12 X. H. Agr. Experiment Station [Bulletin 310 



last week, these groups showed a materially reduced gain in weight. This 

 sustained gro\\i;h may have been due to a greater intake of vitamin A 

 during the first four or eight weeks. An oil of greater potency per gram 

 was used this year than last year, i. e., standardized to contain at least 

 2,000 U.S.P. units per gram. 



Reserve versus Reserve No Oil 



A comparison of these two groups of chicks (Table IV) shows a slight 

 difference in weight, only .134 pounds, in favor of the reserve group. The 

 feed consumption per chick for the twelve-week period is also favorable 

 to the reserve group with a lower feed intake of .602 pounds per chick 

 than the group receiving the reserve ration without cod liver oil. Only 

 3.815 pounds of feed were required to produce one pound of gain up to 

 twelve weeks for the reserve group whereas the group receiving no cod 

 liver oil required 4.242 pounds of feed to produce a pound of gain. 



The mortality record shows but 2 per cent loss in twelve weeks for 

 the group receiving no cod liver oil while the chicks on the Reserve ration 

 with 1% cod liver oil showed a mortality of 8 per cent. 



Neither group showed any evidence of a vitamin A deficiency and 

 from these results a tentative conclusion is that there is enough vitamin A 

 in the New England College Conference ration without the addition of 

 cod liver oil to prevent opthalmia under the conditions of this experiment. 



Increasing Levels of Vitamin A 



In reviewing the results obtained by feeding chicks increasing levels of 

 vitamin A through the medium of a standardized cod liver oil, we find 

 very little difference between that and feeding from the start a level of 

 either 1% or 2% cod liver oil. 



The final weight per chick of 2.826 pounds compared favorably with 

 the group receiving 1% cod liver oil with a weight of 2.842 pounds. The 

 difference in weight is not significant. 



Mortality of two per cent is quite favorable but the same mortality 

 percentage was secured by the group receiving 2% cod liver oil plus the 

 basal ration. 



Since the results secured from feeding increasing levels were no better 

 than through the feeding of a set level of either 1% or 2% of cod liver 

 oil throughout the experimental period, the extra effort and cost ex- 

 pended for labor is not warranted. 



EXPP:RIM1:NT B, TAI?LE V, Estimated conbaiinption of Vitamin A by groups 



;i< rcccixi'd tlirough cod liver oil 



Group Vitamin A unit? ronsumed 



T%C.Lro7 plus" basal ration ~ 99.4()S ' 



2% " " " " 211,036 



3% " " " " 269,040 



Control 0-12 weeks None up to 5 weeks 



Reserve 94.S4,S* 



Control 4-12 weeks 9.120 



Control 8-12 weeks 29.184 



Group X 238.000 



Reserve minua C. L. 0. None* 



•These groups received vitamin A through feed ingredienta contained in ration 

 other than cod liver oil. 



