THE SEARCH FOR SOUND ALTERNATIVE TECHNIQUES FOR DATA PROCESSING
1. It was decided to graph the data points for each market day for the 3 major markets for the period 1989 - 1994. Firstly the price was graphed against liveweight. Viewing the graphs showed a lot of variation, and of course the graphs did not take into account the differences in grade of animal, which is bound to have an effect on value and price.
2. Because of this, the graphs were re-produced showing the price against carcase weight (carcase weight was calculated from liveweight, sex and grade using the Texas A&M tables).
A 3rd Variation was also done - showing the price against edible weight (muscle plus fat - again using percentages from the Texas A&M Study).
Note that these graphs (about 40,000 combinations of them in total) can be viewed by running the MIS Computer System and choosing option SCREEN GRAF - which is present in Column 1 Row 9, and also in Column 10 Row 1. A full explanation of how to use this option is given in the help screen - press F1 key to show....
3. MANY of these graphs showed good apparent data point groupings and coherent patterns emerging (SOME of these graphs were however extremely poor); there appeared to be little difference in pattern between the carcase weight and the edible weight graphs for any and every market-day.
The main findings were:
- the graphs would either be straightline with the origin, or would curve upwards to some extent, or would curve downwards to some extent, but still appearing to head through the origin.
On looking at these patterns theoretically, it was reckoned that the straightline with the origin pattern indicates a linear price vs. weight relationship, i.e. an approximately uniform price/carcase kg or price/edible kg independent of animal weight and animal grade; an upcurving line indicates a premium for heavier carcases - i.e. a premium for heavier animals and for higher grades; a downcurving line indicates a penalty against heavier animals and higher grades - which actually get a lower price per kg of carcase (!).
Out of interest, Dar appeared to be a market which was relatively flat or even penalising heavier and higher quality animals, with Moshi favouring better quality animals to some extent, and Arusha the most. i.e. Dar was generally straight line or downcurving, whereas Moshi was usually upcurving, and Arusha even more so.
4. These graphs of price vs carcase weight or price vs edible weight were now reworked splitting out steers, cows and bulls. For those graphs which had a good initial profile (i.e. most of the graphs), the following findings resulted -
- cows tend to come at the lower range of the carcase weights for the total population (no surprise)
- bulls tend to come at average or above-average on the carcase weight range (no surprise)
- cows seem to come in at above-average price for their weight
- bulls seem to come in at average price for their weight
Because of these findings, it was decided that each sex should be treated as a separate group for data analysis - any ideal wish to amalgamate all sexes for data processing would not appear to be justifiable; although from viewing the data such a move might be gotten away with for these 3 terminal markets, an amalgamating approach would probably not work at primary or intermediate markets, where for example cows are often bought and sold for breeding or milking and not for their meat value (it is uppermost when trying to explore a workable methodology to get one which will work anywhere worldwide for any time period).