UNIVERSITY OF CALIFORNIA AGRICULTURAL EXPERIMENT STATION ~~. . -~- ~- .__._... «■■«.- BENJ. IDE WHEELER, PRESIDENT COLLEGE OF AGR CULTURE " va " , ~ v - THOMAS FORSYTH HUNT, DEAN AND DIRECTOR BERKELEY h. e. van norman, vice-director and dean University Farm School CIRCULAR No. 197 April, 1918 SUGGESTIONS FOR INCREASING EGG PRODUCTION IN A TIME OF HIGH FEED PRICES YELLOW COLOR AS AN INDICATION OF EGG PRODUCTION By J. E. DOUGHERTY Increased egg production per hen per year should offset increased cost of feed and will decrease the cost of producing eggs. If feed should cost $3.00 per 100 lbs. and a laying hen should eat 72 lbs. of feed a year, it would take 77 eggs at an average price of 34 cents per dozen to pay her feed bill ; whereas with feed costing $2.00 per 100 lbs. and eggs selling at an average annual price of 27 cents per dozen (average price in 1916), only 64 eggs would be required to pay the yearly feed cost per hen. Data recently compiled indicate that the cost of feed represents approximately 70 per cent of the total expense per hen on a typical commercial poultry farm in California where no feed but green stuff is grown. On this basis only 92 eggs would be required to pay all expenses per hen if feed cost $2.00 per 100 lbs. and eggs netted the producer an average annual price of 27 cents. With feed costing $3.00 per 100 lbs. and eggs netting 34 cents, however, 109 eggs must be laid per hen per year to meet all expenses. It is evident that as feed prices rise, the average yearly egg yield of the flock must be increased materially if profitable returns are to continue. To secure this necessary increase in the production of the flock, immediate, continued, and rigid culling becomes imperative. Although trapnesting and scientific breeding are much more reliable and far-reaching in results than any method or methods of judging the productive abilities of fowls by means of physical char- acteristics, such as conformation, color of shanks, etc., which are either readily visible or can be determined by handling, the latter means have been shown by careful and rather extended tests to be fairly accurate and therefore of material aid both in culling low producers, which do not lay enough to be profitable, and in indicating the better producers. The percentage of errors is sufficiently small to make the intelligent use of such observational methods of judging of consider- able value in improving the average productiveness of both commercial and farm flocks of fowls used for the production of table eggs and from which the increased productive results, possible by a more ac- curate culling out of the poor layers on the basis of trapnest records would not pay for the added expense of such trapnesting. The culling out of the unprofitable layers will increase the average productiveness of the flock and lower the feed bill. The use of the better layers as breeding stock will aid in building up the laying qualities of the offspring, especially if the males out of high-producing females are mated to these better layers. CONSTITUTION Constitution, vitality, and health are fundamental requirements for heavy egg production. Fowls with weak constitutions cannot be expected to lay well. The constitutionally strong fowl should have a healthy, well- groomed appearance and clean-cut action. The head should be well proportioned, the beak short and blunt, eyes round, full and bright, comb of good normal size for the variety, well carried on head, of rather fine texture and with a rich red color. A long, thin beak, dull, snaky eye, pale, anaemic comb, and spindle-legged, gangling body do not exist on the constitutionally vigorous fowl. The kernel of the whole question of vigor is that the heavy laying fowl must be a well-built, hardy, active bird with sufficient stamina to withstand the strain of abundant egg production. YELLOW COLOR AS AN INDICATOR OF EGG-LAYING ABILITY In all yellow-legged varieties of fowls, the yellow coloring pigment in shanks, beak, ear-lobes and skin (especially noticeable at vent) appears to be drawn from the surface of the body as the number of eggs laid increases during each laying season. During the molting period in the fall, when fewest eggs are laid, the amount of yellow color pigment in shanks, etc., appears to increase and to coach a maximum at about the close of the molt; as egg-production increases during the following spring and summer those hens that lay the most eggs apparently draw more of the yellow pigment from the surface of the shanks, beak, etc., than do hens laying fewer eggs. Therefore, the comparative shades of yellowness of the shanks, beak, ear-lobes, and skin around vent in different fowls would seem to be a fairly accurate indication, in late spring, during summer, and until the beginning of the molt, of the relative productive abilities of the fowls in any one flock where they are all subject to the same feeding conditions. It is possible that the amounts fed (if any) of feed-stuffs, such as yellow corn, which contain considerable yellow pigment, might affect the rate of loss of yellow from shanks, beak, ear-lobes, and vent of birds in different flocks. For this reason it would seem advisable to make yellow- color comparisons only of birds in the same flock or known to be fed the same or similar rations. The following tables, which were compiled from observations made during the spring and summer of 1917 upon trapnested S. C. White Leghorns of different ages just as they would be found in a typical flock, show in detail how yellow-color observations compare w T ith actual trapnest records. The trapnest records are for the year ending August 31, 1917, which represents about the normal laying year from molt to molt. "While these tables indicate considerable inaccuracy in the color observations as compared with actual trapnest performance, especially as regards the medium and poor layers, the general trend of the results secured is such, as to warrant a reasonable measure of dependence on such observations in culling and grading for egg production. A study of table 1 would indicate that May is perhaps somewhat early and September a little late to secure best results from the use of yellow-color indications for culling. This is probably due to the fact that the fowls do not lay enough eggs before June to affect sufficiently the yellowness of their shanks, beak, and vent, and by September, many of the poorer layers whose production approaches the line of separation between the culls and the profit-earning hens, have already begun to slow down rapidly in their laying. The average production of the pale birds, however, is so uniformly high in the June, July, and September observations as to show that the better layers may be picked out with considerable accuracy during these months. 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EH r^ OQ ft lis r-H CO o xHH t> t~ CO Lf r-H CO t]H O t> xHH as O t>- LO CO ft o ^ CO OQ CM H OQ H 3 O r , CO CO xHH r-H LO L> CO LO # CM O CM o bo kO in CO LO CN o CD LO O CO CO CO w rt r*i : w rH -t^ CO LO CO r- CD CO Ol LO CO CM r* ^ (0 i—i r— i r-l i— 1 r-i r- i— 1 i— 1 r-H I— 1 rH rH o p a- o > £ < w 6 pi o 00 lO x* co a CM as lt LO HH HH £j2 - CO CO CO CO O O C- CO O rH P H pa w M 01 1—1 CO CM co o si o o .5 fe S fe ^ £ rU H a> nd o CD ^3 i £ • rH O rT-H r-H 13 Ph ■3 Ph t- t- l> b- ■ W T3 r-H T— 1 T— 1 r-i CO © > \ \ \ Q 5S No. of Hens Average Eggs per year 1,273 157.7 139 129.5 TABLE 2 Summary of all Shank Color Observations made during Summer of 1917 (Taken from Table 1) Shade of Yellow No. of Hens Average Eggs per year Pale 1,161 156.1 Medium 282 139 Yellow 162 123.8 TABLE 3 Summary op all Vent Color Observations made in Summer of 1917 (Taken from Table 1) Shade of Yellow Pale Medium Yellow 109 129.1 TABLE 4 Summary of all Beak Color Observations made in Summer of 1917 (Taken from Table 1) Shade of Yellow No. of Hens Average Eggs per year Pale 761 160 Medium 200 145.5 Yellow 190 126.3 The data presented in tables 2 to 6 indicate that shank color and beak color are somewhat more reliable to use for summer culling and grading than vent color. This is perhaps due to the fact that the yellow pigment leaves and returns to the vent more rapidly than it does to shanks and beak. The Connecticut Agricultural Experiment Station found that the average length of time required for a bird's vent to become yellow after it had stopped laying was fourteen days, whereas for shanks and beak a much longer time was necessary. 1 TABLE 5 Summary of all Shank and Vent Color Observations made in Summer of 1917 (Taken from Table 1) Shade of Yellow No. of Hens Average Eggs Pale 1,232 158.8 Medium 76 142.8 Yellow 92 138.6 i A Further Investigation of Selection of High-producing Tiers. D. E. War- ner, Journal of American Ass 'n of Instructors and Investigators in Poultry Husbandry, Vol. 3, No. 1 (Oct., 1916), p. 45. TABLE 6 Summary of all Shank and Beak Color Observations made in Summer of 1917 (Taken from Table 1 ) Shade of Yellow No. of Hens Average Eggs per year Pale 1,051 159.8 Medium 135 133.4 Yellow 129 124.6 TABLE 7 Summary of all Color Observations made on Shanks, Beak, and Vent during Summer of 1917 Shade of Yellow No. of Hens Average Eggs per year Pale 5,848 158.2 Medium 859 137.0 Yellow 690 128.4 Table 7 gives the summarized results secured by combining all observations included in tables 2 to 6. The average results thus secured further check the quite consistent trend of the previous tables in pointing out the utilitarian value of differences in the brightness of yellow color in shanks, beak, and vent of yellow-legged breeds of fowls as an aid in selecting high layers and in culling out poor layers. Although the investigation reported here was carried on with S. C. White Leghorns, similar work done at other stations with Plymouth Rocks, Wyandottes, and Rhode Island Reds indicates that the results of this investigation will apply to any distinctly yellow- legged breed. STTMMAEY Increased egg production will offset increased cost of feed. Health and vigor are fundamental to high egg production. A more efficient culling of the low-producing hens and the use of the better layers mated to males out of superior layers for breeding will build up the average productiveness of the flock. The yellowness of vent, beak, and shanks of yellow-legged breeds is a fairly accurate guide to the laying abilities of different fowls in the same flock. The amount of yellow coloring materials contained in the ration fed may affect the rate of change from yellow to paleness, and vice versa, in different flocks or even in different pens of fowls. Yellow-color indications would seem to be of the most value during June, July, and August. Such indications should apply to all dis- tinctly yellow-legged breeds. BIBLIOGRAPHY Correlation between egg-laying activity and yellow pigment in the domestic fowl. A. F. Blakeslee and D. E. Warner. Science, N.S. 41 (1915), No. 1055, pp. 432-34. Method of selecting the high-producing hens. B. O. Kent. Cornell Country- man, 12 (1915), No. 6, pp. 481-84. External characters as indications of egg production. B. O. Kent. Journal of American Assoc, of Instructors and Investigators in Poultry Flusb., Vol. 2, No. 8 (May, 1916), pp. 63-64. A further investigation of selection of high-producing hens. D. E. Warner. Journal of American Assoc, of Instructors and Investigators in Poultry Husb., Vol. 3, No. 1 (Oct., 1916), p. 4. The histological basis of shank color in the domestic fowl. H. R. Barrows. Me. Agr. Exp. Sta. Bull. 232, pp. 237-52. Correlation between egg-laying and yellow pigment in the domestic fowl. A. F. Blakeslee and D. E. Warner. Amer. Nat., 49 (1915), pp. 360-68. Sudan III deposited in the egg and transmitted to the chick. S. II. Gage and S. P. Gage. Science, N.S. 28 (1908), p. 494. The behavior of fat-soluble dyes and stained fat in the animal organism. L. B. Mendel and A. L. Daniels. Jour. Biol. Chem., 13 (1912), p. 71-95. Xanthophyll, the principal natural yellow pigment of the egg yolk, body fat, and blood serum of the hen. The physiological relation of the pigment to the xanthophyll of the plant. L. S. Palmer. Jour. Biol. Chem., 23 (1915), pp. 261-79. Studies with Sudan III in metabolism and inheritance. O. Riddle. Jour. Exp. Zool., 8 (1910), pp. 163-84. Feeding color — an aid in studying physiological development. C. A. Rogers. Rep. Proc. Inst. Asst. Inst, and Invest, in Poul. Husb., 1 (1912), pp. 77-81, pi. 1. Prolific layers and how to select them. D. E. Warner. Field, 26 (1916), pp. 24-25. The correlation between body pigmentation and egg production i n the domestic fowl. J. Arthur Harris, A. F. Blakeslee, and D. E. Warner. Genetics, Vol. 2, No. 1 (Jan., 1917). The correlation between egg production during various periods of the year in the domestic fowl. J. A. Harris and A. F. Blakeslee. Genetics, Vol. 3, No. 1 (Jan., 1918), p. 27. STATION PUBLICATIONS AVAILABLE FOR FREE DISTRIBUTION 1897. Resistant Vines, their Selection, Adaptation, and Grafting. Appendix to Viticultural Report for 1896. 1902. Report of the Agricultural Experiment Station for 1898-1901. 1903. Report of the Agricultural Experiment Station for 1901-03. 1904. Twenty-second Report of the Agricultural Experiment Station for 1903-04. 1914. Report of the College of Agriculture and the Agricultural Experiment Station. 1915. Report of the College of Agriculture and the Agricultural Experiment Station. 1916. Report of the College of Agriculture and the Agricultural Experiment Station. 1917. Report of the College of Agriculture and the Agricultural Experiment Station. BULLETINS No. No. 230. 241. 242. 246. 248. 250. 251. 252. 253. 255. 257. 261. 262. 263. 264. 265. 266. 267. 268. 270. No. 113. 114. 115. 121. 124. 126. 127. 128. 129. 131. 133. 135. 136. 137. 138. 139. 140. 142. 143. 144. 147. 148. 150. 151. 152. 153. 154. 155. 156. 157. 158. Enological Investigations. 271. Vine Pruning in California, Part I. 272. Humus in California Soils. 273. Vine Pruning in California, Part II. The Economic Value of Pacific Coast 274. Kelps. The Loquat. 275. Utilization of the Nitrogen and Organic Matter in Septic and Imhoff Tank 276. Sludges. 277. Deterioration of Lumber. 278. Irrigation and Soil Conditions in the 279. Sierra Nevada Foothills, California. 280. The Citricola Scale. New Dosage Tables. 282. Melaxuma of the Walnut, "Juglans regia." 283. Citrus Diseases of Florida and Cuba 284. Compared with Those of California. 285. Size Grades for Ripe Olives. 286. The Calibration of the Leakage Meter. 288. Cottony Rot of Lemons in California. A Spotting of Citrus Fruits Due to the 290. Action of Oil Liberated from the Rind. Experiments with Stocks for Citrus. 291. Growing and Grafting Olive Seedlings. A Comparison of Annual Cropping, Bi- ennial Cropping, and Green Manures on the Yield of Wheat. CIRCULARS No. Correspondence Courses in Agriculture. 160. Increasing the Duty of Water. 161. Grafting Vinifera Vineyards. 162. Some Things the Prospective Settler Should Know. 164. Alfalfa Silage for Fattening Steers. 165. Spraying for the Grape Leaf Hopper. House Fumigation. 166. Insecticide Formulas. 167. The Control of Citrus Insects. 168. STjraviner for Control of Walnut Aphis. County Farm Adviser. 169. Official Tests of Dairy Cows. 170. Melilotus Indica. Wood Decay in Orchard Trees. 172. The Silo in California Agriculture. 174. The Generation of Hydrocyanic Acid 175. Gas in Fumigation by Portable Ma- chines. 176. The Practical Application of Improved Methods of Fermentation in Califor- 177. nia Wineries during 1913 and 1914. 181. Practical and Inexpensive Poultry Ap- pliances. 182. Control of Grasshoppers in Imperial Valley. 183. Oidinm or Powderv Mildew of the Vine. 184. Tomato Growing in California. 185. "Lungworms." Round Worms in Poultry. 186. Feedinc and Management of Hoes. 187. Some Observations on the Bulk Hand- 188. ling of Grain in California. 19°. Announcement of the California State 191. Dairv Cow Competition. 1916-18. 192. Irrigation Practice in Growing Small 193. Fruits in California. 196. Bovine Tuberculosis. 197. How to Operate an Incubator. Control of the Pear Scab. 198. Home and Farm Canning. Feeding Dairy Calves in California. Commercial Fertilizers. Preliminary Report on Kearney Vine- yard Experimental Drain. The Common Honey Bee as an Agent in Prune Pollination. The Cultivation of Belladonna in Cali- fornia. The Pomegranate. Sudan Grass. Grain Sorghums. Irrigation of Rice in California. Irrigation of Alfalfa in the Sacramento Valley. Trials with California Silage Crops for Dairy Cows. The Olive Insects of California. Irrigation of Alfalfa in Imperial Valley. The Milch Goat in California. Commercial Fertilizers. Potash from Tule and the Fertilizer Value of Certain Marsh Plants. The June Drop of Washington Navel Oranges. The Common Honey Bee as an Agent in Prune Pollination. (2nd report.) Lettuce Growing in California. Potatoes in California. White Diarrhoea and Coccidiosis of Chicks. Small Fruit Culture in California. Fundamentals of Sugar Beets under California Conditions. The County Farm Bureau. Feeding Stuffs of Minor Importance. Spraying for the Control of Wild Morn- ing-Glory within the Fog Belt. The 1918 Grain Crop. Fertilizing California Soils for the 1918 Crop. Wheat Culture. Farm Drainage Methods. Progress Report on the Marketing and Distribution of Milk. Hog Cholera Prevention and the Serum Treatment. Grain Sorghums. Control of the California Ground Squirrel. Extending the Area of Irrigated Wheat in California for 1918. Infectious Abortion in Cows. A Flock of Sheep on the Farm. Beekeeoing for the Fruit-Grower and Small Rancher, or Amateur. Poultry on the Farm. Utilizing the Sorghums. Lambing Sheds. Agriculture Clubs in California. Pruning: the Seedless Grapes. Cotton in the San Joaquin Valley. A Study of Farm Labor in California. Dairy Calves for Veal. Suggestions for Increasing Egg Pro- duction in a Time of High-Feed Prices. Syrup from Sweet Sorghum.