132 CITY MILK SUPPLY 



head track running immediately behind the cows and along the edge of 

 the manure gutter. In the rod-track the carrier runs on a cable wire 

 which is stretched so as to permit the carrier to run by gravity from the 

 barn to the dumping point where by striking a trigger it is discharged 

 automatically. Since this type of carrier cannot be raised and lowered, 

 much labor is required in lifting the manure to fill it. The end of the rod- 

 track is attached to .a post in such a way that it may be kept at proper 

 tension by the use of a turn buckle which, except when new, is apt to 

 require frequent attention and so is annoying. 



The rigid-track carrier is more 

 expensive than the other but is 

 more satisfactory. An overhead 

 trestlework supports a rigid iron 

 track on which, suspended below 

 on a swiveled iron frame, the car- 

 rier runs. It is pushed along the 

 gutter as the stables are cleaned, 

 all high-lifting of the manure being 

 avoided by lowering the carrier 



FIG. 28,-Manure carrier. tiU {t little m re than clears the 



floor. When the carrier is full it is 



raised by a gear arrangement and pushed out of the barn to the dumping 

 point where it is emptied by pulling a trigger. 



Litter. The availability and cost of bedding materials usually de- 

 termines the choice as to which shall be used ; other qualities to be consid- 

 rred are their absorptive power and cleanliness. Doane of the Maryland 

 Station made a series of tests to determine the value of different materials 

 for litter, comparing them with the material most widely used by dairy- 

 men for the purpose, whole wheat straw, as a standard. It was found 

 that chopped wheat straw is easily kicked about and packs down closely 

 so that more is required to keep the cows clean. Rye straw which is 

 highly esteemed for horse litter seemed poorly adapted for cows because 

 it is hard and stiff and has low absorptive capacity. Barley straw is not 

 used because the beards irritate the animals. About one-third more by 

 weight was required of corn stover but it is not easily shoved about and 

 keeps the cows cleaner. All of these materials were a little dusty but not 

 objectionably so. Wet or mouldy straw is wholly unfit for bedding. In 

 some places weeds and fallen autumn leaves are used for bedding; they 

 are to be condemned for litter because of the dust they contain. Sawdust 

 stayed in place better and kept the cows cleaner than any other bedding. 

 It was often damp but this produced no ill effects. Sawdust makes the 

 manure so light that loss of ammonia may occur; it decays slowly and 

 tends to loosen up the soil so that it is possibly not the thing to apply to a 

 light sandy soil, but on heavy ones it is unlikely to do harm and may be 



