DAIRY FARMING DAIRYING. 783 



450 lbs. each, while the other 2 were only 1 year old and weighed less 

 than 300 lbs. each. The method of determining the yield was to weigh 

 the pigs each time before and after suckling, keeping them confined 

 between times in a pen near the dam. This weighing was continued 

 on 3 days every 2 weeks until the pigs were weaned. In this way it 

 was found that the average milk yield of the 4 sows ranged from 4.1 to 

 5.8 lbs. per day for the whole period of observation. The highest yield 

 of milk in any one day was 8.7 lbs. and the lowest 1.2 lbs., the latter 

 occurring just before weaning. 



Some difficulty was had in securing samples of milk for analysis. " It 

 was found that more milk could be obtained with less trouble by allow- 

 ing a pig to empty an udder in part. At this stage the young animal 

 was pushed aside, and the attendant quickly drew what milk he could 

 from the teat before the dam became aware of what was happening." 

 By this means small samples were obtained, seldom more than 1 fluid 

 ounce. The analyses of 9 samples are tabulated. The average of 

 these showed : Water 80.35 per cent, total solids 19.65, fat 8.24, and 

 solids-not-fat 11.41. Excluding the first 2 analyses, which, owing to the 

 smallness of the samples, were incomplete, the following averages are 

 given for 7 samples : 



Average composition of sotvs' milk, with variation. 



These results are compared with those given for sows' milk by other 

 writers and with the averages for cows' milk. The results of G8 analyses 

 reported by Dietrich and Konig, Petersen and Oetken, and the authors 

 show the fat in sows' milk to range from 1 to 16.1 per cent, the average 

 being 6.74 per cent. The wide variations in the composition of sows' 

 milk are explained by the fact that the samples obtained represent 

 fractional milkings. 



"The average daily yield of milk of the 4 sows ranged from 4.1 to 5.8, or about 5 

 lbs. a day. If we consider this yield an average for good sows, and the fat content 

 above given, 6.74 per cent, an approximately correct figure, we have that a sow will 

 yield 0.337 lb. of fat a day, a very fair performance for an animal weighing only 

 one-third as much as an average cow, especially since the milk-producing faculties 

 of the sow have hardly received any thought from the breeder or the feeder. 



"The microscopic examination of the milk shows that the fat globules of sows' 

 milk are of a very minute size, on the average only about one-quarter that of aver- 

 age-sized fat globules in cows' milk. On the other hand, the number of globules in 

 a given volume of milk is about 8 times as large in sows' milk as in cows' milk." 



