Mineral Content of Southern Poultry Feeds 
21 
The bird has no sweat gland and only one oil gland, the latter a 
double lobulated tubular gland located dorsally at the base of the tail, 
and which gland furnishes oil for the bird to distribute to each feather 
by aid of its beak. The excretions from the body of the fowl are by 
way of the lungs, kidneys, and intestinal tract. The ureters, large 
intestine, oviduct, and vassa deferentia, all empty into a reservoir, 
an expansion of the terminal end of the gut, called the cloaca which, 
in turn empties through the anus to the external world. This arrange¬ 
ment makes the isolation of elements eliminated by the kidneys a diffi¬ 
cult task, in fact impossible except through surgical interference, and 
this has many difficulties. In these particular experiments here dis¬ 
cussed this has not been attempted. 
In an average of two lots in this series of experiments, the following 
amounts of feeds were required to produce one gram of gain in weight: 
milk, 7.49; mash and grain mixtures, 2.91; green feed, 1.00; total, 
11.44 grams. In these cases the feed was kept constantly before the 
flocks, so that the amount of consumption was a maximum amount 
and by selection, so far as the milk, mash, and grain mixtures were 
concerned. The rape, finely chopped, and the milk were likewise kept 
in separate containers. Thus, where Single Comb White Leghorn chicks 
in their first eight weeks are given all the skim milk and green feed they 
will consume, there will be required approximately 3 grams grain and 
mash per gram gain, or in practical terms 3 pounds mash and grain 
for each pound gain in body weight. In these two lots 75.2 per cent 
of the carbohydrates was digested and 80.2 per cent of the fat digested. 
These are averages for the eight periods, the digestibility varying from 
period to period. We do not believe the methods used to separate the 
ammonia and uric acid of the feces from the undigested protein of the 
feed sufficiently accurate to give here. The problem of separating the 
mineral elements, from those passed out with the feces unused, is quite 
a different matter. If it were possible by surgical interference to sepa¬ 
rate the urine from the feces, there would yet remain that eliminated 
by way of the bowel, which could not be separated from that taken 
with the food and not utilized. At this time only one practical way is 
seen to measure mineral requirements, which is by comparing the intake 
with the outgo and the amount contained in the new constructed tissue, 
and study the mineral balances left over unaccounted for. 
From the table, giving the mineral contents of the bodies of fowls, 
can be seen the requirements in utilizable mineral to construct a given 
gain. From the above estimate of the quantity of feeds to produce a 
pound of gain can be estimated the amount of mineral elements con¬ 
tained in the feed. 
