Performance Recording

Stockscan is an alternative performance recording scheme which has adapted an overseas ultrasound appraisal technique which is far superior to any method being used in Australia. This will give you Growth, Fat, Eye Muscle Area and Width which promotes big long well muscled sheep. With visual appraisal and Stockscan rankings we aim to produce bigger, longer, meatier rams that will sire prime lambs to meet all market specifications .

The Meat Ranking is a means to Rank a group of young sheep with different liveweights, eye muscle dimensions and fat depth.

First a calculation is carried out to determine the average Eye Muscle Width(A). Eye Muscle Depth(B) and Fat Depth(C) for each Kilogram of liveweight. This calculation is known as a linear regression and is used to plot a straight line on a graph through all the readings (i.e. Eye Muscle Width plotted against liveweight). Any measurement positioned above this line will have a positive deviation (above average for the live weight), and any below the line will have a negative deviation (below average for that live weight).

Once the deviations have been calculated for each measurement, a formula is used to calculate the Meat Ranking. The formula adds value for excessive fat depth.

These calculations are based on giving more emphasis on Eye Muscle Width and Eye Muscle Depth. Muscle width is more to do with the type of animal, e.g. shape and leanness. Depth is associated with the environment, e.g. feeding etc. And is subject to change which would alter ranking if animals were under stress at time of scanning.

The formula does not give the leanest animal a higher rank as this group often lacks constitution etc.

The meat score is best used on a uniform group of rams or ewes to rank the group. This would usually mean rams or ewes bred by a single breeder in a given year, and is an attempt to decrease the difficulties arising from confusion of animals from different studs.

Ultrasonic rib eye scanning in live sheep.

Contrasts and reference points of scan images as a guide for operators in the placement of cursors on screens to measure eye muscle length (A), width (B) and fat over the eye muscle (C).

• Growth = Highest weight gain rams.
• Fat = Lowest Measurement is leanest.
• Eye Muscle Area = Largest area will give you longest rams and more meat on carcase for over hook sales.

In the ideal world you are looking for high weight gain rams, lowest fat measurements and highest eye-muscle area rams to turn off lambs to any market specification in the Quickest Possible time.

STOCKSCAN like any other scanning system is only a tool to assist you in your endeavours to produce the perfect carcase. You must always remember that a ram must be structurally sound and well balanced and be able to walk, eat, drink and serve ewes.