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):

  1. Highest priority
  2. Middle priority
  3. Low middle priority
  4. 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

Growth curves; growth and development

 

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

Slaughter point for optimum carcass tissue proportions; growth and development

Sex-class breed differences in composition at different slaughter points; growth and development

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.

Optimum carcass composition; growth and development

Marbling; growth and development

Fat thickness; growth and development

Do not hold

What happens if we allow the animal to go beyond the point in weight at which it would produce the optimal carcass composition?

  • Decreased rate of gain
  • Decreased feed efficiency
  • Undesirable carcass composition

Decreased rate of gain

Decreased feed efficiency

Undesirable carcass components

Review of Material — What the student should know:

(1) The influence of full feeding on achievement of optimum body composition.

(2) Optimum body composition and the factors that influence it.

(3) Why overfeeding is a problem in the beef industry.

J.W. Savell, updated March 28, 2021


 

Links to related sites on the Internet

Value-Based Marketing of Beef

 


 

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