104 MASS. EXPERIMENT STATION BULLETIN 191. 



record. This date is determined in part by the date she was hatched and 

 in part by the age at which she matures, and this in turn is influenced by 

 various growth factors, some hereditary, some environmental. Of the 

 latter, parasites, visible or invisible to the naked eye, especially those that 

 are concerned in causing disease, must be under control. It is a biological 

 law that just as a chicken or a dog requires parents so all life arises from 

 pre-rBxisting life. As far as is known with certainty, with the exception of 

 the parasite that causes bacillary white diarrhoea, the chick enters the world 

 free from parasites. If, therefore, a means can be found to keep such 

 parasites away, the chick will never have them, and will not suff'er from 

 them. The means is found in a quarantine of the chicks, and in an exten- 

 sion of the rotation method introduced by the Maine Agricultural Experi- 

 ment Station. 



A suitable quarantine, which presupposes the use of artificial methods of 

 hatching and rearing, is a very efficient method of keeping out parasites 

 and disease resulting therefrom, and in many circumstances is the simplest 

 and least laborious method of securing the desired end. In the work at the 

 Massachusetts Agricultural Experiment Station a plot of ground was 

 selected that had not had a chicken or chicken manure on it for several 

 years. All buildings, appliances and utensils were either new or were 

 scrubbed clean enough to eat from. Then everything not new was 

 drenched outside and inside with 5 per cent coal tar disinfectant. One 

 spraying was made before the buildings were moved, another after their 

 removal to the clean ground. The chicks were hatched in carefully disin- 

 fected incubators. A separate attendant did the brooding and was 

 quarantined from all other poultry. At the entrance to the rearing ground 

 he changed his foot gear for a set reserved for use on the rearing ground, 

 and, after changing, walked through a pan of strong disinfectant. Every 

 loop-hole by which parasites might gain entrance was closed if at all 

 possible. The result is that the parasite problem has been largely solved 

 as long as the cliicks remain quarantined. 



The quarantine method of rearing chicks should be of particular advan- 

 tage to any one who is starting a new poultry plant, because by purchasing 

 eggs of stock free from bacillary white diarrhoea, and using only artificial 

 methods for hatching and rearing, the proverbial good luck of the beginner 

 should endure. 



