Agricultural Research in New Hampshire 19 



der for human nutrition, augmented by war conditions, it is important that 

 other ingredients be found to replace it in animal feeding. 



These animals are still too young to indicate definite conclusions. 



In addition to recording the usual data on growth and general health 

 conditions, carotene and Vitamin A determinations of feed and blood will 

 be made at regular intervals. The blood carotene and Vitamin A levels 

 will be studied in relation to growth, the carotene and Vitamin A intake, 

 environmental temperature, respiratory and bowel disturbances, and the 

 minimum values for blood carotene and Vitamin A. (K. S. Morrow and 

 H. A. Keener) 



Efficiency of Dairy Herd Management Practices 



Permanent records of 4,132 lactations of cows in New Hampshire 

 D. H. I. A. herds have been tabulated on individual cards for statistical 

 study of the relation of herd management practices to milk production. 

 The breed distribution is Ayrshire 700, Devon 80, Guernsey 750, Holstein 

 1,973, Jersey 470, and Shorthorn 180. All production records have been 

 converted to a common 4.0 per cent, butterfat basis (Gaines formula) and 

 mature equivalent production values. 



The following comparisons have been set up to date for each breed 

 for statistical study: 



1. Actual milk production vs. age. 



2. Actual milk production vs. grain consumed during lactation. 



3. Actual milk production vs. grain consumed during dry period. 



4. Milk production vs. month of freshening. 



5. Milk production vs. length of dry period. 



6. Milk production vs. total length of lactation. 



7. Total length of lactation vs. age. 



8. Total length of lactation vs. month of freshening. 



9. Total length of lactation vs. ratio of grain fed to milk produced. 



10. Ratio of grain fed to milk production vs. month of freshening. 



1 1 . Ratio of grain fed to milk production vs. age. 



, _ , . , . ,_ . . (K. S. Morrow) 



Causes of Abnormal Relationship (Ratio) 



Of Fat to Solids-not-fat in Milk 



Fifteen sets of samples taken at two-week intervals from August 15, 

 1940, to March 25, 1941, comprising a total of 115 samples from Jersey 

 and 173 from Holstein cows of the University herd, were analyzed for fat, 

 total solids, solids-not-fat, total protein, casein, albumin, proteoses-peptones. 

 nonprotein-nitrogen, lactose, ash, calcium, and phosphorus. 



The average composition of Jersey and Holstein milk as determined 

 by this experiment has been tabulated and summarized. Jersey milk was 

 definitely higher than Holstein milk in total solids, fat, and solids-not-fat. 

 Total protein and casein showed similar differences, but considerable 

 overlapping was found in the minor constituents within the total protein 

 component. The two breeds contained the same percentage of proteoses- 

 peptones and nonprotein-nitrogen. Lactose and ash exhibited considerable 

 overlapping but Jersey milk averaged higher in both. The calcium and phos- 

 phorus content was also higher and did not overlap the lower Holstein 

 averages. 



