Wednesday, March 21, 2012

Automatic milking; a little history

As you might know, I am working in the field of animal health management since 1989, the year I started with my PhD work. Yes, that is already quite a long time. In the meantime I have gathered an enormous amount of materials, reports, scientific papers, students theses that I have been advising etc. Because my work is split over two locations (Wageningen University and the Faculty of Veterinary Medicine of Utrecht University) and as now and then I work at home as well, this gives sometimes problems. If you need something it is always at the other place. So I am trying to digitalize everything. Which is a large task that I do when I have a large lack of inspiration to do something else. Therefore, this project might take a couple of years.

Anyhow, last week I was having such an hour and I ran into an old IMAG report. This report marks, in my opinion the start of the automatic milking era in the dairy production, so it is worthwhile to give it a little attention in my blog.

IMAG was the institute for Agricultural and Environmental Engineering. It does not exist anymore and most of the work they were doing is now done by Livestock Research of Wageningen UR. With people such as Wim Rossing, IMAG was one of the key players in developments with regard to automation in the dairy sector. One of the developments was the transponder which enabled individual cow management. One of the first developments building on this transponder was the concentrate feeding box. Cows could enter these boxes, were recognized and the concentrates ration was determined by the computer.
A modern concentrate feeder box
The possibilities of individual cow identification enabled researchers to think about many sensors that could be used to monitor individual cow statuses (milk temperature, electrical conductivity, steps, body weight etc.). One other thing researchers thought about was the possibility to automatically milk a cow: a milking robot. One method of to reach this was to install a robot arm in a feeder box, where cows are coming anyway to get concentrates and milk the cow at that place. Many other possibilities have been thougth about as well but it goes too far to discuss these here.

In 1984, at IMAG a feasibility study was done. In their experimental farm (de Vijf Roeden), a concentrate feeder was made as a 1-side, 1 place milking parlour. Cows could enter the concentrate feeder and if eligible for milking, a student attached and removed the milking cluster. To resemble a real automatic milking situation, students were in the "milking parlour" for 24 hours per day during the total experiment of 11 weeks.
Setup of the milking in a feeder box experiment
 What were the  results: the cows visited the feeder box on average 5.4 times per day, of which they were, on average, milked 4 times per day. This gave an increased production level: cows produced 5 kg milk more per day than they did normally (when milked twice per day). No negative side effects were found, so the researchers concluded that the feeding box is a useful place for milking. The door was open for further development of automatic milking and this report is truly a mark in this development. For those interested, I have put a copy of the report on Slideshare

Tuesday, March 13, 2012

Parasites in cattle

Some years ago, I gave a presentation for the Flemish for Veterinary Epidemiology and Economics (VEE; http://www.fsvee.be/). It was about the economics of production diseases. During the drinks (always useful) after this meeting a young Belgan research from Gent University, Johannes Charlier approached me. He was working on the epidemiology of parasitic diseases in dairy cattle and was thinking about the possibilities to add an economic component to his work. In fact I had never considered parasites in dairy cattle very much. From my BSc years I remember the problem of parasites in calves and the things you can do with grazing of calves in order to prevent infection with certain parasites. Moreover I knew a few things about the use of anthelmintics.
Recently I learned that the whole topic of parasite infections in calves is quite a nice equilibirum with many trade-offs. Exposure of young stock to parasites builds up their immunity which prevents them for serious negative effects of parasitic infections when they are olders. In the Netherlands Harm Ploeger has published much about those items, e.g., this paper on relation between treatment of one-year old calves and milk production in the first lactation, and it is a fascinating field. An interesting summary of this knowledge can be found in the "parasietenwijzer" or "parasite compendiuim": http://www.parasietenwijzer.nl/

But let's go back to the work of Johannes Charlier. At that time Johannes was focussing on parasites in lactating cattle. He wanted to make a tool for farmers and their advisors to calculate the costs of parasites in dairy cattle, so they can think about proper measures (or not) in case the economic losses are large. The result was a programme called ParaCalc®.

Recently the scientific paper associated with this calculation tool was published in the journal Veterinary Parasitology. Besides a description of the tool, default calculations are provided, based on input parameters from 93 Belgian dairy herds. For those herds, the estimated median cost per year per cow was  € 46 [25th-75th percentile: € 29 - € 58] for gastrointesitnal nematode infections. For liver fluke infections the median costs were € 6 [25th-75th percentile: € 0 - € 19] per cow pwer year. The most important components of these costs are milk production losses.

Six veterinarians evaluated the programme and thought it was a useful tool to raise the farmer's awareness with regard to worm infections.