Growth and Development of Meat Animals

Objectives:

(1) To discuss how to produce a desirable carcass by full feeding, marketing livestock when ready and not holding for excessive periods before slaughter.

(2) To show how the priority of nutrient utilization determines where growth and development will take place.

(3) To demonstrate the importance of using growth curves to determine the optimum composition of livestock slaughtered.

Reading material: Principles of Meat Science (4th Ed.), chapter 3, pages 60 to 67.

To produce a desirable carcass:

Full feed

Market when ready

Do not hold

Full feed

Why full feed? Well-bred animals with high inherent potential for growth will produce most efficiently on a full feeding program (high plane of nutrition).

Priority of nutrient utilization (tissues with the greatest importance to life are first priority):

Highest priority

Middle priority

Low middle priority

Lowest priority

Tissue	Body area	Fat depot
(A) Nervous	(A) Head	(A) Perinephric
(B) Skeletal	(B) Neck and shoulder	(B) Intermuscular
(C) Muscle	(C) Hind limb	(C) Subcutaneous
(D) Fat	(D) Rib and loin	(D) Intramuscular

The higher the plan of nutrition, the more rapidly optimum composition is achieved; growth and development

The higher the plane of nutrition, the more rapidly optimum body composition is achieved.

Market when ready

At some point and with the inherent growth potential of the specific animal involved, the proportions of muscles, bone and fat are optimal.

Obviously, optimal weight or age at which to slaughter market animals differs among sex classes and among breeds: Steers versus heifers, steers versus bulls, Charolais versus Angus, Chianina versus Shorthorn, etc. This is primarily a difference in composition caused by either hormonal activity or by frame size and maturity.