22 MAINE AGRICULTURAL EXPERIMENT STATION. 



There is every reason to believe that any effect would only ap- 

 pear in fairly comprehensive statistics. The matter is one of 

 much practical consequence to the stock breeder. Because this 

 is so we would caution the reader against misinterpreting these 

 results. A trial of a half dozen individuals will not in any 

 sense whatever adequately test the accuracy of the results set 

 forth above. 



The probability that the sex ratio can be changed by careful 

 attention to this matter of time of service is sufficiently great, 

 in our judgment, to warrant any man in modifying his breeding 

 practice in accordance with it, particularly since in so doing he 

 will be incurring no added risk of any kind. In the every day 

 affairs of life in regard to business, investment of funds, and 

 the like, practical men every day undertake courses of action 

 on the basis of probabilities much smaller than that in favor of 

 getting an increased number of males if cows are served late 

 in heat. The practical cattle breeder in most cases would like, 

 if he could get it, an excess of female calves. All the evidence 

 at hand warrants the belief that by taking care that cows are 

 served as soon as possible after the onset of heat there will 

 be some reduction in the proportion of male calves born. In 

 short, the facts warrant the breeder in paying attention to the 

 time of service in his cattle breeding operations, but he must 

 not suppose that by so doing he can absolutely control the sex 

 of the offspring, or even approach measurably close to absolute 

 control. He can at best merely modify, over a period of years, 

 the sex ratios in greater or less degree, in the direction which 

 he desires. 



The Fear of Inbreeding. 



A careful study of the history of the best improved strains 

 of live stock of all sorts leaves no room for doubt that the 

 attainment of the highest degree of excellence has always been 

 associated with the practice of a very considerable amount of 

 inbreeding, of rather close degree. It is a curious paradox of 

 animal husbandry in general that while, as a matter of fact, 

 every successful breeder of high grade stock practices inbreed- 

 ing to a greater or lesser extent, a great many of these men 

 are violent, even fanatical, opponents to inbreeding in theory. 

 Most of them will deny stoutly that they ever practice inbreed 

 ing. They contend that they practice "line breeding," but never 

 "inbreeding." 



