Abstract
Immature rats were fed a highly purified low-fiber diet supplemented with massive doses of Myrj 45, Myrj 52, Tween 20, Tween 60 or Span 20, non-ionic surfactant agents with HLB (hydrophile-lipophile balance) values of 11.1, 16.9, 16.7, 14.9 and 8.6, respectively. Supplements of Myrj 45 at a 15 or 20% level in the diet resulted in a slight retardation in growth but had no deleterious effects on either gross appearance or survival during an experimental period of 21 days. Supplements of Myrj 52, Tween 20, Tween 60 or Span 20 at a 15 or 20% level in the diet, however, caused significant growth retardation, diarrhea, an unthrifty apearance and death. The deleterious effects of Myrj 52, Tween 20 and Tween 60 administration were completely counteracted by the concurrent feeding of alfalfa meal at a 20% level in the diet. Supplements of alfalfa meal were without protective effect, however, in rats fed diets containing Span 20. The protective factor (or factors) in alfalfa was retained in the alfalfa residue fraction (the water-washed pulp remaining after extraction of the juice). Supplements of protein, fat and the known vitamins and minerals were without protective effect. Purified cellulose, however, when incorporated in the diet had significant activity in counteracting the toxic effects of Myrj 52, Tween 20 and Tween 60 administration. The corrective effect of cellulose was proportional to the level fed; but at each level of feeding between 2.5 and 10% of the diet its protective effect was less than that of a comparable amount of alfalfa meal. In addition to alfalfa meal and alfalfa residue, rye grass, fescue grass, oat grass, orchard grass and wheat grass as well as carrageenin and sodium alginate also had significant activity in counteracting symptoms of Tween 60 toxicity in the immature rat.