FORTY-THIRD ANNUAL CONVENTION 153 



with the fact that years ago we did not appreciate the importance 

 of fresh air for dairy cattle, for you see hundreds of bams from 

 60 to 80 feet long with only three windows 2x2 on the long sides 

 of the bam. Now, it has been proven that at least 4 square feet of 

 window surface is necessary for each mature animal that is 

 housed in a barn, and you can readily see when you compare that 

 fact, which is advocated today by all agricultural engineers as a 

 result of experiments, how far the barns that were built ten or 

 fifteen years ago are from meeting this modern requirement. 



It has been proven that sunlight is the best and cheapest de- 

 stroyer of those bacteria that produce disease and that contami- 

 nate the milk in the barn ; that sunlight will help to dry up some 

 of the moisture that there is in the barn ; that sunlight will make 

 the bam a more cheerful place for any human being to work 

 in or any animal to live in, and for all of these reasons there 

 ought to be an abundance of sunlight admitted to the stable. 



Now in planning new barns it is an easy matter to plan them 

 so that there will be four square feet of window surface to each 

 animal, but it is more of a problem where you have an old barn 

 which has to be remodeled. Statistics show that a barn with- 

 out ventilation, a dark and musty one affords the best oppor- 

 tunity for propagating the bacteria that cause tuberculosis; and 

 the bams that have a ventilating system and an abundance of 

 lighting are rarely troubled with those germs, because the con- 

 ditions are such as not to be favorable for propagating the bac- 

 teria that causes that disease. 



These are modern facts with reference to barn construction 

 and equipment of which it is time that we take notice. In the 

 second place it has been discovered and proven that fresh air is, 

 an important factor to successful dairying. A cow needs the 

 oxygen which is in the air in order to purify her blood. With- 

 out being able to do that, she cannot digest and assimilate food 

 properly, and that means she cannot produce milk as she might 

 under other conditions. So it has been found that a mature 

 animal needs at least 3,900 cubic feet of fresh air every hour in 

 the day in order to have a sufficient amount of oxygen to remain 

 in a healthful condition. Tests have been made that show that 

 in breathing, the animal gives off ten pounds of moisture in a 

 day; in the breath of forty animals in a stable they would give 



