Question

Explain why range animal nutrition is different from that of classical animal nutrition. State and discuss the factors that influence the nutritional status of grazing animals

Answer 1

Animals that live and graze in the grassy open land are called range animals. They are primary consumers of the vegetation formed by trapping the solar energy. The range animals can be categorized into small browsers such as white- tailed deers, intermediate feeders like sheep and goats and grazers such as cattle.

Forage intake in the grazing animals are influenzed by various factors such as

1. Physiological state of animal

The nutritional requirement of grazers mainly depend on their life stages such as young animal, pregnancy period, lactation and non lactating period. The lactating grazers have highier nutrient demand and greater intale than the pregnant one. Hormonal changes during lactating may reduce the rumen sensitivity and pressure and so the animal eats more. Pregnancy does not affect the intake untill the last trimester where the intake decreases slightly.

2.Topography

The nutritional requirement of grazers also depend on environment. Grazers require more energy expenditure as they walk long distances in search of food. So it is observed that cattle grazing range land use 30% more energy than confined ones . Thus grazers spend more time in eating and foraging for food.

3. Climate

Climate especially the temperature influenze the amount of food taken by grazers to maintain body functions. Each herbivore species have their own comfort zone of upper and lower temperature limits. As the thermoneutral zone is stimulated or depressed due to various factors like preciipitation, snow etc intake of food decreases due to decreased grazing time. In cooler temperature the animals metabolic rate increases to maintain internal heat and thus stimulate more intake than in summer.