IO8 FEEDING FARM ANIMALS 



With females such unrest occurs at certain regular inter- 

 nals. Those intervals are known as seasons when in heat, 

 and they occur with unfailing regularity, when conditions 

 are normal, from the time that females are capable of con- 

 ception until they reach an age when they are no longer 

 able to conceive. Of course the period of pregnancy and 

 for some time subsequently to parturition are exceptions. 

 It is in a sense surprising, that with domestic quadrupeds 

 the interval between those periods is practically the same, 

 notwithstanding the marked difference in the natural longev- 

 ity of the different species. They occur at intervals of 

 21 days, and last for about three days. During those periods 

 the animals are in a condition of unrest, and one of its 

 worst features is that it tends to disturb other animals of 

 the herd. Because of this, where it is practicable, such 

 animals should be confined until the season of heat is 

 passed. During their continuance production in the form 

 of either milk or meat is greatly hindered. 



When animals are reared for meat only, unrest from 

 sexual desire is prevented by castration or spaying opera- 

 tions, which may be performed with greater safety when 

 the animals are young than when considerably advanced 

 in age. These operations have a beneficial influence on 

 development with reference to increase in certain parts of 

 the carcass that are more valuable for meat and decrease 

 with reference to parts that are less valuable. This is more 

 especially true of males. The influence thus exerted is far 

 reaching and has an important bearing on the relative price 

 that shall be paid for the finished carcass. 



When males are kept mainly or solely for breeding 

 purposes, as a rule they should be kept separate from 

 the females, because of the unrest from sexual desire caused 

 by unrestrained access to the presence ot the latter. This 

 unrest is of course greatest when some of the females are 

 in heat, and 'in such instances it results in needless waste 

 of energy on the part of the male. Even when kept apart 

 but in adjoining fields, the unrest thus occasioned may lead 



