HerdView

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Veterinary Herd Analysis with HerdView: A Short Introduction to Practical Use

Contents

Introduction

Getting started

Go to the directory where the analysis programme is stored with examples of herd data. If the programme and the data are on a floppy disk, then put the floppy disk in the floppy disk drive and type 'a:'. (It is however more appropriate to install the programme on the hard disk of the PC.)

Type 'herdview' and press the 'Enter' key. Now the HerdView programme is started.At the top and bottom of the screen, menus appear on 'bars'. Move the mouse cursor to 'Files' and 'click with the mouse', i.e. press the left button and let go immediately. Now a new menu appears. Click 'Definitions'. On the menu a series of file names appears. They serve to group events (mainly disease diagnoses made at treatment).

When the programme is used for the first time, the mouse cursor is moved to 'dk-herd.def' followed by a click after which the file name is highlighted. The mouse cursor is then moved to 'OK' followed by a click. The highlighting is now off, but the name of the selected definition file appears at the bottom right corner of the screen. Again the mouse cursor is moved to 'Files'. Click and click again at 'Data'. Now a list of available herd files appears. The herd of interest is selected by clicking the file name followed by clicking 'OK'. Now the herd data are retrieved with a speed according to the capacity of the PC. The name of the selected data file also appears on the bottom bar.

In case the number of events (symbols) are high, the lists may be very crowded. This may be solved by clicking 'Edit', and a menu appears. Click 'Events', and a menu box appears in the middle of the screen listing the definitions of symbols used in the list. By moving the mouse cursor to the 'right arrow' at the bottom of the menu box and keeping the mouse button down, the list of symbols can be scrolled down. The same procedure with the 'left arrow', will scroll up the list. If the mouse cursor is placed on the 'button' between the right and left arrow at the bottom of the menu box, it is possible to move fast up or down in the menu box by keeping the mouse button down and moving the mouse to either right or left. Moving up or down is also possible by using arrow keys (up and down).

Now highlight the symbol for one or more events to be deleted - for example 'High SCC' - by clicking the line in question. Then press the 'Delete' key on the keyboard which makes the line grey. To cancel the choice, recall the event by pressing the 'Insert' key. After having chosen symbols - click 'OK'. By repeated retrievement of data (which takes some time), the list is restored without the deleted symbols. By suitable combinations of 'xx.def'- files and editing of events whatever complexitivity of the event list can be designed.

HerdView can now provide precise answers to the following questions - questions, which are crucial to an epidemiological analysis of data from a dairy herd.

Which events occur and at what time of year

The chart can be erased by clicking somewhere on the chart box. Thus a green so-called 'icon' appears at the top left corner of the chart box. By clicking on this icon, the screen is cleared. The chart box can also be removed by clicking 'Statistics' again and then clicking 'Delete' on the menu.

Select 'Statistics' again and then 'Frequency' and 'Udder treatment'. HerdView only shows the cows with this treatment symbol and the symbols are highlighted. At the bottom of the screen, the number of udder treatments per week during the year appears. Thus it is possible to evaluate, whether the event occurs in connection with a calving or at a certain time of year. Clear the screen again.

When did the events occur as related to lactation stage?

Click 'OK'. After a while - depending on herd size and PC capacity - a new screen picture appears. For each cow, the time from start to event marked with a coloured bar appears. By pressing the keys 'Page down' and 'Page up' (often abbreviated 'PgDn' and 'PgUp') it is possible to 'browse' the list. The arrows and the button farthest to the right on the screen can also be used when browsing up and down. It is now clear, whether the time from start to event varies during the year. If a larger number of bars for cows having calved at different times of year end at the same time, the events probably take place independently of calving.

At the bottom of the screen, a chart with number of weeks after start on the horizontal axes is shown. On the vertical axis, the 'accumulated' percentage, where the event took place as related to any time after start, is shown. The highest bar shows for example '% pregnant of calvings', if 'Positive pregnant check' is 'Event'. The slope shows how large the 'Event risk' (hazard) is at any time after start (calving). A steep rise during a lactation period means that a large part of so far 'event-free' animals has experienced the event in question during the period. As the number of event-free animals at the end of the lactation often may be very low in typical (small) herds, slopes later than 36 weeks after calving should be interpreted very carefully. If a frequency analysis of the event in question is carried out at the same line, a rather complete picture of the occurrence of the event in question as related to time of year and lactation stage appears. Whatever event can be selected as start of time for such a event analysis. Clear the screen once again.

Differences in analysis results for different groups of cows in the herd - do they exist?

Single cows can be deleted from the list by clicking 'Animal' on the 'Edit' menu. Single cows to be deleted from the list (and thus the analysis), are highlighted by clicking the mouse. Press the 'Delete' key to delete animals. Press the 'Insert' key to recall animals. It may, for instance, be relevant to delete purchased animals or animals with specific diagnoses (e.g. ketosis) from an analysis. This will make it possible to compare analysis results among well-defined groups of animals.

How were the insemination and pregnancy rates in the herd?

Now chose 'Repro' on the statistics menu. Two charts appear showing the development in insemination and pregnancy ratios during the year. The calculation method is described in a Thysen & Enevoldsen (1994). These two key figures together have a major influence on the time expected to pass before a cow becomes pregnant after calving. The slope in a 'Lactation time analysis' of time from calving to pregnancy is primarily a product of these two parameters and the interval from calving to onset of the voluntary weight period. Analyses performed at The Danish Institute of Animal Science show, that the number of days from calving to the time, when 50% are pregnant, is a valid expression for reproduction efficiency in a herd.

Other possibilities with HerdView

How to save and print results from an analysis with HerdView

Without a mouse

Exit programme

Literature