UNIVERSITY OF CALIFORNIA PUBLICATIONS COLLEGE OF AGRICULTURE AGRICULTURAL EXPERIMENT STATION BERKELEY, CALIFORNIA A Study of the Relative Values of Certain Succulent Feeds and Alfalfa Meal as Sources of Vitamin A for Poultry BY D. E. DAVIS AND J. R. BEACH BULLETIN No. 384 March, 1925 UNIVERSITY OF CALIFORNIA PRINTING OFFICE BERKELEY, CALIFORNIA 1925 A STUDY OF THE RELATIVE VALUES OF CERTAIN SUCCULENT FEEDS AND ALFALFA MEAL AS SOURCES OF VITAMIN A FOR POULTRY By D. E. DAVIS and J. B. BEACH CONTENTS PAGE Introduction 3 Plan of experiment 4 Final results obtained in the different groups 7 Discussion of the experiment 10 Tabulated results of the experiment 11 Conclusions 13 INTRODUCTION The occurrence of a nutritional disease of poultry resembling roup was reported, in 1919, by Haring, Beach, and Jaffa. 1 Beach, 2 in 1924, reported further studies of this disease in which he showed that it is caused by a deficiency of vitamin A in the ration. Green food is the chief source of vitamin A in poultry rations in California and a shortage of this food-stuff is the most common cause of the occurrence of this deficiency disease here. Although green feed can be grown throughout the year in most of the poultry raising districts of the state, poultrymen are frequently confronted with a shortage of this feed on account of lack of irrigation facilities, limited acreage, or cold weather. Another common cause of a shortage of green food is the failure, on the part of some poultrymen, to make provision for an emergency supply when the usual supply, as a result of climatic or other conditions, fails. When conditions, therefore, are such that the growing of sufficient green food is rendered difficult, it is important to know the comparative value of different varieties of green feeds as sources of vitamin A for poultry. The same is true regarding such products as artificially sprouted grains, alfalfa meal, and root crops, such as carrots and mangel beets, 'which might be utilized as an emergency substitute for greens during periods of shortage. It was with these points in view that the investigation herein reported was undertaken. i Calif. Agr. Exp. Sta. Ept., p. 79, 1920. 2 Beach, J. B., Studies on a nutritional disease of poultry caused bv vitamin A deficiency. Calif. Agr. Exp. Sta. Bull. 378: 1-22, figs. 1-7, 1924. UNIVERSITY OF CALIFORNIA EXPERIMENT STATION PLAN OF THE EXPEEIMENT The general plan of the experiment was to feed fowls a basal ration which previous experiments 2 had shown to be deficient in vitamin A and to supplement this with different varieties of green food commonly used, alfalfa meal, carrots, or mangel beets. The basal ration was a dry mash mixture which was constantly before the birds in hoppers and which consisted of : Bran 25 per cent Shorts 25 per cent Ground Barley 25 per cent Soya Bean Meal 10 per cent Meat Scrap 15 per cent and a scratch grain mixture which was fed twice daily in the litter and which consisted of: Wheat 33% per cent Recleaned Barley 33% per cent Egyptian White Corn 33% per cent Grit and oyster shell were available at all times. The birds were confined in houses which had tight board floors covered with shavings for litter. The supplements used were field-grown green barley cut when six to ten inches high ; red clover cut when two to four inches high ; the large leaves of Jersey kale; leaves and tender stems of green alfalfa; blue grass lawn clippings; the entire plant 3 (root, grain, and stalk) of artificially sprouted barley grown indoors to the height of three or four inches; common market varieties of carrots; mangel beets; and alfalfa meal of good color which contained 17.2 per cent protein and 25.4 per cent fiber. 4 A weighed amount of a supplement was fed individually to each bird daily except Sunday. Feeding was accomplished in a specially constructed coop (fig. 1) provided with removable partitions which divided it into six small compartments for individual birds. The grilled sides of the cage permitted the birds to eat food placed in a cup suspended on the outside. Birds which did not voluntarily consume all of their daily supply were forcibly fed the remainder. 3 The weight of the green stalk was found to be approximately 12.5 per cent of the weight of the entire plant. 4 The writers are indebted to Mr. H. Goss, Division of Nutrition, for analysis of alfalfa meal. BULLETIN 384] SUCCULENT FEEDS AS SOURCES OF VITAMIN A 5 It was desired to employ at the start of the experiment less than the minimum requirements of each supplement. Since no definite data on this point were available the minimum daily supply was arbitrarily fixed at one gram for each bird. The daily amount of any supplement was doubled for all birds in a group when any bird in that group exhibited definite indications of suffering from vitamin A deficiency. When additional birds became affected after an increase in the supplement, the daily amount was again doubled. The appear- Fig. 1. — Coop used for the individual feeding of supplements. ance of either the characteristic ophthalmia, or pustules in the mouth or esophagus, described by Beach, 5 was regarded as a definite indica- tion of vitamin A deficiency. White Leghorn pullets three months old were used. They were divided into ten groups of six birds each and placed in five pens of two groups each. Table 1 gives the ration for each group. The birds were procured and divided into the various groups on December 10, 1923, but, since it was thought desirable to allow them to accustom themselves to the basal ration and the new environment, the actual experimental feeding was not started until January 14, 1924. 5 Beach, I.e. p. 1. b UNIVERSITY OF CALIFORNIA EXPERIMENT STATION The feed consisted of the basal ration with the addition to the grain mixture of 25 per cent of yellow corn which, it was thought, would supply sufficient vitamin A during the preparatory period. On December 26, bird 229 (group 7) died. Post-morten examina- tion showed a heavy infestation of intestinal round worms (A. galli), a few pustules in the esophagus, and a slight ophthalmia. On December 27, each bird was examined and one (217, group 5), was found with marked lesions due to vitamin A deficiency. This bird died on the following day and was found to be also heavily infested with intestinal worms. The ration was then changed by the substitution of corn meal TABLE 1 Pen No. Group No. Bird No. Ration I 1 2 201-206 207-212 Basal ration plus field grown barley. Basal ration plus red clover. II 3 4 237-242 243-248 Basal ration plus kale. Basal ration plus green alfalfa. III 5 6 213-218 219-224 Basal ration plus blue grass lawn clippings. Basal ration plus sprouted barley. IV 7 8 225-230 231-236 Basal ration plus carrots. Basal ration plus mangel beets. V 9 10 249-254 255-260 Basal ration plus alfalfa meal. Basal ration only (Control). for the ground barley in the mash mixture and of yellow corn for the grain mixture. Three per cent tobacco dust was added to the mash mixture to control the intestinal round worms. Greens were liberally fed to all birds for a period of six days. Ophthalmia was observed in one other bird on December 29. Local treatment of the lesions and the administration of a 5 cc. dose of cod-liver oil, twice daily, for five days resulted in complete recovery. As the condition of the flock rapidly improved, feeding of the basal ration was resumed and the feeding (one gram to each bird daily) of supplements was begun, on January 14, 1924. The loss of the two birds reduced the number in groups V and VIT from six to five. On January 18, weekly weighing of each bird, and on February 1, daily (except Sunday) examination of each bird for indications of the effect of vitamin A deficiency was begun. On March 3, chicken-pox appeared and affected a few birds. All fowls were vaccinated on March 7 and 14, respectively. This disease BULLETIN 384] SUCCULENT FEEDS AS SOURCES OF VITAMIN A 7 was controlled with the loss of but one bird (206, group 1) which died after vaccination. The average daily food consumption per bird, over the period of 102 days was 22 grams of mash and 44 grams of grain, a total of 66 grams. On this basis, the proportion of the daily amounts of supple- ments fed, to the total food consumption was as follows : 1 gram daily of supplement — 1.5 per cent of the total ration. 2 grams daily of supplement — 2.9 per cent of the total ration. 4 grams daily of supplement — 5.7 per cent of the total ration. 8 grams daily of supplement — 10.8 per cent of the total ration. 16 grams daily of supplement — 19.5 per cent of the total ration. 32 grams daily of supplement — 32.6 per cent of the total ration. FINAL KESULTS OBTAINED IN THE DIFFERENT GEOITPS Pen I, Group 1. — Basal ration plus field-grown green barley. Lesions of nutritional disease appeared early in this group. One bird (204), showed pustules on February 18, and bird 206 on February 20, the thirty-sixth and thirty-eighth days. The amount of green barley was increased to two grams (2.9 per cent of the total ration) daily for a period of one week, at the end of which time, 206 had recovered and 204 was showing improvement. After this, the barley was reduced to one gram. The last pustule was observed in 204 on March 3. No other cases of nutritional disease occurred. Two birds in this group died; one (206) on March 16, after vaccina- tion, and the other (202) was picked to death on April 16. Pen 1, Group 2. — Basal ration plus red clover. One bird (210) showed lesions of nutritional disease for a period of six days, February 18-23 (the thirty-sixth to the forty-first days). The amount of clover was increased from one to two grams for a period of one week, February 21-28, and then reduced to one gram during the remainder of the experiment. No further evidence of the effects of vitamin A deficiency appeared. Four birds in this group died. Two of them, 207 and 210, were picked to death on April 19, and 20, respectively. The cause of death of the other two, 212 on March 19, and 211 on March 27, was undetermined. All birds in this pen (group 1 and 2) were unthrifty in appearance throughout the experiment. They persisted in eating eggs, and three birds were destroyed by their mates. This is the only pen in the experi- ment in which these troubles were encountered. 8 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION Pen II, Group 3. — Basal ration plus kale. Only one bird (238) showed positive lesions of nutritional disease. In this bird, a few pustules appeared on the eighty-seventh day and persisted until the close of the experiment. During the period of 102 days, the amount of kale was maintained at one gram (1.5 per cent of the total ration) daily. No birds in this group died. Pen II, Group 4. — Basal ration plus green alfalfa. One bird (247) developed positive lesions of nutritional disease on the eighty-seventh day. These lesions, although not severe, were more extensive than those in the bird receiving kale, and persisted for the same length of time. The amount of green alfalfa was maintained at one gram (1.5 per cent of the total ration) daily. No deaths occurred in this group. Pen III, Group 5. — Basal ration plus blue grass. All birds remained well throughout the experiment. • Pen III, Group 6. — Basal ration plus sprouted barley. Pustules appeared in the esophagus of bird 222, February 8, the twenty-sixth day. On February 14, the amount of sprouted barley was increased to two grams (2.9 per cent of the total ration). Bird 224 developed lesions on February 16, the thirty-fourth day. Since the condition of these birds did not improve, the amount of sprouted barley was increased to four grams (5.7 per cent of the total ration) on February 21. As these birds still failed to improve, the amount of sprouted barley was increased to eight grams (10.8 per cent of the total ration) on February 28. Two additional birds, 221 and 223, exhibited lesions on March 11 (the fifty-eighth day). Bird 222 was killed by its mates on March 13. A fifth bird, 220, developed pustules on March 17. Four birds showed pustules and were unthrifty in appearance on March 19, therefore, the amount of sprouted barley was increased to sixteen grams. The sprouted barley supplied, from this time on, amounted to 19.5 per cent of the total ration. Within two weeks after this increase, the pustules disappeared in birds 222 and 224. Birds 221 and 223, however, showed numerous pustules until the close of the experiment but were, otherwise, apparently in good con- dition. Although five of the six birds showed evidence of vitamin A deficiency, no deaths from this cause occurred. BULLETIN 384] SUCCULENT FEEDS AS SOURCES OF VITAMIN A 9 Pen IV, Group 7. — Basal ration plus carrots. Bird 226 showed slight lesions in the esophagus for three days (April 10-11-12), the eighty-eighth, eighty-ninth and ninetieth days. These were the only indications of nutritional disease found in this group. All fowls remained otherwise healthy throughout the experi- ment. Pen IV, Group 8. — Basal ration plus mangel beets. Two birds, 231 and 232, developed pustules in the esophagus on February 8, the twenty-sixth day. The amount of beets was increased to two grams on February 9. Since the condition of these birds increased in severity, the amount of beets was increased to four grams on February 18, and to eight grams (10.8 per cent of the total ration) on February 21. On February 23 (the forty-first day) bird 232 died of nutritional disease and, on the same day, bird 235 showed pustules. Bird 231 died of nutritional disease on February 24 (the forty-second day). Two new cases of nutritional disease developed, on February 26 and 27 (forty-fourth and forty-fifth days) in birds 236 and 233, respectively. Beets were increased to sixteen grams (19.5 per cent of the total ration) on February 28. Bird 234, the last bird of the group, developed pustules on March 4 (the fifty-first day). As all four remaining birds of the group showed nutritional disease lesions, the amount of beets was increased to thirty -two grams (32.6 per cent of the total ration) on March 7. From this time until their death or until the close of the experiment, each bird received thirty -two grams of beets daily. One bird voluntarily consumed this amount. The others refused to eat this quantity, even though they were allowed to remain in the feeding coop three or four hours after the beets were placed before them. These birds were hand fed until the lesions in the esophagus became so severe that "forced" feeding was thought to be harmful, which in every case was only a few days prior to death. Bird 236 died, April 2 (eightieth day) of nutritional disease. Post- mortem examination of 234, which died April 6 (eighty-fourth day) showed kidney lesions characteristic of nutritional disease, deposit of urates, and ruptured yolk. Bird 235 died of nutritional disease April 18 (ninety-sixth day). Bird 233, after showing pustules for a period of forty-two days, began to improve and at the close of the experiment, although weak and unthrifty in appearance, it was free from any characteristic lesions. Five of the six birds in this group died of nutritional disease. The remaining one was severely affected but was apparently recovering when the experiment was terminated. 10 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION Ten V, Group 9. — Basal ration plus alfalfa meal. Lesions of nutritional disease appeared in this group in bird 249, on February 16, the thirty-fourth day. The amount of alfalfa meal was increased to two grams (2.9 per cent of the total ration) on February 21. The second bird, 250, became affected February 29, the forty-seventh day. Lesions appeared in the third bird, 253, on March 7, the fifty-fourth day. The alfalfa meal was increased to four grams (5.7 per cent of the total ration) on March 20, and to eight grams (10.8 per cent of the total ration), on April 14. No more birds became affected. Bird 249 showed some improvement while receiving two grams daily, and after the meal had been increased to four and to eight grams, fluctuated between negative and positive throughout the remainder of the experiment. Bird 253 showed some improvement on eight grams of alfalfa meal but the lesions did not entirely disappear. The condition of bird 250 remained unchanged. It did not respond to the feeding of an increased amount of the meal. No deaths occurred in this group. These birds, however, were not so thrifty in appearance as the birds receiving kale, alfalfa, blue grass or carrots. Ten Y, Group 10. — Control. All controls died of nutritional disease. Five showed the character- istic pustules in the esophagus, and ophthalmia. One showed pustules only. Bird 257 died February 19, the thirty-seventh day. Bird 255 died March 2, the forty-ninth day. Bird 260 died March 2, the forty-ninth day. Bird 258 died March 18, the sixty-fifth day. Bird 256 died April 4, the eighty-second day. Bird 259 died April 16, the ninety-fourth day. A tabulated summary of the experiment is given in Table 2. DISCUSSION OF THE EXPERIMENT Group 5, the supplement for which was blue grass lawn clippings,, was the only one to remain free from any indications of vitamin A deficiency. The daily amount of lawn clippings supplied remained at one gram throughout. The kale, green alfalfa, and carrots groups (Nos. 3, 4, and 7) were about equally affected, each having one bird showing a few pustules on the eighty-seventh or eighty-eighth days. Although the daily amount of these supplements was not increased above the initial one gram, no other birds became affected. Neither did the lesions on the three become more severe nor was their general health impaired. The BULLETIN 384] SUCCULENT FEEDS AS SOURCES OF VITAMIN A 11 only discernable difference between the the three groups was in the duration of the pustules of the one affected bird in each group. This was three days only for the carrots bird and until the close of the experiment for the kale and green alfalfa birds. The results in groups 1 and 2, fed field-grown barley and red clover, were very similar. One bird in each group exhibited pustules in the TABLE 2 Tabulated Eesults of the Experiment Started January 14; Terminated April 24 Pen No. Group No. Supplement Num- ber of birds January 14 Mini- mum amount of supple- ment supplied daily Maxi- mum amount of supple- ment supplied daily Num- ber of birds devel- oped nutri- tional disease Num- • ber of birds recov- ered nutri- tional disease Num- ber of birds died nutri- tional disease Num- ber of b ; rds died other causes I 1 2 Green Barley Red Clover 6 6 1 gm 1 gm 2 gm 8 2 gm 8 2i 12 2 1 2 4 II 3 4 Kale 6 6 1 gm 1 gm 1 gm 1 gm l 3 l 3 3 3 Green Alfalfa III 5 6 Blue Grass 5 6 1 gm 1 gm 1 gm 16 gm 5 2 5 Sprouted Barley.. 1 IV 7 8 Carrots 5 6 1 gm 1 gm 1 gm 32 gm 1* 6 1 16 5 Beets V 9 10 Alfalfa Meal None (Control).... 6 6 1 gm 8 gm • 3 6 V 6 1 Observed on the thirty-sixth and thirty-eighth days and persisted fifteen and two days, respectively. 2 Observed on the thirty-sixth day and persisted six days. 3 Observed on the eighty-seventh day and persisted until the close of the experiment. 4 Observed on the eighty-eighth day and persisted three days. 5 Lesions in two birds persisted until the close of the experiment. One bird, with lesions, killed by mates. 6 One bird lost characteristic lesions but was weak and unthrifty when experiment ter- minated. 7 Lesions in two birds persisted until the close of the experiment. 8 Two grams fed for one week only. Pullets seven months old at close of experiment. § esophagus on the thirty-sixth day. Two days later, one additional bird in the barley group had a few pustules which remained for two days only. The daily amount of the supplement was increased to two grams for a period of one week and then reduced to one gram. No further definite evidence of nutritional disease appeared in these groups. How- ever, all of the birds appeared less thrifty than those in the four groups discussed above, and the mortality from other causes was greater than in any other group. 12 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION In the alfalfa meal group, three birds suffered from nutritional disease. After the daily feeding had been increased to eight grams, two of these birds improved and no more became affected. The results with sprouted barley as a supplement were distinctly inferior to those obtained with any other form of green food. Five of the six birds developed pustules. It was necessary to increase the daily amount to sixteen grams (19.7 per cent of the total ration) before the condition of the affected birds improved, and additional birds ceased to become affected. This amount is equivalent to but two grams of the green tops, since the weight of this part was found to be approximately 12.5 per cent of that of the whole plant. All of the six birds in the mangel beets group were severely affected with nutritional disease and five died from this cause. The sixth bird appeared to be recovering when the experiment was terminated. The daily amount of beets was increased from one to thirty-two grams but the birds suffering from vitamin A deficiency were not benefited. Since three of the five deaths did not occur until twenty-six to thirty-eight days after the thirty-two gram daily feeding was started, the recovery of the one bird must be ascribed to natural resistance or to a tolerance for the ration deficient in vitamin A. All birds in group 10, the control group, developed the character- istic lesions due to vitamin A deficiency and died. This demonstrated that the basal ration was deficient in vitamin A. The number of birds in each group and the variation in the results are both too small to make possible an exact comparison between blue grass, carrots, kale, green alfalfa, field-grown green barley, and red clover as sources of vitamin A for poultry. The apparent differences between them which the results indicate, might be found non-existant by further experiments. The results do, however, clearly demonstrate that carrots are equal in value to any of the others with the possible exception of blue grass. Blue grass might be considered superior to the others since this is the only group that remained free from definite evidence of vitamin A deficiency. Carrots, kale, and green alfalfa might be slightly inferior to blue grass because one bird in each group showed evidence of suffer- ing from vitamin A deficiency which appeared the eighty-seventh or eighty-eighth day of the experiment. The daily amount of these sup- plements given, however, was not increased above one gram. Field- grown green barley and red clover might be considered somewhat less effective than the preceding because one bird in each group exhibited definite indications of suffering from vitamin A deficiency on the thirty-sixth day, which is much earlier than in the carrots, kale, or BULLETIN 384] SUCCULENT FEEDS AS SOURCES OF VITAMIN A 13 green alfalfa groups. Furthermore, the birds were less thrifty in appearance and the mortality from causes other than nutritional disease was greater than in the other groups, and the amount of these supplements was increased to two grams for a period of seven days. However, as previously pointed out, considering the small number of birds in each group, the variation in the results is not sufficient to warrant the conclusion that definite differences exist between these supplements as sources of vitamin A for poultry. Alfalfa meal was distinctly inferior to any of the above mentioned supplements since it was necessary to increase this to eight grams daily. This is four times the maximum daily amount of any of the others. It was necessary to increase the amount of sprouted barley from one to sixteen grams to prevent development of lesions resulting from vitamin A deficiency. This was twice the maximum amount of alfalfa meal and eight times the maximum amount of blue grass, carrots, kale, green alfalfa, field-grown green barley or red clover. The weights of the sprouted barley represent the weights of the entire plant, although the green top is the only part of the plant from which any appreciable amount of vitamin A is derived. This, however, was thought to be the best basis for determining its value because it is in this form that sprouted barley is commonly used by poultrymen. Had we supplied only the green tops, the results would probably have been comparable to those obtained from some of the other forms of green food since the largest amount supplied contained only two grams of green top. The results with mangel beets indicated that they were entirely ineffective and, therefore, as a source of vitamin A for poultry, valueless. CONCLUSIONS In conclusion, the writers desire to point out that the amount of supplements fed represent the minimum requirements to prevent the occurrence of lesions characteristic of vitamin A deficiency and do not necessarily represent the actual requirements for good health and productivity. Furthermore, this experiment deals only with greens as a source of vitamin A and gives no consideration to the value of green food in providing succulence, bulk, or minerals in the ration. There- fore, no recommendations as to the exact amount of greens that should be fed to poultry can be made. The following general suggestions, however, for the practical application of the results of this work can be made. 14 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION First. — All of the varieties of field-grown greens used are good sources of vitamin A for poultry. In making selections among them, the poultryman needs consider only their adaptability for culture in his locality. Second. — Carrots appear to be equal in value to the field grown greens and. therefore, should make satisfactory substitutes for them. Third. — If sprouted barley is used as the entire source of vitamin A for poultry, the amount fed should be in excess of 20 per cent of the total ration. Fourth. — If alfalfa meal is used as the entire source of vitamin A for poultry, the amount fed should be in excess of 10 per cent of the total ration. Fifth. — Mangel beets appear to be valueless as a source of vitamin A for poultry. Finally, the writers desire to call attention to the utilization of cod-liver oil as an emergency source of vitamin A when no greens can be obtained. The incorporation of at least 2 per cent 6 of this oil in the mash will, in all probability, prevent any loss due to vitamin A deficiency. The use of yellow corn as the grain ration will also be effective for this purpose. 6 Based on results of experiments described in California Experiment Station Bulletin 378. STATION PUBLICATIONS AVAILABLE FOR FREE DISTRIBUTION BULLETINS No. No. 253. Irrigation and Soil Conditions in the 346. Sierra Nevada Foothills, California. 347. 261. Melaxuma of the Walnut, "Juglans regia." 348. 262. Citrus Diseases of Florida and Cuba 349. Compared with Those of California. 263. Size Grades for Ripe Olives. 350. 268. Growing and Grafting Olive Seedlings. 351. 273. Preliminary Report on Kearney Vine- 352. yard Experimental Drain. 275. The Cultivation of Belladonna in Cali- 353. fornia. 354. 276. The Pomegranate. 357. 277. Sudan Grass 278. Grain Sorghums. 279. Irrigation of Rice in California. 358. 280. Irrigation of Alfalfa in the Sacramento Valley. 359. 283. The Olive Insects of California. 360. 285. The Milk Goat in California. 286. Commercial Fertilizers. 361. 287. Vinegar from Waste Fruits. 294. Bean Culture in California. 362. 298. Seedless Raisin Grapes. 363. 304. A Study of the Effects of Freezes on Citrus in California. 364. 310. Plum Pollination. 312. Mariout Barley. 366. 313. Pruning Young Deciduous Fruit Trees. 317. Selections of Stocks in Citrus Propa- 367. gation. 319. Caprifigs and Caprification. 368. 321. Commercial Production of Grape Syrup. 324. Storage of Perishable Fruit at Freezing 369. Temperatures. 370. 325. Rice Irrigation Measurements and Ex- 371. periments in Sacramento Valley, 1914-1919. 372. 328. Prune Growing in California. 331. Phylloxera-Resistant Stocks. 373. 334. Preliminary Volume Tables for Second- 374. Growth Redwood. 335. Cocoanut Meal as a Feed for Dairy Cows and Other Livestock. 375. 336. The Preparation of Nicotine Dust as an Insecticide. 376. 339. The Relative Cost of Making Logs from Small and Large Timber. 377. 340. Control of the Pocket Gopher in Cali- 378. fornia. 343. Cheese Pests and Their Control. 344. Cold Storage as an Aid to the Market- ing of Plums. Almond Pollination. The Control of Red Spiders in Decidu- ous Orchards. Pruning Young Olive Trees. A Study of Sidedraft and Tractor Hitches. Agriculture in Cut-over Redwood Lands. California State Dairy Cow Competition. Further Experiments in Plum Pollina- tion. Bovine Infectious Abortion. Results of Rice Experiments in 1922. A Self-mixing Dusting Machine for Applying Dry Insecticides and Fungicides. Black Measles, Water Berries, and Related Vine Troubles. Fruit Beverage Investigations. Gum Diseases of Citrus Trees in Cali- fornia. Preliminary Yield Tables for Second Growth Redwood. Dust and the Tractor Engine. The Pruning of Citrus Trees in Cali- fornia. Fungicidal Dusts for the Control of Bunt. Turkish Tobacco Culture, Curing and Marketing. Methods of Harvesting and Irrigation in Relation to Mouldy Walnuts. Bacterial Decomposition of Olives dur- ing Pickling. Comparison of Woods for Butter Boxes. Browning of Yellow Newtown Apples. The Relative Cost of Yarding Small and Large Timber. The Cost of Producing Market Milk and Butterfat on 246 California Dairies. Pear Pollination. A Survey of Orchard Practices in the Citrus Industry of Southern Cali- fornia. Results of Rice Experiments at Cor- tena, 1923. Sun-Drying and Dehydration of Wal- nuts. The Cold Storage of Pears. Stwdies on the Nutritional Disease of Poultry Caused by Vitamin A De- ficiency. CIRCULARS No. No. 70. Observations on the Status of Corn 155. Growing in California. 157. 87. Alfalfa. 160. 111. The Use of Lirae and Gypsum on Cali- 161. fornia Soils. 164. 113. Correspondence Courses in Agriculture. 165. 117. The Selection and Cost of a Small Pumping Plant. 166. 127. House Fumigation. 167. 129. The Control of Citrus Insects. 170. 136. Melilotvs indica as a Green-Manure Crop for California. 172. 144. Oidium or Powdery Mildew of the Vine. 173. 151. Feeding: and Management of Hogs. 152. Some Observations on the Bulk Hand- 174. ling of Grain in California. 178. 154. Irrigation Practice in Growing Small 179. Fruit in California. Bovine Tuberculosis. Control of the Pear Scab. Lettuce Growing in California. Potatoes in California. Small Fruit Culture in California. Fundamentals of Sugar Beet Culture under California Conditions. The County Farm Bureau. Feeding Stuffs of Minor Importance. Fertilizing California Soils for the 1918 Crop. Wheat Culture. The Construction of the Wood-Hoop Silo. Farm Drainage Methods. The Packing of Apples in California. Factors of Importance in Producing Milk of Low Bacterial Count. CIRCULARS — ( Continued ) No. 184. 190. 193. 198. 199. 202. 203. 205. 208. 209. 210. 212. 214. 215. 217. 219. 220. 228. 230. 231. 232. 233. 234. 235. 236. 237. 238. 239. 240. 241. 242. 243. 244. No. A Flock of Sheep on the Farm. 245. Agriculture Clubs in California. 247. A Study of Farm Labor in California. 248. Syrup from Sweet Sorghum. Onion Growing in California. 249. County Organizations for Rural Fire 250. Control. Peat as a Manure Substitute. 251. Blackleg. Summary of the Annual Reports of the Farm Advisors of California. 252. The Function of the Farm Bureau. 253. Suggestions to the Settler in California. 254. Salvaging Rain-Damaged Prunes. Seed Treatment for the Prevention of 255. Cereal Smuts. Feeding Dairy Cows in California. 256. Methods for Marketing Vegetables in 257. California. 258. The Present Status of Alkali. 259. Unfermented Fruit Juices. 260. Vineyard Irrigation in Arid Climates. Testing Milk, Cream, and Skim Milk 261. for Butterfat. 262. The Home Vineyard. 263. Harvesting and Handling California 264. Cherries for Eastern Shipment. Artificial Incubation. 265. Winter Injury to Young Walnut Trees 266. during 1921-22. Soil Analysis and Soil and Plant Inter- 267. relations. The Common Hawks and Owls of Cali- 268. fornia from the Standpoint of the Rancher. 269. Directions for the Tanning and Dress- 270. of Furs. 271. The Apricot in California. 272. Harvesting and Handling Apricots and Plums for Eastern Shipment. 273. Harvesting and Handling Pears for 275. Eastern Shipment. Harvesting and Handling Peaches for 276. Eastern Shipment. 277. Poultry Feeding. Marmalade Juice and Jelly Juice from 278. Citrus Fruits. Central Wire Bracing for Fruit Trees. Vine Pruning Systems. Colonization and Rural Development. Some Common Errors in Vine Pruning and Their Remedies. Replacing Missing Vines. Measurement of Irrigation Water on the Farm. Recommendations Concerning the Com- mon Diseases and Parasites of Poultry in California. Supports for Vines. Vineyard Plans. The Use of Artificial Light to Increase Winter Egg Production. Leguminous Plants as Organic Fertil- izer in California Agriculture. The Control of Wild Morning Glory. The Small-Seeded Horse Bean. Thinning Deciduous Fruits. Pear By-products. A Selected List of References Relating to Irrigation in California. Sewing Grain Sacks. Cabbage Growing in California. Tomato Production in California. Preliminary Essentials to Bovine Tuber- culosis Control. Plant Disease and Pest Control. Analyzing the Citrus Orchard by Means of Simple Tree Records. The Tendency of Tractors to Rise in Front; Causes and Remedies. Inexpensive Lavor-saving Poultry Ap- pliances. An Orchard Brush Burner. A Farm Septic Tank. Brooding Chicks Artificially. California Farm Tenancy and Methods of Leasing. Saving the Gophered Citrus Tree. Marketable California Decorative Greens. Home Canning. Head, Cane, and Cordon Pruning of Vines. Olive Pickling in Mediterranean Coun- tries. 20m-l,'25 The publications listed above may be had by addressing College of Agriculture, University of California, Berkeley, California.