PRINCIPLES OF LIVESTOCK BREEDING.
By SEWALL WRIGHT,
Senior Animal Husbandman, Animal Husbandry Division, Bureau of Animal Industry.
CONTENTS.
Page Page.
Evolution of animal breeding.--- 1 I Mendelian heredity in livestock—Continued.
Reproduction. 2 Colors of swine. 33
The cell theory. 2 Colors of horses. 31
The reproductive cells. 3 Colors of sheep. 32
Sexual maturity. 4 Colors and comb shape of poultry. 33
The breeding season and oestrous cycle. 6 Heredity of form and function in livestock. 34
The gestation period. 7 Relations of theory to practice. 34
Fecundity. 8 Equality of inheritance from the sexes. 34
Sex ratio. 10 Prepotency. 34
The reproductive cells in relation to heredity. ll Fixation of heredity by selection. 37
General considerations. ll Fixation of heredity by inbreeding. 37
Modification of heredity. 12 Isolation of genetic differences by inbreeding. 39
Inheritance of acquired characteristics. 13 The effect of inbreeding on vigor. 40
Telegony. 14 Crossbreeding. 41
Maternal impressions. 15 The system of breeding. 42
Details of hereditary transmission. 15 The purposes of livestock breeding. 42
Blending and alternative inheritance. 15 Uniformity of type. 43
Hereditary units. 15 Crossbreeding for the market. 44
Color and albinism in guinea pigs. 16 Improvement. 45
Mendelian inheritance. 18 Grading. 46
The chromosomes and heredity. 20 Methods of selection. 47
Sex det…