872 EXPERIMENT STATION EECOED. 



The influence of type and of age upon the utilization of feed by cattle, 

 H. P. Armsby and J. A. Fries (Pennsylvania Sta. Rpt. 1910, pp. 32J,-606, pis. 17, 

 fig. 1; U. S. Dcpt. Agr., Bur. Anini. Indus. Bill. 128, pp. 2'io, pis. 3, figs. 17).— 

 This contains a more detailed account of worli previously noted (E. S. R., 24, 

 p. 468). 



Measurements of the experimental animals made from day to day show that 

 the body of the pure-bred steer was longer at the start, but that after irregu- 

 larities of the first 6 months both animals gained in length at a similar rate for 

 the next months, after which time the growth of the pure-bred steer was 

 much less rapid than that of the scrub steer so that the former was Anally 

 overtaken. At the beginning of the experiment both steers were about the same 

 height, but the scrub steer increased more rapidly than the pure bred and the 

 rate of increase diminished in both animals as they grew older. The chest 

 girth of the scrub was less than the pure bred at first, but its growth was in 

 this respect more rapid for about 18 months. The increase in weight of the 

 pure-bred steer was due much more largely than that of the scrub to an 

 increase in size of the body. After slaughtering, the carcass of the pure bred 

 was rated as prime and the scrub as common and there was a much higher 

 percentage of dressed weight in the former and likewise the predominancy of 

 the loin cut over the less valuable cuts of the forequarter as compared with 

 the scrub. The scrub steer made relatively greater gains in live weight and 

 required on the average a smaller amount of air-dried feed to produce a unit 

 of gain, and a greater tendency toward gain of protein tissues than the pure 

 bred. 



Different amounts of hay v/ere fed each year, one being slightly below the 

 maintenance requirements and the other considerably below it, and designated 

 maintenance and submainteuauce rations, respectively, without implying that 

 the former was an exact maintenance ration. The digestibility of the crude 

 fiber of the hay was less in every instance, and that of the nitrogen-free extract 

 in every case but one upon the heavier of the 2 rations, while the percentage 

 of digestibility of the organic matter and total dry matter was less on the 

 heavier ration. The same was true of the total carbon and total energy, but 

 in 4 cases out of 6 the digestibility of the protein as here computed, assuming 

 the nonprotein to be entirely digestible, was greater in the heavier ration, and 

 the same was true of the total nitrogen, although the cases were not identical 

 with those under protein. Ether extract in all cases showed a higher digesti- 

 bility in the heavier rations. 



The scrub consumed in every case relatively more hay, so it would be ex- 

 pected that any effect of the quantity of hay consumed would be to lower the 

 digestibility, but the contrary was actually found to be the case the first 2 years, 

 and this was true of the total dry matter, the organic matter, the crude fiber, 

 the nitrogen-free extract, the carbon, and the energy with but a single excep- 

 tion — the energy of the submaintenance ration of 1905. In the third season the 

 pure-bred steer seemed to have overtaken the other as regards the ability to 

 digest hay, but the difference in every case was slight. The percentage of 

 digestibility appeared to increase from year to year with both animaLs, the 

 most striking difference being the notable increase in the digestibility of the 

 nonnitrogenous ingredients in 1907 as compared with 1906. 



In 1905 wheat bran constituted the exclusive grain ration ; in the other 2 

 years the grain consisted of a mixture of bi'an, corn meal, and old-process lin- 

 seed meal 1:3:3. The digestibility of the bran was greater on the heavier 

 ration, with the exception of the ether extract, total carbon, and organic hydro- 

 gen in the case of the pure-bred steer, but the diffei'ences were small. With 



