1^1®! DAIRY FARMING DAIRYING. 871 



DAIKY FARMING— DAIRYING. 



Factors influencing the development of dairy heifers, C. H. Eckles ard 

 T. C. Reed (Missouri Sta. Bui. m (1916), pp. 26, 27).— Continuing worli pre- 

 viously noted (E. S. R., 33, p. 274) efforts are being made to find tlie protein 

 requirements of growing animals and the normal rate of growth. 



One heifer has now been carried from the age of six months to the time of 

 calving at the age twenty-eight months on a ration containing less than 0.5 lb. of 

 digestible protein dailj', or about half of that prescribed by the Armsby feeding 

 standard. This amount is apparently below the minimum required, since, al- 

 though plenty of energy for growth was supplied, the growth of the animal was 

 retarded in both skeleton and tissue development, and her calf was born with 

 rudimentary eyes. 



As a control ration with which to regulate the amount of protein and energy as 

 desired and at the same time supply a complete protein, skim milk powder as a 

 source of protein, a small amount of timothy hay for roughage, and a mixture of 

 starch and sugar to supply the energy have been found satisfactory. Mineral 

 matter is added in the form of bone meal and citrates of potassium and mag- 

 nesium. A heifer on a ration made up in this manner has shown practically 

 normal growth for seven months with a protein consumption of approximately 

 0.75 lb. per day. 



In a preliminary study of the normal rate of growth of dairy heifers it appears 

 that under normal conditions the curve of the growth is very similar for each 

 individual animal. If one animal is below the average in the beginning it is gen- 

 erally about the same distance below the normal during the growing period. 

 Pregnancy exerts but little effect upon the curve of growth, but lactation results 

 in a decided check to growth. A low mineral content of the ration does not show 

 any appreciable effect upon the rate of gi-ewth. A ration containing less than 

 half the protein called for by Armsby's standard for growing animals resulted 

 in the animal making 73 per cent of normal growth in height and 54 per cent of 

 normal growth in weight. 



Feeding cotton-seed meal and hulls to dairy cows, J. S. Moore (Mississippi 

 Sta. Bui. 174 U914), PP- 1-10). — In an experiment which lasted over six years, 

 9 cows in their first lactation period were divided into three lots of 3 cows each ; 

 later on 2 heifers were added to each lot. Lot 1 received a heavy ration of cot- 

 ton-seed meal with little other grain feed and no cotton-seed hulls for roughage ; 

 lot 2 received a heavy ration of cotton-seed hulls with no cotton-seed meal ; and 

 lot 3 received no cotton-seed products. During the greater part of the first period 

 (ISO weeks) the cows were fed the maximum amounts of cotton-seed meal and 

 cotton-seed hulls, and during the second period (144 weeks) they were fed these 

 amounts only when giving a fair yield of milk and when pasture was not avail- 

 able. As a rule, during the second period little cotton-seed meal was fed for 30 

 days before calving and no cotton-seed meal for a time after calving. 



The cows in lot 1 were bred 56 times and dropped 22 calves, with an average of 

 14 months between calvings ; the cows in lot 2 were bred 41 times and dropped 24 

 calves, with an average of 13 months between calvings ; and the cows in lot 3 

 were bred 29 times and dropped 24 calves, with an average of 12 months between 

 calvings. The average daily production per cow during the first period was for lot 

 1, 13.7 lbs. of milk and 0.6 lb. of fat ; lot 2, 14.3 lbs. of milk and 0.6 lb. of fat ; and 

 lot 3, 11.7 lbs. of milk and 0.5 lb. of fat i and during the second period, lot 1, 10 

 lbs. of milk and 0.45 lb. of fat ; lot 2, 12.5 lbs. of milk and 0.54 lb. of fat ; and lot 

 3, 11.9 lbs. of milk and 0.56 lb. fat. Abnormal conditions, if any, occurring in the 

 case of each animal are noted. 

 69107°— No. 9—17 6 



