

The first chapter in the book is called "The psychology of the dairy cow' and the lead in paragraph states:

'On his arrival in New Zealand, Dr Petersen was asked to deliver a broadcast over all the national stations. Little or no time was available for preparation, so the address which follows was really an impromptu talk to farmers. It was given on Saturday October 9, and while some ground it covers was given in his other addresses to farmers, it contains many worthwhile points'.

In this talk Dr Petersen makes points which are well accepted today, but were clearly revolutionary at the time. Here's two of them:

'I think farmers and people in general have not recognised the cow as an individual and how she behaves'.

'The way she performs in the making of milk is dependent not only on the feed she gets, but also on the way she is handled'.

Key message points
The crux of the Petersen message in this introductory chapter of the book is stated in these words:
  • Number 1. The cow must be relaxed and must want to be milked or we won't get all the milk out of her.
  • Number 2. This a relatively new one: that she should be stimulated by a proper massage of the udder and teats to let down her milk approximately one minute before the milking is to begin.
  • Number 3. That the milking machine should be operated properly and that the vacuum levels should be watched carefully or injury may result to the cow.
  • Number 4. That all the milk can be gotten out of a cow by proper manipulation of the teat cups.
  • Number 5. The mechanical milker is removed as soon as the milk ceases to flow.

This is summarised again in a little box on page 20 in the Chapter on 'Modern Milking Methods'. Here they are:
  1. Avoid anything that will excite or disturb the cow.
  2. Stimulate the let-down of milk about a minute before milking begins.
  3. Operate the machine according to the manufacturer's instructions.
  4. Don't strip by hand.
  5. Take the teat cups off the cow the moment milk ceases to flow.

Impact on farms
I have spoken to many people who were milking cows on the family farm at the time of the Petersen visit, and despite their advancing years, they still have vivid memories of the lecture attended and the 'take-home' message.

The positive result was to banish leg ropes, udder cloths and stripping for ever from the cowshed. The less enthusiastic took a few more years to accept the message - and changed in the end because or neighbour pressure. They didn't want to be the 'talk of the district' and be a farm where nobody wanted to work for them.

Some old farmers even remember the confrontations they had with their fathers (and mothers) who were not keen to leap into overnight changes encouraged by someone from America! There were even threats by the young ones to leave home if the Petersen changes were not made.

Ruakura Research Station
Dr Petersen's message fell on very fertile ground in New Zealand as Dr C.P. McMeekan was in control of dairy research at the Ruakura Animal Research Station which was formed in 1939. Dr W.G.(Watty) Whittlestone was the main researcher on milking along with physicist Doug Phillips who joined the team in 1947. Below is a famous photo of Petersen and Whittlestone meeting.

This Ruakura team drove the development of the revolutionary Ruakura Milking Machine, and it was into this environment of researching how a milking machine really worked that Petersen's message was promoted.

The Ruakura Milker is now a museum piece. Thousands sold around the world

Farmers were told about what was inside the cow's udder and the hormonal control of milk 'letdown' starting off in the cow's brain. Then they could appreciate what was going on outside the cow when she came into the dairy for milking.

Whittlestone and Phillips were starting to introduce this message to farmers as part of their early research findings, but they had not got involved in its wide extension In any case, spreading the good news was the work of the Advisory Department of the Ministry of Agriculture and Fisheries at the time. Petersen's visit was clearly an almighty boost to Ruakura's work.

There are many photos in the book of Dr Petersen viewing cows at Ruakura, and being photographed with scientific and farm staff. This picture below is a classic example of men who made a massive contribution to agriculture in New Zealand.

Meeting of great minds
There was a wonderful co-incidence reported and photographed in the book. One of the world's most influential geneticists, Dr J.L. Lush from Iowa State College was in the New Zealand at the same time as Dr Petersen - and they met at Ruakura. See picture below.

Lush wrote the 'bible' for students of animal breeding and genetics, and the principles outlined in his book are still relevant today.

All of us who were students of animal breeding treasured this book in its familiar green cover - 'Animal Breeding Plans', Iowa State College Press, Ames, Iowa, first edition 1937, third printing 1949.

The elevated milking bail

This is another fascinating chapter as it must have had a major influence on milking developments in New Zealand. The introduction reads:

'This article gives information about the elevated milking bail system now being introduced in America. It should be emphasised that in New Zealand milking sheds must comply with regulations laid down by the Dairy Division. Moreover, as some adaptation of the American system will be needed in this country, farmers should be warned against adopting the system till some authoritative trials have been made here'.

The 'official warning' tells you a lot, as MAF must have been suspicious of farmers coming up with innovative ideas to first get cows up off ground level to save the agony of back bending, and then to squeeze them up together for milking. This is what drove the invention of the Herringbone in the 1950s..

Questions and answers
There are 24 pages of the 191 detailed questions and answers that arose from Dr Petersen's travels around New Zealand. This must have been a major job for the Dairy Exporter's journalists who collected them and the editor who collated them. Somebody from the Dairy Exporter staff must have covered all the meetings.

Then these questions and answers are all indexed in the back of the book totally 296 cross-referenced entries. This would all have been done by hand- no automatic computer indexing by word processing packages in 1945.


  1. thank you for your wounderful help i am so pleased that you could help