226 THE CREAMERY PATRON'S HANDBOOK. 



appetites in the presence of an abundance of food quite makes up for any 

 loss incurred in the movement necessary to obtain that food. Hence it is 

 desirable that stall fed milk cows should have daily exercise. Very violent 

 exercise sometimes has the effect of producing very much change in the 

 quality as well as the quantity. It always has the effect of lessening the 

 quantity but the effect upon chemical composition is not known. There 

 are numerous instances, however, in which the physiological effect of taking 

 milk from an exhausted animal has proven injurious. It is generally 

 recognized among farmers that it is unsafe to allow a calf or colt to suckle 

 when the dam is overheated. Two observations upon this point are recorded 

 as follows: 



On April 30, 1893, at Lake City, Fla., a fine cow was owned by Mr. P. 

 She had a calf some five miles from home and the calf was a week old, strong 

 and healthy. The calf was hauled home in a buggy and the cow made to 

 walk. She ran a considerable of the distance and was exhausted when 

 the barn was reached. The calf suckled on arrival home and soon became 

 very sick with a violent diarrhoeal discharge. 



In 1895 the cows owned by some people in West LaFayette, were herded 

 by a boy. He drove them home very hurriedly one night to avoid a rain 

 storm. They were somewhat overheated and gave a small quantity of milk 

 that night. Two calves became attacked with diarrhoea. Several people 

 were also affected. In two cases mammitis was the result of the bruising 

 of the udder in running. 



EFFECT OF CHANGE OF LOCATION. The effect of a change of quarters 

 on the quantity and quality of milk was experimented upon by the Vermont 

 Station. The herd was milked and then driven three and one-half miles 

 to new quarters. Composite samples were taken of the milk of seven cows 

 for four milkings before and after the change. There were six and one- 

 tenth per cent, larger yields of milk ingredients followed the change. Bab- 

 cock found in a similar experiment a falling off in both quantity and quality, 

 but the increase of the succeeding days more than compensated for the 

 decrease. A change in the stable routine, as feeding out of order or at 

 irregular times, may have like effect. 1 



EFFECT OF NERVOUSNESS. Both the secretion and the excretion of 

 the milk are under the control of the nervous system, but the exact mode 

 whereby the nervous influence is exerted, remains to be worked out. In- 

 directly, however, the secretion of milk must largely be affected through 

 the sympathetic nervous system, whose center is a chain of nervous element 

 extending along the general body cavity just beneath the back bone. The 

 nerves act 4 by controlling the caliber of the blood vessels, and thus regulating 

 the blood going to the udder. It is a well established fact, that anxiety of 

 the mother, caused by removal of the young, as well as by sudden fear 

 all chance excitement of any kind will cause a partial and sometimes 



1 Bulletin 116, North Carolina Exp. Sta. F. E. Emery. 



