by the increased proportion of large thyroids 

 among the heavy animals. 



Rats losing weight on stock, SP 8 HVO, 

 and SPE diets.— The thyroid weights of sick or 

 moribund rats fed stock, SP 8 HVO, or SPE diet 



Table 45. — Thyroid weight in relation to body weight of rats maintaining weight on stock, SP 8 HVO, and 



SPE diets 



are summarized in table 46, with the results for 

 rats that lost less than 100 grams before sacrifice 

 separated from those for rats with more extensive 

 weight losses. On stock diet, thyroids tended 

 to be somewhat larger in moribund rats than in 



Diet and body weight 

 (grams) 



Rats 



Average 



body 



weight 



Thyroid 

 (mg.) to 

 body 

 weight 

 (grams) 



Thyroid weight 



Average 



Range 



Thyroids weighing — 



Less 



than 



lO.Omg. 



10.0 to 

 14.9mg. 



15.0 to 

 19.9mg. 



20.0 mg. 

 and 

 over 



Stock: 



300 to 399... 



400 to 449_._ 



450 to 499___ 



500 to 599... 

 SP 8 HV(): 



400 to 499—. 



500 to 599__. 



000 to 699... 



700 and over 

 SPE: 



400 to 499... 



500 to 599... 



600 to 691)... 



700 to 799... 



Number 

 16 

 26 



41) 

 12 



lit 



'20 



26 



8 



5 

 43 

 30 



s 



Grams 

 372 

 430 



471 

 547 



466 



547 

 646 

 730 



471 

 560 

 641 

 736 



Percent 

 2. 5 

 2. 5 

 2. 4 

 2. 4 



2.0 



2. 1 

 1.9 



1. 9 



3. 



2. 8 

 2.5 

 2. 4 



Mg. 

 9. 3 



10. 8 



11. 5 

 13. 3 



9. 4 

 11. 4 

 12.5 



13. 6 



14. 



15. 7 



16. 3 

 18. 



Mg. 



6. 0-13. 2 

 5. 6-21. 7 



5. 8-17. 



7. 5-18. 4 



6. 6-12. 

 0. 7-17. 5 



8. 7-19. 9 



7. 8-17. 5 



9. 1-16. 9 

 10. 3-25. 4 



6. 1-26. 1 

 9. 5-21. 7 



Percent 

 69 

 38 



25 

 25 



60 

 35 

 19 

 12 



20 







7 



12 



Percent 

 31 

 54 

 65 



42 



40 

 50 

 69 



38 



40 



Hi 

 37 



(i 



Percent 







4 



in 



33 



i) 

 15 

 12 

 50 



40 

 46 

 37 



Percent 



(I 

 4 

 

 





 



n 



i) 



'J I! 



38 



Table 46. — Thyroid weights of rats losing weight at different ages on stock, 



SP 8 HVO, and SPE diets 





Rats 



Average 

 age 



Average 



weight 



loss 



Thyroid weight 





Thyroids weig 



ling — 





Weight loss, diet, and 

 age (days) 



Average 



Range 



Less 

 than 

 10.0 

 mg. 



10.0 to 

 14.9 



mg. 



15.0 to 

 19.9 



mg. 



20.0 to 

 29.9 

 mg. 



30.0 

 mg. 

 and 

 over 



Losing less than 100 

 grams : 

 Stock: 



300 to 699 



Number 

 5 

 4 

 5 



8 



12 



8 



9 

 39 

 17 



8 

 4 

 2 



5 



15 



9 



20 

 23 

 32 



Days 

 592 

 763 

 853 



250 

 491 

 663 



185 



■KM 

 590 



521 



776 

 80S 



422 

 600 

 829 



352 



443 

 583 



Grams 

 56 

 65 

 66 



24 

 61 

 50 



23 

 51 

 52 



125 

 193 

 161 



155 

 169 

 205 



150 

 164 

 160 



Mg. 

 11.9 



14. 7 



17. 1 



9. 5 

 13. 4 



13. 



11. 5 



19. 8 

 24. 8 



14. 5 

 13. 7 

 16. 1 



20. 1 



20. 4 



18. 9 



22. 6 



24. 2 



25. 9 



Mg. 



8. 6-17. 5 



9. 4-17. 7 

 14. 2-19. 9 



5. 7-12. 5 

 7. 2-19. 6 

 5. 1-19. 4 



7. 5-14. 4 



11. 0-32. 9 



13. 3-36. 7 



10. 8-18. 8 



12. 0-14. 8 



14, 4, 17. 8 



4. 4-30. 4 

 9. 3-32. 4 



8. 9-30. 8 



8. 3-37. 4 



7. 6-46. 1 



18. 8-36. 2 



Percent 

 20 

 25 

 



50 

 17 

 12 



33 

 

 





 

 



20 



7 



11 



5 

 4 

 



Percent 

 60 

 25 

 40 



50 

 50 

 50 



67 

 15 

 12 



62 



100 



50 





 13 



22 



5 

 

 



Percent 

 20 

 50 

 60 





 33 



38 





 46 

 18 



38 







50 





 40 

 33 



35 



26 



9 



Percent 

 

 

 





 

 





 31 

 59 





 

 



60 

 20 

 11 



40 

 48 

 69 



Percent 

 



700 to 799 







800 and over 



SP 8 HVO: 



Less than 400 



400 to 599 









 



600 to 799 







SPE: 



Less than 300 



300 to 499 . .-. 







8 



500 to 699 . _ - 



12 



Losing more than 100 

 grams: 

 Stock: 



300 to 699 . . . 







700 to 799.. 







800 and over . 



SP 8 HVO: 



Less than 500 



500 to 699 







20 

 20 



700 and over .. 

 SPE: 



Less than 400 



400 to 499 . . - 



22 



15 

 22 



500 to 699 



22 







58 



