One has to mention here that the different working animals
deal differently with stress and fear.
Are very sensitive, i.e. they react to even the smallest
change in their environment. Hence, they are prone to heart attacks, if
they are pushed too hard or exposed to jerky movements in the transporter.
If the animal is calmed down (by spraying with water) it reduces stress
and fear in a relatively short period of time (within 6 to 12 hours) and
the effect on the quality of the meat is less.
Are less sensitive momentarily yet once they are under stress they do not calm down for a long period of time. Spraying with water would not suffice, not even when done for 48 hours. Cattle are herd animals, and hence have to fight for hierarchy when locked up with strange animals. The position in this hierarchy is established by means of the smell.
For animals who have never in their lives been leashed,
this is the first stress factor. In addition to this, there are strangers
in the stable who further unsettle the animals. The usually steep and slippery
ramps seem an unconquerable obstacle. On the truck, there will be other
cattle, with which the animal wants to fight for rank but it is impossible.
Effects of Stress on the Quality of the Meat:
The cattle want to run away or defend themselves against other animals. This requires energy. However, the anatomic structure of the mammal does not permit to just run away. You might have tried to run a thousand meters without warming up and achieve a good time. It is not possible because one looses strength and air after 100 meters. On the other hand, when one is frightened one?s capacity is remarkably increased.
In a situation of fear or when exposed to stress, the
brain sets free the hormone adrenaline, which enters the nervous system.
This causes in each individual muscle cell, which has to be contracted,
that the stored glucose (meat sugar) turns into energy. The produced energy
is no more used up, and is hence stored in the meat, which leads to negative
overacidification (pH value) of the meat.
The Stress-Free or Gentle Slaughtering:
No stranger should enter the stable, in order not to cause unrest among the animals. The farmer himself should lead the animal to the stable door where it is soothed with a delicacy (hay or bran). Then the animal is put to sleep without noticing it. The animal is not frightened or tense and hence it bleeds much more easily. Furthermore, this procedure guarantees that sufficient energy reserves (glycogen) remain in the muscles. The glycogen is broken down into lactic acid and causes positive overacidification. The pH value drops within a few hours after slaughtering from 7 to 5.6. The reduction is caused by lactic acid, which is produced by the glycogen. The reduction of the pH value is desirable for the durability and the good taste of the meat.
When the meat is overacid due to the animal?s exposure to stress, it becomes gluey and dark, has a bland taste and reduced durability.