256 A TICK-RESISTANT CONDITION IN CATTLE. 



Spot, horn December, 1915 ; dam, Brownie. A little 

 light yellow Jersey with a yellow skin. 



This young cow was by far the tickiest subject on the 

 .place, with the exception of some of the yearling stock 

 and control heifers. She was not milking but came up each 

 day with the milkers and was examined regularly from 

 January 16th-February 11th, 1918. Males, half-bloated 

 females, nymphs and larvae could always be found on her, 

 while from 2-3 fully-matured females were removed each 

 day, the total number being 64. During this time no trace 

 of exudate was observed. March 19th- 25th : five examin- 

 ations were made and 18 mature females were removed, 

 numerous immature ticks were observed. The escutcheon 

 was coated with a dry yellow substance resembling exudate. 

 June 7th : small ticks were still numerous and a few mature 

 female specimens were secured. 



Sprite, born November, 1911 ; dam, Tinkerbell. A 

 brindle Jersey with a dark skin. (Allowed to run wild from 

 birth as her calf has also been allowed to do ; neither have 

 ever been treated for ticks, March, 1916. 1/2/16 : clean, 

 — out on roads. No ticks found to date 23/1/18. Stock 

 book). 



June 24th, 1916 : Free from ticks — exudate present 

 but somewhat blood-stained. During the January- February 

 examinations, 1918, this cow was not a milker, being allowed 

 to rear her calf, but was examined each day ^dth a few 

 exceptions. No ticks were observed on any occasion. 

 Fresh exudate appeared on January 27th, 28th, February 

 5th and 10th. March 19th-24th : no mature ticks except 

 two or three very poorly developed females were found. 

 Larvse were numerous on the escutcheon. On 22nd March, 

 a clear yellow fluid was observed exuding from the part 

 about some tick-sores on the escutcheon, while fresh exudate 

 was also seen at the side of the escutcheon. June 7th : a 

 few very small females were removed. 



Squib, born May, 1915 ; dam, Rhinca. Ayrshire- 

 Jersey strain : light red cow with white face, yellow skin. 

 {Clean, November, 1916 ; clean, February, 1917 ; a few smaU 

 ticks on escutcheon, April, 1917 ; few mature females, 

 December, 1917. Calved, December, 1917. Stock book). 



