Quiz 20: Adaptation to the Environment
Intensive management includes integrated poultry enterprises, confined swine operations and large dairies. Under intensive management, the environmental conditions are highly controlled along with the availability of adequate feed and water. The feed rations are balanced carefully and health programs are monitored closely. The temperature, humidity and other weather influences are controlled by the provision of well planned engineered housing system. Extensive management contains low producer control, all environmental conditions. The ruminant animals are managed extensively under various climatic conditions because the grazing forage availability becomes seasonally limited. The livestock are capable of performing under such conditions because they are genetically adapted to the environment. This can be accomplished by a process known as acclimatization.
Genetic adaptation is resulted in population that exists in a specific environment and climatic conditions over a period of time and develops distinct characteristics to cope up with the conditions. For example, the British cattle breeds such as Hereford, Shorthorn and Angus exhibit the growth of thick hair coats that enables them to survive in cold winter conditions. They can better handle of warm temperatures late in the spring and summer. The Brahman cattle can handle heat, humidity and parasite exposure at the normal level and therefore, these cattle have slick hair, increased skin folds, dark skin pigmentation and they sweat more than the cold weather adapted breeds. Acclimatization involves series of biological adaptations to reduce the physiological stress caused due to climatic conditions. The process requires duration of several weeks to months and during the period of transition livestock are moved from one type of climatic conditions to new environment for careful observation and management. For example, evaluation of cost effective constructions to provide shade or sprinkler systems to increase the performance of Bos taurus when exposed to heat compared with Bos indicus cattle that are genetically heat tolerant. In some cases, the genetic selection favors in combination with environmental modifications therefore, acclimatization is very important for animal productivity to make effective management decisions.
Shift in the seasons result in changes in temperature and changes in daylight length. In the Western hemisphere, the temperature and daylight increase during the summer and increased amount of heat is provided to the animal. In autumn the length daylight and temperature would decrease. Seasonal changes result in hormonal changes in animals to enable them to respond physiologically according to the seasons.