It is well established that responses in milk production to incremental increases in energy intake above maintenance are not constant and there is a curve of diminishing returns. This is illustrated by the curve shown in the below diagram (Figure 1).
a. When ME intake is below maintenance requirements, what is occurring in relation to body tissues and milk production? (5 marks)
b. Metabolic bodyweight and metabolic rate determine energy requirements. Discuss and compare each of these components and briefly describe: what impacts them (think physiology), assumptions these calculations make and how these values will change as animal increase in size (20 marks)
c. When ME intake is in excess of maintenance requirements incremental increases in consumed energy do not result in continued increases in milk production (i.e. there is a maximum production level reached). List 3 factors (physiological or metabolic) that contribute to this phenomenon. (20 marks)