VARIETIES OF SILAGE CORN FOR MILK PRODUCTION Applying the digestive coefficients, (27) one pound contains 0.148 pound digestible protein and 0.7171 pound total digestible nutrients having a nutritive ratio of 1 to 3.805. A ration of 50 pounds of average or herd silage, 4 pounds of hay and 8 pounds of grain provided a nutritive ratio of about 1 to 6.73. The same roughages with 10 pounds of grain provides a ratio of about 1 to 6.38; 12 pounds of grain, about 1 to 6.13; and with 6 pounds of grain, about 1 to 7.21. With 6 pounds of hay the nutritive ratios were slightly wider in the second and third trials. The grain was fed twice daily immediately after the milking periods and preceding the feeding of the silage, at about 6:00 A. M. and 5:00 P. M. The daily live weight was used as a basis for feeding grain. When an animal showed a tendency to gain the grain was reduced either two-tenths or three-tenths of a pound and often followed in a day or two by a further alteration to make a full half pound reduction. In case of loss of weight, the procedure was reversed. The grain fed each year was from a special lot mixed in a commercial plant under the direction of one of the authors. SALTING AND WATERING Salt was placed before the animals about three times each week. Water was placed before them in the forenoon, afternoon and at night during the first two years. In the third trial, water was before the animals in automatic drinking cups. THE ANNALYSIS OF THE FEEDS AND THE MILK In the first two trials, two pounds of hay were taken from each fourth bale. In the third trial samples were taken daily during the last half of the trial, and composited. The grain was sampled at the plant from nearly all bags during the process of filling, by the official sampler of the Connecticut Experiment Station, at New Haven.* The silage was sampled from the surface of each silo during each ten-day period. A two quart fruit jar was filled during the time the silage was being removed from the silo on three middle consecutive days. The three days' samples of All of the feed analyses were made at the Chemistry Department of the Connecticut Agricultural Experiment Station at New Haven, to whom our sincere thanks are due, each type of silage were analyzed, making ten determinations for each silo. A sample of the morning and night's milk of one day from each cow was taken at ten-day intervals, composited and tested for fat and total solids by means of the Babcock Test and the Lactometer. THE WEIGHTS The plan of the experiment was based upon the conception that an animal kept at uniform weight will use its food entirely for maintenance and milk production. This plan reduced the factor of gain or loss of weight to the minimum. With few exceptions, the body weights were kept within very satisfactory limits. The animals were weighed daily. Weighings were made between 8:30 and 9:30 o'clock in the morning and the average of the day's weight with the nine preceding days was recorded opposite the daily weight. This ten-day average as well as the daily weight was charted each day, and this information provided the basis for grain feeding as described above. TIME OF BREEDING The animals were mostly bred about three months after calving. Eckles (26) has shown that the amount of nutrients used for the fetus is small. During the period of the experiment, one group counterbalanced the other in this respect. MILKING This operation was performed with a milking machine twice daily by the regular barn force. TYPE OF RATION FOR EACH GROUP REMAINED THE SAME The cows were kept on the same type of rations throughout. The rations were not sufficiently different in character to warrant alternating the groups. Such a procedure would also have increased the difficulties of keeping the weight uniform. With the same amount of silage and hay fed throughout, and the weight constant, the only variables other than type of silage, were the amount of milk produced and the amount of grain eaten. In this plan the basic idea was to have absolute control over the animals in an attempt to secure accurate individual results. VARIETIES OF SILAGE CORN FOR MILK PRODUCTION PRELIMINARY FEEDING All animals were placed upon the experimental hay and grain ration, but using the regular herd silage (Early Mastodon) for preliminary observations. After 10 to 20 days on this they were given their respective experimental silages for at least ten days before the experiment proper began. During this time they were weighed daily and an effort was made to determine the exact grain requirements. It is of interest that the group which received mature silage would gain, while that which received immature silage would lose in weight when the animals were placed upon the experimental silages, necessitating an immediate adjustment of the grain ration. DATA CONCERNING FEEDS THE CORN VARIETIES The varieties used in all of these trials were as follows: Early maturing, PRIDE OF THE NORTH; Medium maturing, LEAMING; Late maturing, EUREKA. Hereafter, they will be referred to as Early, Medium and Late silage, and the corresponding groups of experimental cows will be similarly designated. All were planted and harvested at the same time each year. GROWING AND HARVESTING First year, 1920. The three types of corn were planted in blocks, side by side, in a field of about 20 acres of corn. The Early was planted on May 28, and harvested on October 5, having a growing season of 129 days. Most of it was ripe enough to shock, the husks and base of stalk being quite dry and the kernels in the hard dough stage. The filling was too rapid for the best packing of mature silage, but satisfactory silage resulted. In this silo were placed 13.8 tons. The Medium was planted on May 28. and harvested on the afternoon of October 4, and the afternoon of October 5, having a growing season of 129 and 130 days. The stalks and husks were green and the kernels were mostly in the soft dough stage. The seed procured was not representative in yield as it produced at the rate of only 12 tons. In this silo were placed 14 tons, the packing being somewhat better than in the case of the Early silage. The Late was planted on May 28 and 29. The silo was filled in the forenoon of October 5, receiving 13.5 tons. The growing season was 129 days, and the kernels were in the early milk stage. "Medium" is not in the "Dent" stage; this ear dryed slightly before photographing. The corn was cut in the field just fast enough to keep the teams busy, none lying on the ground for more than an hour. The regular College Farm equipment and crew were used, power being furnished by a 10 h. p. electric motor. VARIETIES OF SILAGE CORN FOR MILK PRODUCTION Second year, 1921. The corn was planted May 27 and 28 in the same field as that of the first year. The Early was harvested on September 14, 15 and 16; Medium on September 13, 14 and 15; and Late on September 13 and 16. The growing season was, therefore, about 111 days. The amounts of corn placed in the silos were 14 tons of Early, 15.7 tons of Medium and 16 tons of Late. The heights of settled silage were 32 feet of Early, 30.5 feet of Medium, and 29.6 feet of Late. The Early was ripe (hard dough) enough to shock, and lower leaves drying; the Medium in late milk (soft dough) with 20 to 25% of ears beginning to dent; the Late was in the early milk stage. This year, special equipment and crews were used. The silos were filled slowly and packed much better than in 1920. Eureka (Late) Corn, Sept. 1921 Third year, 1922. The corn was planted on May 26, on a different field than in 1920 and 1921. The conditions were very similar, however. The Early was harvested September 16 and 18; the Medium September 19 and 20; and the Late |