1917] DAIRY FARMING DAIRYING. 171 



" The nitrogen compounds of rations containing alfalfa hay are more 

 digestible than the nitrogen compounds of rations containing clover hay ; they 

 are more completely absorbed from the intestine, but are more largely elimi- 

 nated in the urine. The greater digestibility of the alfalfa nitrogen, therefore, 

 seems not to signify corresponding nutritive superiority. The percentages of 

 utilization of the nitrogen compounds of rations containing clover and of those 

 containing alfalfa were the same. 



" The deficient utilization of the minerals by cows . . . has practical bear- 

 ings in the malnutrition of the bones of cattle, which is not uncommon after 

 seasons of drought and overstocking of pastures, particularly in regions of 

 unfertile, sandy soils or soils of granitic origin, especially if these be worn 

 through long cropping with deficient fertilization. Further practical bearings 

 are probably seen in the rather common failure of cows to breed after a season 

 of forced milk production; also in the failure of many cows fed for high pro- 

 duction to maintain high records during con.secutive periods of lactation; 

 perhaps also as a contributory cause in the usual shrinkage of milk flow, 

 with advance in the period of lactation. . . . Thus far, under no circumstances, 

 have we been able to cause calcium storage or to maintain calcium equilibrium." 



Feeds for dairy cows, M. P. Jarnagin and O. T. Goodwin (C«. State Col. 

 Agr. Circ. 45 (1911), pp. 8, figs. 2). — The rations u.sed in the experiments here 

 reported consisted of a maximum and minimum feed of sorghum and Kafir-corn 

 silage and a minimum and maximum feed of mixed concentrates, with a check 

 ration of silage and cottonseed meal. Twelve cows were divided into three 

 lots of four cows each and fed by the reversal system for 90 days in 30-day 

 periods, so that each group received each of the rations for 30 days. 



On a ration of 36 lbs. of silage and 6 lbs. of cottonseed meal per head daily, 

 the cows lost an average of 5 lbs. each in weight during the 90 days, and 

 produced 6.829.9 lbs. of milk and 335.99 lbs. of butter at a feed cost of $49.35. 

 On a ration of 36 lbs. of silage, 7 lbs. of peavine hay, and 5 lbs. of a mixture 

 of cottonseed meal, wheat bran, and corn-and-cob meal (4:3:3), the cows 

 produced 6,820.7 lbs. of milk and 327.84 lbs. of butter at a feed cost of .$61.20. 

 Each cow lost an average of 9 lbs. in weight during the 90 days on this 

 rat'on. On a ration of 12 lbs. of silage, 10 lbs. of hay, and 10 lbs. of the 

 above grain mixture, the cows produced 7,078.5 lbs. of milk and 341.14 lbs. 

 of butter at a feed cost of $79.92. On this ration they lost in weight an average 

 of 5.5 lbs. each during the 90 days. The prices per ton charged for feeds were 

 for cottonseed meal $27.50, wheat bran .$30, corn-and-cob meal $23, hay $14, 

 and silage $3. 



[Feeding cows with the subcutaneous matter of skins intended for tan- 

 ning], Gerlach {Dent. Landw. Prcsse, 43 {1916), No. 26, p. 229; abs. in Inter- 

 nat. Inst. Agr. [Rorne'^, Internat. Rev. Sci. and Pract. Agr., 7 {1916). No.. 7, 

 p. 906). — Feeding experiments are reported with a subcutaneous material, glue 

 leather — i. e., leather cuttings containing gelatinous matter and consisting, 

 according to the author's analysis, of 14.72 per cent of water, 55.77 per cent 

 of protein, 12.35 per cent of fat, and 10.06 per cent of mineral matter. Nine 

 milch cows between the second and third months of lactation Mere fed by the 

 reversal system for 63 days, the basal ration consisting of chopped forage, hay, 

 beet-leaf silage, mangels, potatoes, wheat bran, and lupines with the bitter taste 

 removed. In addition, one group received 3 kg. of linseed meal and the other 

 1.5 kg. of glue leather per head daily. 



The animals at once took to the latter ration. The milk secretion was 10 

 per cent less during the first period and a little greater during the .second 

 period in the glue-leather group than in the linseed-meal group. The milk 

 was a little richer in fat during both periods in the glue-leather group. 

 105033°— No. 2—17 6 



