1917] DAIRY FARMING— DAIRYING. 669 



as they are for mammals. Further, the chicken's ability to tolerate, without 

 disaster and without modification of the ration, the toxic material of wheat 

 speaks for a metabolism distinct from that of swine or rats. 



" Where half-grown chickens were used there was no important improvement 

 in the rates of growth or egg-lying capacity by supplementing the grains with 

 either salts, casein, or butter fat, or a combination of the three, as contrasted 

 with the results secured with the grain, grain protein concentrate, and calcium 

 carbonate ration. The protein level in all cases was approximately 12 per 

 cent. On all of these rations the number of eggs produced, although fertile, 

 was limited. This fact, at variance with the best results of practice where 

 animal protein concentrates have proved of great value as supplements to 

 cereal grains for a large egg production, would suggest that either the higher 

 plane — 20 to 25 per cent — of protein intake of superior quality secured in 

 practice by the use of the animal protein concentrates (meat scraps, milk, etc.) 

 explains these differences, or else the latter contribute certain factors neces- 

 sary for large egg production which the cereal grain concentrates or casein 

 fail to carry. The matter needs further investigation." 



Winter egg production, A. R. Lee (U. S. Dept. Agr., Office Sec. Circ. 71 

 (1917), pp. 4)- — Suggestions are given for the stimulation of winter egg pro- 

 duction in pullets and to some extent in hens by proper methods of feeding, 

 housing, and handling. 



DAIRY FARMING— DAIRYING. 



The influence of the plane of nutrition of the cow upon the composition 

 and properties of milk and butter fat: The influence of underfeeding, C. H. 

 EcKLES and L. S. Palmer (Missouri Sta. Research Bui. 25 (1916), pp. 3-107, 

 figs. 15). — The investigations reported in this bulletin are in continuation of 

 those already noted (E. S. R., 35, p. 774). 



In these experiments three pure-bred Jersey, one pure-bred Holstein, one 

 pure-bred dairy Shorthorn, and two pure-bred Ayrshire cows were used. Six- 

 teen experimental feeding periods were carried out with these cows, six of 

 which were begun immediately after parturition, four within 30 days after 

 parturition, and six somewhat later in the lactation period. In addition five 

 experimental periods with the above cows, involving the reduction of a super- 

 normal plane of nutrition, and seven experimental periods with cows other 

 than the above, involving physiological underfeeding, are discussed. 



The three types of underfeeding considered are those in which (1) the plane 

 of nutrition of the cow is reduced to subnormal, (2) the plane of nutrition 

 is reduced but not to subnormal, and (3) the cow is unable for physiological 

 reasons to consume sufficient food to support the milk flow immediately after 

 parturition. Of the factors which influence the effects of underfeeding on the 

 composition and properties of milk and butter attention is given to (1) the 

 stage of lactation period of the cow, (2) the degree of underfeeding, (3) the 

 character of the ration, (4) the state of flesh of the cow, (5) the plane of 

 nutrition of the animal previous to underfeeding, and (6) the length of the 

 underfeeding period. 



Data connected with the experiments are tabulated and shown graphically 

 in the appendix. The following conclusions are drawn : 



"A subnormal plane of nutrition causes a cow in lactation to lose more or 

 less weight, depending on the state of flesh of the animal, the degree of under- 

 feeding, and the length of time the animal is underfed. 



" The effects of a subnormal plane of nutrition on the milk flow depend upon 

 the stage of the lactation period at the time of underfeeding. Cows subjected 



