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A Comparison of Digestible Coefficients for Cattle, Swine and Poultry as Suggesting a More Accurate Basis for Computing Poultry Rations
come.
in these calculations. If I am correctly informed, the station computes the nutritive ratio in all instances from the total composition of the grain, disregarding digestibility entirely. Most of the stations, however, in the lack of data for poultry, are using digestible coefficients for cattle. This has been spoken of as the best we have, and on these grounds has been used rather widely, although there is a feeling that the figures for swine would be more accurate. But here again, we are little better off than with poultry, for the amount of data available on digestibility by swine is scarcely as voluminous as that for poultry. In an attempt to justify the use of digestible coefficients by cattle, or to work out some other method that might be more nearly accurate, I wish to present a few tables for comparison. Before doing this, however, I wish to give credit to Prof. J. M. Bartlett, of Orono, Maine, for the data on "Digestion Experiments With Poultry" as found in Bulletin No. 184 of that station, and also to acknowledge free use of the appendix tables in Prof. W. A. Henry's handbook on "Feeds and Feeding," where the coefficients of digestion for cattle and swine were obtained. In Table No. 1 are compared the per cent, of the various nutrients in several feeds as digested respectively by poultry, swine, and cattle. Unfortunately, we cannot compare these figures for the entire sixteen feeds which I am able to find as having been used in poultry digestion experiments. for only eight feeds are common to each of the three groups of animals, and one of these—potatoes—is not ordinarily considered as being of great value from a nutrition standpoint. We are limited, therefore, to the comparison of only seven feeds. Of these I wish particularly to call attention to the one feed which has been used in digestion experiments most widely, viz., corn. Comparing the per cent, of protein that is digested from corn, we find the averacte from sixteen trials with poultrv to be 81.5%; the average from twelve trials with cattle to be 76%; and the one trial with swine to be 69%. Next let us compare the trials with wheat: Protein digested from wheat with ten trials by poultry averaged 75%; with four trials bv cattle 74%; and with an unknown number of trials bv swine 80%. From these instances it would appear that r>oultrv digest protein more nearly like cattle than like swine. Comparing the digestion of nitrogenfree-extract from these feeds, we find for corn: poultrv 91 per cent., cattle 93 per cent., swine 89 per cent. For wheat: poultrv 87 per cent., cattle 93 per cent., swine 83 per cent. In other words, poultrv are about midway between swine and cattle in their ability to digest nitrogen-free-extract.
EDWARD BROWN, F.L.S.
A
COMPARISON OF DIGESTIBLE COEFFICIENTS FOR CATTLE, SWINE AND POULTRY AS SUGGESTING A MORE ACCURATE BASIS FOR COMPUTING POULTRY RATIONS. Before presenting this paper I wish, first, to correct a clerical error in the topic as it appears on the program. It should read "A Comparison of Digestible Coefficients for Cattle, Swine, and Poultry as Suggesting a More Accurate Basis for Computing Poultry Rations." In other words, I wish to offer this merely as a suggestion, with the hope that it may eventually lead to the use of a more uniform method of computing nutritive ratios by the different Poultry Departments. Due to the difficulty of obtaining coefficients of digestion of feeds by poultry, which has resulted in the very meager data now available, we have come to freely use the coefficients for other animals, and in 10
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community as to the importance of development in relation to the capacity of the country, which is far from being exhausted. One direction in which the United Kingdom has lagged behind British colonies and the United States of America is in the domain of educational and investigational work, more especially the last named. Several of our agricultural colleges have done practically nothing in either direction; others have given a modest attention to poultry husbandry; a very few include systematic teaching and have well-equipped demonstration plants. The most noteworthy effort is in the county instruction. Men and women are engaged in conducting classes and holding meetings and paying visits to farmers and other poultry keepers in the rural districts, in order to stimulate production by introduction of better poultry and improved methods. In this direction the results achieved have been most marked and very substantial. The whole question of home food supplies is under consideration. Committees are sitting for the purpose of making recommendations. The Board of Agriculture and other public bodies are promoting schemes in which poultry hold a prominent place, for increasing home supplies, and I look forward to the very near future when production will be to a much greater extent in conformity with the national requirements. To that end advanced, as well as elementary, instruction in this subject, experimental and investigational work, will take the position these deserve. We have, however, to train men for the great task which is before them. This will mean money, and that is where the difficulty may arise, for with the vast expenditure on war the need for economy, public and private, will be very great. That, however, can be over-
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some cases to use the total composition of since they are quite different in character foods direct, without considering digesti- from the dry grains and ground feeds. bility at all. To quote from a fairly recent Taking an average of the seven grain feeds bulletin: "With the present experiments, common to each group we find: the nutritive ratio has been considered as Protein— the ratio of the protein to the sum of the Poultry 75.66 per cent. fat multiplied by 2.3, and the nitrogenCattle 73.00 per cent. free-extract matter. That is, the digestiSwine 77.86 per cent. bility has not been taken into consideraN. F. E.— tion, and the fiber has not been included Poultry 82.66 per cent. Comparing the digestion of fat from Cattle 86.57 per cent. these feeds we find for corn: poultry 88 Swine 87.00 per cent. per cent., cattle 86 per cent., swine 46 per Fatcent. For wheat: poultry 53 per cent., catPoultry 71.33 per cent. tle 71 per cent., swine 70 per cent. A Cattle 75.00 per cent. rather wide variation, but the balance in Swine 63.14 per cent. favor, of the likeness to digestion by cattle. TABLE I.—COMPARATIVE TABLE OF COAnd so we might enumerate for other feeds, finding a good many exceptions, but EFFICIENTS OF DIGESTION. nevertheless, as will be shown by the sumPoultry. mary of averages, a tendency toward a likeness of poultry to digest more nearly Feed. like cattle than like swine. o'C •8 !5H Oh Three general averages have been taken. fe few fn First, the average of the percentage di- Whole Corn 16 81.58 91.32 88.11 gestibility of each nutrient for all the feeds Cracked Corn 2 72.20 88.10 87.60 used in trial experiments by each group of Corn Meal 2 74.60 86.00 87.60 animals. This, it must be remembered, is Wheat 10 75.05 87.04 53.00 an average from feeds not common to each Barley 3 77.32 85.09 67.86 group. But it is interesting to note that Rye 2 66.90 86.70 22.60 here again the figures, if indicating any- Oats 13 71.31 90.10 87.89 thing, show that poultry digest more like Buckwheat 2 59.40 86.99 89.22 cattle than like swine. Thus we have: India Wheat 3 75.00* 20.9 83.40 83.80 Protein— Can. Field Peas 3 87.00 84.80 80.01 Poultry 73.6 per cent. Millet 2 62.40 98.39 85.71 Cattle 72.4 per cent. Hominy Meal Swine 80.4 per cent. Wheat Midds. N. F. E.— Wheat Bran 3 7170* 13.5 4o!66 37'66 Poultry 79.4 per cent. O. P. Oil Meal Cattle 83.3 per cent. Clover 3 7O60* 10.4 K30 35^50 Swine 87.9 per cent. Beef Scrap 95.00 2 92.60 Fat— , Beef (leanmt, 2 90.20 86.30 Poultry 72.4 per cent. Potatoes 84.46 6 46.94 Cattle 78.7 per cent. Average of Swine 67.6 per cent. All Feeds 73.43 79.48 72.48 Now to compare the eight feeds common Average of 8 to each group, viz., Whole Corn, Corn feeds common Meal, Wheat, Barley, Canada Field Peas, 72.33 71.33 to each group 72.07 Millet, Wheat, Bran, and Potatoes. Average of 7 We find: grain feeds Protein— common to Poultry 72.0 per cent. 75.66 82.66 71.33 each group Cattle 70.2 per cent. Swine 78.6 per cent. •Calculated. N. F. E.— Swine. Poultry 72.3 per cent. Cattle 87.0 per cent. Feed. rt Swine 88.3 per cent. [H OP-i ZH S5W h Fat1 69.00 38.0 89.00 46.00 Whole Corn Poultry 71.3 per cent. Cracked Corn Cattle 75.0 per cent. Corn Meal Swine 63.1 per cent. 8a66 39^6 9400 8o!66 Vz 80.00 60.0 83.00 70.00 We still find our digestive relationship of Wheat 8 76.00 15.0 90.00 65.00 poultry to cattle holding good, although the Barley variation is rather wide, especially in nitro- Rye gen-free-extract. Oats A third method of comparison is on the Buckwheat basis of seven feeds—potatoes being omitted, India Wheat 11
dealing with individual nutrients rather than with the digestibility of the feed as a whole. It is very essential to speak of 73.00 3716 87.00 7L66 fiber at this time, however, since it is upon 75,00 34.0 66.00 72.00 this part of the feed that our next com86.00 12.0 85.00 80.00 parison will hinge. Cattle are apparently the most efficient animals we have, in difiber, and poultry, on the contrary, 97166 87166 gesting seem to be the most inefficient. To guote a few writers on this subject: 84166 9a66 Kalugine (E. S. R. 8, p. 915) : "Poultry 80.45 87.90 67.67 digest crude fiber even less than horses or swine, and the crude protein of buckwheat and wheat is digested in an inferior de78.62 88.37 63.14 gree." F. Lehrman concludes that fiber is indigestible by poultry. (Dent, landw. Presse, 1901, No. 39, p. 341.) H. Weiske in experimenting with geese 77.86 87.00 63.14 concluded that crude fiber is not digested by them. (Landw. Vers. Sta. 21, p. 411.) Cattle. Prof. J. ,M. Bartlett records digestion of fiber only in the case of a few feeds such Feed. cd as cut clover, India wheat, and a small £H UP< fe isw h Whole Corn 12 76.00 58.0 93.00 86.00 amount in whole oats and wheat bran, and states that "poultry digest very little crude Cracked Corn .... fiber." (Me. Bu. 184, p. 327.) Corn Meal 21 66166 92166 9L00 I think we are fairly safe in concluding Wheat 4 74.00 93.00 71.00 Barley 4 70.00 50.0 92.00 89.00 that, if poultry digest fiber at all, it is only Rye 2 84.00 92.00 64.00 to an inferior degree, and that we may dis6 77.00 3L0 77.00 89.00 regard it with apparent safety. Oats In order to reduce our comparisons to 2 75.00 24.0 76.00 100.00 Buckwheat simpler terms and to introduce two other India Wheat on which to compute the nutritive Can. Field Peas 2 83166 26.6 9400 55.00 bases 2 65.00 51.0 71.00 70.00 ratio of poultry feels, let us compare the Millet Hominy Meal 8 65.00 67.0 89.00 92.00 amount of digestible nutriment in one hunpounds of feed according to five difWheat Midds. 6 77.00 30.0 78.00 88.00 dred Wheat Bran 11 77.00 41.0 71.00 63.00 ferent bases of computation, viz.: (1) the composition of the feed, (2) the nuO. P. Oil Meal 3 89.00 57.0 78.00 89.00 total digested by swine, (3) the nutrients 18 58.00 54.0 64.00 55.00 trients Clover digested by cattle, (4) the nutrients diBeef Scrap gested by cattle but omitting the fiber, (5) Beef (lean mt.) the nutrients digested by poultry. Potatoes 30 5L00 9Q.00 These values have been worked out in Average of Table II — the figures representing the 83.33 78.71 amount of nutrient per one hundred pounds All Feeds 72.47 Average of 8 of feed. As the table is arranged, all figfeeds common ures in the same horizontal row are com87.00 75.00 parable, to each group 70.25 and if these are compared it will Average of 7 be found that just about 72% of them folgrain feeds low our previous correlation of similarity common to digestion by cattle and poultry. But here 86.57 75.00 in each group 73.00 a new and closer correlation is brought Our correlation is still present, and it out, which is that between the fiber-free would seem that if we were to judge from values for cattle and the values for poulthe rather scanty data available, we could try. With just one exception—that of milonly conclude, because the exceptions to let—the carbohydrates as digested by cattle, the rule are so few, that the coefficient of minus the fiber, approach more nearly the digestibility for the nutrients in the case of carbohydrate value for poultry. In other poultry is more nearly like that of cattle words, if we eliminate the fiber from the nutrients digested by cattle, we apparently than it is like that for swine. It will be noted that fiber has been en- have, as it appears from this data, the most tirely omitted in our comparisons, but since accurate available measure of digestibility we have considered only the nitrogen-free- by poultry. This is still more clearly shown extract from the carbohydrates, it would where the results for the seven feeds are in no way affect the results. We have been summarized. 12 iber
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89.00 78.0 95.00 50.00 68.00 33.0 92.00 59.00
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Can. Field Peas 1 1 Millet Hominy Meal Wheat Midds. "l 2 Wheat Bran O. P. Oil Meal 4 Clover 8 Beef Scrap Beef (lean mt.) 4 Potatoes Average of All Feeds Average of 8 feeds common to each group Average of 7 grain feeds common to each group
Editorial An organization of individuals and institutions primarily engaged in instruction, investigation and extension in poultry husbandry. Publication Committee. W. F. KTRKPATMCK, RAYMOND PEARL. JAMES E. RICE.
Editor. HARRY R. LEWIS,
TABLE II.—COMPARISON OF METHODS OF WORKING OUT THE VALUE OF FEEDS FOR POULTRY BASED ON DIGESTIBILITY OF N U TRIENTS—PER 100 LBS. OF FEED.
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Whole Corn. Protein 10.3 7.1 C. H. (N. F. E.) 70.4 63.5 Fat 5.0 2.3 T. N. 91.9 75.8 Corn Meal. Protein 9.2 8.1 C. H. 68.7 65.5 Fat 3.8 3.0 T. N. 86.5 80.4 Wheat. Protein 11.9 9.4 C. H. 71.9 68.8 Fat 2.1 1.8 T. N. 88.5 82.3 Barley. Protein 12.0 9.1 C. H. 68.7 62.5 Fat 1.8 1.2 T. N. 84.8 74.3 Canada Field Peas. Protein 23.7 21.1 50.2 48.5 C. H. 0.8 0.2 Fat T. N. 75.7 70.1 Millet. Protein 10.9 7.4 C. H. 62.6 57.6 3.5 2.1 Fat T. N. 81.4 69.7
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66.8 4.3 84.3
65.5 4.3 83.0
64.3 4.4 82.6
6.1 64.3 3.5 78.3
6.1 63.2 3.5 77.2
6.9 59.1 3.3 73.4
8.8 67.5 1.5 79.7
8.8 66.9 1.5 79.1
8.9 62.6 1.1 74.0
8.4 65.3 1.6 77.3
8.4 63.2 1.6 75.2
9.3 58.5 1.2 70.5
19.7 19.7 49.3 47.2 0.4 0.4 69.9 67.8
20.6 44.1 0.6 66.1
7.1 44.4 2.5 57.1
6.8 61.6 3.0 75.2
7.1 48.5 2.5 61.2
11.6 44.1 2.9 62.2
11.9 42.0 2.5 59.5
11.9 38.3 2.5 55.8
11.0 26.0 1.5 40.4
SUMMARY OF AVERAGES.
Per 100 Lbs. Averages of 7 Feeds. Protein. C.H. Fat. 53.74 2.16 10.27
T.N. Poultry 68.87 Cattle (Fib.Free)* 9.97 55.53 2.33 70.74 Cattle 9.97 57.68 2.33 72.89 Swine 10.54 58.64 1.93 73.52 Total Chem'l 83.87 Compos'n 13.34 63.77 3.00 From this table it would seem that fowls are a little more efficient in digesting protein and less efficient in digesting carbohydrates and fat than are cattle. They appear, on the other hand, to be less efficient than swine in digesting protein and carbohydrates, but more efficient in digesting fat. But the point of particular interest lies in the comparison of the Total Nutriment when computed as an average for the seven feeds for each group. The fiber-free cattledigested factor (70.74) seems to most closely approach the corresponding value for poultry (68.87), and it is this factor that I wish to leave with you for your consideration. The difference here is so slight that it might be accounted for by a difference in composition of the grain used, by experimental error in readings or in computations, or by the individual characteristics of the animal. But in any case, the results seem rather consistently comparable and it is hoped that further investigation may be carried on to check up the accuracy of the method. I wish to say just a word here as to the reliability of the figures used in these tables. It is interesting to note that, according to Henry's "Feeds and Feeding" and Maine Bulletin 184, we have recorded more digestion trials with corn, with wheat and with oats by poultry than we have for cattle, viz.—corn: by cattle 12, by poultry 16; oats: by cattle 6, by poultry 13; wheat: by cattle 4, by poultry 10, and yet we place considerable confidence in Professor Henry's computations which give us his "Table III." Another point I wish to make is, that in the event that it were found desirable, upon further investigation, to use for our poultry the fiber-free coefficients for cattle, it is a very easy matter to compute the amount of digested nutrients direct from the appendix tables of Professor Henry's book, and in fact, for personal interest I have already made computations for over one hundred feeds, and find that they appear to check up very well and to look reasonable. •Computed by omitting fiber values. 13
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New Brunswick, N. J. This Journal is published monthly for ten months each year. While published primarily for the use of the members, additional copies may be secured for individual or library files at the following rates: Subscription Price, $1.00 per year. Price of a single copy, IS cents. •
Wheat Bran. Protein 15.4 C. H. 53.9 Fat 4.0 T. N. 78.3
THE VALUE
OF GRIT IN POULTRY FEEDING. Introduction: Grit in the bird's gizzard, according to a long accepted theory, performs a function similar to that of teeth in mammalia. Dr. T. P. Shaw (McGill University), who has recently made some close observations on the physiology of digestion in the domestic fowl, states: "The function of the gizzard is to crush the hard grains. This it accomplishes by muscular contractions which rub the grains one against the other. This process is very much facilitated if sharp particles of grit are mixed with the grain. Some writers claim that grit is unnecessary for poultry. We fail to notice the report of any experiments which prove that fowls without grit in the gizzard, when fed on whole grain, did as well as fowls with free access to grit. Some experiments have been reported where the observers have taken for granted that the gizzard did not contain grit because the birds had not acc- ss to any for a month. The author has cc unted between fifteen and twenty-five paiticles of grit, varying in size from that of a pin-head to that of a split-pea, after birds have been without grit for three months. In young chicks the soft food given may become impacted in the gizzard. This is prevented by allowing chicks access to sharp sand. The sharp sand particles stimulate the muscular action of the gizzard which is sluggish when soft food is given." Passing from the finding of a scientist to those of a practical poultryman, we read the following in "Principles and Practices of Poultry Culture," by John H. Robinson.
Reasoning from analogies observed between birds and ruminants, and from the fact that small particles of stone, glass, earthenware, etc., were often found in the gizzards of fowls in course of preparation for the table it was long ago assumed that the gizzard itself was inadequate for its function, and that the bird swallowed these substances because they were required for the mastication of its food I followed the common practice (of feeding grit) long after I was convinced in my own mind that the birds had no need of grit to grind their food, but finally abandoned it, and since about 1902 have given no grit to chickens." John H. Robinson, however, rears his chickens largely on free range, so that there is all likelihood of their obtaining an abundance of grit without it being given as a particular feed. The same poultryman further reports: "A pen of twenty-five extra large hens in my yards supplied with indigestible grit and oyster shell, consumed in eight months less than a pint of grit." Presuming the hens in question to have had an average amount of grit in the gizzard at the commencement of the experiment, the weight of this argument against the feeding of grit to chickens is counterbalanced by the findings of Dr. Shaw regarding the length of time grit is retained in the gizzard. Some experiment stations, as well as individual investigators, have taken up work along this line. In a Bulletin entitled, "Experiments with Poultry," compiled from the twenty-sixth annual report of the New York Agricultural Experiment Station the results obtained from experiments made with nineteen lots of chickens, ranging from one to three weeks of age, showed that "the mixing of sand in the food, both in a ration containing food and in one without, resulted in better health for the chickens, and more efficient use of the food." The U. S. Department of Agriculture published, in 1904, a Bulletin entitled "Digestion Experiments with Poultry." In a section with the heading "The Utilization of Sand by Poultry," we find the following: "The consumption of sand is much greater on an oat than a corn diet. This is no doubt occasioned by the greater proportion of fibre in the oats." Experiments with individual chickens' were also recorded. Grit was withheld from two chickens for a period of six months. Up to five months, the lack of gravel "had apparently not led to any serious impairment of digestion, but after this the animals appeared gradually to become debilitated." In another individual, grit was found to be retained in the gizzard "after a lapse of seven months." It is evident from the foregoing, that work in connection with the feeding of grit to poultry cannot be out of place, the lack of authenticity in the work heretofore undertaken being largely due to the factor
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Considering these two points and in view of the fact that it will undoubtedly be a great many years before we have sufficient data to allow the use of digestible coefficients obtained direct from poultry, and also because we have constant need for working out nutritive ratios, total nutrimnet, and the like, I am wondering if, for the sake of uniformity alone, we would not be justified in adopting a standard method, even though it may not be entirely grounded on good statistical experimental data. If so, what would this system be? The total chemical composition of feeds is undoubtedly the most inaccurate. We have seen, further, that digestion by poultry seems to be more nearly like cattle than it is like swine, and coupled with this fact, if we agree that fowls do not digest fiber, I offer you the suggestion that we might find it advantageous, at the present time, to use the easily computed method of eliminating the fiber from the digested nutrients as obtained from experiments with cattle, and adopt these values in the computation of our poultry rations. A. B. DANN.
in these calculations. If I am correctly informed, the station computes the nutritive ratio in all instances from the total composition of the grain, disregarding digestibility entirely. Most of the stations, however, in the lack of data for poultry, are using digestible coefficients for cattle. This has been spoken of as the best we have, and on these grounds has been used rather widely, although there is a feeling that the figures for swine would be more accurate. But here again, we are little better off than with poultry, for the amount of data available on digestibility by swine is scarcely as voluminous as that for poultry. In an attempt to justify the use of digestible coefficients by cattle, or to work out some other method that might be more nearly accurate, I wish to present a few tables for comparison. Before doing this, however, I wish to give credit to Prof. J. M. Bartlett, of Orono, Maine, for the data on "Digestion Experiments With Poultry" as found in Bulletin No. 184 of that station, and also to acknowledge free use of the appendix tables in Prof. W. A. Henry's handbook on "Feeds and Feeding," where the coefficients of digestion for cattle and swine were obtained. In Table No. 1 are compared the per cent, of the various nutrients in several feeds as digested respectively by poultry, swine, and cattle. Unfortunately, we cannot compare these figures for the entire sixteen feeds which I am able to find as having been used in poultry digestion experiments. for only eight feeds are common to each of the three groups of animals, and one of these—potatoes—is not ordinarily considered as being of great value from a nutrition standpoint. We are limited, therefore, to the comparison of only seven feeds. Of these I wish particularly to call attention to the one feed which has been used in digestion experiments most widely, viz., corn. Comparing the per cent, of protein that is digested from corn, we find the averacte from sixteen trials with poultrv to be 81.5%; the average from twelve trials with cattle to be 76%; and the one trial with swine to be 69%. Next let us compare the trials with wheat: Protein digested from wheat with ten trials by poultry averaged 75%; with four trials bv cattle 74%; and with an unknown number of trials bv swine 80%. From these instances it would appear that r>oultrv digest protein more nearly like cattle than like swine. Comparing the digestion of nitrogenfree-extract from these feeds, we find for corn: poultrv 91 per cent., cattle 93 per cent., swine 89 per cent. For wheat: poultrv 87 per cent., cattle 93 per cent., swine 83 per cent. In other words, poultrv are about midway between swine and cattle in their ability to digest nitrogen-free-extract.
EDWARD BROWN, F.L.S.
A
COMPARISON OF DIGESTIBLE COEFFICIENTS FOR CATTLE, SWINE AND POULTRY AS SUGGESTING A MORE ACCURATE BASIS FOR COMPUTING POULTRY RATIONS. Before presenting this paper I wish, first, to correct a clerical error in the topic as it appears on the program. It should read "A Comparison of Digestible Coefficients for Cattle, Swine, and Poultry as Suggesting a More Accurate Basis for Computing Poultry Rations." In other words, I wish to offer this merely as a suggestion, with the hope that it may eventually lead to the use of a more uniform method of computing nutritive ratios by the different Poultry Departments. Due to the difficulty of obtaining coefficients of digestion of feeds by poultry, which has resulted in the very meager data now available, we have come to freely use the coefficients for other animals, and in 10
Downloaded from http://ps.oxfordjournals.org/ at University of Bath, Library on June 9, 2015
community as to the importance of development in relation to the capacity of the country, which is far from being exhausted. One direction in which the United Kingdom has lagged behind British colonies and the United States of America is in the domain of educational and investigational work, more especially the last named. Several of our agricultural colleges have done practically nothing in either direction; others have given a modest attention to poultry husbandry; a very few include systematic teaching and have well-equipped demonstration plants. The most noteworthy effort is in the county instruction. Men and women are engaged in conducting classes and holding meetings and paying visits to farmers and other poultry keepers in the rural districts, in order to stimulate production by introduction of better poultry and improved methods. In this direction the results achieved have been most marked and very substantial. The whole question of home food supplies is under consideration. Committees are sitting for the purpose of making recommendations. The Board of Agriculture and other public bodies are promoting schemes in which poultry hold a prominent place, for increasing home supplies, and I look forward to the very near future when production will be to a much greater extent in conformity with the national requirements. To that end advanced, as well as elementary, instruction in this subject, experimental and investigational work, will take the position these deserve. We have, however, to train men for the great task which is before them. This will mean money, and that is where the difficulty may arise, for with the vast expenditure on war the need for economy, public and private, will be very great. That, however, can be over-
rudt rot.
iber
rude rot.
iber
0.
rials
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some cases to use the total composition of since they are quite different in character foods direct, without considering digesti- from the dry grains and ground feeds. bility at all. To quote from a fairly recent Taking an average of the seven grain feeds bulletin: "With the present experiments, common to each group we find: the nutritive ratio has been considered as Protein— the ratio of the protein to the sum of the Poultry 75.66 per cent. fat multiplied by 2.3, and the nitrogenCattle 73.00 per cent. free-extract matter. That is, the digestiSwine 77.86 per cent. bility has not been taken into consideraN. F. E.— tion, and the fiber has not been included Poultry 82.66 per cent. Comparing the digestion of fat from Cattle 86.57 per cent. these feeds we find for corn: poultry 88 Swine 87.00 per cent. per cent., cattle 86 per cent., swine 46 per Fatcent. For wheat: poultry 53 per cent., catPoultry 71.33 per cent. tle 71 per cent., swine 70 per cent. A Cattle 75.00 per cent. rather wide variation, but the balance in Swine 63.14 per cent. favor, of the likeness to digestion by cattle. TABLE I.—COMPARATIVE TABLE OF COAnd so we might enumerate for other feeds, finding a good many exceptions, but EFFICIENTS OF DIGESTION. nevertheless, as will be shown by the sumPoultry. mary of averages, a tendency toward a likeness of poultry to digest more nearly Feed. like cattle than like swine. o'C •8 !5H Oh Three general averages have been taken. fe few fn First, the average of the percentage di- Whole Corn 16 81.58 91.32 88.11 gestibility of each nutrient for all the feeds Cracked Corn 2 72.20 88.10 87.60 used in trial experiments by each group of Corn Meal 2 74.60 86.00 87.60 animals. This, it must be remembered, is Wheat 10 75.05 87.04 53.00 an average from feeds not common to each Barley 3 77.32 85.09 67.86 group. But it is interesting to note that Rye 2 66.90 86.70 22.60 here again the figures, if indicating any- Oats 13 71.31 90.10 87.89 thing, show that poultry digest more like Buckwheat 2 59.40 86.99 89.22 cattle than like swine. Thus we have: India Wheat 3 75.00* 20.9 83.40 83.80 Protein— Can. Field Peas 3 87.00 84.80 80.01 Poultry 73.6 per cent. Millet 2 62.40 98.39 85.71 Cattle 72.4 per cent. Hominy Meal Swine 80.4 per cent. Wheat Midds. N. F. E.— Wheat Bran 3 7170* 13.5 4o!66 37'66 Poultry 79.4 per cent. O. P. Oil Meal Cattle 83.3 per cent. Clover 3 7O60* 10.4 K30 35^50 Swine 87.9 per cent. Beef Scrap 95.00 2 92.60 Fat— , Beef (leanmt, 2 90.20 86.30 Poultry 72.4 per cent. Potatoes 84.46 6 46.94 Cattle 78.7 per cent. Average of Swine 67.6 per cent. All Feeds 73.43 79.48 72.48 Now to compare the eight feeds common Average of 8 to each group, viz., Whole Corn, Corn feeds common Meal, Wheat, Barley, Canada Field Peas, 72.33 71.33 to each group 72.07 Millet, Wheat, Bran, and Potatoes. Average of 7 We find: grain feeds Protein— common to Poultry 72.0 per cent. 75.66 82.66 71.33 each group Cattle 70.2 per cent. Swine 78.6 per cent. •Calculated. N. F. E.— Swine. Poultry 72.3 per cent. Cattle 87.0 per cent. Feed. rt Swine 88.3 per cent. [H OP-i ZH S5W h Fat1 69.00 38.0 89.00 46.00 Whole Corn Poultry 71.3 per cent. Cracked Corn Cattle 75.0 per cent. Corn Meal Swine 63.1 per cent. 8a66 39^6 9400 8o!66 Vz 80.00 60.0 83.00 70.00 We still find our digestive relationship of Wheat 8 76.00 15.0 90.00 65.00 poultry to cattle holding good, although the Barley variation is rather wide, especially in nitro- Rye gen-free-extract. Oats A third method of comparison is on the Buckwheat basis of seven feeds—potatoes being omitted, India Wheat 11
dealing with individual nutrients rather than with the digestibility of the feed as a whole. It is very essential to speak of 73.00 3716 87.00 7L66 fiber at this time, however, since it is upon 75,00 34.0 66.00 72.00 this part of the feed that our next com86.00 12.0 85.00 80.00 parison will hinge. Cattle are apparently the most efficient animals we have, in difiber, and poultry, on the contrary, 97166 87166 gesting seem to be the most inefficient. To guote a few writers on this subject: 84166 9a66 Kalugine (E. S. R. 8, p. 915) : "Poultry 80.45 87.90 67.67 digest crude fiber even less than horses or swine, and the crude protein of buckwheat and wheat is digested in an inferior de78.62 88.37 63.14 gree." F. Lehrman concludes that fiber is indigestible by poultry. (Dent, landw. Presse, 1901, No. 39, p. 341.) H. Weiske in experimenting with geese 77.86 87.00 63.14 concluded that crude fiber is not digested by them. (Landw. Vers. Sta. 21, p. 411.) Cattle. Prof. J. ,M. Bartlett records digestion of fiber only in the case of a few feeds such Feed. cd as cut clover, India wheat, and a small £H UP< fe isw h Whole Corn 12 76.00 58.0 93.00 86.00 amount in whole oats and wheat bran, and states that "poultry digest very little crude Cracked Corn .... fiber." (Me. Bu. 184, p. 327.) Corn Meal 21 66166 92166 9L00 I think we are fairly safe in concluding Wheat 4 74.00 93.00 71.00 Barley 4 70.00 50.0 92.00 89.00 that, if poultry digest fiber at all, it is only Rye 2 84.00 92.00 64.00 to an inferior degree, and that we may dis6 77.00 3L0 77.00 89.00 regard it with apparent safety. Oats In order to reduce our comparisons to 2 75.00 24.0 76.00 100.00 Buckwheat simpler terms and to introduce two other India Wheat on which to compute the nutritive Can. Field Peas 2 83166 26.6 9400 55.00 bases 2 65.00 51.0 71.00 70.00 ratio of poultry feels, let us compare the Millet Hominy Meal 8 65.00 67.0 89.00 92.00 amount of digestible nutriment in one hunpounds of feed according to five difWheat Midds. 6 77.00 30.0 78.00 88.00 dred Wheat Bran 11 77.00 41.0 71.00 63.00 ferent bases of computation, viz.: (1) the composition of the feed, (2) the nuO. P. Oil Meal 3 89.00 57.0 78.00 89.00 total digested by swine, (3) the nutrients 18 58.00 54.0 64.00 55.00 trients Clover digested by cattle, (4) the nutrients diBeef Scrap gested by cattle but omitting the fiber, (5) Beef (lean mt.) the nutrients digested by poultry. Potatoes 30 5L00 9Q.00 These values have been worked out in Average of Table II — the figures representing the 83.33 78.71 amount of nutrient per one hundred pounds All Feeds 72.47 Average of 8 of feed. As the table is arranged, all figfeeds common ures in the same horizontal row are com87.00 75.00 parable, to each group 70.25 and if these are compared it will Average of 7 be found that just about 72% of them folgrain feeds low our previous correlation of similarity common to digestion by cattle and poultry. But here 86.57 75.00 in each group 73.00 a new and closer correlation is brought Our correlation is still present, and it out, which is that between the fiber-free would seem that if we were to judge from values for cattle and the values for poulthe rather scanty data available, we could try. With just one exception—that of milonly conclude, because the exceptions to let—the carbohydrates as digested by cattle, the rule are so few, that the coefficient of minus the fiber, approach more nearly the digestibility for the nutrients in the case of carbohydrate value for poultry. In other poultry is more nearly like that of cattle words, if we eliminate the fiber from the nutrients digested by cattle, we apparently than it is like that for swine. It will be noted that fiber has been en- have, as it appears from this data, the most tirely omitted in our comparisons, but since accurate available measure of digestibility we have considered only the nitrogen-free- by poultry. This is still more clearly shown extract from the carbohydrates, it would where the results for the seven feeds are in no way affect the results. We have been summarized. 12 iber
rude rot.
o. rials
89.00 78.0 95.00 50.00 68.00 33.0 92.00 59.00
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Can. Field Peas 1 1 Millet Hominy Meal Wheat Midds. "l 2 Wheat Bran O. P. Oil Meal 4 Clover 8 Beef Scrap Beef (lean mt.) 4 Potatoes Average of All Feeds Average of 8 feeds common to each group Average of 7 grain feeds common to each group
Editorial An organization of individuals and institutions primarily engaged in instruction, investigation and extension in poultry husbandry. Publication Committee. W. F. KTRKPATMCK, RAYMOND PEARL. JAMES E. RICE.
Editor. HARRY R. LEWIS,
TABLE II.—COMPARISON OF METHODS OF WORKING OUT THE VALUE OF FEEDS FOR POULTRY BASED ON DIGESTIBILITY OF N U TRIENTS—PER 100 LBS. OF FEED.
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Whole Corn. Protein 10.3 7.1 C. H. (N. F. E.) 70.4 63.5 Fat 5.0 2.3 T. N. 91.9 75.8 Corn Meal. Protein 9.2 8.1 C. H. 68.7 65.5 Fat 3.8 3.0 T. N. 86.5 80.4 Wheat. Protein 11.9 9.4 C. H. 71.9 68.8 Fat 2.1 1.8 T. N. 88.5 82.3 Barley. Protein 12.0 9.1 C. H. 68.7 62.5 Fat 1.8 1.2 T. N. 84.8 74.3 Canada Field Peas. Protein 23.7 21.1 50.2 48.5 C. H. 0.8 0.2 Fat T. N. 75.7 70.1 Millet. Protein 10.9 7.4 C. H. 62.6 57.6 3.5 2.1 Fat T. N. 81.4 69.7
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7.8
7.8
8.4
66.8 4.3 84.3
65.5 4.3 83.0
64.3 4.4 82.6
6.1 64.3 3.5 78.3
6.1 63.2 3.5 77.2
6.9 59.1 3.3 73.4
8.8 67.5 1.5 79.7
8.8 66.9 1.5 79.1
8.9 62.6 1.1 74.0
8.4 65.3 1.6 77.3
8.4 63.2 1.6 75.2
9.3 58.5 1.2 70.5
19.7 19.7 49.3 47.2 0.4 0.4 69.9 67.8
20.6 44.1 0.6 66.1
7.1 44.4 2.5 57.1
6.8 61.6 3.0 75.2
7.1 48.5 2.5 61.2
11.6 44.1 2.9 62.2
11.9 42.0 2.5 59.5
11.9 38.3 2.5 55.8
11.0 26.0 1.5 40.4
SUMMARY OF AVERAGES.
Per 100 Lbs. Averages of 7 Feeds. Protein. C.H. Fat. 53.74 2.16 10.27
T.N. Poultry 68.87 Cattle (Fib.Free)* 9.97 55.53 2.33 70.74 Cattle 9.97 57.68 2.33 72.89 Swine 10.54 58.64 1.93 73.52 Total Chem'l 83.87 Compos'n 13.34 63.77 3.00 From this table it would seem that fowls are a little more efficient in digesting protein and less efficient in digesting carbohydrates and fat than are cattle. They appear, on the other hand, to be less efficient than swine in digesting protein and carbohydrates, but more efficient in digesting fat. But the point of particular interest lies in the comparison of the Total Nutriment when computed as an average for the seven feeds for each group. The fiber-free cattledigested factor (70.74) seems to most closely approach the corresponding value for poultry (68.87), and it is this factor that I wish to leave with you for your consideration. The difference here is so slight that it might be accounted for by a difference in composition of the grain used, by experimental error in readings or in computations, or by the individual characteristics of the animal. But in any case, the results seem rather consistently comparable and it is hoped that further investigation may be carried on to check up the accuracy of the method. I wish to say just a word here as to the reliability of the figures used in these tables. It is interesting to note that, according to Henry's "Feeds and Feeding" and Maine Bulletin 184, we have recorded more digestion trials with corn, with wheat and with oats by poultry than we have for cattle, viz.—corn: by cattle 12, by poultry 16; oats: by cattle 6, by poultry 13; wheat: by cattle 4, by poultry 10, and yet we place considerable confidence in Professor Henry's computations which give us his "Table III." Another point I wish to make is, that in the event that it were found desirable, upon further investigation, to use for our poultry the fiber-free coefficients for cattle, it is a very easy matter to compute the amount of digested nutrients direct from the appendix tables of Professor Henry's book, and in fact, for personal interest I have already made computations for over one hundred feeds, and find that they appear to check up very well and to look reasonable. •Computed by omitting fiber values. 13
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New Brunswick, N. J. This Journal is published monthly for ten months each year. While published primarily for the use of the members, additional copies may be secured for individual or library files at the following rates: Subscription Price, $1.00 per year. Price of a single copy, IS cents. •
Wheat Bran. Protein 15.4 C. H. 53.9 Fat 4.0 T. N. 78.3
THE VALUE
OF GRIT IN POULTRY FEEDING. Introduction: Grit in the bird's gizzard, according to a long accepted theory, performs a function similar to that of teeth in mammalia. Dr. T. P. Shaw (McGill University), who has recently made some close observations on the physiology of digestion in the domestic fowl, states: "The function of the gizzard is to crush the hard grains. This it accomplishes by muscular contractions which rub the grains one against the other. This process is very much facilitated if sharp particles of grit are mixed with the grain. Some writers claim that grit is unnecessary for poultry. We fail to notice the report of any experiments which prove that fowls without grit in the gizzard, when fed on whole grain, did as well as fowls with free access to grit. Some experiments have been reported where the observers have taken for granted that the gizzard did not contain grit because the birds had not acc- ss to any for a month. The author has cc unted between fifteen and twenty-five paiticles of grit, varying in size from that of a pin-head to that of a split-pea, after birds have been without grit for three months. In young chicks the soft food given may become impacted in the gizzard. This is prevented by allowing chicks access to sharp sand. The sharp sand particles stimulate the muscular action of the gizzard which is sluggish when soft food is given." Passing from the finding of a scientist to those of a practical poultryman, we read the following in "Principles and Practices of Poultry Culture," by John H. Robinson.
Reasoning from analogies observed between birds and ruminants, and from the fact that small particles of stone, glass, earthenware, etc., were often found in the gizzards of fowls in course of preparation for the table it was long ago assumed that the gizzard itself was inadequate for its function, and that the bird swallowed these substances because they were required for the mastication of its food I followed the common practice (of feeding grit) long after I was convinced in my own mind that the birds had no need of grit to grind their food, but finally abandoned it, and since about 1902 have given no grit to chickens." John H. Robinson, however, rears his chickens largely on free range, so that there is all likelihood of their obtaining an abundance of grit without it being given as a particular feed. The same poultryman further reports: "A pen of twenty-five extra large hens in my yards supplied with indigestible grit and oyster shell, consumed in eight months less than a pint of grit." Presuming the hens in question to have had an average amount of grit in the gizzard at the commencement of the experiment, the weight of this argument against the feeding of grit to chickens is counterbalanced by the findings of Dr. Shaw regarding the length of time grit is retained in the gizzard. Some experiment stations, as well as individual investigators, have taken up work along this line. In a Bulletin entitled, "Experiments with Poultry," compiled from the twenty-sixth annual report of the New York Agricultural Experiment Station the results obtained from experiments made with nineteen lots of chickens, ranging from one to three weeks of age, showed that "the mixing of sand in the food, both in a ration containing food and in one without, resulted in better health for the chickens, and more efficient use of the food." The U. S. Department of Agriculture published, in 1904, a Bulletin entitled "Digestion Experiments with Poultry." In a section with the heading "The Utilization of Sand by Poultry," we find the following: "The consumption of sand is much greater on an oat than a corn diet. This is no doubt occasioned by the greater proportion of fibre in the oats." Experiments with individual chickens' were also recorded. Grit was withheld from two chickens for a period of six months. Up to five months, the lack of gravel "had apparently not led to any serious impairment of digestion, but after this the animals appeared gradually to become debilitated." In another individual, grit was found to be retained in the gizzard "after a lapse of seven months." It is evident from the foregoing, that work in connection with the feeding of grit to poultry cannot be out of place, the lack of authenticity in the work heretofore undertaken being largely due to the factor
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Considering these two points and in view of the fact that it will undoubtedly be a great many years before we have sufficient data to allow the use of digestible coefficients obtained direct from poultry, and also because we have constant need for working out nutritive ratios, total nutrimnet, and the like, I am wondering if, for the sake of uniformity alone, we would not be justified in adopting a standard method, even though it may not be entirely grounded on good statistical experimental data. If so, what would this system be? The total chemical composition of feeds is undoubtedly the most inaccurate. We have seen, further, that digestion by poultry seems to be more nearly like cattle than it is like swine, and coupled with this fact, if we agree that fowls do not digest fiber, I offer you the suggestion that we might find it advantageous, at the present time, to use the easily computed method of eliminating the fiber from the digested nutrients as obtained from experiments with cattle, and adopt these values in the computation of our poultry rations. A. B. DANN.