Agricultural Research in New Hampshire 47 



total of 5885 pH readings were taken. The feed used was commercially 

 mixed poultry feed. 



Preliminary analysis of the data indicates that the pH of the digestive 

 tract, with the exception of the gizzard, is relatively stable up to 164 days 

 of age. The pH of the gizzard changed from a range of two to three 

 during the early growth period to a range of three to four during the 

 middle and later growth period. A complete summary of the data is be- 

 ing prepared for publication. 



R. C. Ringrose, T. B. Charles, S. R. Shi.mer, H. A. Davis 



A Study of the Cause and Prevention 

 Of Gizzard Lesions in Chickens 



One of the major problems in this study has been the uniform pro- 

 duction of the gizzard lesion. Without uniform production of the lesion 

 at a fairly high rate of incidence it is difficult to evaluate effectiveness of 

 the corrective measures applied. 



During the year, a semi-purified basal ration has been developed 

 which thus far has given very good results. Growth has been exception- 

 ally good and averages 340 grams at four weeks of age. Gizzard scores, 

 the method of measuring results, have been within the range of 1.4 to 1.7. 



Attention also has been directed toward methods of measuring re- 

 sults to supplement the visual scoring used in the past. Cholic acid is 

 known to be effective in preventing the lesion and is also known to be 

 present in the gizzard lining. Cholic acid determinations on pooled giz- 

 zard linings are now being used to supplement the visual scoring. To 

 date the cholic acid content of the gizzard lining has varied in the same 

 direction as the visual scores. 



Alfalfa meal and oats have been reported as good sources of the "an- 

 tigizzard erosion factor." Under test conditions 45 per cent of ground 

 oats or 20 per cent of alfalfa meal has but slight, if any, protective action. 



R. C. Ringrose, H. A. Davis 



Choline in the Nutrition of Poultry 



During the year, a study of the choline requirements of laying hens 

 was initiated. For this purpose a semi-purified ration which analyzed 

 .037 per cent choline was developed. New Hampshire pullets which had 

 been laying for six months were placed in individual laying cages. Twelve 

 birds were placed on the low choline control ration and six birds were 

 placed on each of the rations to which various amounts of choline chlo- 

 ride had been added. 



Records of feed consumption, egg production, and body weight 

 were taken for a period of 84 days. Choline analyses of pooled egg yolks 

 were made at the end of each 28-day period. No significant differences 

 which could be related to the choline content of the rations were re- 

 corded. 



One group on a so-called low methionine low choline ration was in- 

 cluded in the study. This ration analyzed .04 per cent choline. Amino 

 acid composition of the ration was calculated from average analyses for 



