164 Blood Fat in Fowls 



Riddle utilized very much larger quantities of blood and probably 

 the error involved in the individual determinations was thus 

 reduced. The later and larger series of blood fat determinations 

 therefore confirms the results obtained by Lawrence and Riddle. 



Most readers of Warner and Edmond s paper will certainly 

 get the impression that the blood of 1 year old hens has an aver 

 age fat value of 0.407 per cent, while that of 3 year old hens ha. 

 a value of only 0.171 per cent. The actual relation of thest 

 two groups is as 0.199 to 0.171. The group of 3 year old hen: 

 which gave an average of 0.171 were all non-layers and only non 

 layers among the 1 year old hens may properly be compared wit! 

 them. 



It may next be pointed out that the data &quot;on the presence o 

 food in the alimentary tract&quot; do not justify the conclusion drawr 

 nor indeed any conclusion whatsoever. The following state 

 ment is made: 7 &quot;It has been reported by Mathews that in ma 

 and animals the blood is much richer in fat after they have bee 

 eating than it is after fasting. This is not true with hens, as show 



from Table VIII The [small] difference . . . 



would indicate that fasting for 16 hours has no effect upon tt 

 amount of fat in the blood.&quot; In reality, 16 hours is not a fas 

 ing period in the fowl. It more nearly represents the length &amp;gt; 

 time between meals, at least on many of the very short days 

 winter; and certainly there is some food still in the alimenta 

 tract of a fowl for more than 16 hours after feeding. 



There are, however, two reasons why the data cannot answ 

 the question of the relative amount of fat in the blood soon aft* 

 as compared with 16 hours after a meal. These are, first, th 

 the female fowl was used, and in these birds the individual variati 

 is enormous, the really decisive factor associated with blood i 

 values being the &quot;laying&quot; or &quot;non-laying&quot; condition of t 

 hen. Other figures by these authors show that the blood fato 

 laying hen (1.953) may be more than twenty times greater th 

 that of a non-laying hen (0.083). Their figures (Table VI) a 

 indicate that this value in laying hens may vary between 0.$ 

 and 1.953. It is therefore obvious that one may not expect &amp;gt; 

 find differences due to fasting for 16 hours in the averages obtaii 1 



7 Warner and Edmond, ibid., 289. 



