Экзаменационный перевод текста ВМиЗ
The anatomy and physiology of the cattle
Cattle are raised as livestock for meat (beef and veal), as dairy animals for milk and other dairy products, and as draft animals (pulling carts, plows and the like). Other products include leather and dung for manure or fuel. In some countries such, as India, cattle are sacred. It is estimated that there are 1.3 billion cattle in the world today.
Cattle have one stomach with four compartments. They are rumen, reticulum, omasum, and abomasum, with the rumen being the largest compartment. The reticulum, the smallest compartment, is known as the “honey comb”. Cattle sometimes consume metal objects which are deposited in the reticulum and irrigation from the metal objects causing hardware disease. The omasum’s main function is to absorb water and nutrients from the digestible feed. The omasum is known as the “many plies”. The abomasums is like the human stomach; this is why it is known as the “true stomach”.
Cattle are ruminants. They have a digestive system that allows use of otherwise indigestible foods by repeatedly regurgitating and rechewing them as “cud”. The cud is then reswallowed and further digested by specialized microorganismus in the rumen. These microbes are primarily responsible for decomposing cellulose and other carbohydrates into volatile fatty acids that cattle use as their primary metabolic fuel. The microbes inside the rumen are also able to synthesizeamino acids from nonproteinnitrogenous sources, such as urea and ammonia. As these microbes reproduce in the rumen, older generations die and their carcasses continue on through the digestive tract. These carcasses are then partially digested by the cattle, allowing them to gain a high quality protein source. These features allow cattle to thrive on grasses and other vegetation. The gestation period for a cow is nine months. A newborn calf weighs 25–45 kg (55 to 99 lb). Breeding stock usually lives to about 15 years (occasionally as much as 25 years).
Резюме оценивания
Скрыто от студентов | Нет |
---|---|
Участники | 60 |
Ответы | 20 |
Требуют оценки | 1 |