REQUIREMENTS OF ANIMALS 587 



recommeiided."^^'^"*'^'^'^'*^ The ^'itanlin A requirements of cattle, as recal- 

 culated by Mattson'^^ from various sources, are given in Table 11. 



(i) Sheep. The A'itamin A requirement of sheep was reported bj' Guil- 

 bert et al.^*^ to be 17 to 26 I.U. of \'itamin A/kg. bodj' weight when night 

 blindness was used as the criterion. When the requirements for growth, 

 reproduction, and storage were considered as the criteria, values of 66 

 I.U.^^^ and 66 to 92 I.U. kg. bodj' weight^^^ were observed. Carotene is 

 beheved to hare an acti^'ity of one-sixth that of \itamin A, on the weight 

 basis. 



(/) Horse. The A'itamin A requirements of the horse were recorded by 

 Guilbert et a/.«^^ as 17 to 22 I.U. of \itanmi A/kg. body weight, or 20 to 30 

 ug. of /^-carotene, when the amount needed to prevent or cure night blind- 

 ness was the basis of the test. "WTien growth, reproduction, and lactation 

 were the physiologic functions tested, 66 I.U. of vitamin A/kg. body weight 

 were required, or 132 ;Ug. of /3-carotene (220I.U.)/kg. body weight. ^^^ 



{k) Other Animals. Undoubtedly the hamster and the cotton rat re- 

 quire vitamin A, but no data are available on the quantitative aspects of 

 this requirement. In the case of the macaque or rhesus monkey (Macaca 

 mulatta), Truscott and A'an Wagenen^"^'' demonstrated a requirement for 

 \Titamin A, but no quantitative figures were reported. In various species, 

 the deficiency symptoms include diarrhea as the most consistent sign, 

 while xerophthalmia, night bhndness, edema, cessation of the menstrual 

 cycle, mild gingi^'itis, reduction of bile secretion, and a mild increase in leu- 

 cocji;es have been recorded. 



Foxes de\"elop certain characteristic sjinptoms when deficient in vita- 

 min A. Using this criterion as a method of evaluation, Smith^"^^ placed 

 the daily %'itamin A requirement of this species in the range of 15 to 25 

 I.U. of ^-itamin A/kg. bodj' weight. According to Bassett et al.,^^^"^ an in- 

 take of 25 I.U. /kg. /day is the minimal level which allows normal growth 

 and a detectable content of vitamin A in the blood stream. Storage of 

 \-itamin A in the hver did not occm' until the ^'itamin A intake was 50 to 

 100 I.U./kg./day. 



M»8 J. K. Loosli, C. F. Huffman, W. E. Petersen, and P. H. Phillips, Reommended 

 Nutrient Allowances for Domestic Animals. III. Recommended Nutrient Allowances for 

 Dairy Cattle, Comm. Animal Nutrition, Nat. Research Council (U.S.), Washington, 

 D.C., 1950, pp. 1-30. 



loo' H. R. Guilbert, P. Gerlaugh, and L. L. Madsen, Recommended Nutrient Allowances 

 for Domestic Animals. IV. Recommended Nutrient Allowances for Beef Cattle, Comm. 

 Animal Nutrition, Nat. Research Council (U.S.), Washington, D.C., 1950, pp. 1-32. 



1010 B. L. Truscott and G. van Wagenen, Yale J. Biol, and Med., 25, 139-146 (1952). 



1011 S. E. Smith, J. Nutrition, £4, 97-107 (1942). 



1012 C. F. Bassett, J. K. Loosli, and F. Wilke, /. Nutrition, 35, 629-638 (1948). 



