various conditions have been given.The results indicate that the alfalfa effect in the experiments of Cary and associates4 is not due to the same factor for which our procedure tests. I t appears likely that, aside from the principal factor under consideration the yeast and pure vitamin preparations which Cary an.d associates have in their diet do not satisfy the conditions for best growth of the young. Whatever significant nutritional factors occur in alfalfa are in our case adequately supplied by other diet components, probably the large amount of cottonseed flour.Discussion. The data constitute evidence on two points: 1) that the amounts of alfalfa, dried grass or fresh grass fed do not contain effective amounts of zoopherin and 2 ) that whatever unknown factors affecting growth of young rats are contained in alfalfa are also otherwise provided by the all-plant ration. The first of these points stands on its own feet. The second becomes more significant if there is other evidence for a factor in alfalfa which can play the role we attribute to it in the experiments of Cary and associates4 Ball and Barnes6 have reported that purified diets containing 8% of yeast are not adequate for lactation of mice (measured by the pre-GBall, Z. B., and Barnes, R. II., PRoC. Soc. E n . BIOL. AND MED., 1941, 48, 692.weaning growth). Both dehydrated cereal grass and wheat bran effectively improved the situation but these two substances when added to the basal diet alone or combined did not give as good results as the stock commercial diet, Bawland, Ensminger and Cunha7 in observations with purified diets (alcohol extracted casein, pure B factors, etc.) on rats have found that when 15% of dried young alfalfa was used as a supplement, 43% of the young given to the female to raise, were weaned. This contrasts with 13% weaned when the same 10 B factors, including folacin, were given without alfalfa. Spitzer and Phillipss have also shown evidence for a marked effect of alfalfa on lactation in rats. Their later brief communication," however, indicates that at least a part of this is attributable to known factors.Summary. A postweaning growth inhibition in the offspring of rats on a well fortified allplant ration has been described. While this is corrected by a factor in liver, neither alfalfa leaf meal, dried grass nor young fresh grass have such an effect.

No abstract

No abstract