THESIS NPV EMBO Rael OF FAT IN MILK ae S. Frank Yabina. ele THESIS [33 G35 THS WCHIGAN STATE \NIVERSITY LIBRARY VARIATION IN PEROENT OF PAT IN MILK. by , : kya’ s!"F Frank Yebine, Michigan Agricultural dollege, August 3, 1895. 133 935 THS VARIATION IN PERCENT OF FAT IN MILK. By the introduction of the Babcock test in 1889, the testing of milk became a simple operation, This gave wider opportunities for the study of the fat content of milk. It having been my privilege to test milk so many times, my attention has been called to numerous circumstances affecting the composi- tion of milk as shown by the variation in the percent of fat. Of these I will treat but three and they will be considered as follows: 1. Sickness and Excitement. ll. Period of Lactation. 111. Temperature. My chief purpose is to find the relation between the temperature and the quality of the milk, so that the first two subjects will be treated very briefly. Excitement and Sickness,- Numerous tests have been made of dairy cows at Agricultural fairs with but poor success, those cows having shown good tests at their home on the farm or in the deiry barn, have been so affected by the excitement caused by the change and the strange surroundings that the remits were very unsatisfactory. It was a notable fact that the breed test at the World's Fair did not come up to many reliable private tests made with the same animals for this same reason. 404006 2. Change of milker and manner of milking.- The Wiscon- sin Station (R. 1889, P. 42) found that ch ange of milker, manner of milking, and change of environment all exert a more or less decided infiaence, temporarily at least, on the quantity and qual ity of the milk produced, the fat being, as a general rule, more sensitive to such changes than the other ingredients or the total yield of milk. The excitement attendant upon dehorning also has different effects upon the milk of individual cows. Table 1 is taken from the regular herd record of the Minnesota College Herd, showing the pounds of milk given by the cows for the three milkings before they were dehorned and the percent of fat. Table il. First milking Second milking Third milking Milk Percent Milk § percent Milk Percent Ibs. fat lbs. fat Lbs. fat Betty 11.5 4.3 11 3.8 11.5 4.1 Clara 9.5 4.6 9 3.7 7.1 4.0 Orassy 6.5 4.7 6.5 4.9 6.5 4.4 Franc 13.5 309 13.5 4.0 15 .0 3.6 Gran 10.0 3.8 9.25 3.4 9.5 4.3 Patsey 10.5 3.5 11.0 36 11.25 4.0 Rossie 10.9 4.2 10.0 3.3 10.9 307 Roxy 13.9 4.1 12.75 3.5 13 5 3.9 Sully 21.0 4.5 20 .0 4.3 20.75 4.0 Total 107.3 103 106 Average 4.17 3.83 4.0 Table 11 shows the pounds of milk and percent of fat given by each cow during the three milkings immediately follow- Ling dehorm ing. Se _ Tabdie ii. Name of First milking Second milking Third milking. _ cows Milk Percent Milk Percent Milk Percent “lbs. fat Tbs. fat _1bs. fat Betty 10.6 2.9 11.5 4.3 9.25 4.6 Olara 18.25 7.0 9.0 5.6 9.25 4.7 Qrossy 15 .5 5.5 6.0 6.1 6.5 5.9 Franc 12.75 3.5 13.0 3-9 13.5 4.3 Gran 9.5 2.7 7.5 3.8 8.5 4.7 Patsey 10.0 4.0 10.5 Sel 60.5 3.8 Rossie 9.0 Bef 9.75 3-8 9.25 So Roxy 11.0 4.6 11.0 4.8 11.75 4.3 8ully 19.0 3.1 19.75 4.0 20.0 3 6 Total 97 .6 98 98.5 Average 4.05 4.37 4.4 Conelusion.- Immediately after dehorning--cow give less amount fat and milk. 1. Sickness.- Conn. Exp. 1886, P. 112. Effect of sickness on the yield and composition of milk. "Cow No. 10 for @ week previous had been giving on the average 22-1/2 powumds of milk per day. Sixteen ounces of butterfat, while the per- cent of fat in the morning’s and evening's milk ranged from 3.5 to 4.3 percent. On the £2 of February, 1886, it was noticed that she did not eat well. Her yield of milk and butterfat for the next few days were as follows: February Wilk Fat Ibs. ounces 84 15 .5 13.2 25 12.0 11.3 26 15 .0 10.4 27 17 633 11.4 2. Sickness.- Mr. J. Be White made an analysis of the milk of cows suffering from Pleuro Pneumonia. The results Obtained were as follows :- 4, Bet 1 Lot 11, Water 89.80 % 89.18 % Fat 1.18 * 1.30 * Sugar 4.20 * 4.50 * Casein 4.16 * 4.30 * Satt 66 * 64 * Il. The Period of Lactation: The milk from the first portion of any single milking is relatively poor and increases in richness to the stripplings, which are relatively very rich. Thus the New York State Station found that in the case of fine cows the first pint of milk con- tained only 0.3 percent of fat, while the last pint contained 6,85 percent. The Jersey cow, Early Morn of the Purdue University gave a test at the em of rer period of lactation of 9.2 percent fat. The text was taken October 8, 1891. Early Morn calving November 5, 1891. Her normal amoumt of fat was 6 percent. Effect of the period of lactathon on the percentage of fat in the mils found by H. H. Dean of Ontario Agricultural dol- lege 1891, "The milk of six cows of the college hesa was tested for two hundred and seventy four days, All cows had been giving milk for about fifty days when the test began. The time was divided into three periods of ninety days each. The results were as follows: First period Second period Third period Cows 91 days 91 days 91 days 1 3.535 3.84 4.29 £ 344 3.88 4.35 3 5-49 3.29 4.01 4 3.65 3.78 3.88 5 5 65 3075 3.58 6 5 27 5 045 __ 3-98 Ave. 35.49 3 66 3-95 The difference petween first 91 days and third 91 days is .46 percent. Morning's and Bvening's milk and Fat.- As regards the com- position of the milk secreted during the day and that secreted during the night, ana lyses of a large number of samples at the New York Station ( R. 1890, P» 14) showed very little differsrce,— although the night's milk contained on an average siightily more water, The quantity of milk secreted per hour was practically the same during day and night, but the amount of fat secreted averaged 11.5 perdent more during the day than during the night. Average milk secreted per hour Date Morning ibs. Evening lbs. Morning og. Evening 02. | April 19 9.69 7.16 | . . 20 10.06 6.65 11.58 11.51 " 2b 10.19 7.16 " 22 10.31 7.09 " 23 10.41 7.84 . 24 11.51 §.78 "e 25 11.75 5.41 11.48 10.96 " 286 11.38 5.25 " 27 8.94 8.59 1.71 11.40 " £8 8.636 8.50 The same report of New York shows that evening's milk has ea higher percent of fat than morning. Average of percent fat in 6. morning's milk 5.53 percent, evening's milk 6.11 percent. Comparison of fats in morning's and evening's milk. Average percent of fat in milk. Period _Morn ing Even ing Days L 4.63 5.27 6 2 5.15 5.72 6 3 §.13 6.01 7 4 5.62 6.42 6 5 6.09 6.10 3 6 5 .95 6.56 6 7 5.91 6.46 6 8 5 .80 6.40 6 Average 51535 6.11 At M, A. CG. in the case of Belle Sarcastic and Houwtje D. the following results were noted, Cows were milked three times a day. It shows that both Bele and Houwtje gave more fat at noon that at morning or evening. Belle Sarcastic Milk Mi lk Mi Uk : Lbs. Fat lbs. Fat Lbs. Fat 1804 A.M. % Ms % Pe Me % May 22.6 8.65 80.9 3.0 82.2 8.0 * 2 25.4 8.25 20.8 8.2 23.2 3.0 " 3 #g4.5 3.25 282.9 9.85 265.1 3.6 *" 4 86.3 3.00 983.3 2.90 28.6 3.1 * § 25.4 2.80 23.4 2.75 25.4 2.48 " 6 27.4 2.55 20.7 2.90 23.2 2.65 “ $7 87.0 3.05 28.1 3.80 284.7 98.98 June 1 23.8 2.40 23.0 3.00 24.6 3-05 " @ 24.5 2.55 24.5 2.90 23.0 &.55 " 8 28.2 2.35 22.9 2.05 284.0 # £2.00 " 4 26.0 2.60 24.6 38.40 28.5 2.85 " § 868.0 2.40 228.6 2.94 283.8 2.968 *" 6 280.4 8.75 280.4 3.40 24.0 1.90 " 7 #24.5 8.80 22.8 8.18 24.2 # 2&.00 Total 348 315.2 333.58 Ave. 2.74 2.03 2.72 Houwtje D. Milk Mi 1k Mi lk " Lbs. Fat Lbs. Fat Mibs. Fat 1894 Ae M. % M. % P.M. % May 1 16.6 3.70 17.9 3.60 17.4 £8.00 * 2 88.2 2.78 20.7 8.80 28.2 # 8.60 " 3 26.1 2.80 21.1 3.38 23.5 £2.80 " 4 87.1 2.75 25.1 3.35 27.4 3.10 * 5 27.8 28.55 287.38 1.80 26.1 2.785 " 6 29.0 2.00 25.5 2.35 28.7 8.00 "7 89.8 2.60 27.1 8.40 29.0 2.30 June 1 28.4 8.90 28.7 2.55 23.2 # £3.45 " 2 29.5 8.15 3831.0 8.10 284.5 # £3.35 " 3 28.4 2.65 28.7 2.80 28.8 28.68 " 4 89.0 2.40 25.4 3.40 29.4 2.20 "8&8 29.8 2.20 25.4 2.94 26.6 28.20 " 6 34.8 3.10 28.9 3.10 25.5 2.70 _" _7 381.6 3.20 28.3 2.40 25.0 2.80 Total 390.7 358.1 358 Ave. 2.74 3.48 2.85 ete, 8. III. Temperature: Mr. Hills of the Vermont Experiment Station Report, 1898, stated that when cows are out on pasture the percent of fat in the milk increase as the temperature rises; in other words, the fat in milk varies inversely with the temperature changes. The present test indicates that this is also true of both total solids and solid not fat; that changes in tempera- ture in either direction from normal tend to decrease the quantity of milk. | Nebraska Station Bulletin No. 30, 1893.- The meteorology of the period wider consideration was carefully gone over, noted in connection with the milk yiled and amowmt of fat present. _ Table Vill, February 1898. Temperature Snow Milk, lbs. Percent No. of Feb. Ave. Ave. fat _Gows 1 25.9 9.00 4.40 6 2 54.5 9.06 4.47 6 5 38.5 9,48 4.61 6 4 30.5 1.5 8.92 4.91 6 5 32.0 9.91 6 .20 6 6 31.3 055 10.00 6.31 6 7 18.3 2.0 10 .25 6 8 17.6 9.50 4.97 6 9 22.3 9.58 4.39 6 10 24.3 9.17 4.62 6 11 15 -6 9.75 4.77 6 12 37.8 9.42 5 .06 6 13 28.8 9.50 4.85 6 14 13.3 9.08 6 18 85 .3 8.58 5.30 6 16 56.35 9.08 4.91 6 17 31.5 9.25 4.68 6 18 17.0 9.85 4.80 6 19 23.8 9.25 4.42 6 20 33.5 9.17 5.15 6 21 37.5 8.67 6 22 41.5 8.68 4.88 6 235 44.4 8.42 5-10 6 os 38.0 8.66 4.60 6 39.1 9. 4.63 6 86 41.8 33 4.76 6 8.353 9. In my investigation concerning the influence of temper- ature upon the percent of butterfat I have used the College berd. The testing was done by H. E. Van Norman and others for 1894 ,- from January 1, 1895 by mpself. The cows sued were, (ea) Belte Sarcastic a thorough bred Ho’stein, four years old that gave in 365 days, 21,096.2 pounds of milk and 634.67 pounds of butterfat. (ob) Houwtje D. a thorough bred Holstein, six years old giving in 365 days 19,180.2 pounds of milk and 655.45 pounds of butterfat. Time for milsing.- Belle was milked regularly three imes a day-- 6 300 Ae Me, 1:00 B., and 7:00 P, M. Houwtje was milked regularly three times a day at the same hours as Belle until Merch 8, 1805, after that tméce a day~--6:00 A. M. and 5:30 P. Me The days of each month are divided into three groups according to temperature, and the groups designated according ly as those of Nigh, Low, and Medium temperatures. The three groups containing nearly equal number of days. The percents of fat were taken from the College herd. I have taken for consideration the reoords of those two cows for two months, May and Jume, in 1894 and also May and Jue in 1895. T have also used the record of these cows, by months, for the year 1894. Temperature was taken from the Meteorological observa- tions at M. A. O. The thermometer was exposed in the open air and temperature taken three times a day, 7:00 A. M., 2:00 P. M. 10. Table 1. 1894. Temp. Percent fat Percent fat ‘Percent fa daily at high at low at medium Mey mean temp. Temp. temp. Temp temp. 63--73°R. ave. 31--5390F. ave. ,§443620 — Belle Houwtje Belle Houwtje Belle houw 1 66 2.88 38.4 2 56 8.15 8.388 3 61 3.28 2&.88. 9 63 2.73 2.74 4 53 2.83 £48.06 5 61 2.48 2.03 12 638 2.91 2.70 18 40 8.01 38.30 (6 60 2.70 2.45 13 68 8.08 928.80 19 37 #4=3.00 2.96 7 59 +«+8.06 2.85 14 63 2.76 2.75 20 43 2.98 3.41 ‘8 55 8.10 2.51 16 64 38.01 2.65 281 53 38.35 3.11 10 56 2.86 271 17 #73 2.98 2.83 22 53 2.91 2.96 Il 54 2.88 2.81 25 64 28.90 2.55 28 46 2.71 2.98 15 56 £8.05 28-60 26 65 2.88 2.55 29 51 2.98 3.73 24 57 «2.96 2-56 65.4 2.9 2.77 30 81 38.01 430 27 =§7 122.80 3.18 31 51 28.71 2.96 57.6 2.91 &.65 4667 2.96 38.29 Summary.- Belle Houwtje % fat %& fat Average high temperature 65.4° 9 days 2.90 2.77 Average low temperature 46.7 I1 days 2.96 5.29 Ave. medium temerature 57.6 10 days 2.91 2&.65 There were nine days of high temperature, ten days of medium and eleven days of low temperature. Houwtje’s average percent of fat for the days of high temperature was2.77 percent, while on the days of low temperature it was 3.29 percent, a difference of .52 percent in favor of low temperature. Belle shows only a difference of .01 percent in favor of the low temperature. $2 fa 92 ht ae et 22 (2 ot ot eS et ee St tr of Tv # 6? IX / | 7 i / | 3 | a Fd. \ | i ie | ! | | : A A i o\ ny ryt . i : \ Ls 1 5 P f > < N K_ oS | — NK \, / V | \ ‘ | / V LIAL EAE ; : i a tr Temp. Percent fat Table 11. 1895 Percent fat A Li. Percent fa daily at high Temp at low at medium June mean temp. ave. temp. Temp temp £38408 1° 49--69 ave 70--7" Belle Houwtje Belle Houwtje Be 1 le Hout 11 78 2.61 2.01 1 60 2.81 2.96 9 70 2.98 3.40 14 179 2.71 8.93 3 69 8.435 #£=2&.66 7 676 2.75 3.11 | 15 80 £2.41 3.15 4 §8 28.28 28.66 20 71 2.53 3.18 16 #678 3.60 3.28 G6 49 #=2.85 2.45 25 76 2.63 2.53 21 79 2.11 2.83 6 54 28.68 28.95 26 75 2.15 2.90 22 si 2.51 2.50 7 60 2.87 2.80 27 #74 2.36 1,98 23 80 2.46 3.00 8 69 2.81 2.86 289 6 2.30 2.45 £4 178 2.43 2.90 18 61 2.75 2.66 30 77 2.45 2.15 ae 79 2.55 2.55 19 66 2.35 2.85 28 73 2.51 28.61 Ave. 9 2.60 2.74 61.2 2.66 2.77 14 2.53 2.75 Summary.- Belle Houwtje % fat % fat Average high temperature 79° 10 days 2.60 2.76 Average low temperature 61.2 10 days 2.66 2.77 Average medium temperature 74 10 days 2.535 2.75 In table 11, Belle s ows avery slight difference of -06 percent in favor of low temperature, while Houwtje shows a difference of .01 percent in favor of low temperature. 9% 47 43 57 eerefoy ph § enn Temp Percent fat _ fable 111. 1895 Temp.Percent fat 12. Temp Percent fat daily at high at low ave.at medium May mean temp. Ave. temp. temp. ' 12--84 35--50 | §5<071 May Belle Houwtje Belle Houwtje Belle Houwtje — $3 73.3 3.65 4.70 11 44.3 3.18 4.70 165.6 3.10 4.32 4 76.3 3.75 4.10 12 43.3 3.08 4.37 267.6 3.21 4.30 § 80.0 3.55 4.21 18 45.3 3.00 3.87 771.0 4.47 4.00 6 72.6 3.07 3.70 14 33.35 3.06 4.25 8 69.0 3.26 3-86 “9 77.6 3.10 4.50 15 48:6.2.55 3.75° 17 56.6 2.80 4.20 10 78.6 3.01 3.77 16 46.3 2.75 4.17 18 54.0 2.61 4.00 30 81.0 2.71 3.10 20 44.8 2.61 4.10 23 62.0 2.88 4.00 S31 84.0 2.95 4.05 21 48.6 2.78 4.40 24 62.3 2.60 3.00 26 49.6 8.57 4.90 25 68.3 2.81 3.00 ; 27 49.0 5.16 3.37 28 70.0 2.76 3.55 Ave.77.7 3.18 4.01 45.5 82.84 4.16 63.9 3.00 3073 Summary.- Belle Houwtje % fat % fat Average high temperature 77.7° 9 days 3.18 4.01 Average low temperature 45.5 11 days 2.84 4.16 Average medium temperature 63.9 11 days 3200 3.73 Belie favor of difference in high temperature .34 % Houwtje favor of difference in low temperature.11 % /) yf ¢ / Ald i Vi-B (jeetd. fe ce 43 82, bp 1 Ot ot ot i nL i 4 + 7 | || | | N , LAA AL 4 A it WU T/A LA Lu. MAT | FEA ae EL ti SUA LR ATEN LD | / WoT NAVAL mi VL, +ty 13. Table lV. 1895. Temp. Percent fat Percent fat Percent fat Daily at high Temp. at low Temp. at medium mean temp. av. temp. QV. temp. 7@--81° 53--680 Be 69--75° Jue Belle Houwtje __ Belle Houwtje Belle Houwt ja. 1 80 3.80 4.30 5 57 8.80 3.90 873 $3.05 3.80 2 80 3.15 4.55 6 56 8.95 3.70 1274 2.76 3.50 3 77 8.15 440 7 59 3.10 3.65 1470 8.96 3.70 4 81 8.60 4.10 13 65 28.95 3.95 1675 2.96 3.85 ‘9 76 8.76 33.92 6 67 8.83 3.57 18 75 3.15 3.60 10 80 3.11 3.70 19 $3 3.63 4.17 2169 2.91 3&.62 ll 79 $3.68 4.00 80 64 2.98 3.32 2275 3.75 3.18 172677 :«=— 8.800 38637 «686 =CB5 CS .00 SS. 80 2474 2.90 3.65 23 «O77 8.90 3.50 27 67 3.11 38.87 30 75 3.00 4.00 25 80 3.20 3.31 28 68 2.88 3.65 29 61 3.10 3.85 Ave. 78.7 3.14 3.91 61.8 3.30 3.83 73.3 3.06 3.65 Summary : - Belle Houwtje | % fat % fat Average high temperature 78.7° 10 days 3.14 3.91 Average low temperature 61.2 11 days 3.30 5.83 Average medium temperature 73.3 9 days 3.06 3.65 Belle,difference in favor of low temperature 0.16 % Hountje * " " " high " 0.08 % OY 7 ay 4) 4:5) 14. This table shows the Summary of results shown in above four tables. Belle Sarcastic. High Percent Low Percent Favor fat temp. fat High temp. Low temp. May 1894 65.4 2.90 46.7 2.96 06 gtne " 79.0 2.60 61.2 2.66 06 May 18908 77.7 5.18 45 .6 2.86 0 34 dune " 78.7 3.14 61.8 £3.30 216 Favor 1.16 % Houwt je D. High Percent Low percent Favor Date cer fat temn, fat High temp. Low temp. June 1894 79.0 2.76 61.8 28.77 OL May 1898 «677.7 4.01 45 .8 4.16 e 15 Favor °§8 % To more clearly show the effect of temperature on the quality of the milk I have taken four doldest angufour hotest days in the four months used above and compared in the following tables. ____—Belile, 1804 Low temp High &% Favor May temp. % fat Date temp. fat low o7 2.907 17 173 2.83 .14 12 43 3.30 13 68 2.80 55 20 43 3.41 14 63 2.75 .1 1 64 2.85 26 65 2.55 .85 Ave. 44.5 Se lS 67 eL 4 0.4 percent difference in favor of low temperature. Houwtje D._ Low percent May High Percent Favor May temp fat __temp fat High temp Low temp. sO 31 4.830 17 %3 2.83 1.47 19 837 2.96 Ww 68 3.08 12 20 43 3.41 1 66 35.40 ol 28 46 2.98 6 65 2.55 043 Ave. 39.2 3.41 67.2 2.96 1 047 0.47 percent difference in favor of low temperature. Betile Sarcastic, 1894. Low Percent High Percent Favor Jjwme temp. fat ne temp. fat low temp. bs) 49 2.85 15 80 2.41 044 6 54 2.68 28 81 2.51 o 17 q 60 2.87 23 80 2.46 041 18 61 &.75 21 #79 B, 11 »64 Ave. 56 2.78 80 2.39 Al 0.51 percent difference in favor of low temperattre. Houwtje D., 1894. Low percent High percent Favor ime Lemp fat ims te ems fat low high 8.45 3. 18 °7 : 54 8.95 oR a1 2.80 .46 4 60 2.80 23 80 3.00 o2 18 61 2.66 gi. 79 £2.23 .435 | Ave. 56 8.71 80 2.78 .02 0.09 percent difference in favor of low temperature. __ Belle Sarcastic, 1895. Low Percent High Percent § Favor May temp. fat May temp. fat iow high 14 33.3 3.06 31 84 8.95 O11 lt 4 44.3 3.1% 30 81 2.75 ,88 12 43.3 £8.60 10 78 301 oA1 Ave. 41.3 98.85 80.7 3.09 °87 0.15 percent difference in favor of high temperature. Hountje D., 1895 Low Percent High Percent Favor May temp. fat Hey _Heup. fat low high 14 33-3 430 4.00 .8% ll 44.8 4.70 30 at 3.70 1.0 80 44.3 4.10 5 80 4.00 .1l 1 43.3 4.37, 10S 78 3.77 6 Ave. 41.3 4.356 80.7 3-85 .51 0.88 percent difference in favor of low temperature. Belle Sarcastic, 1895. Low Percent High Percent Favor une temp. at Jume temp. fat tow High 5 57 8.80 4 81 £&.60 2 6 56 2.95 1 80 3.80 638 4 §9 3.0 g 80 3.158 005 Ww 58 8.63 28 80 3.20 .48 Ave. 60.4 3.12 80.2 3.03 005 O.11 percent difference in favor of iow temperature. __Houwtje D., 1895 Low Percent High Percent Favor gune temp. fat gume temp. fat low high 02 § 57 §.90 4 81 4.10 6 86 3.70 1 80 4.30 6 ”" 59 3.65 2 80 4.56 9 19 —+63 4.17 26 89 3.20 8.3 Ave. 80.4 8.80 80.2 4.03 36 0.83 percent difference in favor of high temperature. The two following diagrams show graphically the reila- tive changes of temperature and percent of fat in the milk of Belle Sarcastic and Houwtje D. during the year 1894. This seems to show thet the change of temperature has a very remarkable effect on the percent of fat. During cold weather the percent of fat seems to rise while in hot weather the percent falls. Summary of results where féup days of low and high temperature's were compared. Be lle Houwt je May percent fat percent fat percent fat Percent fat favor of low favor of favor of low favor of = temp. high temp. temp. high temp, 1894 044 o51 June '94 .§1 ° 209 May "95 o 15 e828 gune ‘95 ,11 283 Belle: 0.87 percent difference favor of low temperature. Houwtje: 0.55 percent difference in favor of low temperature. a] LA kD Y fo fat AF \— 50 Tf 40 4g 17. In regard to the results of this investigation, I give the following summary, though I am not satisfied to draw fixed conclusions. I. Sickness and Excitement causes a low percent of fat in milk: II, Period of Lactation: | (a). At the beginning of lactation the milk is poor. (bd). Morning's milk is richer in fet than evening or noons. III. Temperature: . (a). 80 far my investigation shows that low temperature gives a high percent of fat. (b). Bffect is different in the different cows. Belle seems to have given a decidedly higher percent of fat during cold weather, while in the case of Hountje D. the effect seemed to be the same but in a less degree. Pet ee 178 2059 il