Old animals of all species are normally slaughtered for food in most parts of the developing tropics. This choice is dictated by the fact that animals take a long time to mature. Tradition also plays a role in selection, as younger animals are often tabooed or barred from diets.
In addition, meat from older animals such as cattle fits in well with food preparation practices and eating habits because of its tough muscle fibres, a property which makes for prolonged cooking and produces chewable rather than tenderized meat, which is greatly desired in these cultures.
A few guidelines are however worth observing in selecting livestock for slaughter. These deal with the health condition and the physical quality characteristics of the animal, two important factors in the production of wholesome, good quality meat.
The Health Aspect
The obvious mark of a healthy animal is a quick, smart appearance underlying which are keen, well-disposed body reflexes. When such animals move, they do so steadily with ease, not jerkily or with difficulty. Animals that are not fat or bulky, yet unable to move or walk with ease, must be suspect of unsound condition.
When resting, the animals must not be entirely motionless. Some movement or reaction must take place when disturbed. Extremely weak, old and highly emaciated animals often have poor reflexes due to a weak muscle condition which does not produce desirable meat upon slaughter. Also, animals in an advanced state of pregnancy must be spared from slaughtering, the reason being that their blood has large accumulations of harmful waste materials associated with the developing foetus which should not form part of food intended for human consumption.
Ordinary signs of ill-health should not escape the attention of the individuals making selection. Abnormal conditions like a high breathing rate, high temperature and fever, a foamy or frothy mouth, diarrhoea and discharges of various sorts from the body are all evidence of a state of ill-health. Such animals must be separated from the rest of the stock and treated before being brought for slaughter.
A usual practice in the villages of poorer countries is the slaughter of sick, diseased and dying animals in an attempt to salvage their meat value. This is contrary to accepted conventions and must be prohibited as such meat can be a source of infection or food poisoning.
It must be emphasized, however, that these are mere guidelines for the layman and should not substitute for the services of a professional veterinarian or a trained animal health inspector. Where possible such people should be brought in to assist.
The Quality Aspect
Maturity as a criterion for selection of livestock for slaughter in developing countries does not necessarily mean very old animals. A mature animal simply means a fully developed animal. Thus in sheep the following forms of maturity exist: Lambs (sheep under 1 year); yearlings (sheep about one year old), and mutton (sheep over 1 to 2 years old). According to this scale, the prime choice in developed countries such as the USA or UK might be a lamb, whereas in developing countries, it may be a 2-year old or over, although this is not always the case. Of importance is that some other selection criteria should engage the butcher's attention such as the weight of the animal (if this can be determined at the market) and its build and shape or what is referred to as conformation. These two criteria help in assessing the amount of meat on the animal and the quality of the carcass.
The heavier an animal is, the more likely it is that it may dress higher, i.e. produce a carcass of heavier weight. This is true of well-fattened animals. Nevertheless other factors sometimes have an effect on carcass yield. For instance, an animal that has a thick skin, pelt or a heavy cover of hair over the body will most likely yield a lower dressing weight. Similarly, if the amount of “fill” of the gut of ruminants is high, carcass yields tend to be lower. In other words, as the offal or non-carcass components of the animal body increase in weight there is a corresponding drop in the yield of the dressed meat. The butcher should thus acquaint himself with the key criteria of animal selection to make a better choice in the stock he purchases.
Another yardstick of a meaty, good quality animal is the conformation or build of the animal which is seen in its stocky, rounded full-bodied nature. Such animals must also be short-necked, short-legged, and so on. The converse is true of the thin and leggy animals. Often thin animals are also poor-fleshed with bones jutting out. Bulk and wide-framed configurations as occur in some Zebu cattle, though not so much in sheep and goats, often reflect both poor conformation and low meatiness. Well-conformed animals are usually also well-fattened younger stock with fine-textured, palatable meat.
Unless an animal has reached an advanced age or is weak and diseased, an effort should be made to condition it prior to slaughter. This can be achieved by feeding concentrates (grain byproducts) and cut herbage for about 2 months. Again, no rule will be established here as some animals have a limited genetic capability to put on the desired weight or to improve their conformation by feeding. Individual norms must therefore be established for the different breeds of stock.