220 
Journal of Agricultural Research 
Vol. XXXI, No. 3 
VITAMIN A IN PORK 
Six lots of pork loins, representing 18 hogs, and 1 lot of pork 
tenderloins, representing 12 hogs, were tested for their content of 
vitamin A by means of feeding tests with 12 groups of 4 rats each, or 
a total of 48 rats. In general, the results obtained with dried fresh 
pork as a source of vitamin A are less satisfactory than those obtained 
with beef. The rations tested contained dried pork in percentages 
ranging from 15 to 95 per cent, but in no instance did a ration furnish 
sufficient vitamin A to meet the requirements of growing rats. Fair 
growth was made by a number of rats that were fed rations containing 
30 to 40 per cent of dried pork (figs. 10, 11, and 12) and by a few rats 
receiving a ration containing 20 per cent of dried pork (fig. 11), 
but even 50 per cent of dried pork tenderloin in a ration proven to be 
inadequate as a source of vitamin A (fig. 16). A ration containing 
95 per cent of dried pork loins did not furnish sufficient vitamin A 
to induce normal growth in young rats (fig. 17). Four rats were fed 
this ration, and, although they grew fairly well for a time*, all finally 
declined in weight and developed ophthalmia. 
The results of the experiments with fresh pork show that the sam¬ 
ples tested were relatively poor in vitamin A. 
VITAMIN A IN LAMB 
A total of 6 samples of lamb, representing 7 animals, were tested 
for their vitamin A content by means of feeding tests with 9 groqp^ 
of rats of 4 members each, or a total of 36 rats. There were rather 
wide differences in the vitamin A content of the several samples of 
lamb. Samples Nos. 876, 897, and 933 were poorer in vitamin A 
than the others. Each of these samples was used in the proportions 
of 15 and 30 per cent in rations, but none of the rats made much 
growth (figs. 19, 20, 21). 
Sample of lamb No. 870 was somewhat richer in vitamin A, and 
rats that were fed a ration containing 30 per cent of this sample 
made considerable growth, although they finally declined in weight 
and developed ophthalmia (fig. 18). One male rat reached a maxi¬ 
mum weight of 176 grams in 30 days, and a female a maximum weight 
of 160 grams in 37 days. 
Samples of lamb No. 992 and 994 were the richest in vitamin A 
of any of the samples of beef, pork, or lamb that are reported in this 
paper. The four rats fed the ration containing 20 per cent of sam¬ 
ple No. 992 made normal growth, and three of the rats were still 
gaining in weight at the end of the 90-day test, but the fourth rat, 
a male, declined rapidly in weight after having reached a maximum 
weight of 243 grams in 53 days (fig. 22). The rats that were fed a 
ration containing 20 per cent of the other sample of lamb, No. 994, 
made even better growth. The two male rats in this group attained 
weights of 268 and 304 grams, respectively, in 90 days, while the 
females weighed 171 and 200 grams, respectively, at the end of the 
same period (fig. 23). 
The results of the vitamin A tests with lamb show that three of 
the six samples examined were rather poor in vitamin A, one con¬ 
tained a fair proportion, while the remaining two samples were richer 
in vitamin A than any of the other samples of meat that are reported 
in this paper. 
