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Minimize Mustering Distance
Mustering distance prior to yarding for transport should be minimised as well as other stresses, such as poor handling facilities or mixing of mobs, should be avoided.
Minimising stress in the days leading up to slaughter is also essential to achieve a low pH in meat, which in turn means meat is tender, bright coloured, and has a long shelf-life.
The low pH comes from conversion of glycogen in the muscles to lactic acid after slaughter, Gordon explained. Undue stress on the animal prior to stunning at the processing plant depletes muscle glycogen stores, so pH doesn’t drop so low post slaughter and meat quality is impaired. High feed quality in the final months of finishing boosts glycogen storage so animals are better able to cope with stresses, should any be unavoidable.
Stress may be induced psychologically, such as by unusual handling or yarding procedures or introduction of new animals into a mob, and/or physiologically for example due to hunger, thirst, oestrus, temperature extreme or injury.
Age is another key factor in meat quality. Older animals lay down more connective tissue, jeopardising meat quality, so good growth rates throughout their lives are needed to ensure they “finish” before too much connective tissue is laid down.
“Finishers need to understand which lines of cattle grow best for them and know with some certainty they will hit their target weight and quality by a certain date.”
Adequate fat cover, the traditional measure of whether an animal is finished, is important to prevent cold shortening post slaughter. Too little and meat chills too rapidly causing it to go tough, Gordon explained. Too much fat and it needs to be trimmed, which is costly and inefficient – both on farm and for the processor.
Fat colour is driven by breed and feed, certain breeds such as Jersey take up more of the fat-yellowing compound found in pasture, β-Carotene. Fat stores ‘turn-over’ in about 60 days which is why feedlots hold cattle on grain for at least that long to ensure all fat has gone white by slaughter.
“There’s not much we can do about fat colour because we use pasture based systems but fodder beet will reduce it,” Gordon noted.
Fodder beet finishing has also been shown to increase marbling scores, provided other stresses don’t undo the increased fat deposition the high carbohydrate feed promotes, he added.
Ensuring good animal health throughout finishing by minimising parasite pressures and avoiding mineral deficiencies is also important to maximise the chances of achieving the best quality grading, said Gordon.
“I’ve been on farms where all the deer get selenium and copper, but the cattle don’t. If in doubt, get a test done. The cattle might not get as clinically sick but they can still be deficient.”
