5*?: THE UNIVERSITY g| OF^ILLINOIS LIBRARY . , t 6 S . 7 1C G l> " " ' . . . "' J%- 9 , UBPARY OF THE UNIVERSITY OF ILLINOIS WON CIRCULATING UNIVERSITY OF ILLINOIS Agricultural Experiment Station BULLETIN No. 170 COEFFICIENTS OF DIGESTIBILITY OF SOME COMMON RATIONS FOR SWINE BY WIIyLJAM DIETRICH AND H. S. GRINDIyEY URBANA, ILLINOIS, MAY, 1914 CONTENTS or BULLETIN No. 170 PAGE 1. EXPERIMENT 1 (a) Object and plan 165 (b) Composition of feeds and feces; weights of pigs, feeds, and feces; and nutrients consumed per day per 100 pounds live weight... 166 (c) Coefficients of digestibility of rations of ground corn, ground corn and middlings, and ground corn and tankage determined directly. . 167 (d) Coefficients of digestibility of middlings and tankage deter- mined indirectly 167 2. EXPERIMENT 2 (a) Object and plan 170 (b) Periods 1 to 6. Full feed for both pigs 170 (1) Composition of feeds and feces; weights of pigs, feeds, and feces; and nutrients consumed per day per 100 pounds live weight 17J (2) Coefficients of digestibility of rations of ground corn, ground corn and red dog flour, ground corn, red dog flour, and pork cracklings, ground corn and tankage, and ground corn, tankage, and pork cracklings determined directly 173 (3) Coefficients of digestibility of red dog flour, pork cracklings, and tankage determined indirectly 175 (c) Periods 7 to 10. Transition from full feed to maintenance for both pigs, and two periods of maintenance feeding for pig A 177 (1) Composition of feeds and feces; weights of pigs, feeds, and feces; and nutrients consumed per day per 100 pounds live weight 178 (2) Coefficients of digestibility of a ration of ground corn, red dog flour, tankage, and pork cracklings determined directly 179 (d) Periods 11 to 15. Maintenance feeding for both pigs, before and after a period of fasting 181 (1) Composition of feeds and feces; weights of pigs, feeds, and feces; and nutrients consumed per day per 100 pounds live weight 181 (2) Coefficients of digestibility of a ration of ground corn, red dog flour, tankage, and pork cracklings, determined directly 183 (e) Periods 16 to 23. Full feed for pig A, and two-thirds cf full feed for pig B 184 (1) Composition of feeds and feces; weights of pigs, feeds, and feces; and nutrients consumed per day per 100 pounds live weight 184 (2) Coefficients of digestibility of a ration of ground corn and pork cracklings determined directly 187, 189 (3) Coefficients of digestibility of pork cracklings deter- mined indirectly 188 3. SUMMARY OP DATA OF BOTH EXPERIMENTS 19.0 4. CONCLUSIONS 193 5. APPENDIX . 196 COEFFICIENTS OF DIGESTIBILITY OF SOME COMMON RATIONS FOR SWINE 1 BY WILLIAM DIETEICH, ASSISTANT CHIEF IN SWINE HUSBANDRY, AND H. S. GRINDLEY", CHIEF IN ANIMAL NUTRITION EXPERIMENT 1 OBJECT AND PLAN The object of the first experiment reported in this bulletin was to determine the coefficients of digestibility for ground corn alone; ground corn and middlings; and ground corn and tankage, when given to pigs as full-fed rations. Two barrows a little over a year old, one a Berkshire and the other a Large Yorkshire, were selected for this work and put into di- gestion crates. The crates were of sufficient size for the pigs to stand up and lie down in them comfortably, and were provided with troughs in the front for the feed, and pans in the back to catch the feces. The feeding troughs were in such a position that the animals could eat from them conveniently, and were so arranged that they could be easily removed. The pans for collecting the feces were of galvanized iron, and from them the floors of the crates were sloped toward the front to prevent the urine voided from coming into contact with the feces. The pigs were taken out of the crates twice daily for exercise. The different rations were given in amounts that the pigs would eat readily. These were determined during a preliminary period im- mediately preceding the experimental period. The preliminary feed- ing periods before the second and third experimental periods were of only a few days' duration, but that preceding the first experi- mental period was continued for several weeks in order that the pigs might have sufficient time to become accustomed to their crates before any experimental data were recorded. The first ration for which the coefficients of digestibility were de- termined consisted of 7 pounds of ground corn per day; the second, of 3.5 pounds of ground corn and 3.5 pounds of middlings per day; and the third, of 5 pounds of ground corn and 1 pound of tankage per day for the Berkshire pig, and 4 pounds of ground corn and 1 pound of tankage per day for the Yorkshire pig. Each of these rations was fed for an experimental period of 7 days, during which time samples of the feed and feces Avere taken for chemical analysis. 1 The coefficients given thruout this bulletin represent merely the apparent coefficients of digestibility, as none of the metabolic products were determined in the feces. 165 166 BULLETIN No. 170 EXPERIMENTAL DATA [May, Table 1 gives the percentage composition of the feeds. In Table 2 will be found the weights of the pigs, the feeds, and the feces in each experimental period. Table 3 gives the percentage composition of the fresh feces, and Table 4, the total nutrients consumed per day per 100 pounds live weight. TABLE 1. PERCENTAGE COMPOSITION OF FEEDS (H. S. Grindley and L. F. Shackell, Analysts) Feed Dry sub- stance Crude protein (Nx6.25) Nitrogen- free extract Crude fiber Total carbohy- drates Crude fat Ash Ground corn. Middlings . . . Tankage. . . . 86.38 87.52 94.56 9.80 18.04 60.91 70.03 54.40 4.30 1.91 5.52 3.95 71.94 59.92 8.25 3.47 5.12 13.69 1.17 4.44 11.71 TABLE 2. WEIGHTS OF PIGS, FEEDS, AND FECES (Results expressed in pounds) Date 1906-1907 Period Days Pig Live weight Feeds eaten Feces Ground corn Mid- dlings Tank- age Dec. 24-30 1 2 )> 3 it 7 7 7 }> Berkshire Yorkshire Berkshire Yorkshire Berkshire Yorkshire 370 325 390 333 410 330 49.0 49.0 24.5 24.5 35.0 28.0 24.5 24.5 7.0 7.0 12.6 10.2 16.0 15.5 14.6 10.3 Jan. 4-10 Jan. 20-26 TABLE 3. PERCENTAGE COMPOSITION OF FRESH FECES (H. S. Grindley and L. F. Shackell, Analysts) Period Pig Dry sub- stance Crude protein (Nx6.25) Nitrogen- free extract Crude fiber Total carbohy- drates Crude fat Ash 1 Berkshire 36.48 6.83 16.72 4.93 21.65 4.65 3.35 Yorkshire 49.02 9.97 22.07 6.42 28.49 5.50 5.06 2 Berkshire 32.28 5.26 14.70 5.49 20.19 2.54 4.29 Yorkshire 29.71 5.57 12.93 4.91 17.84 2.15 4.15 3 Berkshire 39.35 14.03 12.57 6.24 18.81 1.77 4.74 M Yorkshire 42.22 14.63 14.91 5.17 20.08 1.77 5.74 From the data given in Table 4, it will be noted that the amounts of dry substance, nitrogen-free extract, and carbohydrates consumed during the various periods decreased continuously from the begin- ning to the close of the experiment, and the amount of crude protein increased. 1914] DIGESTIBILITY OF SOME COMMON RATIONS FOR SWINE 167 The quantities of the other three feed constituents consumed, i. e., the crude fiber, crude fat, and ash increased from the first ration to the second, and decreased from the second ration to the third. TABLE 4. TOTAL NUTRIENTS CONSUMED PER DAY PER 100 POUNDS LIVE WEIGHT (Ecsults expressed in pounds) Period Pig Dry sub- stance Crude protein (Nx6.25) Nitrogen- free extract Crude fiber Total carbohy- drates Crude fat Ash 1 Berkshire . . . . 1.634 0.185 1.330 0.036 1.361 0.066 0.022 Yorkshire . . . 1.860 0.211 1.508 0.041 1.549 0.075 0.025 Average . . . 1.747 0.198 1.419 0.039 1.455 0.071 0.024 2 Berkshire . . . . 1.556 0.250 1.117 0.067 1.183 0.077 0.050 Yorkshire . . . 1.828 0.293 1.308 0.078 1.386 0.090 0.059 Average . . . 1.692 0.272 1.212 0.073 1.284 0.084 0.055 3 Berkshire . . . . 1.284 0.268 0.864 0.033 0.897 0.076 0.043 Yorkshire . . . 1.334 0.303 0.862 0.035 0.897 0.050 0.084 Average . . . 1.309 0.286 0.863 0.034 0.897 0.080 0.047 Table 5 gives the coefficients of digestibility as determined di- rectly for the ground corn alone, the corn and middlings combined, and the corn and tankage combined. In Table 6 will be found the co- efficients of digestibility of the middlings and the tankage as deter- mined indirectly. Ground Corn. It is apparent from the data given in Table 6 that the coefficients of digestibility of the dry substance, nitrogen- free extract, total carbohydrates, and crude fat of the ground corn for the two animals agreed closely, but that those for the crude pro- tein and the crude fiber showed variations of 3.3 and 3.6 percent, respectively. Ground Corn and Middlings. For the ration consisting of equal parts of ground corn and middlings, the coefficients of digestibility of the dry substance, the crude protein, the nitrogen-free extract, and the total carbohydrates for the two animals did not vary significantly, but the results for the crude fiber and the crude fat showed varia- tions of 6.5 and 3.5 percent, respectively. On comparing the average coefficients of the ration of ground corn and middlings combined, with the corresponding averages for the ration of ground corn alone, it will be noted that the dry sub< stance, nitrogen-free extract, and the carbohydrates of the ground corn and middlings combined were digested to practically the same extent as those of the ground corn alone, while the crude protein, crude fiber, and crude fat of the ground corn and middlings were digested much more thoroly than those of the ground corn alone. 168 BULLETIN No. 170 [.May, 8~ 1O O CO t^ - co o * CXI 00 O OS d* CD CO co oo oo oo 00 OS co a* CO OO o r-lrH fc- co o <0 -2 o -2 - j ,_( CXI O i-H o os o 05 i2'2 S O5 OS OS 05 03 05 oo os 00 V ^3 GO co ^ O O CO t~ CXI OS CD^ o J 0) bo rH 2 co' d CO CO rH CO rH 00 W 1C S CO' -*' CO OS' rH ^ J Q} T3 o EH w o a be I rt "S hn 0? rt OS -# co CO * 05 CO CO ^ a *r Q H > 1 1 < H j 22 22 22 3 1 60 'II 11 H 03 W O PM CO o -a -a o o EH q 1 ft ft fe h o TJ O 03 09 2 rH ' OQ *^ ** CO *~ EH pE B Z 9 PM w G Ij EH M w H ! ^^ f o Tl s~*s~^ co a. C^- Tl Tl 9 PQ lO ^^ m ^j OO &0 ^^ -D H 00 pi Is 60 EH o [2 rrf " 1 M T cT 4* rt" , " g. S- bo IH * CO be O * rt o - rt 0~ rt O B o IH B B V O) S 2 PI ^H B ^ o ** 3^ IH " Vi " cb IH 3^ os oo co oo * co O o o os os co OS CO TH i 1 i 1 rH i-l o I-H rH ra rt " co (M rH OO OS OS O rQ rt 00 OS OS oo OS b CO CXI ' O OS OS O3 00 O 00 t- lO CO CXI 1* cc rH |> ^ ^ S o CXI 10 oo O CO llll o eo os os r-H 05 CO OS t-H rH co S r O a> ^^ |2x d exj os os CO os TjJ CO CO 00 eo exj b- Is t-> rt g-g co o 00 OS CO 00 COt- t- H < O o 8 PM > B 237 28.0 .... .... 56 8.88 Dec. 23-30 . 2 8 A 338 32.0 16.0 .... 88 18.35 " 25-30 . 2 6 B 256 19.2 9.6 .... 54 9.78 Jan. 5-12 . . . 3 8 A 357 32.0 16.0 .... 1.6 88 16.60 j i > > B 277 25.6 12.8 .... 1.6 72 10.94 Jan. 20-26 . . 4 7 A 379 38.5 6.3 .... 70 22.13 " 19-25 .. > t j > B 292 30.1 .... 4.9 63 14.25 Feb. 2-8 . . . . 5 7 A 388 33.6 8.4 .... 70 23.01 " 2-7 .... ) > 6 B 301 21.6 .... 5.4 54 15.50 Feb. 14-21 . . 6 8 A 412 38.4 9.6 3.2 82 22.82 6 ) > B 314 28.8 7.2 3.2 75 17.74 172 BULLETIN No. 170 [May, TABLE 9. PERCENTAGE COMPOSITION OF FRESH FECES (A. D. Emmett and H. S. Grindley, Analysts) Period Pig Dry sub- stance Crude protein (Nx6.25) Total carbohy- drates Crude fat Ash Nitrogen Phos- phorus 1 A 32.39 4.90 21.68 1.76 4.05 0.783 0.61 a B 36.75 6.60 23.67 2.19 4.29 1.056 0.65 2 A 29.11 4.79 17.73 2.77 3.82 0.766 0.67 t > B 33.91 5.97 20.82 3.13 3.99 0.956 0.66 3 A 29.51 5.79 15.70 3.60 4.44 0.926 0.64 B 34.11 6.93 18.48 3.75 4.95 1.109 0.73 4 A 30.27 10.85 12.16 2.78 4.48 1.735 0.23 B 34.66 13.08 13.42 3.02 5.13 2.093 0.33 5 A 28.73 10.86 11.81 2.74 3.32 1.738 0.29 > > B 30.18 13.23 10.77 2.76 3.42 2.116 0.39 6 A 30.23 11.95 12.11 2.33 3.84 1.913 0.38 > ? B 34.86 13.90 14.40 2.48 4.08 2.224 0.45 TABLE 10. TOTAL NUTRIENTS CONSUMED PER DAY PER 100 POUNDS LIVE WEIGHT (Results expressed in pounds) Period Pig Dry sub- stance Crude protein (Nx6.25) Total carbohy- drates Crude fat Ash Phos- phorus 1 > > A B 1.370 1.461 0.137 0.147 1.167 1.245 0.044 0.047 0.021 0.023 0.0042 0.0045 Average 1.415 0.142 1.206 0.045 0.022 0.0043 t > A B 1.550 1.637 0.209 0.221 1.261 0.042 1.332 0.044 0.037 0.039 0.0079 0.0084 Average 1.593 0.215 1.296 0.043 0.038 0.0081 3 A B 1.520 1.581 0.228 0.243 1.195 1.233 0.060 0.067 0.036 0.038 0.0076 0.0079 Average 1.550 0.235 1.214 0.063 0.037 0.0077 4 t> A B 1.477 1.498 0.267 0.270 1.094 1.110 0.074 0.075 0.043 0.043 0.0069 0.0070 Average . 1.487 .0.268 1.102 0.074 0.043 0.0069 5 > > A B 1.359 1.314 0.290 0.281 0.944 0.912 0.078 0.076 0.047 0.045 0.0072 0.0070 Average 1.336 0.285 0.928 0.077 0.046 0.0071 6 > > A B 1.372 1.380 0.326 0.338 0.891 0.877 0.109 0.119 0.046 0.046 0.0071 0.0070 Average 1.376 0.332 0.884 0.114 0.046 0.0070 DIGESTIBILITY OF SOME COMMON RATIONS FOR SWINE 173 CO CT X cv s '-jo c > CO '.O O 5 L- OS <* 5 TJ< 1:- U 5 CO CO CO p t- ^ (C t- 5 >o LO r IO IO U 5 O o o c ) O OS O > CXI CM CN . os cs o 1 O i 1 r- > Oi C7S O H OJ OS C 1 CO OO OI 5 ' O CO Oi > cs oo oo 03 t^ M *"O bo u fl 8 .s ^ M a oc w oo e: > CO 05 > O H O vj C X ir l> oc t> OO CO 0( ) ko 10 ir > co co oc 5 CD CO CC ) CO CO C 5 CO OJ Cf 3 CO LO 3 Tt< O CM > l~ t- b- Is 1C cc CM OO C t^ CO C OS OS T II CO W> t- CM Tjl QQ fl 1- ac to GC oc 00 00 CC CO OS O oo oo oc CM CO cr CO CO 0( (MO r- ) OO JO OC 00 00 00 _bp 4 PC 4* ^ o >H L| T ~ Ol ^ co ^ ^* ^ IO ^ CO * B On rH t-l 00 iH iH *~^ 00 I-H CXI C^ IO 00 CM F S) .2 o 3 t> ^ ^~N/^*N ^ifl 03" rH r-l o \ fe 2, P4 W ^^ v^*s X^Vx'^v M 1 1 T 1 t-H i j *- hi p *^ EC 0^ rt ** co co ^t 1 ^ PH" P O ^ ** '^ / S '^ _' .2 (^ r C rj ^ 03 o> c ^ c<3 bc~ O *"* bo bo PH o ^ P1 S QJ tJD fl fl* tJD ^ ^ o *^ CS CC f* B r w rW ** ^3^ "g w US a "" S" CO" CO *^ *i -*-> I : I g b 3 S" b O 9 D ~ b C3 O o C - b fT 03 t- * tt i* I S" ~ CC O'- c- o- n S " w 4 T: i i 9 j " ? a a 8 C 0" i i 5 C5 O O O 174 BULLETIN No. 170 [May, Ground Corn. From the data given in Table 11, it is apparent that the coefficients of digestibility of the dry substance and the total carbohydrates of the ground corn for the two animals agreed closely, but that between the coefficients of the crude protein and the crude fat there was considerable difference. On comparing the coefficients of digestibility of the nutrients of the ground corn obtained in this second experiment with those ob- tained with the same ration in Experiment 1 (See Tables 11 and 5), it will be noted that the dry substance, carbohydrates, and crude pro- tein were somewhat less digestible in the second experiment than in the first, and the fat much more digestible. Ground Corn and Red Dog Flour. On comparing the average coefficients of digestibility for the ration of ground corn and red dog flour combined with the corresponding averages for the ration of ground corn alone, it will be noted that the dry substance and the carbohydrates were digested to the same extent in both rations; that the crude protein of the ground corn and red dog flour combined was digested somewhat more thoroly than that of the ground corn alone ; and that the crude fat of the ground corn and red dog flour was di- gested very much less thoroly than that of the ground corn alone. On comparing the average coefficients of digestibility for the ra- tion of ground corn and red dog flour combined with the correspond- ing averages for the ration of ground corn and middlings (see Tables 11 and 5), it will be noted that the dry substance and the carbohy- drates were digested to practically the same extent in both rations; that the crude protein of the ground corn and middlings was di- gested somewhat more thoroly than that of the ground corn and red dog flour; and that the crude fat of the ground corn and middlings was digested very much more thoroly than that of the ground corn and red dog flour. Ground Corn, Red Dog Flour, and Pork Cracklings. It is ap- parent that the dry substance and the total carbohydrates of the ground corn, red dog flour, and pork cracklings combined were very slightly more digestible than those of the ground corn alone, while the crude protein of the mixed ration was somewhat more digestible, and the crude fat somewhat less digestible, than that of the ground corn alone. The addition of one part of pork cracklings to a ration consist- ing of twenty parts of ground corn and ten parts of red dog flour increased the digestibility of the dry substance, the crude protein, and the total carbohydrates slightly, and increased the digestibility of the crude fat decidedly. Ground Corn and Tankage. On comparing the average coef- ficients for the two rations of ground corn and tankage combined with the corresponding averages for the rations of ground corn alone, ground corn and red dog flour combined, and ground corn, red dog 1914} DIGESTIBILITY OF SOME COMMON BATIONS FOR SWINE 175 flour, and pork cracklings combined, it is apparent that the crude protein of the ration of ground corn and tankage was digested very much less thoroly than that of any of the other rations, and that the dry substance of the corn and tankage combined was digested much less thoroly than that of any of the other rations. The crude fat of the rations of ground corn and tankage combined was somewhat less digestible than that of the ground corn alone, but considerably more digestible than that of the ground corn and red dog flour combined. The average coefficients of the nutrients of a ration of ground corn and tankage obtained in the four trials of this second experiment were as follows : dry substance, 82.3 ; crude protein, 65.0 ; total car- bohydrates, 90.4; and crude fat, 69.9. The corresponding data ob- tained in the two trials of the first experiment were as follows : dry substance, 85.1 ; crude protein, 75.9 ; total carbohydrates, 89.6 ; and crude fat, 89.3. Ground Corn, Tankage, and Pork Cracklings. The dry sub- stance and the crude protein of the rations consisting of ground corn, tankage, and pork cracklings combined were somewhat less digestible than those of the ground corn alone, while the crude fat of the mixed ration was decidedly more digestible than that of the ground corn alone. It seems evident from the results obtained that the addition of one part of pork cracklings to rations consisting respectively of twelve parts of ground corn and three parts of tankage, and nine parts of ground corn and two and one-fourth parts of tankage increased the digestibility of the crude protein and the crude fat decidedly, but affected the digestibility of the dry substance and the total carbohy- drates only slightly. Red Dog Flour. In Table 12 are given the coefficients of diges- tibility of the nutrients of red dog flour as calculated indirectly from the results of the first two periods of this experiment. The negative value for the crude fat was due to the fact that the digestibility of the crude fat of ground corn and red dog flour together was much lower than that of the corn fed alone. The method of calculation nec- essarily credited all of this difference to the red dog flour, altho possi- bly part of it should have been credited to the corn. On comparing the average coefficients of digestibility of red dog flour with the corresponding averages for middlings (See Tables 12 and 6), it will be noted that the dry substance was digested to the same extent in both rations; that the crude protein of the middlings was digested somewhat more thoroly than that of the red dog flour: and that the total carbohydrates of the middlings was digested some- what less thoroly than that of the red dog flour. On account of the irregularity of the results obtained for the red dog flour it is useless to compare the coefficients of digestibility of the fat of the two feeds. 176 BULLETIN tfo. 170 [May, O >O "M C^ Oi CD C< t^ IO r- CD O CC O r-l IO 3 C3 l^ 1C Tj* OJ O^ t^ oo >> t oj o c< oo K 00 O OC O) |H iH O r- o o> a WO r- S I M J t^ r-i * t^* OS OC 1 bJG i .9 ^ CO IO O" C-l -^ K OS ^^ r~ r-l OS L- IOCO <* OC O T tH PH ^s i 10 * r( t- OO Cv (M OS C > >n oo oo ac O Id CD m cc ) O r-t rH C-1 O rH II rH rH 8 ft * S 3 S 3-2 1 > .* ^ 9 > .s ) -PH c^ 0^ J 13 ' JO Jl t & w~ t o ^3! \ bo t I 1 (5 ^ ? 5 ^-'v-x o 3 ^-'v-^ a i 'S^ 03 bX) J ' | \ 9 i >. fi < o3 fe o ^ t 3 bo I 4 03 < bo > ^ o3 ^ ^ ^ H ^s ' A!^ "* ^! ' rM h D ^ O ~ o3 o! O *^ M PH E-< H PH"* 1914] DIGESTIBILITY OF SOME COMMON RATIONS FOR SWINE 177 Pork Cracklings. The unreliability of the coefficients obtained for a single feed by calculation from the data obtained from a combi- nation of feeds is clearly shown from the results obtained for pork cracklings. When pork cracklings were fed with ground corn and red dog flour, the average coefficients of digestibility of their nutrients, as calculated from the results of Periods 2 and 3 of this experiment, were as follows : dry substance, 138.2 ; crude protein, 96.3 ; and crude fat, 92.2. On the other hand, when they were fed with ground corn and tankage, the average coefficients of their nutrients, as calculated indirectly from the results of Periods 5 and 6 of this experiment, were : dry substance, 111.2 ; crude protein, 111.4 ; and crude fat, 113.5. Tankage. The coefficients of digestibility of tankage alone, as calculated from the data obtained from the ration of corn and tank- age in this second experiment are decidedly different from the co- efficients of the same feed obtained in a similar manner in the first ex- periment. Thus, the average coefficients of the nutrients of tankage alone obtained in the four trials of this second experiment were as follows : dry substance, 62.2 ; crude protein, 55.3 ; total carbohydrates, H8.0; and crude fat, 63.7, while the corresponding data obtained in the two trials of the first experiment were : dry substance, 70.1; crude protein, 72.3 ; total carbohydrates, -5.9 ; and crude fat, 115.6. PERIODS 7 TO 10. TRANSITION FROM FULL' FEED TO MAINTENANCE FOR BOTH PIGS, AND Two PERIODS OF MAINTENANCE FEEDING FOR PIG A The six seven-day periods of full feeding were followed by four periods of three days each, during which a full-feed ration consisting of ground corn, red dog flour, tankage, and pork cracklings was grad- ually reduced to the maintenance ration determined for pigs by Diet- rich 1 in a previous experiment. This reduction was effected for Pig A during Periods 7 and 8, and for Pig B, during Periods 7, 8, 9 and 10. During Periods 9 and 10, Pig A was kept on the maintenance ration. In Table 13 will be found the percentage composition of the feeds for these periods. The weights of the pigs, the feeds, and the feces for Periods 7 to 10 are given in Table 14. Table 15 gives the percentage composition of the fresh feces for the same periods, and Table 16, the weights of the total nutrients consumed per day per 100 pounds live weight. '111. Agr. Exp. Sta., Bui. 163. 178 BULLETIN No. 170 [May, TABLE 13. PERCENTAGE COMPOSITION OF THE FEEDS (A. D. Emmett and H. S. Grindley, Analysts) Feed Dry sub- stance Crude protein ( NX 6.25) Total carbohy- drates Crude fat Ash Nitrogen Phos- phorus Ground corn. . . Bed dog flour. . Tankage 86.61 88.26 93.35 8.69 17.87 59.19 73.80 65.30 10.18 2.76 1.55 14.30 1.36 3.54 9.68 1.391 2.863 9.366 0.260 0.803 1.279 Pork cracklings 95.25 54.26 36.98 2.01 8.684 0.267 TABLE 14. WEIGHTS OF PIGS, FEEDS, AND FECES (Results expressed in pounds) Feeds eaten Date 1908 Period Days Pig Live weight Ground f*ATTI Red dog Tank- ' t o i Pork crack- Water Fcces CU ' 11 flour <*6 lings Feb. 26-28.. 7 3 A 426 9.0 2.4 2.3 0.9 30 8.13 T> ) } > j j y B 328 7.3 1.8 2.1 1.2 27 6.80 Mar. 4-6 8 3 A 430 5.4 2.4 1.1 0.6 30 4.01 } > T> > > B 333 6.2 1.8 1.7 0.9 27 3.59 Mar. 11-13.. 9 3 A 430 4.8 2.4 0.9 0.6 30 3.90 j . ) > ) ) B 335 5.2 1.8 1.2 0.8 27 3.27 Mar. 18-20.. 10 3 A 431 4.8 2.4 0.6 0.6 30 3.06 t > 11 > > j i B 336 3.8 1.8 0.6 0.6 27 2.51 TABLE 15. PERCENTAGE COMPOSITION OF FRESH FECES (A. D. Emmett and H. S. Grindley, Analysts) Period Pig Dry sub- stance Crude protein (Nx6.25) Total carbohy- drates Crude fat Ash Nitrogen Phos- phorus 7 A 29.48 10.59 13.80 1.31 3.78 1.694 0.52 f i B 34.22 13.00 15.06 1.76 4.40 2.080 0.61 8 A 31.95 11.06 14.10 1.65 5.14 1.771 0.79 7 > B 37.49 13.91 16.46 1.70 5.42 2.225 0.79 9 A 34.70 11.06 16.55 1.73 5.36 1.769 0.86 > > B 38.01 13.62 16.64 2.40 5.35 1.180 0.80 10 A 33.88 9.70 17.27 1.81 5.10 1.552 0.84 > > B 37.52 11.78 18.28 2.31 5.15 1.885 0.74 DIGESTIBILITY OF SOME COMMON RATIONS FOR SWINE 179 TABLE 16. TOTAL NUTRIENTS CONSUMED PER DAY PER 100 POUNDS LIVE WEIGHT (Results expressed in pounds) Period Pig Dry sub- stance Crude protein (Nx6.25) Total carbohy- drates Crude fat Ash Phos- phorus 7 A 1.011 0.239 0.662 0.074 0.035 0.0058 t> B 1.119 0.290 0.691 0.099 0.040 0.0065 8 A 0.651 0.145 0.440 0.044 0.022 0.0038 B 0.941 0.236 0.595 0.078 0.033 0.0055 9 A 0.596 0.140 0.404 0.040 0.019 0.0035 B 0.793 0.191 0.513 0.064 0.027 0.0045 10 A 0.573 0.118 0.401 0.037 0.017 0.0032 }> B 0.596 0.132 0.402 0.044 0.018 0.0033 As would be expected, Pig B, whose ration was reduced from full feed to maintenance during four periods, consumed more of each nu- trient than Pig A, in whose case the same reduction was effected in the first two periods alone. In Table 17 are given the coefficients of digestibility for Periods 7 to 10. The experimental data suggest that there was an increase in the coefficients of digestibility of the dry substance, the crude protein, and the total carbohydrates of the mixed ration for the two pigs from Period 7 to Period 8. During this time there was a reduction in the dry matter consumed from 1.011 to 0.651 pounds per day per 100 pounds live weight for Pig A, and from 1.119 to 0.941 pounds for Pig B. However, it is not apparent that during the remaining periods there were any significant changes in the coefficients of digestibility of any of the nutrients of the ration due to reductions in the food intake. The average coefficients of digestibility of the nutrients of the ration consisting of ground corn, red dog flour, tankage, and pork cracklings for Pig A for the two periods during the reduction from a full-feed ration to a maintenance ration and during two periods of a maintenance ration were as follows : dry substance, 83.6 ; crude pro- tein, 76.2 ; total carbohydrates, 88.5 ; and crude fat, 88.1. The average coefficients of the constituents of the same ration for Pig B for the four periods during the reduction to a mainte- nance ration were : dry substance, 83.3 ; crude protein, 74.6 ; total carbohydrates, 88.2 ; and crude fat, 88.6. 180 BULLETIN No. 170 ^ 00 I- CC rH Ob- TH 00 rH tO S CS in '-H a 30 b- OO. CO b- 1- b-b- 00 b- CO "*' b- I ^ft > TH05 b-b- ^-* OCO to co r?.S rHQO ^^O C I rji O^ co' co' 1 GOt> QOQO OO OO CCOO 00 00 rH : ' ^ o "rH t,.. a, .s ,,... o;; 4> r~i O< I II II I ' ^ us . i ^ oa ^ 7! Og r-i 71 7! 71 <^' "CO rH CO O5 b- OO tO ?2-tO 3> CD > > 00 (O J EL bo bo bo | c .3 .9 .S " 13 'S .s.a c o3 es g 1-1 1-l rH rH rH 3 p ^ ^^ ^^ rg b- b- O ^ O "" O ^ O ~ to m cc &H r-^4 r-^H ^^ a o r-J 173 ^ r3 ^ .2 "rt M eS~ S^ o3~ rt ^ 4> O QJ 3) be be o3 cd O*^ O~ O^ O*^ rH rH O> 4) "^ r ^ r O r 3 > r- 9 -~ 2^ 2 - 2 14-15 86.48 8.68 73.69 2.76 1.36 1.389 0.259 Red dog flour. . 11-12 88.02 17.82 65.11 1.55 3.53 2.853 0.801 t) j> 14-15 88.18 17.86 65.23 1.55 3.54 2.858 0.802 Tankage 11-12 91.49 58.00 9.98 14.01 9.48 9.280 1 253 14-15 90.81 57.57 9.91 13.91 9.42 9.211 1.244 Pork cracklings. 11-12 95.22 54.23 2.00 36.96 2.01 8.678 0.266 > > 14-15 96.14 54.76 2.02 37.32 2.03 8.763 0.269 TABLE 19. WEIGHTS OF PIGS, FEEDS, AND FECES (Results expressed in pounds) Feeds eaten Date 1908 Period Days Pig Live weight Ground corn Red dog flour Tank- age Pork crack- lings Water Feces Mar. 25-27.. 11 3 A 431 3.6 1.8 0.6 0.6 30 2.81 > > j > B 336 2.7 1.2 0.6 0.6 27 1.55 April 36... 12 4 A 427 4.0 2.4 0.8 0.8 40 2.67 } > > > ) > B 332 3.2 1.2 0.8 0.8 36 1.93 April 7-14.. 13 8 A 418 19 0.76 >> j j B 323 ... ... ... 30 0.39 April 15-19. 14 5 A 415 4.0 3.0 1.0 1.0 50 1.01 i } } > > j 3 B 320 2.4 0.6 0.6 0.6 27 1.27 April 20-25. 15 5 A 416 4.0 3.0 1.0 1.0 50 4.14 '* " > > 7 > B 319 4.0 1.0 1.0 1.0 45 1.82 1.82 BULLETIN No. 170 [May, From the data given in Table 19, it will be seen that during the two periods preceding the fast each of the pigs lost four pounds, while during the two periods following the fast Pig A gained one pound, and Pig B lost one pound. In Table 21 will be found the weights of the total nutrients con- sumed per day per 100 pounds live weight. TABLE 20. PERCENTAGE COMPOSITION OF FRESH FECES (A. D. Emmett and H. S. Grindley, Analysts) Period Pig Dry sub- stance Crude protein (Nx6.25) Total carbohy- drates Crude fat Ash Nitrogen Phos- phorus 11 > > A B 36.17 43.78 10.89 13.63 17.04 20.89 2.41 2.29 5.83 6.97 1.743 2.181 0.87 1.05 12 13 A B A 36.48 41.61 11.29 14.80 16.79 18.51 1.96 1.73 6.44 6.57 1.807 2.367 0.97 0.97 B 14 A B 42.63 47.16 10.92 14.98 19.15 20.92 2.69 2.77 9.87 8.49 1.748 2.396 1.41 1.23 15 A B 36.71 43.60 10.47 15.11 17.04 20.89 1.56 1.41 7.64 6.19 1.676 2.418 1.02 0.87 TABLE 21. TOTAL NUTRIENTS CONSUMED PER DAY PER 100 POUNDS LIVE WEIGHT (Results expressed in pounds) Period Pig Dry sub- stance Crude protein (Nx6.25) Total carbohy- drates Crude fat Ash Phos- phorus 11 A B 0.450 0.448 0.101 0.111 0.302 0.282 0.034 0.040 0.014 0.015 0.0026 0.0026 12 13 A B A 0.414 0.401 0.098 0.105 0.270 0.244 0.033 0.039 0.014 0.014 0.0025 0.0023 B 14 > > A B 0.384 0.388 0.097 0.103 0.242 0.232 0.032 0.040 0.013 0.013 0.0024 0.0021 15 A B 0.383 0.389 0.096 0.103 0.241 0.233 0.032 0.040 0.013 0.013 0.0024 0.0021 Both pigs being on nearly the same maintenance ration during these periods, they consumed, as would be expected, practically the same amounts of nutrients. The percentages of the nutrients digested are given in Table 22. 1014] DIGESTIBILITY OP SOME COMMON RATIONS FOR SWINE 183 * rH CDIO ** O CO COO in co 2=H Tt< -H rH TO fi O O CD H *\ 22 *^ 3 *^ ^j s *. #\ rH rH rH rn 0, rH rH rH rH t-H rH rHCX|rH0 .. .. rH rH ....... CO rH IO W5 CO W CO CO rH rH rH C0_^ 10^^^ ^-^^ ^J,^ a n CO CQ cd . bfi SP Bl ^ ^ g* g .9 "^ ^ rH rH ^** ^*N C^ N M ~* o rt c4 w cxTcxr cd H IB C 3 w ^ w o rH rH i-Tr-T "%" o ^ 0^ *^" 05 EC = g, & ^ ^ O O d 1~ " " I" C'C oT aT g. be be gJQ ^ri CQ ^H h^ 5= 1- 1- l~ 9 o bo^bc 1-2 -S 5 JH W -+J t-c >H tj tl rH 3*S Jj\ J3*\ S** 2 42 42 ^ a a bo ^** ^** ^c\ _ r^^ ^^ ^ r" '3 'S 'g^ '.; ^: : 0> 4) ^l (-1 MM t> o s\ g\ s^ s^^ be bjc 03 o3 "^ f * t) f ~ -> T3 ^ 5P "2 "2 > > a- 9- .9 9~ 9~ ^ ^! O to " O O (H M ej M 17 IS ) > 19 > > 20 21 > ) 22 23 >> 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 A B A B A B A B A B A B A B A B 428 328 42S 328 437 331 4-i8 334 452 342 457 345 461 348 471 350 23.5 14.7 24.5 12.5 31.5 15.5 30.6 15.2 '26.0 13.0 25.0 12.5 25.0 12.5 25.0 12.5 2.4 1.6 2.4 1.4 3.0 1.5 3.0 1.5 2.6 1.3 2.5 1.3 2.5 1.5 2.5 1.5 42 47 50 45 50 45 51 46 52 47 52 47 52 47 52 47 6.08 3.59 7.91 4.75 10.62 4.21 10.48 4.15 6.89 2.84 8.32 4.29 6.44 3.84 6.79 2.87 )) April 30-May 4 > > > > May 5-9 )> May 10-14 )* May 15-19 }> >t May 20-24 > > May 25-29 May 30- June 3 >} a TABLE 25. PERCENTAGE COMPOSITION OF FRESH FECES (A. D. Emmett and H. S. Grindley, Analysts) Period Pig Dry sub- stance Crude protein (Nx6.25) Total carbohy- drates Crude fat Ash Nitrogen Phos- phorus 16 A 37.31 9.30 20.50 2.06 5.45 1.489 0.78 B 42.76 12.44 22.86 2.14 5.32 1.991 0.77 17 A 32.93 5.94 20.83 2.89 3.27 0.950 0.45 > > B 36.97 7.61 23.43 2.76 3.17 1.219 0.48 18 A 31.88 6.82 18.30 3.39 3.37 1.092 0.58 B 37.78 8.54 21.94 3.36 3.94 1.367 0.60 19 A 31.07 7.16 17.42 2.86 3.63 1.146 0.59 B 35.91 9.04 20.08 2.43 4.36 1.443 0.70 20 A 30.32 6.69 17.76 2.44 3.43 1.070 0.57 B 38.73 8.63 23.62 2.16 4.32 1.380 0.69 21 A 29.83 6.10 18.56 1.88 3.29 0.975 0.56 B 37.00 7.77 23.26 2.04 3.93 1.243 0.61 22 A 31.52 5.81 20.66 1.36 3.69 0.930 0.61 B 37.54 7.19 34.53 1.90 3.92 1.151 0.65 23 A 32.37 5.53 21.24 1.75 3.85 0.885 0.66 " B 38.55 6.85 25.46 2.08 4.15 1.108 0.69 136 BULLETIN No. 170 [May, From the data given in Table 24, it will be seen that Pig A, on full feed, gained 43 pounds from Period 16 to the end of the experi- ment, and Pig B, on two-thirds of a full-feed ration, gained only 22 pounds. Table 26 shows the nutrients consumed by the two pigs during the last eight periods of the experiment. TABLE 26. TOTAL NUTRIENTS CONSUMED PER DAY PER 100 POUNDS LIVE WEIGHT (Kesults expressed in pounds) Period Pig Dry sub- stance Crude protein (Nx6.25) Total carbohy- drates Crude fat Ash Phos- phorus 16 A B 1.048 0.861 0.152 0.127 0.806 0.658 0.073 0.062 0.017 0.014 0.0031 0.0025 17 A B 1.088 0.735 0.15G 0.109 0.841 0.560 0.074 0.053 0.017 0.012 0.0032 0.0021 18 A B 1.366 0.889 0.194 0.127 1.059 0.688 0.092 0.060 0.022 0.014 0.0040 0.0026 19 A B 1.298 0.866 0.186 0.124 1.003 0.668 0.088 0.059 0.021 0.014 0.0038 0.0025 20 A B 1.096 0.724 0.158 0.104 0.845 0.558 0.075 0.050 0.017 0.012 0.0032 0.0021 21 A B 1.042 0.693 0.150 0.101 0.804 0.532 0.072 0.049 0.017 0.011 0.0030 0.0020 22 A B 1.033 0.698 0.149 0.106 0.796 0.528 0.071 0.052 0.016 0.011 0.0030 0.0020 23 > > A B 1.011 0.694 0.146 0.106 0.780 0.525 0.070 0.052 0.016 0.011 0.0030 0.0020 Table 27 gives the coefficients of digestibility as determined di- rectly for the ration used during the last eight periods. In Table 28 will be found the coefficients of digestibility for the pork cracklings as determined indirectly. 1914] DIGESTIBILITY OF SOME COMMON RATIONS FOB SWINE 187 W fi OJ ^ o I O IO Ol IO TtH OJ O OJ O OJ * OJ Ol CO OJOJ OOOO OOOO 0000 OJOJ OJOO OJOJ O-.OJ OJ oc oj "S -g co-* oooj H a B OJ OJ C> l~* rH rH i-H OJ CO CO rH OJ OJ IO Ol OJ OJOJ OJCO OJ'JJ OJOJ OJOJ OJQO OJOO OJOJ OJ O OJ OJ bC rj >O eg ,2 -3 <*! -M ~ O> !^ tO ^O OJ OJ OJ OJ OJ OJ rH CO OJ t** rH rH rH Tf* 10 co 8 5 8 * n """' OJOO lo'oJ OJJJ rHi-H t^?D* ICO Oj'rt' Oj'oj' OOt- OOC- OCX) OOOO OOCO OOOJ COCO OOOO 30 CO 9 P OJrH 00^ t-01 OOt^ !OrH (0 t- 1C rH OOOJ OJ on P OJ OJ CO IO 00 OJ CO* Oj' (rH rH Cs' o' rH CO O rH cooo'ooco oooo oooo rH OJ CO *s o> PH [usive lusive P R co co OJ OJ + -*-> O CO X X OJ IO CO OJ I-H O O O O O .2 .2 'rH "C Q} ^ PH PH Rations 9 fl fl .9 .9 .9 .9 .9 3- 3" 3^ 3^ 3i; 3- 3- 3" ci c3 oi rt rt c3 rt be^be ss H to 0:0 o^> oon ost- loco om oos FH 00 bo O5OJ OJ3> OJO OO O O JHO OO W CO , ^ ~* fi S> 9) O & g be IH FH -Q 5 ^-s s?*3B tO COCO 00 'O (MO iHO COW C ^ Xt~ OiiO 00 'JO 0000 OSOi OiOO OO1 OO iH i-l rH O CO ~- 30 "A M -9 < 3 o MrH THO 00!M 00 COrH s^ o^ H^ n^ o^ o^ o^ o O" O " O" O " O " O *" O * O^ wooooiy P s -^^ =2" H" S~ S" H^ =2- H^ tf3 U3 CflCQtHGQQQWGGHJ s s _a _g _g ^g _g _g (y*^ t?** W^ O** W*^ O*^ O** o*^ B 5 5> it H & 6 H t-l^ t-l * '-* tl h * I-, " I-l ^ ^1 IN *^i Qj p i p . A I Pi p i p . Average coef Average coef 1914] DIGESTIBILITY OF SOME COMMON RATIONS FOR SWINE 189 Ground Corn and Pork Cracklings. From the experimental data given in Table 27 it is not apparent that there were any significant differences in the coefficients of digestibility of the nutrients for the two pigs, altho Pig A received a full-feed allowance and Pig B re- ceived approximately only two-thirds of a full-feed ration. It is clearly evident that the ration consisting of approximately ten parts of ground corn and one part of pork cracklings was de- cidedly more digestible than the ration of ground corn alone. The coefficients of digestibility of the protein of the ration of ground corn and pork cracklings tended to increase from Periods 16 to 23; in other words, as the length of the time of feeding the same ration was increased the coefficients of digestibility of the ration were also increased. Pork Cracklings. In Table 28 are given the coefficients of di- gestibility for the nutrients of pork cracklings as calculated from the data of Periods 16 to 23. When the pork cracklings were fed with ground corn the average coefficients thus obtained for the sixteen trials were as follows : dry substance, 104.2 ; crude protein, 91.8 ; and crude fat, 103.4. When the pork cracklings were fed with ground corn and red dog flour, the average coefficients for pork cracklings as determined indirectly were as follows : dry substance, 138.2 ; crude protein, 96.3 ; and crude fat, 92.2. When the pork cracklings were fed with ground corn and tankage, the average coefficients of their nutrients, as determined indirectly were : dry substance, 111.2 ; crude protein, 111.4; and crude fat, 113.5. Such variable results demon- strate clearly the inaccuracy of coefficients of digestibility determined indirectly. The results obtained by difference for the pork cracklings were so irregular and so variable that a detailed study of them is not worth while, but it is evident that the digestibility of the nutrients of the corn was decidedly increased by the addition of the pork cracklings to the ration. 190 BULLETIN No. 170 [May, SUMMARY A summary of the coefficients of digestibility for the rations of the two experiments is given in Table 1 of the Appendix, and a sum- mary of the coefficients for the single feeds, in Table 2. Figure 1 of the Appendix shows the curves for the coefficients for the rations. 1. Ground Corn, The average of four tests in which a ration consisting of ground corn alone was fed to pigs at the rate of 1.83 pounds per day per 100 pounds live weight gave the following co- efficients of digestibility : dry substance, 87.7 ; crude protein, 79.3 ; total carbohydrates, 90.9 ; and crude fat, 71.3. In two of these tests the average coefficients of the nitrogen-free extract and the crude fiber of ground corn were 93.6 and 31.8, respectively. 2. Ground Corn and Middlings. The average of two tests in which a ration consisting of one part of ground corn and one part of middlings was fed to pigs at the rate of 1.95 pounds per day per 100 pounds live weight giving the following coefficients: dry substance, 88.6 ; crude protein, 87.5 ; nitrogen-free extract, 92.9 ; crude fiber, 54.9 ; total carbohydrates, 90.7 ; and crude fat, 82.5. 3. Ground Corn and Red Dog Flour. The average of two tests in which a ration consisting of two parts of ground corn and one part of red dog flour was fed to pigs at the rate of 1.83 pounds per day per 100 pounds live weight, gave the following coefficients : dry sub- stance, 87.0; crude protein, 83.6; total carbohydrates, 90.2; crude fat, 55.0. 4. Ground Corn and Tankage. The average of six tests in which rations consisting of one part of tankage to four, five, or six parts of ground corn were fed to pigs at the rate of 1.48 pounds per day per 100 pounds live weight gave the following coefficients: dry sub- stance, 83.2 ; crude protein, 68.7 ; total carbohydrates, 90.2 ; and crude fat, 76.4. In two of these tests the average coefficients of the nitrogen- free extract and the crude fiber of these rations were 92.4 and 19.0, respectively. 5. Ground Corn and Pork Cracklings. The average of sixteen tests in which a ration consisting of one part of pork cracklings to approximately eight to ten parts of ground corn was fed to pigs at the rate of 1.09 pounds per day per 100 pounds live weight gave the following coefficients : dry substance, 89.4 ; crude protein, 84.6 ; total carbohydrates, 91.3 ; and crude fat, 89.6. The average of eight tests in which a ration consisting of one part of pork cracklings to ten parts of ground corn Avas fed to a pig aver- aging 448 pounds in weight at the rate of 1.3 pounds per day per 100 pounds live weight gave the following coefficients : dry substance, 90.0 ; crude protein, 85.5; total carbohydrates, 92.1; crude fat, 89.1. DIGESTIBILITY OF SOME COMMON RATIONS FOR SWINE 191 The average of eight tests in which a ration consisting of one part of pork cracklings to approximately eight to ten parts of ground corn was fed to a pig averaging 338 pounds in weight, at the rate of 0.9 pound per day per 100 pounds live weight gave the following co- efficients : dry substance, 88.9 ; crude protein, 84.3 ; total carbohy- drates, 90.5 ; and crude fat, 90.1. 6. Ground Corn, Tankage, and Pork Cracklings. The average of two tests in which rations consisting of ground corn, tankage, and pork cracklings in the ratio of 12 :3 :1 and 9 :2.25 :1 were fed to pigs at the rate of 1.55 pounds per day per 100 pounds live weight, gave the following coefficients : dry substance, 83.4 ; crude protein. 72.7 ; total carbohydrates, 89.5 ; and crude fat, 85.3. 7. Ground Corn, Red Dog Flour, and Pork Cracklings. The average of two tests in which a ration consisting of twenty parts of ground corn, ten parts of red dog flour, and one part of pork crack- lings was fed to pigs at the rate of 1.77 pounds per day per 100 pounds live weight, gave the following coefficients: dry substance, 89.0 ; crude protein, 85.6 ; total carbohydrates, 92.7 ; and crude fat, 68.9. 8. Ground Corn, Red Dog Flour, Tankage, and Pork Crack- lings. The average of sixteen tests in which rations consisting of ground corn, red dog flour, tankage, and pork cracklings in ratios varying from 4 :1 :1 :1 to 10 :4 :2.6 :1 were fed to pigs at the rate of 0.67 pound per day per 100 pounds live weight, gave the following coefficients : dry substance, 84.6 ; crude protein, 78.7 ; total carbo- hydrates, 89.0 ; and crude fat, 90.0. 9. Middlings. The average of two tests in which a ration con- sisting of one part of ground corn and one part of middlings was fed to pigs at the rate of 1.95 pounds per day per 100 pounds live weight gave the following coefficients for middlings as determined by difference : dry substance, 88.4 ; crude protein, 91.3 ; nitrogen-free extract, 91.8; crude fiber, 62.9; total carbohydrates, 89.1; and crude fat, 93.3. 10. Red Dog Flour. The average of two tests in which a ra- tion of two parts of ground corn and one part of red dog flour was fed to pigs at the rate of 1.83 pounds per day per 100 pounds live weight gave the following coefficients for red dog flour as determined by difference : dry substance, 87.4 ; crude protein, 88.9 ; total car- bohydrates, 91.2 ; and crude fat, -36.3. 11. Tankage. The average of six tests in which rations con- sisting of one part of tankage to four, five, and six parts of ground corn were fed to pigs at the rate of 1.48 pounds per day per 100 pounds live weight gave the following coefficients for tankage as de- termined by difference: dry substance, 64.8; crude protein, 60.0; total carbohydrates, 76.7; and crude fat, 81.0. 192 BULLETIN No. 170 [May, 12. Pork Cracklings. The average of sixteen tests in which ra- tions consisting of one part of pork cracklings to approximately eight to ten parts of ground corn were fed to pigs at the rate of 1.09 pounds per days per 100 pounds live weight gave the following coefficients for the pork cracklings as determined by difference: dry substance, 104.3; crude protein, 91.8; and crude fat, 103.5. The average of eight tests in which a ration consisting of one part of pork cracklings to ten parts of ground corn was fed to a pig averaging 448 pounds in weight, at the rate of 1.3 pounds per day per 100 pounds live weight, gave the following coefficients for the pork cracklings as determined by difference : dry substance, 110.3 ; crude protein, 95.1 ; and crude fat, 103.1. The average of eight tests in which a ration consisting of one part of pork cracklings to approximately eight to ten parts of ground corn was fed to a pig averaging 338 pounds in weight, at the rate of 0.9 pound per day per 100 pounds live weight gave the following coefficients for pork cracklings as determined by difference : dry sub- stance, 98.2 ; crude protein, 88.5 ; and crude fat, 103.8. The average of two tests in which rations consisting of ground corn, tankage, and pork cracklings in the ratios of 12 :3 :1 and 9 :2.25 :1 were fed to pigs at the rate of 1.77 pounds per day per 100 pounds live weight gave the following coefficients for the pork cracklings as determined by difference: dry substance, 111.2; crude protein, 111.4; and crude fat, 113.5. The average of two tests in which a ration consisting of twenty parts of ground corn, ten parts of red dog flour, and one part of pork cracklings was fed to pigs at the rate of 1.55 pounds per day per 100 pounds live weight, gave the following coefficients for the pork cracklings as determined by difference : dry substance, 138.2 ; crude protein, 96.3; and crude fat, 92.2. 13. Dry Matter. The order of the rations according to de- creasing coefficients of digestibility of their dry substance was as follows: ground corn and pork cracklings, 89.4; ground corn, red dog flour, and pork cracklings, 89.0 ; ground corn and middlings, 88.6 ; ground corn, 87.7; ground corn and red dog flour, 87.0; ground corn, red dog flour, tankage, and pork cracklings, 84.6 ; ground corn, tankage, and pork cracklings, 83.4; and ground corn and tankage, 83.2. 14. Crude Protein. The order of the rations according to decreasing coefficients of digestibility of their crude protein was as follows : ground corn and middlings, 87.5 ; ground corn, red dog flour, and pork cracklings, 85.6 ; ground corn and pork cracklings, 84.6 ; ground corn and red dog flour, 83.6 ; ground corn, 79.3 ; ground corn, red dog flour, tankage, and pork cracklings, 78.7 ; ground corn, tank- age, and pork cracklings, 72.7 ; and ground corn and tankage, 68 7. 1914] DIGESTIBILITY OP SOME COMMON RATIONS FOR SWINE 193 15. Crude Fat. The order of the rations according to de- creasing coefficients of digestibility of their fat was as follows : ground corn, red dog flour, tankage, and pork cracklings, 90.0 ; ground corn and pork cracklings, 89.6 ; ground corn, tankage, and pork cracklings, 85.3 ; ground corn and middlings, 82.5 ; ground corn and tankage, 76.4; ground corn, 71.3; ground corn, red dog flour, and pork cracklings, 68.9 ; and ground corn and red dog flour, 55.0. 16. Carbohydrates. The average coefficients of digestibility of the carbohydrates of all the eight rations varied only slightly, the minimum value being 89.0 for the ration consisting of ground corn, red dog flour, tankage, and pork cracklings, and the maximum value being 92.5 for the ration consisting of ground corn, red dog flour, and pork cracklings. CONCLUSIONS The following tentative conclusions may be drawn from the re- sults reported in this bulletin : 1. Dry Substance. The coefficients of digestibility of the dry substance of rations composed of ground corn, ground corn and mid- dlings, and ground corn and red dog flour are apparently about equal. The dry substance of rations consisting, respectively, of ground corn and tankage; ground corn, tankage, and pork cracklings; and ground corn, red dog flour, tankage, and pork cracklings, is signifi- cantly less digestible than that of rations consisting, respectively, of ground corn ; ground corn and middlings ; and ground corn and red dog flour. On the other hand, the dry substance of rations consisting of ground corn and pork cracklings; and ground corn, red dog flour, and pork cracklings, is on the average slightly more digestible than that of rations composed, respectively, of ground corn; ground corn and middlings; and ground corn and red dog flour; and decidedly more digestible than that of rations consisting, respectively, of ground corn and tankage; ground corn, tankage, and pork cracklings; and ground corn, red dog flour, tankage, and pork cracklings. 2. Crude Protein. The coefficients of digestibility of the crude protein of the two rations composed, respectively, of ground corn and a combination of ground corn, red dog flour, tankage, and pork crack- lings are about equal. The crude protein of rations consisting, respectively, of ground corn and tankage, and ground corn, tankage, and pork cracklings is significantly less digestible than that of rations composed of ground corn, and ground corn, red dog flour, tankage, and pork cracklings. On the other hand, the crude protein of a ration consisting of ground corn and middlings is digested much more thoroly than that 194 BULLETIN No. 170 of rations composed of ground corn and ground corn, red dog flour, tankage, and pork cracklings; and the crude protein of rations com- posed of ground corn and red dog flour; ground corn and pork cracklings; and ground corn, red dog flour, and pork cracklings is digested somewhat more thoroly. 3. Crude Fat. The individual coefficients of digestibility of fat for the same ration often show wide variations. In general, however, the following conclusions may be drawn: The coefficients of digestibility of the crude fat of rations com- posed of ground corn; ground corn and tankage; and ground corn, red dog flour, and pork cracklings, are on the average about equal. The crude fat of a ration consisting of ground corn and red dog flour is significantly less digestible than that of rations com- posed of ground corn; ground corn and tankage; and ground corn, red dog flour, and pork cracklings. The crude fat of rations consisting, respectively, of ground corn and pork cracklings, and ground corn, red dog flour, tankage, and pork cracklings is digested much more thoroly than that of rations composed of ground corn ; ground corn and tankage ; and ground corn, red dog flour, and pork cracklings; while the crude fat of rations composed of ground corn and middlings and ground corn, tankage, and pork cracklings is digested somewhat more thoroly. 4. Carbohydrates. Apparently there are no significant differ- ences between the average coefficients of digestibility of the carbohy- drates of the eight rations fed in these experiments. 5. Coefficients by Difference. The coefficients of digestibility obtained for a single feed by calculation from the data obtained for a combination of feeds are not reliable, especially when the single feed has been fed in comparatively small quantities. By this method of calculation all of the difference between the values for the single feed and the corresponding values for the combined feeds is credited to the single feed, whereas it is probable that in the combined ration each feed exerts an influence upon the digestibility of the other. 6. Influence of One Ration Upon Another. The results of these experiments indicate that the coefficients of digestibility of one feed or ration may be increased or decreased by the addition of another feed or ration. For example, the addition of pork cracklings to ra- tions of ground corn alone, ground corn and tankage, and ground corn and red dog flour, clearly increases the digestibility of the dry substance, the crude protein and the crude fat of the basal rations. On the other hand, it seems probable that the addition of tankage to a ration consisting of ground corn alone decreases the digestibility of the dry substance and the crude protein in the basal ration. 1. Influence of Quantity of Ration. There is a significant de- crease in the coefficients of digestibility of the dry substance, the crude 1014} DIGESTIBILITY OF SOME COMMON RATIONS FOR SWINE 196 protein, and the total carbohydrates of a ration consisting of ground corn, red dog flour, tankage, and pork cracklings, when there is a re- duction of 26 percent in the dry substance consumed. On the other hand, there are no significant differences in the coeffi- cients of digestibility for the nutrients of a ration consisting approxi- mately of ten parts of ground corn and one part of pork cracklings when fed as a full-feed allowance and in amounts equal to two-thirds of a full-feed ration. Further digestion experiments kave been undertaken to confirm the preliminary results reported in this bulletin. The authors wish hereby to acknowledge their indebtedness to Mr. A. D. Emmett, Assistant Chief in Animal Nutrition, who did niost of the analytical work connected with the experiments here reported. They wish to express their appreciation also of the efficient editorial assistance rendered by Miss Leonora Perry in connection with the preparation of the manuscript of the bulletin. 196 BULLETIN No. 170 [May, < 10 o os oo co t- 01 to rH O O "* t- 10 rH t^ CS * I 43 10 r- t- "* rH O * O O OO O OO CO rH CO t CO OS CO CO t- I a^l CO CO CO CO OS r-lTH l^ IO O CNJ * O5 O CO 1-- CO CQ o N i 1 OS OS O OS OS OO OO OS O rH O os os os o o o os os os Oi Oi O OS O rH C oo cc 01 oo o; os o: -2 CD ^ o o co t~ (M OS . . . ._}, ^ . . n J m _be CO O rH co co io rH OO -^ IO IO IO : : : * CO Os CO rH o M 0) ' , ~V CO * 05 . . eo o ^ M ft bo g8* s l co' co' M OS CS OS G\j ro be 0) p o - ~ - i Is rt 03 . _ > p * < > P i c - C3 > P CD c *.... be 8- - - g p < " 8- i > ^ i i < i ^ C i 1 < 1 < i. o o S- 6 1914] DIGESTIBILITY OF SOME COMMON RATIONS FOR SWINE 197 O O rH oiHiob>fr^ioceaoooioo^i CO CO CO CO CO 1C 01 o oo ic CO CV rH O "f M ic (M ** ' o o ^t* w oi >c if.- oi c>i oi ?i ro" OlOOOOOOOlOlOlOSCJlOOCDOOOiaOGlOl Oi 1C 1C 00 OO OO 1C 1C O3 OO CO O CO S5 ^ 00000 OlOOOOrHTf.OSC500rH>0 co to * 1C * D 1C 00 rH O O CQ 5D OO t- O5 Ol Ol rH CO* rH CJ Ol C\i 1^ rH S-l CO' Ol 1C S-J oiaioiooioioooiwioioooooi rH O 00 01 01 oo 01 Cl - CO O O3 Ol Ol Cl to O Cd 1C aoooooooo; oooiOioooooooooiooooai Ol * ~ ., 03 (-. o- - s* g| 53 B " o 2 ^ t)' o^ o i D 2- O" n3 P* 6 a 6 i 53 > 2 c - ^ ^ rl " " 0^ - d 8^ : us d s^ ^ 2- 2 3 E O 198 BULLETIN No. 170 [May, M T I ^3 CH O l-^r-i OS iH O iH t-^r4l>I|3>ego tO* oo os oo os os os t~ os c-i co co t t I i-t i-i S ^ ^ OO5O5 00 O5 3 w 06 1>^ oi ' ' ' Cvi 06 n3 ^^ 5tO to ^to bio ". ^3 . O D~" oaiq oq ooo ,rC> o'co'r-? lOJCO N 13 os os os rt -u x _ 8 fS 'S o| ^ "-J ^ f^ W 'O r-l OS CO * OS ^ O tO CO 00 (M i-| CO CO rH tO O tO S -u to' o c-i i-4 oo' os' oo i-i os' oo' to' oq t^ fcl !x! OSOS OS OOOO OO tOTt-,cS OOO5 00 OOOO OO tCtfJt-tOmtO tO OOSOSOSCXIOINrHOtOO ft" 8 ^; bn . ' m oooo co m o i i ; oq oq in in oq cxj to t^ *_ w 5x5 in in c-i oq i-j M. os oq o So a : A 05 200 BULLETIN No. 170 {.May, r O -+- 3 iq t- rs in o> T(5 as co ui i-^ in oj q CO ^ OJ o co oj O{ C r-J O5 rH i-H cc i i e \ I r*~ CO if! : : : : : : : : : : : ; 1 1 ! i 4 p O) 11 gj O bC i Cj O >H 1* be *H -g 5 3 S S5 : : : : : : : : : : : ; J 5 i i i ^ 3 '~ v *" (T) fl *^ P-l ^ " is < O y u ^^ o o oq in co (O t- CO CM Oq CO OJ 00 OJ O i-H co oq TJ< iH O Oq' OJ OJ O I 1 co iq co CJ O i-l r-l r-l i i i-i 4 ) i -l 4 H 2 S O 01 S bi p ro o i-j oci * o 06 oq' od r-5 in O Oq t- OJ rH i-i i-i i-i co t~ cq * o in O CO * r-\ iH T-l oq oq o CO O r-J co oq o r-l r-l i-l I-H i 1 I 1 4 14 ^^ PH < lA -4-i ** X^ ,2 o oq oq oq cq cj m o o m m >q t- oq E: j 1 '* '"S ^ -In H o o 4 i 1 r-l O O in* -1 / ^*^C ) ) i Average . . Pork cracklings y ) ) > 1 Average . . 1914] DIGESTIBILITY OF SOME COMMON BATIONS FOR SWINE 201 UNIVERSITY OF ILLINOIS-URBANA Q.630.7IL6B COO 1 BULLETIN. URBANA 166-181 1914-15 3 Oil 2 O 1 9528436 "*