Aug. 1, 1925 
Vitamin A in Beef, Pork, and Lamb 
219 
This sample of dried lamb is even richer in vitamin A than the pre¬ 
ceding sample (No. 992, fig. 22). It is interesting to record that the 
two hind saddles of lamb from which samples Nos. 992 and 994 were 
prepared were purchased at the same time from a local meat-packing 
establishment. On inquiry it was found that the two lamb carcasses 
probably came out of a carload of lambs purchased in Chicago and 
slaughtered at Benning, D. C. No information was available as to 
how the lambs had been fed. 
SUMMARY OF RESULTS AND CONCLUSIONS 
Since the rats fed the basal rations alone made a certain amount 
of growth for a time, due, no doubt, principally to the store of vitamin 
A in their tissues, in interpreting the results of any experiment 
allowance must be made for the growth made by rats fed the basal 
ration. Unfortunately, as yet, a satisfactory unit for measuring the 
vitamin A content of a food product is lacking, so that the values 
obtained are reported only; in very general terms. Since the energy 
values of the different rations are practically the same, the growth 
value obtained for one ration may be compared directly with that 
obtained from another. 
VITAMIN A IN BEEF 
A total of 10 samples of beef, representing a like number of cattle, 
were tested for their vitamin A content by means of feeding tests 
with 11 groups of rats of 4 members each, or a total of 44 rats. Six 
samples of dried beef Nos. 869, 874, 902, 906, 912, and 934 were used 
in the proportions either of 15 or 30 per cent in rations, fed to 9 groups 
of rats. The results of these tests show that none of those samples of 
dried beef, in the quantities fed, furnished sufficient vitamin A to induce 
normal growth in young rats. The best growth was made by rats 
fed rations containing 30 per cent, respectively, of samples of beef 
Nos. 869, 874, and 934, as shown in Figures 2, 3, and 7. 
When the proportion of dried meat in the ration was increased to 
50 per cent, much more satisfactory results were obtained. A group 
of tour rats was fed a ration containing 50 per cent of dried beef, 
samples Nos. 1018, 1021, and 1024 being used in succession. One 
male rat made excellent growth, two other male rats did nearly as 
well, and a female rat made nearly normal growth (fig. 8). All four 
rats were in fair condition at the close of the test. Apparently 50 
per cent of these samples of dried beef in a ration furnished nearly 
sufficient vitamin A for normal growth. 
Another group of rats was fed a ration containing 95 per cent of 
dried beef, the same samples that were used in the tests reported in 
Figures 2 to 7, inclusive, being used in succession; and, in addition, 
another lot of beef, No. 957 (fig. 9). The rats in this group, one male 
and three females, made nearly, but not quite, normal growth, and 
all were in good condition at the end of test. 
The results of these tests show that the samples of beef tested were 
relatively poor in vitamin A, but that when used in rations in pro¬ 
portions of 50 or 95 per cent, nearly sufficient vitamin A for normal 
growth was furnished. 
