Animal behaviour and welfare. Training heifers for milking routines

Training heifers for milking routines

By Dr Clive Dalton

Research knowledge
There is now plenty of research to show that cattle can learn basic routines in a very short time, and these can result in economic benefits to the farming business.

With hand milking and in the early days of machine milking when herds were small, the importance of the ‘human-animal bond’ was well known.  In the recent move to large herds, there has been a massive tendency to forget about cow behaviour and the importance of ‘stockmanship’, which is all about this intriguing bond.

Rising costs
With the rising costs and worldwide shortage of skilled labour, especially in large herds, management needs to exploit the human-animal bond to produce more milk with high animal welfare standards, which will achieve high returns on capital invested.

The animal's view

On the animal side, because milking letdown is under hormone control, cows which are less stressed produce more milk, have lower Somatic Cell Count (SCC) so milk quality is improved, and they have less mastitis with less pain and suffering, and reduced veterinary costs.

The human's view

On the human side, when the milking routine is a pleasant experience, the milkers’ positive vibes are automatically transferred to the cow, and especially the maiden heifer calving for the first time.

If the human has trained the heifer well for this first lactation so she won’t meet any novel or traumatic experiences during milking, then a successful outcome in achieved in terms of animal welfare, animal health, veterinary costs and more milk in the silo for the rest of her life.

Heifer training routine



The heifer training routine below has been developed by Landcorp Pastoral Farming near Taupo, under the supervision of Farm Manager David Morgan. 

It is to be highly commended as an example of how the human- animal bond should be exploited.




Routine details
Stage 1

1. Bring heifers from the paddock into the collecting yard at the dairy and let them stand without disturbance. This allows them to experience the smells and sounds and feel the hard concrete under their feet. 
   

  

2. No people should be present and no radio playing  or any other noise.

3.  No access to milking bails (note gate across entrance to bails to close them off).  

 

 4.   Gate between entry and exit to and from the platform open (see picture above).   This allows free exit from the yard.

5.  Heifers should exit and move away from the yard and out of sight of those standing waiting. They have got to appear to be escaping back to a paddock.

  

6. Do this routine for 3 days.

Stage 2

1. Bring heifers into the collecting yard.
2.  No people present.
3. Radio on.
4. Allow access to 3 bails with feed (molasses) in the troughs.
5. Allow free exit from the yard, again making sure heifers appear (to their mates standing in the yard) to be escaping in a regular flow.
6. Do this for 4 days.  Over this time, most heifers will have learned to enter a bail to taste the feed, and back off while it is stopped.

Stage 3

1. The platform is set moving at the lowest speed possible.
2.  Radio on.
3. Milking machines turned on.
4. All the bails are kept full of feed.
5. Heifers are allowed to enter and leave the bail on their own.
6. While on the bail, udders are treated with wetit and/or teatspray.
7. Near the end of each session, a person gently guides any reluctant heifers to enter the platform with a small backing gate. By the end of 2 days of this practice, all heifers are happily going on the platform. (See picture below - manager showing where he stands holding gate).
   

  
 

Farm manager showing where he stands to encourage any of the last reluctant heifers to go on to the platform.  He quietly closes the gate behind them so they walk on.

8. The total training has taken 2 weeks.

Stage 4

1.  Heifers calve with the cows.
2.  They come in for their first milking after their calves have been picked up in the calving paddock.
3. Their udders are massaged before the cups are put on for the first time.

 Heifers return to grazing on their own with no dogs or stress, attracted by a new feed break.

Agriculture communication. Part 1. Making moving images - Video and DVD

Making moving images - Video and DVD

By D.C Dalton and G. R. Moss


The power of moving images
Moving pictures are much more powerful than still pictures and the written word in getting a message across. Everyone knows that, and it’s especially true in farming where so many things we do are concerned with ‘action’.

In the old days this meant films. They were not easy to make, were expensive, editing was tedious, and in the public sector you needed a ‘ticket’ to operate a movie projector correctly.  Digital equipment to produce videos and DVDs has thankfully made things a lot simpler.  It’s easy these days to record moving pictures with equipment getting smaller, cheaper, easier to use, and of ever-improving quality.

However, there’s still a need to appreciate some basic principles about using moving images for successful agricultural communication.

Audience benefits of moving images

• In a well-made video they receive factual information in a clear, direct and logical manner.
• They see things not readily accessible.
• They can hear and see experts on the topic.
• They can see condensed (time lapse) sequences of events over a period of time.
• They can see and hear varying points of view.
  

Presenter benefits
The presenter also benefits from the above audience points, plus these extra two:

• Videos and DVDs tell the same story each time shown. The message is consistent over many venues and times by the same or different presenters.
•  The length of the presentation time is accurately known.
  

So you can see how the cry of ‘let’s make a video or DVD’, is always heard when communication ideas are discussed.

Right at the start - key points to consider

1. Is there a budget?  This question is so often left to the end. Deal with it at the start, and if there is no budget, forget the idea.  So often people have half a budget, or a vague figure of some money which they think will appear from a somewhere!  Or they expect you will have ideas where they can get the money.  The budget should be clear with some written guarantee that it will appear before the bills come in.
2.  Packaging. The biggest risk these days is that your masterpiece will go straight into the ‘junk mail’ bin and never be opened. So packaging is critical so at least it will end up on the kitchen table and be opened.  Someone else in the family (e.g. the children) may grab it to see what it’s about and if there are any freebees inside.  They may be the ones to encourage Dad or Mum to at least open it and even put into the player for them.
3. Distribution.  Decide how to distribute the finished product. This must be built into the budget.  There are all sorts of ways of getting your message out, but they all cost money. Some professional marketing advice is a good idea, in the very first stages of planning the project.
4. Time involved.  Never believe the video maker. If they say it will take ‘a couple of hours’ then write off half a day, and if they say ‘half a day’, write of at least two days!  Inevitably, they never start on time and certainly don’t think there is such a thing as a finishing time. The finish is when their job is done. Also be prepared for the message the next day that something has gone wrong somewhere with the film, or there’s a bit that’s not right and they need to shoot some parts again.  They’ll assure you it won’t take long! Never believe them.
5. Who are the clients? This is an obvious question but so often it’s only half researched, because the producers don’t ask the right people or the right questions. They ask those who give will them the answer they want – and of course they are delighted to get it.
6. Will your client watch the video/DVD?  When will they find the time?  Farmers are outdoors people and sitting in the house watching a TV screen sounds and looks like laziness!  This question should be the first question asked, but rarely is. Check the number of unwatched promotional videos and DVDs on shelves that have never been watched.  Research years ago in the hight of video recording of TV programmes showed that only 9% of them were actually watched.  Your product is going to have to be different.
7. What’s your message? Is it clear and simple, and is it something that your clients will want to hear – or something you think they want to hear. What’s in it for them – more money or just something nice to have? It had better make more money or your money will be wasted.
8.  Is a video/DVD the best format?  Have you got material to suit an action message?  There’s no point in providing moving pictures of talking heads.  You need to show some action in saying how good your product is and how easy it is to use.
9. How long should it run?  It’s hard to get through to people how much information you can cover in 60 seconds. In the old days people insisted on at least a half hour video, because Country Calendar had gone for decades for an hour each time. Today, people want videos under 10-15 minutes maximum.
10. A shooting script or storyboard?  This is an early essential before you start thinking about recording any action. Write the message out showing the pictures. Alongside write the words that will be spoken to go with it.  The spoken words will be very different to the written words as the commentary must be in conversational English.  Keep the talking heads to a minimum – they soon get boring.
11. Front person.  This is critical to your message.  You’ll need someone to front the programme, add continuity at various points, and give the final message.  Listeners/viewers remember the first and last things they hear, so the start and end must be very strong.  Choosing a person can be tricky.  Things like age, credibility, personality and public persona are all important, and easy to get wrong.  Hiring a professional will cost you big money – but this could be worthwhile.
12. Narrator. As well as a front person as presenter, you may also need a narrator to do a ‘voice over’ commentary.  This is a ‘professional voice’ which again will cost money.  Don’t underestimate the importance of this in generating the credibility of your message.  The ‘voice’ must fit the tone of your message. The narrator's  'accent' is very important in this.
    
13. Location.  Where are you going to shoot the action?  Make sure the person who is going to do the filming has a good look at the location well before the event. They will be able to see what gear they need, as they may have to hire it.  And make sure you have a plan B if the weather breaks up.  Down time can cost you money.
14. Accommodation and meals.  Those involved in the project will need to be looked after, so this needs to be sorted out early and go into the budget.
15. Clearances. You may need clearances from a number of people and organisations. Having these in written form is a good idea, and it would be best to get something from a lawyer about what’s needed.  Professional photographers have a ‘model release form’ for pictures they take of people.  You may need permission to enter properties, use animals without compromising their welfare, and avoiding doing things that will cause accidents or damage to people or property.  You may also need insurance.
16. Borrowed material.  There are very strict rules on copyright on other people’s material (words and pictures) which must be respected.  Check with the sources you use and get their written permission to be doubly sure you won’t end up in court or have to scrap your end product.
17. Music. Remember that any music you use as background could have copyright on it too with royalties to pay.  There is some general music around with no copyright needed so check this out.  The important point is that the music must suit the message.
18. Acknowledgements. It’s better to go overboard on acknowledgements than end up with complaints and threats, resulting in having to dump all your hard work and risk court action.
19. Final check.  How often you hear of situations where, despite all the checking, some faux pas has slipped through.  The problem with pictures is that the human brain often filters out things that the camera records. The biggest risks are in the areas of food safety, occupational health and safety and animal welfare where pictures have slipped through that are well below approved standards. So have all areas checked by appropriate experts, and even get them checked after the experts have viewed them.
    

Agriculture communication. Part 2. Using moving images. Video and DVD

Using moving images. Video or DVD

D.C Dalton and G.R. Moss


How long can we concentrate for?
Research some years ago showed that students’ concentration times averaged around 7 minutes.  This is out of date, and we suggest from personal experience that 2.5 to 3 minutes is now more like it.

This has been driven by the massive increase in TV advertising, and primary school teaching where group activity and talking all the time are actively encouraged.  So expecting mature people to learn,(whose learning patterns are no different to children) and enjoy the experience while sitting and listening for long periods of an hour or more has long gone, and today’s farmers are no exception.

Things to check before using video or DVD

• What are you going to play it on? 
• Is the power source reliable?
• Have a Plan B in case things go wrong.
• Make sure everything works well before the meeting. Get there at least an hour before and give things a run through.
• Make sure you know what’s on the video!  You could have picked up the wrong one!
• Set the sound levels to what you think is correct, and check again with the audience when things are running.  A full room requires a higher volume of sound.
• If you are not sure how the equipment works, make sure someone who does is at the venue.  This is especially the case with hired gear.  Never trust the batteries in hired gear – always ask for extras.
• Check that everyone in the audience can see the screen.  Remember that apart from the front row (that nobody likes to sit in), participants will have someone sitting in front of them, so get the screen up high.
• Stack up the back row seats (or put reserved on them) till people fill the front rows.
  

Limitations of videos and DVDs
Consider the limitations of videos and DVDs in getting your message across so you’ll provide a positive learning experience for the audience.

• Videos and DVDs are costly to make. They are only cheap to reproduce.
• There’s a rapidly increasing number of them available, but inevitably they are not precisely on the topic you want.  So it’s tempting to use them, with a high risk of confusing your own message.
• In New Zealand, it’s tempting to use overseas material that is not relevant, or is only partly so, so you can waste time putting the message into local perspective.
• Videos and DVDs are ‘one-way’ communication which is a major problem.  There’s something about a movie with soothing music that puts an audience into a relaxed state, so when ‘questions or discussion’ time arrives – there is a deathly silence. They can kill face-to-face communication – nobody can talk back to a video.
• To avoid this trap, run a video through once with sound, then run it with no sound, hitting the pause button at frequent intervals to discuss important points.
  

How to increase benefits

• Don’t show a video or DVD when the audience is tired or hungry – or too well fed and sleepy!
•  Use selective listening exercises. For example: Ask Group 1 to look for things they strongly agree with. Ask Group 2 to look for things they strongly disagree with. Then ask Group 3 to suggest things that could and should have been included in the message.
• Get a spokesperson from each group to briefly summarise their findings.
• Have a team quiz (with prizes) between the three groups on the subject content.  Make this fun and memorable.
  

Further reading.
Moss, Geoffrey. (2006). 'Training secrets'.
www.mossassociates.co.nz
ISBN 0-9583538-8-3

Introduction to Practical Animal Breeding

Clive Dalton's latest1980 Practical Animal Breeding textbook - is devoted to providing a pragmatic person's guide to the sciences of animal breeding, genetics, population genetics, basic biology and Mendelism, with examples and case studies of their application in agriculture, farming, animal production, and livestock improvement.

Detailed information is provided on the practical application of scientific theories for breeding and selection decisions, breeding methods, breeding practice, breeds, breed structure; with a focus on cattle, sheep, pigs, and poultry.

As a student in the early 1950s at King’s College, University of Durham in Newcastle upon Tyne in the UK, I developed a great interest in animal breeding.  Those were the days of text books which we students revered, and they were relevant for decades.

I also worshipped my Kiwi Prof,  M.M (Mac) Cooper who did more for practical animal breeding in UK than anyone before or since.   After my PhD in sheep breeding in North Wales, I went on to teach animal production at Leeds University and do breeding research with laboratory mice. Farm animals were not available which had many advantages in terms of quick turnover of generations.

So by this stage I had seen every textbook on the subject and had ‘tried’ to read them all. They would have made a stack about a metre high and the vast majority of them although editorial masterpieces were terrible to read.

They all started off saying the book was designed for students, and some would even add farmers to the intended audience.  All went well for the first chapter or maybe two, until you hit Mendel and his peas.
Then soon after this, you hit algebra and calculus, and that was the end for most folk who were desperate to know what to do after you had the sheep into the pens, or the cows in the yard. Then what?

How did you sort out the best ones for breeding and the worst for culling?  Students rarely got to this point, and even if they did, they were so switched off by Mendel and algebra that they gave it all away.

Lecturers killed animal breeding for most students.  Having suffered the pain of listening to hours of this as a student, and being very conscious of the pain I inflicted on my students when covering the syllabus to get them to pass exams, frustration motivated me to try to keep things simple.

When I moved into animal breeding research in New Zealand, I really enjoyed the relief of not having to bore students to death any more with genetics and animal breeding.  It was over - so I thought.

Then as our research developed, we had regular groups of farmers and university students coming to the research station to see what was going on, and asking not just the ‘what’ questions, but the more important ‘why’ ones too.

We initiated large scale breeding schemes with 280,000 sheep and 16,000 beef cattle where the staff involved wanted to know the background theory to the programmes.

So I was back in the business of explaining genetics and animal breeding all over again - but this time, the ‘students’ couldn’t get enough of the subject, and drove us to exhaustion with their searching questions.  It was an incredibly rewarding time.

So this book really came from those years. It was written in 1980 and a lot has changed since them in the high-tech end of genetics, and with computers having so much more power to analyse massive amounts of field data.  But not much has changed down at the sheep and cattle yards where we are still looking for the best stock, and deciding what  to mate them to, to bring about improvement.  The book became a recognised text book in English speaking countries and was translated into Japanese and Spanish.

0.2 - The Dalton Multipurpose Statistic

0.2 – The 'Dalton Multipurpose statistic'

By Dr Clive Dalton

Cranking handles in the 1950s

As a student in the 1950s, we did statistics labs on small Brunsviga hand-cranked calculators with tiny levers pulled down to select the numbers wanted. You cranked the handle clockwise until a bell rang (I think when dividing), and then cranked it anticlockwise for a reason I’ve forgotten.

In a class of 20, you could not tell when your bell had rung!

Then for my PhD at Bangor University, the Agriculture Department had one electric Facit machine shared among students and staff. Inside it was a mass of robust little German cogs that whizzed around when you pressed the keys. We thought it was magic, and I pounded it for three years without problems. When I finished, there were rumours that the University was about to get a ‘computer’ to take up the entire space of an old chapel.

The computer age -1960s

In my early lecturing days at Leeds University, the Facit and American Marchant machines (see the interior of a Marchant XL at left) with a massive bank of keys ruled supreme, and were hammered by students for their projects and higher degrees.

A computer had arrived at Leeds and filled a retired church hall, and some of us started to learn to program in a mystery language called Algol, and then punch tape to get simple exercises done that took as long (if you added our errors) as using a calculator.

But our kids loved the reels of error-ridden punched tape that I took home after my failed forays into computing.

What did the end value mean?

The point was, that by the time you got to the end of a calculation, and you hadn’t botched things up a few times on the way, so had to start all over again, you were far too exhausted to think much about what the final values meant. Did they make any sense? Were they of any practical use?

Statistical magicians

When I went into full time research in New Zealand, I started to have suspicions about statistics because we had very bright professional statisticians to give advice at all stages of projects – in my case animal breeding trials. This was both interesting and frustrating.

When the statistician had ‘run your data’, and the miles of ‘line flow’ paper spewed out of the research station computer (that filled a whole room), you needed to go into a scientific trance to work out how to get ‘the results you wanted’ – so the imagined published paper would blow the scientific community away and you would be for ever famous! It was here the statisticians came into their own.

What you wanted?

It was wonderful if the results (explained by the statistician) confirmed your preconceived expectations (which you were not supposed to have), or if you were positively surprised with them. In other words you didn’t expect those results but you would have not trouble getting them published.

What was really bad news was when you were negatively surprised, as when the results went the opposite way to what you wanted and you couldn’t explain why – and would be lucky if any journal would publish the results.

The real pits were when after years of work, you got no result at all, and there was no way you could claim this as a ‘positive surprise’ that was publishable.

Hazards of long-term trials

In long-term trials, we could easily have the services of two or three statisticians as they came and went to further their careers. This could be really nasty as a newly-qualified statistician fresh from University with all A++ papers, would look at the analysis and ask why his predecessor hadn’t used the new XYZ package? It was inevitable that the new chum recommended the whole years of data be reanalyzed –his way.

The other statistician’s comment to bring on a sweat was ‘oh that’s interesting, I wonder what would happen if we put the data through the new ZYX package? I’ll give it a go’.

As the years went on, I found it hard not to scream – ‘for hell’s sake, just leave things alone’, as what came out of these packages became more and more unintelligible, and harder for us oldies to work out what it meant in practical terms. Statistical significance at different levels of probability to prove the null hypothesis was one thing, but making farming sense was very much another.

The trick was to feign knowledge of what all the statistical analysis meant. At times the blank pages in the line-flow printout were the most useful part of the output - for the kids to draw on!

Delays, delays

You knew that extra analysis meant delays in publication of a paper by at least another 12 months and sometimes more. They also meant more questions from editorial committees, whose job you very soon realised were a pack of nitpickers and/or jealous colleagues hell bent on stopping you publishing and having more published papers than they had. In a world of ‘publish or perish’, these antics didn’t help your next application for advancement with the research director.

0.2

So it was in this environment that I realised the value of 0.2 and claimed it as my own ‘Dalton Multipurpose Statistic’. This simple little value has four massive advantages, that I strongly recommend to you:

1. It is extremely versatile.
2. It is non-confrontational.
3. It can be grossly misinterpreted without causing serious harm.
4. It can bring relief and satisfaction to the needy.
   

Correlation coefficients

These are values that tell you how much one thing is related to another, and their interpretation is more abused that anything else on the planet.

• If you need a low correlation coefficient, then 0.2 can be called “low” and will support your case.
• If you need a “low and non significant” correlation to suit a case, then all you need are the numbers of observations (n) below about 60.
• Getting rid of observations is not difficult as there are plenty of reasons to classify values as ‘aberrant’. Animals die, they get pregnant before they should, they give birth before they should, they change sex half way through trials, and so on.
• If on the other hand you have a desperate need for things to be statistically significance at say r = 0.2, then increase the number of observations to over 100, and significance will be easily reached at 5% probability (P<0.05) which is respectable.
• The fact that it is “statistically significant” carries the day, rather than its probability, and not the fact that its practical implications may be total nonsense.
• Squaring a correlation coefficient (r²) should be avoided, as this can so often show how meaningless a correlation coefficient can be.
  

Repeatability and heritability estimates

Repeatability measures how things keep appearing and heritability is how strongly traits are inherited.

• If you need a ‘low’ estimate of either estimate, then 0.2 can be called low.
• This would be, for example, to show breeders that they were wasting their time in selecting for what they thought were important traits. In this case 0.2 could also be called ‘very low’.
• If however you needed it to support your own research, or a new trait that you wanted to claim a reputation from such as:
  

(Muzzle width/teat length) x √heart girth

then a repeatability and heritability of 0.2 could be squeezed from a ‘low’ into the ‘medium’ classification.

• Once it is into the “medium” group – then it can be squeezed into the “medium-high” group.
• Thus ‘low’ could be 0-0.19; ‘medium’ would be 0.20-0.40.
  
• Now 0.4 is really getting ‘high’, so 0.20-0.40 must be in a ‘medium-high’ group. You have created a winner - if that’s what you wanted.
  

Genetic and phenotypic correlations between traits

Again, these are values that tell you how much one thing is related to another. The genetic ones are about what’s inside the animal and the phenotypic ones are things you can see on the outside of the animal.

• Again 0.2 is very valuable.
• If you need a value to support a case, especially if you don’t know or can’t remember the actual value, or if you don't have one and need one, adopt the following rule:
• If you feel unsure or your job or reputation could be under threat, then use 0.19-0.20.
• If you feel confident, then really go for it and use 0.20-0.21
  

General percentages

• Whenever you need a percentage, 20% can be used with enormous confidence.
• If for example you need to show that a major fact is of minor importance, (e.g. the number of geneticists who have not written up their lifetime work), then 20% can be interpreted as small. This will take the heat out of the discussion.
  
• However, if you need to generate some heat, (e.g. to highlight the percentage of geneticists who are homosexuals or atheists, or both), then you can make 20% sound deliciously high!
• The 20% statistic is of course, the core of the 80:20 rule, which has certainly stood the test of time. You can use this rule for anything that comes to mind where you need to prove that 80% of something is caused by 20% of something else.
• Some visionary must have carefully researched this rule, who could see that the 20% part of the ratio was the clincher and would never be questioned, Have you ever met anyone who questioned it?
• If you do meet anyone doubters, simply drop it to 18-20%. If you feel cocky, raise it to 20-25%. But don’t every push it up to 20-30% as the ice gets too thin.
  

General Correction Factors

These are things that are used to get people to believe that mountainous playing fields can been made level by a bit of mathematical manipulation. A better name for them would be ‘Fudge Factors’. Geneticists need them all the time - described below.

• The effects on an animal of both Genetics (G) and the Environment (E) is the big worry.
• E can make a real fool of all your pontifications about G, as there are so many variables involved in the environment.
• But we love these variables, as it can so often save our bacon, especially in arguments with farmers where we use the trick of telling them what they know already, and that the problem is complex. By using the word ‘multifactorial’ – you can sound as if you know what you are talking about!
• You always need to find a plausible reason (excuse) why your years of work and money spent have resulted in a lemon.
• We also have to deal with what is called the ‘G x E interaction’ which is great fun where some animals do well in one environment but not in others. It adds delicious complexity to the situation – which only a host of fudge factors can help disguise.
• So here again, good old 0.2 is comes to the rescue and is perfect for the job.
  

Standard errors and standard deviations

These are tricky things to explain. You use a standard error (SE) to describe how accurate a mean is because of variation around it, and a standard deviation (SD) to describe the variation in a range of data. This is what they used to be anyway!

• 0.2 suits most needs and can be used freely if you do not have one of these statistics, or you forget to work one out, or especially if you don’t really understand what they are.
• Such is the case of a “residual standard error” which few ever knew that they were - 0.2 is ideal.
  
• The ± symbol which appears before these values fools most folk, as they are not sure what it is so move on searching for a heading that says ‘summary’ or ‘conclusions’ or both.
• Have no fear that 0.2 will get you through most editorial committees, that because of their age will ignore statistics because they won’t understand them.
• And the real coup is that they won’t dare to admit it, and stoop to ask some young smart whipper-snapper what it all means. The young always had learned from the old, and never vice versa.
• These old codgers could concentrate on checking if the author had written “data is” instead of “data are”, and if their name was in the list of references.
  

Missing values in a matrix

A matrix is a mass of little squares (cells) with figures in them all joined together in a big table with headings along the top and down the side.

• You need a matrix to show the relationships (correlations) between a host of things, and in all their possible combinations.
• You can’t have empty cells as it looks bad.
  
• It also risks putting a stop to your entire work, as some greater being will declare that things will have to wait, ‘until more data become available’. This is the kiss of death.
• All the meetings you have been attending for the last 18 months or more (expenses paid plus fudge factors) to finish the project will end.
• Never fear though as here again 0.2 can come to the rescue, simply because it can be used with confidence and without causing serious problems – at least problems where you could be blamed for.
• The reason why you don’t need to worry is that there are so many errors and generalities in a matrix that a dusting of 0.2s in empty cells won’t cause any serious damage to the outcome.
• But don’t put 0.2 in every empty cell. Break it up a bit by putting 0.19 in some and 0.21 in others. It’s not prudent go outside this range.
  

Acknowledgements

I have to thank many colleagues over the years, some of whom were distinguished geneticists and statisticians, for stimulating my thoughts in smoke-filled rooms, confirming my fears and excitement about 0.2.

The punched tape the kids loved.

They could throw the role and it would unwind for miles.

The boxes were very useful too.

I owe special thanks to Chris Dyson, Biometrician at the Ruakura Agricultural Research Centre when I worked there in 1980. Chris bristled with Yorkshire wisdom and common sense, and drew my attention to the fact that if you ever needed ‘a number’ - for anything , then 153 was the one to go for.

Chris pointed out that if you take the reciprocal of the natural logarithm of 153, this comes out as 0.199, which rounds up to 0.2. So there’s the magic 0.2 coming to the surface again for air and respect. It’s magic. QED!

Thanks also for comments by Dr Harold Henderson, veteran statistician at Ruakura whose statistical skills were only eclipsed by his patience with non-mathematical scientists like me.

I must also credit a wonderful website where images and information about old calculators abounds - http://www.oldcomputers.arcula.co.uk/calc1.htm#marchant_xl