xiv PIGS, CATTLE, OSTRICHES 137 



averaging over a cow a year, but pure-bred importa- 

 tions will probably only average four to five years. 

 The bull should be kept in good condition ; the extra 

 cost will be many times repaid in the improvement of 

 calves. Overhead protection in yards is desirable, 

 though not absolutely essential ; otherwise the greater 

 the freedom and absence of pampering given to the 

 animals the better for their general health. 



Three diseases in particular have, up to the present, 

 militated against the success of stock-breeders : 

 rinderpest, East Coast fever and gastro-enteritis. Of 

 these rinderpest is the most virulent. In countries 

 where it has not previously existed the mortality on 

 its introduction reaches 90 or 95 per cent. Where, 

 however, the disease is endemic it sometimes falls as 

 low as 10 per cent. Rinderpest first visited British 

 East Africa in 1892, and for the next two or three 

 years caused enormous damage, not only to cattle, but 

 also to wild game. Rinderpest is an inoculable 

 disease, which happy circumstance we owe to the 

 discoveries of Koch in 1897. ^ n 1910-11 rinderpest 

 reappeared in the Protectorate, and was met at once 

 by the introduction of serum, of which nearly 24,000 

 doses were issued. Generally speaking, such inocula- 

 tions were successful, but in some cases large mortality 

 ensued. There is little doubt that this latter result 

 was due to the depreciation of the serum. It may 

 be stated nowadays with some confidence that settlers 

 need no longer look on this disease with excessive 

 dread. 



East Coast fever is a tick-born disease, being carried 

 by two or more varieties of tick, the chief offender 

 being the common brown variety. The difference 

 of mortality is very great, but in the more serious 



