58 THE BREEDING OF ANIMALS 



57. Conditions influencing puberty. The age at 

 which puberty begins in the various breeds of the domestic 

 animals is dependent upon the kind of animal, the 

 breed, the food and general care of the young before 

 puberty. Puberty in the mare comes between the ages 

 of twelve and eighteen months. Under normal condi- 

 tions, the stallion reaches the same stage at twelve or 

 fifteen months. The cow and bull of the modern breeds 

 of cattle under favorable conditions will reach this period 

 at four to six months of age, but under ordinary condi- 

 tions, not until they have attained the age of eight to 

 twelve months. The ewe and ram of the mutton breeds 

 will often arrive at the period of puberty at the age of 

 five or six months, but generally will require longer. 

 The sow and boar will reach puberty sometimes as early 

 as three months of age, but generally at five to six months. 

 The domestic hen has been known to lay eggs at the 

 age of four-and-one-half months. 



The beginning of puberty is greatly influenced by the 

 nutrition of the young animal. This influence begins 

 with the foetus in utero. If the pregnant mother receives 

 a generous supply of nutritious food during the period 

 of gestation, the young will be better developed at birth. 

 The reproductive system along with the other organs will 

 have developed somewhat nearer to the stage of sexual 

 completeness. If such generous nutrition is continued 

 after birth, the young animal will reach the period of pu- 

 berty at an earlier period than when fed on a poorer ration. 

 At the Missouri Experiment Station, Eckles 1 has shown 

 in an investigation comparing generous feeding with a 

 lighter ration that the well-fed heifer on the average comes 

 in heat 92 days earlier than those fed less generously. 



1 Eckles, "Dairy Cattle and Milk Production," p. 209. 



