Important Growth Concepts for Animal

Production.

Luis Nabté-Solís

Outline

1. Introduction 1. Introduction

2. Growth Concepts 2. Growth Concepts

3. Factors affecting growth 3. Factors affecting growth

4. Conclusions 4. Conclusions

Introduction• Growth Growth new cells. (increase in mass, not new cells. (increase in mass, not

water increase)water increase)

• Not only cell multiplication (hyperplasia), also Not only cell multiplication (hyperplasia), also cell enlargement (hypertrophy)cell enlargement (hypertrophy)

• By definition, growth includes deposition of fat By definition, growth includes deposition of fat even though muscle mass is of primary even though muscle mass is of primary interest in meat production. interest in meat production.

• Mature sizeMature size generally is considered the point generally is considered the point at which muscle mass reaches a maximum.at which muscle mass reaches a maximum.

• ME = NEg + NEl + NEy + NEm + HiE

• NEg energy content of the tissue deposited

(Berg and Butterfield, 1976)

Growth curves and tissues growth rate

(Owens et al., 1993)

(Berg and Butterfield, 1976)

Body Composition

Owens, et al., 1995

Owens, et al., 1995

(Owens et al., 1993)

Effect of feeding level on Body Composition

(Diaz et al., 2001)

Problem Review…

(Diaz et al. 2001),

(Diaz et al. 2001),

Breed Effect on Body Composition and Growth

Jenkins and Ferrel, 1997

Jenkins and Ferrel, 1997

Jenkins and Ferrel, 1997

(Berg and Butterfield, 1976)

(Berg and Butterfield, 1976)

Goats Breeds and Crossbreeds and economical assessment

(Pineda et al., 1998)

(Pineda et al., 1998)

(Pineda et al., 1998)

Conclusions

• Growth is a critical period in the animal production

• Body composition is mainly determined by the stage of growth, breed, sex, and age

• Body composition can explain in some extent differences in maintenance requirements differences between breeds

• Growth and Body Composition studies can help to choose the more adequate breed for specific conditions

• Nutrient supply can alter body composition of neonatal ruminants