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In all of the experiments in feeding the rate of increase has not been uniform, nor has there been a fixed relation of the increase of live weight to the feed consumed, when the comparison is made in periods of one week.
If the pigs had been weighed each day, the variation in the relation referred to would be increased. It is only when periods of considerable length are compared, that we are enabled to determine the true law of increase.
Cases like these show the manner in which we may be led into error by single experiments extending over short periods of time, and the impossibility of securing accurate or reliable results when the feed of the animal is changed from week to week for the purpose of ascertaining the relative values of the different articles of feed.
In the next series of feeding experiments it is proposed to test the value of cooked corn meal, and also the advantages of mixing other articles of food with the meal.
SUMMARY OF EXPERIMENTS IN PIG-FEEDING.
BY M. MILES.
The first series of pig-feeding experiments, now completed, have been conducted for the purpose of ascertaining the value of raw corn meal, when fed by itself. The exclusive use of raw meal in pig-feeding is not to be recommended as the best paying method, as better results can undoubtedly be obtained with a proper admixture of other foods.
The leading object in view in the experiments already made was to obtain a reliable standard of value with which to compare the results of experiments with corn in other forms, and when mixed with other foods.
The complexity of the conditions involved in experiments with mixed foods, seemed to require this preliminary experiment with a single article of some standard food as a starting point.
Forty-two pigs of different kinds have been under experiment, and the gross amount of raw corn meal consumed has been over ten tons.
The greatest care has been taken to secure accuracy in every thing relating to the experiments, and every precaution has been taken to eliminate elements of error.
From the close agreement of the numerous experiments embraced in this series, it is believed that the results on the whole may be accepted as approximately correct.
In summing up the results of the entire series, it would be desirable to make a comparison as to the relative merits of the different breeds under experiment, were it not for the fact that the conditions are so varied, as to age, as to prevent any grouping of breeds that would be satisfactory.
The experiments all show that the age and ripeness (degree of fatness) of
the animals have an important influence on the amount of food consumed, in proportion to weight, and on the return received for feed consumed. The younger animals eat more in proportion to their live weight, and they likewise require less food to make a given increase in live weight.
As animals ripen they consume less food in proportion to live weight, and they likewise require a larger amount of feed to make a given increase in live weight.
It is possible that the size of the animals may have an influence on consumption in proportion to weight, and upon the amount of food required to produce a given increase; but this is a difficult matter to determine by experiment, and the data for its discussion have not as yet been obtained.
The incorrectness of the prevalent opinion that the animals that consume the smallest amount of food are the most profitable, is conclusively shown in the results of these experiments. It will be safe to say that the animal capable of eating the most is the most profitable, provided the digestive organs are capable of assimilating the large amount of food, and converting it into animal products. In such cases the proportion of food required to supply the waste of tissues and keep the animal machinery in working order, is less than when the amount consumed is but little. It is only, in fact, from the excess of food, over what is required for repair of the tissues, that a profit in animal products can be obtained.
For the purpose of showing the influence of age and ripeness upon the amount of feed consumed and upon the return obtained for it, the results of the entire series of experiments have been tabulated in periods of four weeks, and in groups of ages over six months and under six months, together with the general average of all ages for each period.
In the table which follows, pen 9 of 1870, and pens 14 and 16 of 1869 have been entirely omitted, for the reason that the irregular progress of these animals indicated an abnormal condition of the digestive organs that rendered their record of no value.
The weights are all given in pounds and decimals of a pound:
SUMMARY of Results of Pig-Feeding Experiments of 1868, 1869, 1870, 1871.
An examination of the tables of preceding reports showed that quite a number of the young animals did not eat full rations when first put on the diet of raw corn meal, and it was thought best to omit from the table the record of their feeding for the first week, as they could not, under the circumstances, give the normal gain of their age for feed consumed. If the first week had been included, the feed consumed for each 100 pounds of live weight would be 32.62 pounds, and the meal required to produce one pound of increase in live weight would be 3.98 pounds. The figures given in the table are, however, believed to be nearer the truth.
As the table now stands, it will be seen that the digestive organs did not fully adapt themselves to work required of them until the second period, when the best results were obtained. It was undoubtedly a mistake to put such young animals at once on a full feed of raw meal. They should have been fed smaller amounts for several days before commencing the experiment, to give their digestive organs a chance to adapt themselves to the new situation.
Another singular fact was obtained in tabulating the first period of feeding of the animals over six months old. If the first week of feeding is omitted from their record, the results for the 2d, 3d, and 4th weeks would show that 18.58 lbs. of meal were consumed for each 100 lbs. of live weight, per week, and that 4.57 lbs. of meal were required to make a pound of increase in live weight.
The average amount of meal consumed per week for each 100 lbs. of live weight, is shown to be greater for the period of three weeks than for the period of four weeks, while a larger amount is required to make a pound of increase. The first week of the experiment the digestive organs of these older animals appeared to be capable of assimilating all the meal consumed, while at a later period they showed that they had been overtasked so that with an increased consumption of food (showing no impairment of the health to affect the ap
petite) they were unable to assimilate and lay up in increase as large a proportion of their food as they did during the first week. This explanation is offered as the only plausible one suggested by a careful examination of the facts.
The fourth period is not included in the general average given at the bottom of the table, for the reason that in all of the experiments the last period of feeding shows a rapid decrease in the amount of food consumed, and a corresponding increase in the amount of meal required to produce a pound of increase in live weight. As the averages during the periods of profitable feeding were thought to be of the greatest value, they were therefore inserted in the table.
If the necessary means can be procured for continuing these experiments, it is proposed to test the value of cooked meal by itself, and the advantages of adding other foods to both the cooked and the raw meal.
EXPERIMENTS WITH MANURES.
BY M. MILES.
"In 1868 several plats were staked out on the lawn north of the Boarding Hall, and planted to corn. All the plats were unmanured, and the treatment was the same in each,-the object being to ascertain the natural variation of soils of a similar character, and to furnish a standard of comparison for future experiments with manures. (See Report of Secretary of State Board of Agriculture for 1868, pp. 122-128.)
"In 1869 barnyard manure of the same quality was applied to each of the F., D., and B. plats at the rate of forty loads (of forty cubic feet each) per acre, and the plats were again planted to corn. (For results of this part of the experiment, see Report of Secretary of State Board of Agriculture for 1869, pp. 87-91.)"
In 1870 the plats were plowed May 4th, and on the 5th, after harrowing, oats were sown at the rate of three bushels per acre, and grass seed at the rate of ten pounds of clover and one peck of timothy per acre. (For results of this part of the experiment see Report of Secretary of State Board of Agriculture. for 1870, pp. 33-36.)
June 29, 1871, the grass was cut and weighed green,--the two north tiers. before noon, and the three south tiers after noon. After stirring and drying, the hay was cocked and capped on each plat before night.
June 30th.-Cocks opened and aired. Hay apparently in good condition for hanling. The two north tiers of plats were weighed, but as there were indications of rain, the hay was all re-cocked and capped before half-past two P. M. The weights obtained at this time are given on the plan of plats in italics.
July 1.-The cocks were opened in the morning, raked together before noon, and weighed between one and five o'clock P. M.
An examination of the plan of plats will show an important difference in the weights of dry hay obtained on the different days. As the shrinkage shown by the last weighing could not be detected by a simple examination, the importance of thoroughly drying all crops under experiment before weighing is fully demonstrated.
Sept. 5.-The second crop on the north two tiers of plats was cut before noon, and raked and cocked before four P. M.
Sept. 6. The south three tiers of plats were cut between one and half-past two, stirred until four, and put into cock before six P. M.