EFFECT OF FEEDING ON THE COMPOSITION OF MILK AND BUTTER 433 THE EFFECT OF FEEDING ON THE COMPOSITION OF MILK AND BUTTER: LINSEED CAKE AND HEMPSEED CAKE. BY H. T. CRANFIELD AND MARGARET G. D. TAYLOR. DURING the present war many feeding-stuffs have been diverted to this country from the Continent-feeding-stuffs which previously have rarely been met with on English farms. One of these-hempeed cake-is now being offered for sale in this country in considerable quantities, and in the autumn of last year it was decided at the Midland Agricultural and Dairy College to compare the feeding value of this substance with linseed cake as regards milk production.Facilities being offered us, we decided to note the effects (if any) of these foods on the composition of milk'and butter. Hempseed cake is somewhat similar in appearance and general characteristics to linseed cake.Its only apparent drawback is its poor keeping quality, especially in the summer time. The two cakes used in this experiment gave the following analyses : Linseed Cake. Hempseed Cake. Moisture ... ... ... 13-85 11-47 Oil ... ... ... ... 8.98 7-87 Albuminoids ... ... ... 27.39 28.87 Soluble carbohydrates ...33.26 23.85 Fibre . . . . . . ... .., 10.42 21.07 Ash ... ... ... 6.10 6-87 100*00 100.00 Total food units . . . . . . ... 124.20 115.7 ... Experimental Details. Two sets of cows (crossbred shorthorns) were selected, four in each set. They were carefully chosen, so as to be as even as possible as regards their milk yields and periods of lactation. They had been out at grass, but a few days before the com- mencement of the experiment they were brought in to the sheds for the winter.- During the first few weeks of the experiment the milk yield increased considerably, this being probably due to the poor quality of the pasture during late autumn. Feeding. First Week.-All the eight cows received the following daily ration: Two Ib. mixed meal (bran and sharps), 14 lb.hay, 7 lb. straw chop, 56 lb. cabbages, 1 lb Egyptian cotton cake, 2 lb. linseed cake, 2 lb. hempseed cake. For the first four days Set A received a gradually diminishing quantity of hempseed cake and an increasing amount of linseed cake. Set B likewise were given a diminishing quantity of linseed cake and a corresponding increased amount of hempseed cake.The last three days of this week the cows were on the following rations ; Second Week-This week the cows passed through a transition period.434 CRANFIELD AND TAYLOR: THE EFFECT OF FEEDING Set A. 2 lb. mixed meal (bran and sharps). 7 ,, straw chop. 1 ,, Egyptian cotton cake. 4 ,, linseed cake. 14 ,, hay. 56 ,, cabbages. Set €3. 2 lb. mixed meal. 7 ,, straw chop. 1 ,, Egyptian cotton cake.4 ,, hempseed cake. 14 ,, hay. 56 ,, cabbages. Third and Fozcrth Weeks.-Rations were the same as above. Fifth Week.-Transition period. Set '4 gradually changed from 4 lb. linseed cake to 4 lb. hempseed cake, and Set B vice versa. Sixth and Seventh Weeks.-Set A received the normal basal ration, plus 4 lb. hempseed cake, while Set B received the basal ration, plus 4 lb.linseed cake. ,Eighth Week.-First three days were a transition period back to equal quantities of linseed cake and hempseed cake. The last four days the cows received the same ration as in the first week of the experiment. MILK. Proportionate samples were taken of successive night's and morning's milk from each set of cows, and the following determinations made : Fat by the Gerber method, Total solid's by evaporation.Proteins by aldehyde figure. Fat. During the whole experiment the percentage of fat varied from 3.3 to 4.5, and the following figures were obtained : Weekly Averages: Per Cent. 1st Week. 2nd Week. 3rd Week. 4th Week. 5th Week. 6th Week. 7th Week. 8th Week. Set A ... 4-14 4.22 3.94 3-81 3.62 3-63 3.59 3.66 Set B ... 4.10 4-23 3.96 3.83 3-65 3.72 3.72 3.92 Set A.Set B. Maximum percentage of fat . . . ... 4.45 4.50 Average percentage of fat ... ... 3.83 3-89 1 3.80 3.75 Minimum percentage of fat . . . ... 3.30 3.40 ( Linseed Cake. Hempseed Cake. Average percentage of fat from It will be seen from the above figures that the percentages of fat in the milk of both sets of cows followed each other irrespective of the change of cake, and therefore it does not appear that those two cukes exerted any influence on the percentage of fat.The difference of 0.05 per cent. in favour of linseed cake is too sinall to be considered. The percentage of fat decreased rather rapidly during the third, fourth, and fifth weeks. This was probably due to the fact that the quantity of milk increased very much during this period, and so exercised a diminishing efiect on the percentage of fat.Solids-no t-Fat. The two sets of cows gave figures which followed one another, but at a rather There is no apparent influence shown, wider interval than in the case of the fat. however, due to the change of cake.ON THE COMPOSITION OF MILK AND BUTTER 435 Weekly ,4 vcragcs : Per Cent. 1st Week.2nd Week. 3rd Week. 4th Week. 5th Week. 6th Week. 7th Week. Sth Week. Set A 8-62 8.80 8-70 8-84 8.95 8.89 8.86 9.05 Set B 8.56 8.67 8.61 8.66 8.75 8.72 8.71 8-76 &laximum percentage of solids-not-fat . . . 9.56 9.17 %himum percentage of solids-not -fat . . . 8.44 8.33 Average percentage of solids-not-fat ... 8.84 8.68 Set A. Set 13. Linseed Cake. Herripseed Cake. { 8-74 8.75 Average percentage of solids-not-fat from Proteins (from Aldehyde Figure).There appears to be some slight variation in the percentage of protein, following the change of cake (see Fig. l), but since the difference in the average percentage is only 0.05, and the method being only an approximate one, this variation is hardly worth consideration. Week19 Averages : Per Cent. Set A 3.38 3.42 3-35 3-42 3-56 3-33 342 3.53 Set B 3.35 3.30 3.35 3.35 3.50 3.39 3-49 3.51 Set A.Set H. Mavximum percentage of protein . . . ... 3.69 3-66 Minimum percentage of protein . . . ... 3.15 3.10 Average percentage of protein . . . 343 3.40 1st Week. 2nd Week. 3rd Week. 4th Week. 5th Week. 6th Week. 7th Wcek. 8th Week. Linsced Cake. Henipseed Cake. { 3.41 3.36 Average percentage of protein from B u TTER. On alternate days a portion of the night’s and morning’s milk from each set of cows was separated, and the cream ripened with a starter and churned in a glass experimental churn.The following determinations were made on the butter fat : Reichert-Meissl value. Kirschner value. Polenskk value. Ref ractom et er figure. Reic her t-Meiss I Va h e . Not the slightest variation due to the linseed and hempseed cake was noticed.A drop during the first ten days was succeeded by t~ substantial rise, which continued until the middle of the sixth week, when the figures began again to fall (see Fig. 2). One notices that the curves for this value are complementary to the curves for the percentage of fat. We draw from this the conclusion that the improved quality of the food (subsequent to the cows leaving the poor pasture) was responsible for the increased percentage of soluble volatile fatty acids as indicated by this value.436 CRANFIELD AND TAYLOR: THE EFFECT OF FEEDING Weekly Averages : Reichert-Mcissl Value.Set A 24.35 23-69 24-89 27-75 29-55 29.92 29-52 28.34 Bet B 24.14 23.04 24-36 26.15 28.56 28.86 28.75 27-61 Set A.Set B. Maximum Reichert-Meissl value . . . 30.58 29-37 Minimum Reichert-Meissl value . . . 93-10 22-76 Average Reichert-Meissl value 97-25 26.43 1st Week. 2nd M7eek. 3rd Week. 4th Week. 5th Week. 6th Week. 7th Week. 8th Week. Linseed Cake. Hempseed Cake. 27.49 Average Reichert-Meissl value for butter from 1 \ 27.56 Kirs c hner Va h e . The remarks made for the Reichert-Meissl value equally apply to the Kirschner value. Weekly Averages : Kirschner Value.Set A 20-32 20-05 20.81 92-56 23.75 23-78 23-31 22-32 Set B 20.30 19.75 20.65 21.30 22-51 22-96 22-41 21.44 Set A. Set B. Maximum Kirschner value . . . ... 24.40 22.98 Minimum Kirschner value . . . ... 19.33 19.12 Average Kirschner value . . . 22-11 2141 1st Week. 2nd Week. 3rd Week. 4th Week.5th Week. 6th Week. 7th Week. 8th Week. Liiiseed Cake. Hemyseed Cake. 22-26 Average Kirschner value for butter from { 22.18 Polenskd Value. The curves for this figure (see Fig. 2) follow approximately the path of .the Reichert-Meissl and Kirschner curves; but it will be noticed that during the fifth week (transition period) the lines intersect, and the results given by cows A show a rather lower set of figures in the sixth week than would have been the case if the curves had been strictly uniform.However, since the difference between the averages for the two cakes is very small (0.08 per cent.), we do not feel justified in making further comment. Weekly Averages : Polenskd Value. 1st Week. 2nd Week. 3rd Week. 4th Weak. 6th Week. 6th meek. 7th Week. 8th Week.Bet A 1-55 1-50 1-67 2.02 2-53 2-33 2-46 2-43 Set B 1.65 1.47 1-62 1.89 2.62 2.50 2.44 2-43 Maximum Polenskk value . . . ... 2.7 2.9 Minimum Polenskh value . . . ... 1.4 1.4 Set A. Set. B. Average Polenskh value ... 2-06 2.08 Liiiseed Cake. Hempseed Cake. { 2-16 2.08 Average Polenskb value for butter from Refractometer Figure. The readings were taken at 35' C. with a Zeiss butyro refraotometer.The two cakes do not appear to have influenoed the refractive index of the The result of leaving the pasture for a more nutritious ration is again butter-fat.ON THE COMPOSI'L'ION OF MlLK AND BUTTER 437 PER I CENl ~ -- -- TI FIG. 1.438 I ON THE COMPOSITION OF MILK AND BUTTER 3 c FIG. 2.CRANFIELD: ON THE VALUES FOR BUTTER 439 indicated by the rapid fall in this figure (see Fig.2). As one of us has previously noticed (ANALYST, 1911, 36, 446), the refractometer figure varies inversely with the Reichert-Meissl and Polenskc5 figures. Weekly Averages : Refradometer Figure. Set A 48-0 48.0 47-62 46-56 46.10 46.17 46.70 46.67 Set B 48.0 48-25 47-87 47.25 46-45 46.33 46-45 46-58 Set A. Set I3. Maximum refractometer figure . . . 48.5 48.75 Minimum refractometer figure .. . 46.0 46-0 1st Week. 2nd Week. 3rd Week. 4th Week. 5th Week. 6th Week. 7th Week. 8th Week. Average refractometer figure 46.98 47.15 Linseed Cake. Hempseed Cake. 46.70 Sverage refractometer figure for butter from { 46.74 Quality of the Butter. On one or two occasions it was noticed that the butter from the hempseed cake feeding was not quite so good as regards flavour and colour as the sample churned from the milk of the cows receiving linseed cake.In the majority of samples, however, there was very little difference, and we are of the opinion that cows receiving hempseed cake would produce a good quality butter. Cone lusions. 1. The composition and quality of milk and butter produced by feeding, hemp- seed cake is quite equal to that obtained by feeding linseed cake. 2. The effect of removing cows from poor pasture on to a well-balanced ration in stall is shown very strikingly by the data obtained from this experiment. It caused a large fall in the percentage of fat, a considerable rise in the Reichert- Meissl, Kirschner and Polenskc5 values, and a fall in the refractometer figure. In conclusion we desire to express our best thanks to Miss N.D.D., and Mr. J. Dunlop, B.Sc., for facilities and help in the churning of the samples. MIDLAND AGRICULTURAL AND DAIRY COLLEGE. * ? B * + € + * Marion Blunt, collection and