682 EXPERIMENT STAHON RECOBD. [Vol.38 



are rather extreme in character the rate of skeleton growth is not affected 

 appreciably. 



Influence of nutrition of heifers and age of breeding upon their subse- 

 quent development, G. H. Eckles and W. W. Swett (Missoui-i Sta. Bui. 151 

 (1911), p. 32). — A progress report of investigations upon the normal growth 

 and protein requirements of growing animals (E. S. R., 35, p. S71). 



The growth records as shown by weight and height measurements in these 

 experiments are proving of great value in connection with other investiga- 

 tions. The data obtained in the study of protein requirements for growth 

 indicate that a ration in which about 15 per cent of the energy is from 

 protein is sufficient for normal skeleton growth, but possibly a little deficient 

 for the best standard as measured by gain in weight. Little difference has 

 so far been noted in the efficiency of protein from skim milk as compared with 

 protein from a mixed ration. Confirming previous results, it has been found 

 that unfavorable conditions exert their effects much more on gi'o\vth as rep- 

 resented by weight than on growth as represented by the development of the 

 skeleton. 



Factors influencing the composition of milk, C. H. Eckles, L. S. Palmek, 

 and W. W. Sweit (Missouri Sta. Bui. 151 (1917), pp. 33-35). — Progress reports 

 are given on the following investigations : 



I. Cottonseed meal and cottonseed by-products (pp. 33, 34). — Previously 

 noted from another source (E. S. R., 37, p. 72). 



II. The cause of the counteracting influence of com silage when fed with 

 cottonseed vieal (pp. 34, 35). — Continuing earlier work (E. S. R., 37, p. 72), 

 corn silage in the rations of two cows was replaced with alfalfa hay which 

 had been treated with lactic acid equivalent in amount and concentration to 

 that found in silage. The results gave substantial evidence that the lactic 

 acid in silage is responsible for the counteracting effect which silage has on 

 milk fat when fed with cottonseed meal. In the second experiment the silage 

 in the rations was replaced by timothy hay treated with lactic acid. The 

 results were entirely negative, but it is noted that great difficulty was experi- 

 enced in causing the timothy hay to absorb the lactic acid. In a third experi- 

 ment the effects of replacing silage with sugar were noted. Commercial 

 glucose sirup equivalent to the glucose contained in the silage fed in the first 

 experiment was fed before the typical silage fermentation had taken place. 

 The amount was calculated from the acid contained in the silage. The hay 

 fed in the sugar period was a mixture of equal parts of alfalfa and timothy. 

 The results secured were entirely negative, except that they confirmed observa- 

 tions on the effects of feeding cottonseed meal. The fat constant during the 

 period of glucose and hay showed only the effects of the cottonseed meal in 

 the ration. 



III. Influence of condition at parturition on the composition of the milk and 

 butter fat (p. 35). — Only one cow was under observation in this investigation 

 during the year (E. S. R., 37, p. 172). This cow calved in July, 191G, at a 

 slightly lower body weight than in 1915. She was continued on the same 

 plane of protein intake with the same ration with the exception of silage, and 

 she produced milk and milk fat of the same general composition as during the 

 previous year. The protein averaged about 3 per cent and the milk fat slightly 

 less than 3 per cent ; the constitution of the milk fat showed a high saponifi- 

 cation value, a high Reichert-Meissl number, and a low iodin value. After 

 she had been in milk 90 days the protein in her ration was increased from a 

 little more than 1 lb. to practically 2 lbs. a day. This caused a marked im- 

 provement in the physical condition, a gain in body weight, and an increase 

 of several pounds in the milk flovv-. The percentage of protein in the milk 



