Quiz 17: Providing Nutrients for Body Functions
Body maintenance depends on nutrients supplied to the body to keep its functioning in a stage of well being. State of maintenance is observed with no gain or no loss of weight or production theoretically. Maintenance functions exhibited by the nutrients include body tissue repair, regulation and control of body temperature, meeting the energy requirements to all vital organs such as respiratory, digestive tracts and etc. functioning. The body maintenance also includes the water balance maintenance which is taken care by nutrient supplements.
Nutrient requirement should meet maintenance needs first before taking care of other body functions. The livestock and poultry require half of all the feed to meet the maintenance requirements. The feedlot animals may use only 30 to 40% of nutrients from their full feed for maintenance purpose. Young animals require sufficient nutrients to build up the growth. The requirement of nutrients to support the growth includes energy, protein, mineral and vitamins. Protein is required for the muscle building. Minerals like calcium and phosphorus help for the bone growth. As the young grow into adults, the nutrient requirement changes due to increase in weight and growth rate. The TDN, protein intake and net energy intake requirements are also increased. Sufficient quantities of macro and micro elements and vitamins are supplied through the feed stuff to support the healthy growth in the animals. Mature breeding animals require 90% of their feed for the maintenance purpose. Most efficient dairy cows that produce 100lb milk per day consume daily feed 4 or 5 times to meet the maintenance requirement.
Young animals require sufficient energy to sustain the growth, metabolic rate and activities. Young animals obtain some energy from milk and additional energy from carbohydrates and fats supplied through forage and supplemental feeds. Feed grains are rich in carbohydrates and some fats. Young ruminants on good pasture obtain sufficient energy from both the pasture and milk. Large animals require more feed to meet the maintenance requirements that are not linearly related to body weight. Whereas, the small animals require more feed per unit of body weight than large animals. Therefore, the approximate maintenance requirement in relation to body weight is expressed as Wt 0.75 rather than Wt 1.00. If a 500lb animal requires a feed of 15lb per day, and a 1000lb animal of same type does not require twice as much feed though the 1000lb animal weighs twice than the 500lb animal. The quantity of 1000 0.75 is determined and applied to show that 1000lb animal requires 1.7 times more feed for maintenance than the 500lb animal. Thus, a 1000lb animal requires approximately 25.5lb daily (15lb x 1.7 = 25.5lb).