Applied Animal Nutrition-I

GROWTH IN ANIMALS

•  Growth is the increase in weight and or size that occurs over time (i.e. age), and can be drawn as an S-shaped (sigmoid) curve.
• Developmet may be defined as the changes that occur in the proportion of various parts of the animal from conception to maturity. As animals grow, they do not simply increase in size and weight but also show what is termed development. By this we mean that the various parts of the animal, defined as anatomical components (e.g. legs), as organs (e.g. the liver) or as tissues (e.g. muscle) grow at different rates, so that the proportions of the animal change as it matures.  

Nutrient requirements for growth 

• The nutrient requirements for growth are determined by the chemical constituents of the body growth.
• The animal growth contains water, protein, glycogen, fat and ash.
• The energy content of the body is almost entirely contributed by the energy contained in protein and lipid.
• The growth of all these components can be investigated by slaughtering and analyzing ani­mals at successive/stages of growth.
• Fat is deposited at an increasing rate and protein at decreasing rates.
• The energy content of the body increases as the fat content increases.
• As the body weight of the animal increases, the protein deposited decreases while the fat and energy content increase.
• The quantitative differences in body composition during growth are very important because they affect the quality of meat and serve as a basis for calculating the energy requirements.