The maturity of a carcass is measured by ossification, which is the process of cartilage turning to bone in the vertebrae. As an animal matures, the fibres in the meat become progressively stronger, more rigid and are less likely to be broken down in cooking, resulting in tougher meat. The Silver Fern Farms Eating Quality system relates carcass weight to ossification - effectively a ‘weight for age’ measure. Nutrition plays a significant role in ossification rates. Cattle with fast growth rates will likely have lower ossification.
RIB FAT/TOTAL RIB FAT
Rib fat is measured as the depth of subcutaneous fat – the fat between the skin and the meat. For high-quality beef, subcutaneous fat must be a minimum of 3mm in depth. This standard aims to reduce temperature variation within the carcass muscles during chilling. Evenly chilled meat has a more consistent and predictable eating quality, as well as improved visual appearance.
Meat colour is assessed on the chilled carcass at the rib eye muscle area. It is scored against a set of colour reference standards that reflect the bright cherry red colour expected from consumers. Stress can play a significant role in meat colour as it affects meat pH levels.
Fat colour measures the colour of the intramuscular fat lateral to the ribeye muscle. Fat colour is determined by the concentration of B-carotene found in the grass which forms the basis of the diet of New Zealand stock. High levels of B-carotene will cause a more intensive yellow colouring in some animals. Breed and nutrition can also have an influence on fat colour.
The area of the eye muscle is measured in square centimetres. While this information is not used as part of the EQ grading process it is believed there is a correlation between this measurement and the value our farmers can gain from their carcases.
WHAT IT TAKES TO BE AN EQ MASTER GRADER
Our accredited EQ Master Graders collect individual carcass attributes using a uniform set of standards. They undergo an intensive training course and are re-tested every 8 weeks.
For consistent and accurate grading our certified graders use the following process:
All animals are assessed on the same part of the carcass
Attributes must be assessed within a specified time
A special torch is used to maintain light consistency
The torch must always be held in the left hand and be positioned at the correct angle.