1.Wolford, J. H. & Zindel, H. C. (1969). Special floor reduces cracked eggs. Michigan State University, Information Services Release, November.Google Scholar

2.Wolford, J. H. and Zindel, H. C. (1970). Oyster shell consumption of caged turkey breeder hens. Poultry Sci. 49: In Press.Google Scholar

3.Tyler, C., (1961). Shell strength: Its measurement and relationship to other factors. Br. Poultry Sci. 2: 3–19.Google Scholar

4.Hammerle, J. R., (1969). An engineering appraisal of egg shell strength evaluation techniques. Poultry Sci. 48: 1708–1717.CrossRefGoogle Scholar

5.Anderson, G. B., Carter, T. C. and Jones, R. M. (1970). Some factors affecting the incidence of cracks in hen's egg shells. Br. Poultry Sci. 11: 103–116.Google Scholar

6.Bowman, J. C. and Challender, N. I. (1963). Egg shell strength. A comparison of two laboratory tests and field tests. Br. Poultry Sci. 4: 103–116.Google Scholar

7.Brant, A. W., Otte, A. W. and Chin, G. (1953). A survey of egg quality at two egg laying tests. U.S.D.A. Tech. Bull. No. 1066.Google Scholar

8.Coles, R., (1938). A preliminary investigation into the occurrence and causes of hair cracks in hen egg shells. II. J. Minist. Agric. Fish. 44: 1204–1213.Google Scholar

9.Tyler, C. and Geake, F. H. (1958). Studies on egg shells. IX. The influence of individuality and season on certain characteristics of egg shells from pullets. J. Sci. Fd. Agric. 9: 473–483.CrossRefGoogle Scholar

10.Tyler, C. and Geake, F. H. (1960). Studies on egg shells. XIII. Influence of individuality breed, season and age on certain characteristics of egg shells. J. Sci. Fd. Agric. 11: 535–547.Google Scholar

11.McNally, E. H., (1965). The relationship of egg shell weight to cracked eggs. Poultry Sci. 44: 1513–1518.Google Scholar

12.Sauter, E. A. and Peterson, C. F. (1969). Shell quality influence on egg breakage during processing. Poultry Sci. 48: 1867 (abst).Google Scholar

13.Wells, R. G., (1967). Egg shell strength. I. The relationship between egg breakage in the field and certain laboratory assessments of shell strength. Br. Poultry Sci. 8: 131–139.Google Scholar

14.Arscott, G. H., Rachapaetayakom, P., Bernier, P. E. and Adams, F. W. (1962). Influence of ascorbic acid, calcium and phosphorus on specific gravity of eggs. Poultry Sci. 41: 485–488.Google Scholar

15.Balloun, S. L. and Marion, W. W. (1962). Relative efficacy of calcium lactate and calcium carbonate in promoting sound egg shells. Poultry Sci. 41: 1625 (abst).Google Scholar

16.Berg, L. R., Bearse, G. E. and Merrill, L. H. (1964). The calcium and phosphorus requirement of White Leghorn pullets from 821 weeks. Poultry Sci. 43: 885–896.Google Scholar

17.Bragg, D. B. and Stephenson, E. L. (1964). The use of radioactive tracer in studying the effect of different levels of calcium and vitamin D₃ and season on egg shell quality and performance of White Leghorn hens. Poultry Sci. 43: 1304–1305 (abst).Google Scholar

18.Buckner, G. D. and Martin, I. H. (1920). Effect of calcium on the composition of the eggs of laying hens. J. Biol. Chem. 41: 195–203.CrossRefGoogle Scholar

19.Collier, P., (1892). Oyster shells as food for laying hens. N. Y. State Agr. Expt. Sta. Bul. 38: 3–10.Google Scholar

20.Cox, A. C. and Balloun, S. L. (1968). Lack of effect of sodium bicarbonate on shell characteristics. Poultry Sci. 47: 1370–1371.Google Scholar

21.Cox, A. C. and Balloun, S. L. (1969). Manganese requirements of laying hens as related to diet calcium. Poultry Sci. 48: 745–747.CrossRefGoogle ScholarPubMed

22.Deobald, H. J., Lease, E. J. and Hart, E. B. (1936). Studies on the calcium metabolism of laying hens. Poultry Sci. 15: 179–185.CrossRefGoogle Scholar

23.Evans, R. J., Carver, J. S., Brant, A. W. (1944). The influence of dietary factors on egg shell quality. II. Calcium. Poultry Sci. 23: 36–42.CrossRefGoogle Scholar

24.Gerry, R. W. and Bird, F. H. (1967). The performance of red x rock sex links as affected by calcium levels in their growing and laying diets. Poultry Sci. 46: 1246 (abst).Google Scholar

25.Harms, R. H. and Waldroup, P. W. (1961). The influence of dietary calcium level and supplementary ascorbic acid and/or dienestrol diacetate upon performance of egg production type hens. Poultry Sci. 40: 1345–1348.Google Scholar

26.Hendricks, W. A., Lee, A. R. and Godfrey, A. B. (1931). The effects of cod liver oil and ultra violet irradiation as Influenced by oyster shell in the diet of confined laying hens. J. Agric. Res. 43: 517–523.Google Scholar

27.Hertelendy, F. and Taylor, T. G. (1961). Changes in blood calcium associated with egg shell calcification in the domestic fowl. 1. Changes in the total calcium. Poultry Sci. 40: 108–114.Google Scholar

28.Heywang, B. W., Reid, B. L. and Kemmerer, A. R. (1964). Effect of sodium ascorbate on egg shell thickness during hot weather. Poultry Sci. 43: 625–629.Google Scholar

29.Hinners, S. W., Gholson, J. T. and Ritchason, M. L. (1963). The effect of varying levels of calcium and phosphorus on egg production and egg quality. Poultry Sci. 42: 1277 (abst).Google Scholar

30.Hunt, J. R. and Aitken, J. R. (1962). Studies on the influence of ascorbic acid on shell quality. Poultry Sci. 41: 219–226.Google Scholar

31.Hunt, J. R., Aitken, J. R. and Hunsaker, W. G. (1961). Influence of dietary tallow on the utilization of calcium by the laying hen. Poultry Sci. 40: 1193–1197.Google Scholar

32.Hurwitz, S. and Bar, A. (1966). Calcium depletion and repletion in laying hens. I. Effect on calcium in various bone segments, in egg shells and in blood plasma and on calcium balance. Poultry Sci. 45: 345–352.Google Scholar

33.Hurwitz, S., Bar, A. and Bornstein, S. (1967). The effect of lactose on egg production and shell quality. Poultry Sci. 46: 1024–1025.Google Scholar

34.Hurwitz, S. and Bornstein, S. (1963). The effect of calcium and phosphorus in the diet of laying hens on egg production and shell quality. Israel S. Agric. Res. 13: 147–154.Google Scholar

35.Hurwitz, S. and Griminger, P. (1962). Egg production and shell quality in temperature and light controlled versus uncontrolled environment. Poultry Sci. 41: 499–508.CrossRefGoogle Scholar

36.Jenson, L. S., Saxena, H. C. and McGinnis, J. (1963). Nautritionl investigations with turkey hens. 4. Quantitative requirement for calcium. Poultry Sci. 42: 604–607.Google Scholar

37.Kienholz, E. W., McPherron, T. A. and Orme, L. E. (1964). The effect of some dietary supplements upon caged hen performance while heat stressed. Poultry Sci. 43: 1334 (abst).Google Scholar

38.Mehring, A. L. Jr., (1964). A comparison of three methods of supplying calcium in the diet of laying chickens. Poultry Sci. 43: 976–981.Google Scholar

39.Mehring, A. J. Jr. and Titus, H. W. (1964). The effects of low levels of calcium in the diet of laying chickens. Poultry Sci. 43: 1405–1414.CrossRefGoogle Scholar

40.Mueller, W. J., (1961). The effect of constant and fluctuating environmental temperatures on the biological performance of laying hens. Poultry Sci. 40: 1562–1571.Google Scholar

41.Nevalainen, T. J., (1969). The effect of calcium–deficient diet on the reproductive organs of the hen (Gallus domesticus). Poultry Sci. 48 653–659.Google Scholar

42.Pepper, W. F., Summers, J. D. and McConachie, J. D. (1968). The effect of high levels of calcium, fish products and sodium bicarbonate on egg shell quality. Poultry Sci. 47: 224–229.Google Scholar

43.Pepper, W. F., Winget, C. M. and Slinger, S. J. (1961). Influence of calcium and ascorbic acid on egg quality. Poultry Sci. 40: 657–662.Google Scholar

44.Petersen, C. F., Lumijarvi, D. H., Sauter, E. A. and Lampman, C. E. (1960). Influence of calcium, zinc and strain differences upon egg shell quality of White Leghorn pullets. Poultry Sci. 39 1283–1284 (abst).Google Scholar

45.Petersen, C. F, Sauter, E. A., Lampman, C. E. and Wiese, A. C. (1961). Influence of uniform versus fluctuating daily temperature upon egg shell quality. Poultry Sci. 40: (abst).Google Scholar

46.Petersen, C. F., Sauter, E. A., Wiese, A. C. and Lumijarvi, D. J. (1959). Influence of calcium and other nutrients upon shell quality of high producing white Leghorn hens. Poultry Sci. 38: 1236 (abst).Google Scholar

47.Potter, L. M., Leighton, A. T. Jr. and Chu, A. B. (1966). Calcium, phosphorus and nopgro as variables in diets of breeder turkeys. Poultry Sci. 45: 1117 (abst).Google Scholar

48.Querner, H. and Tuller, R. (1968). The use of fat in laying rations with free choice feeding of oyster shell. World's Poultry Sci. J. 24: 385 (abst).Google Scholar

49.Reddy, C. V. and Sanford, P. E. (1963). Influence of dietary calcium in laying rations on shell quality and interior quality of eggs. Poultry Sci. 42: 1302 (abst).Google Scholar

50.Reddy, C. V., Sanford, P. E. and Clegg, R. E. (1968). Influence of calcium in laying rations nshell o quality and interior of eggs. Poultry Sci. 47: 1077–1083.Google Scholar

51.Robertson, R. H., Francis, D. W. and Finkner, M. D. (1964). Egg quality factors as affected by calcium, ascorbic acid and reserpne levels of the ration. Poultry Sci. 43: 1356–1357. (abst).Google Scholar

52.Roberson, R. H. and Francis, D. W. (1965). Egg quality factors as affected by calcium, ascorbic acid and reserpine levels of the ration. Poultry Sci. 44: 1409–1410.(abst).Google Scholar

53.Rowland, L. O. Jr., Harms, R. H., Wilson, H. R., Ahmed, E. M., Waldroup, P. W. and Fry, J. L. (1968). Influence of various dietary factors on bone fragility of caged layers. Poultry Sci. 47: 507–511.Google Scholar

54.Sanford, P. E. and Alder, R. L. (1869). Effects of increasing levels of phosphorus with increasing levels of calcium. Poultry Sci. 48: 1866 (abst).Google Scholar

55.Staller, B. L. and Sunde, M. L. (1964). Magnesium carbonate and dolomitic limestone in practical laying rations. Poultry Sci. 43: 1365 (abst).Google Scholar

56.Sullivan, T. W. and Kingan, J. R. (1962). Effect of dietary calcium level. calcium lactate and ascorbic acid on the egg production of S. C. White Leghorn hens. Poultry Sci. 41: 159–1602.Google Scholar

57.Taylor, T. G., Morris, T. R. and Hertelendy, F. (1962). The effect of pituitary hormones on ovulation in calcium deficient pullets. Vet. Rec. 74: 123–125.Google Scholar

58.Walsh, B. M., Kingan, J. R. and Sullivan, T. W. (1963). Studies on the interrelationship of vitamin D³ and protein with calcium in the diet of laying hens. Poultry Sci. 42: 1316. (abst).Google Scholar

59.Walter, E. D. and Aitken, J. R. (1961). The value of soluble and insoluble grit in all–mash and mash–grain rations for caged layers. Poultry Sci. 40: 904–909.CrossRefGoogle Scholar

60.Yates, J. D. and Rutherford, H. O. (1967). The effects of mineral content of ration on the incidence of hen bones broken during processing. Poultry Sci. 46: 1340 (abst).Google Scholar

61.Anderson, D. L. (1966). Pre–laying nutritional and environmental factors in the performance of the adult fowl. 1. Adaptation of litter–reared Single Comb White Leghorn females to different calcium and phosphorus jevels. Poultry Sci. 45: 67–75.CrossRefGoogle Scholar

62.Berg, L. R., Bearse, G. E. and Miller, V. L. (1944). A comparison of two methods of supplying calcium to laying pullets. Wash. Agr. Exp. Sta. Bull. No. 458.Google Scholar

63.Berg, L. R., Bearse, G. E. and Miller, L. V. (1947). The effect of the pre–laying level of calcium on the performance of White Leghorn pullets. Poultry Sci. 26: 463–468.Google Scholar

64.Gutowska, M. S. and Parkhurst, R. T. (1942). Studies in mineral nutrition of laying hens. 11. Excess of calcium in the diet. Poultry Sci. 21: 321–328.CrossRefGoogle Scholar

65.Harbaugh, D. D. and Sanford, P. E. (1969). Effects of zinc–methionine supplement. calcium and phosphorus levels on flock performance, egg size and shell quality. Poultry Sci. 48: 1816.Google Scholar

66.Hull, S. J. and Scott, M. L. (1969). A study to determine the optimum dietary calcium level for laying hens. Poultry Sci. 48: 1823 (abst).Google Scholar

67.Petersen, C. F., Sauter, E. A., Lampman, C. E. and Wiese, A. C. (1963). Comparison of controlled and free–choice feeding of calcium upon calcium intake and egg shell qualit. Poultry Sci. 42: 1299 (abst).Google Scholar

68.Salman, A. J., Ali, M. S. and McGinnis, J. (1969). Effect of level and source of phosphorus and different calcium levels on productivity and phosphorus utilization by laying hens. Poultry Sci. 48: 1004–1009.CrossRefGoogle ScholarPubMed

69.Sullivan, T. W., Adams, J. L., Owings, W. J. and Goodwin, T. L. (1963). Effect of age, strain, dietary calcium level and antibiotic regimen on the egg production and quality, factors. Poultry Sci. 42. 1311–1312. (abst).Google Scholar

70.Yates, J. D. and Schaible, P. I. 1960. Zinc supplementation of hen rations containing different Ievels of calcium. Poultry Sci. 39: 1307–1308. (abst).Google Scholar

71.Atkinson, R. L., Bradley, J. W., Couch, J. R. and Quisenberry, J. H. (1967). The calcium requirement of breeder turkeys. Poultry Sci. 46: 207–214.Google Scholar

72.Balloun, S. L. and Miller, D. L. (1964). Calcium requirements of turkey breeder hens. Poultry Sci. 43: 378–381.Google Scholar

73.Buckner, G. D., Martin, J. H. and Peter, A. M. (1928). The relatite utilization of different calcium compounds by hens in the production of eggs. J. Agr. Res. 36: 263–268.Google Scholar

74.Griminger, P. and Lutz, H. (1964). Observations on the voluntary intake of calcium supplements by the laying hen. Poultry Sci. 43: 710–716.Google Scholar

75.Gutteridge, H. S. and Pratt, J. M. (1945). Egg shells its a source of calcium for laying birds. Poultry Sci. 24: 89–90.Google Scholar

76.Heywang, B. W., (1946). Sources of calcium for laying chickens during hot weather. Poultr Sci. 25: 215–222.Google Scholar

77.Heywang, B. W. and Lowe, R. W. (1962). Egg shell quality during hot weather with calcium gluconate in the diet. Poultry Sci. 41: 1213–1215.Google Scholar

78.Heuser, G. F. and Norris, L. C. (1946). Oyster shells, calcite grit, ground limestone and granitc grit in rations for hens. Poultry Sci. 25: 173–179.Google Scholar

79.Lillie, R. J. and Thompson, W. C. (1947). A comparison of two calcites as calcium supplements to the feed of laying hens. Poultry Sci. 26: 223–228.CrossRefGoogle Scholar

80.Massengale, O. N. and Platt, C. S. (1929). Effect of calcium from different sources on the growth and egg production of poultry. Poultry Sci. 9: 240–246.Google Scholar

81.Roberson, R. H. and Francis, D. W. (1966). Egg quality factors as affected by ascorhac acid. calcium lactate and magnesium sulfate additions to the ration. Poultry Sci. 45: 1119 (abst).Google Scholar

82.Scholes, J. C., (1945). Feeding of coquina shell to laying hens. Poultry Sci. 24: 53–5.Google Scholar

83. Wilkinson, W. S., (1961). Effects of Ievel and source of calcium and the addition of antibiotics. vitamin C. zinc and reserpine in laying hen rations. Poultry Sci. 40: 1470 (abst).Google Scholar

84.Halpin, J. G., (1927). Importance of minerals in rations for laying hens and growing chicks. World's Poultry Cong. Ottawa, 228–231.Google Scholar

85.Balloun, S. L. and Phillips, R. E. (1956), Grit feedinq affects growth and feed utilization of chicks and egg production of laying hens. Poultry Sci. 35: 566–569.CrossRefGoogle Scholar

86.Fuller, H. L., (1958). The value of granite and marble grit for growing chickens and laying hens fed all–mash v mash and grain diet. Poultry Sci. 37: 1136–1143.Google Scholar

87.Salverson, C. A. and Little, T. M. (1966). Grit feeding of caged layers. Poultry Sci. 45: 1120 (abst).Google Scholar

88.Macintyre, T. M. and Jenkins, M. H. (1952). Clam shells, limestone and oyster shells as sources of calcium in rations of laying hens. Sci. Agric. 32: 564–650.Google Scholar

89.Portsmouth, J. I., (1965). Egg shell quality as infuenced by the time of introduction on the laying ration. World's Poultry Sci. J. 21: 179–180.(abst).Google Scholar

90.Howes, J. R., (1967). Calcium for replacement pullets and layers. Poultry Sci. 46: 1272 (abst).Google Scholar

91.Portsmouth, J. I. (1966). Further investigation of the effect of introducing the laying ration on egg shell quality. World's Poultry Sci. J. 22: 158 (abst).Google Scholar

92.Crowley, A., Kurnick, A. A. and Reid, B. L. (1963). Dietary phosphorus for laying hens. Poultry Sci. 42: 758–765.Google Scholar

93.Crowley, T. A., Pasvogel, M. W., Kemmerer, A. R., Vavich, M. G. and Kurnick, A. A. (1961). Effects of soft phosphate and dicalcium phosphate on reproductive performance and egg quality. Poultry Sci. 40: 74–80.Google Scholar

94.Evans, R. J., Carver, J. S. and Brant, A. W. (1944). The influence of dietary factors on egg shell quality. I. Phosphorus. Poultry Sci. 23: 9–15.Google Scholar

95.Gillis, M. B., Norris, L. C. and Heuser, G. F. (1953). Phosphorus metabolism and requirements of hens. Poultry Sci. 32: 977–984.Google Scholar

96.Singsen, E. P., Spandorf, A. H., Matterson, L. D., Seratin, J. A. and Tlustohowicz, J. J., (1962). Phosphorus in the nutrition of the adult hen. 1. Minimum phosphorus requirements. Poultry Sci. 41: 1401–1414.CrossRefGoogle Scholar

97.Walter, E. D. and Aitken, J. R. (1962). Phosphorus requirements of laying hens confined to cages. Poultry Sci. 41: 386–390.CrossRefGoogle Scholar

98.Baruah, J. N., Davies, R. E., Reid, B. L. and Couch, J. R. (1960). Utilization of phosphorus from defluorinated and colloidal phosphate by chicks and laying hens. Poultry Sci. 39: 843–849.Google Scholar

99.Ahmad, M. M. and Moreng, R. E. (1964). Response to dietary ascorbic acid under high temperature environments as influenced by age and breed. Poultry Sci. 43: 1298–1299. (abst).Google Scholar

100.Herrick, R. B. and Nockels, C. F. (1969). Effect of a high level of dietary ascorbicacid on egg quality. Poultry Sci. 48: 1518–1519.Google Scholar

101.Heywang, B. W. and Kemmerer, A. R. (1955). The effect of procaine penicillin and ascorbic acid on egg weight and shell thickness during hot weather. Poultry Sci. 34: 1032–1036.Google Scholar

102.Perek, M. and Kendler, J. (1962). Vitamin Csupplementation to hen's diets in a hot climate. Poultry Sci. 41: 677–678.Google Scholar

103.Thornton, P. A., and Moreng, R. E. (1958). The effect of ascorbic acid on egg quality factors. Poultry Sci. 37: 692–698.Google Scholar

104.Thornton, P. A., (1960). The influence of dietary protein level on the response of S. C. White Leghorns to supplementary ascorbic acid. Poultry Sci. 39: 1072–1076.Google Scholar

105.Thornton, P. A., (1959). Additional studies concerning the use of ascorbic acid in the diet of the laying hen. Poultry Sci. 38: 1254–1255. (abst).Google Scholar

106.Thornton, P. A., (1960). The effect of dietary calcium level on the efficiency of ascorbic acid in maintenance of egg shell thickness at increased environmental temperatures. Poultry Sci. 39: 1401–1406.Google Scholar

107.Thornton, P. A. and Moreng, R. E. (1959). Further evidence on the value of ascorbic acid for maintenance of shell quality in warm environmental temperature. Poultry Sci. 38: 594–599.Google Scholar

108.Berg, L. R., Bearse, G. E. and Miller, V. L. (1951). Thc effect of periodically increasing the level of calcium and/or vitamin D on the performance of laying pullets. Poultry Sci. 30: 799–804.Google Scholar

109.Couch, J. R., James, L. E., and Sherwood, R. M. (1947). The effect of different levels of manganese and different amounts of vitamin D in the diet of hens and of pullets. Poultry Sci. 26: 30–37.Google Scholar

110.Evans, R. J., Carver, J. S. and Wilhelm, L. A. (1944). The influence of dietary factors on egg shell quality. III. Vitamin D. Poultry Sci. 23: 234–238.Google Scholar

111.Titus, H. W. and Nestler, R. B. (1935). Effect of vitamin D on production and some properties of eggs. Poultry Sci. 14: 90–98.Google Scholar

112.Wilhelm, L. A., Robertson, E. I. and Rhian, M. (1941). The effect of the level of vitamin D on egg production and hatchabiltiy of bronze tuFkey hens. Poultry Sci. 20: 565–569.Google Scholar

113.Taylor, L. W. and Martin, J. H. (1928–1929). Factors influencing thickness of eggshell. Poultry Sci. 8: 39–44.CrossRefGoogle Scholar

114.Turk, J. L. and McGinnis, J. (1964). Influence. of vitamin D on various aspects of the reproductive process in mature hens. Poultry Sci. 43: 539–546.Google Scholar

115.Hart, E. B., Steenbock, H., Lepkovsky, S., Kletzien, S. W. F., Halpin, J. G., and Johnson, O. N. (1925). The nutritional requirement of the chicken. V. The influence of ultra-violet light on the production, hatchabiltiy and fertility of the egg. J. Biol. Chem. 65: 579–595.Google Scholar

116.Hughes, J. S. and Payne, L. F. (1924). Influence of ultra–violet light on young laying hens. Science 60: 549–550.Google Scholar

117.Turk, J. L. and McGumnis, J. (1964). Effects of a vitamin D deficiency in mature S. C. W. Leghorn hens. Poultry Sci. 43: 1372 (abst).Google Scholar

118.Donovan, G. A., Henderson, D. C. and Luneau, R. N. (1961). Influence of high level vitamin A feeding on laying hens. Poultry Scr. 50 1395–1396 (abst).Google Scholar

119.Berg, L. R. and Bearse, G. E. (1956). The effect of water–soluble vitamins and energy level of the diet on the performance of laymg pullets. Poultry Sci. 35: 945–951.Google Scholar

120.Berg, L. R., Bearse, G. E., McGinnis, J. and McClary, C. F. (1952). Vitamin B₁₂ in the nutrtion of the laying hen. Poultry Sei. 31: 488–496.Google Scholar

121.Combs, G. F. and Helbacka, N. V. (1960). Studies with laying hens. 1. Effect of dietary fat, protein levels and other variables in practical rations. Poultry Sci. 39: 271–279.CrossRefGoogle Scholar

122.Daghir, N. J. and Balloun, S. L. (1959). Egg production, egg quality and serum cholesterol levels as influenced by animal and vegetable fats. Poultry Sci. 38: 1197 (abst).Google Scholar

123.Coles, R., (1938). A preliminary invatiation into occurrence and causes of hair cracks in hen egg shells. J. Min. of Agric. Fish. 44: 1088–1094.Google Scholar

124.Palafox, A. L. and Rosenberg, M. M. (1951). Dried cow manure as a supplement in a layer and breeder ration. Poultry Sci. 30: 136–142.Google Scholar

125.Flegal, C. J. and Zindel, H. C. (1969). The utilization of dehydrated poultry waste by laying hens. Poultry Sci. 48: 1807 (abst).Google Scholar

126.Johnson, E. A., (1936). Effect of supplementary iodine on egg size and quality. Poultry Sci. 15: 355–361.Google Scholar

127.Mehring, A. L. Jr. and Johnson, D. Jr., (1965). Magnesium in limestone for laying chickens. Poultry Sci. 44: 853–860.Google Scholar

128.Sanford, P. E., (1966). Influence of feeding various levels of zinc proteinate on egg shell quality. Poultry Sci. 45: 121 (abst).Google Scholar

129.Gutowska, M. S. and Parkhurst, R. T. (1942). Studie, in mineral nutrition of laying hens. 1. The magnanese requirement. Poultry Sci. 21: 277–287.Google Scholar

130.Hill, R. and Mathers, J. W. (1968). Manganese in the nutrition and metabolism of the pullet. I. Shell thickness and manganese content of eggs from birds given a diet of low or high manganese content. Br. J. Nutr. 22: 625–633.Google Scholar

131.Atkinson, R. L., Bradley, J. W., Couch, J. R. and Quisenberry, J. H. (1967). Effect of various levels of manganese on the reproductive performance of turkeys. Poultry Sci. 46: 472–475.Google Scholar

132.Hall, K. N. and Helbacka, N. V. (1951). Improving albumen quality. Poultry Sci. 38: 111–114.Google Scholar

133.Helbacka, N. V. L. and Hall, K. N. (1958). Characteristics of albumen and shell quality of eggs from layers fed NH₄CI in the diet. Poultry Sci. 37: 1211 (abst).Google Scholar

134.Hunt, J. R. and Aitken, J. R. (1962). The effect of ammonium and chloride ions in the diet of hens on egg shell quality. Poultry Sci. 41: 434–438.Google Scholar

135.El-Bousky, A. R., (1966). Egg shell quality and microstructure as affected by vitamin C other feed additives and high environmental temperatures. Mededelingen Landbouwho–geschool Wageningen. Netherlands 66: 7.Google Scholar

136.Howes, J. R., (1966). Egg shell quality as affected by the addition of bicarbonate to the feed and water. Poultry Sci. 45: 1092–1093 (abst).Google Scholar

137.Latif, M. A. and Quisenberry, J. H. (1968). Effects of dietary clays and sodium bicarbonate on the performance of commercial laying hens. Poultry Sci. 41: 1688 (abst).Google Scholar

138.Frank, F. R. and Burger, R. E. (1965). The effect of carbon dioxide inhalation and sodium bicarbonate ingestion on egg shell deposition. Poultry Sci. 44: 1604–1606.Google Scholar

139.Deaton, J. W. and Quisenberry, J. H. (1965). Effects of dietary protein level on performance of four commercial egg production stocks. Poultry Sci. 44: 936–942.Google Scholar

140.Hochreick, H. J., Douglas, C. R., Kidd, I. H. and Harms, R. H. (1958). The effect of dietary protein and energy levels upon production of Single Comb White Leghorn hens. Poultry Sci. 37: 949–953.Google Scholar

141.Middendorf, D. F., Helbacka, N. V. and Combs, G. F., (1959). Effect of protein levels and kept ash on performance of laying hens. Poultry Sci. 38: 1229 (abst).Google Scholar

142.Maclntyre, T. M. and Aitken, J. R.. (1957). The effect of high levels of dietary energy and protein on the performance of laying hens. PoultrySci. 36: 1211–1216.Google Scholar

143.Moreng, R. E., Enos, H. L., Whittet, W. A. and Miller, B. F. (1964). An analysis of strain response to dietary protein level. Poultry Sci. 43: 630–638.Google Scholar

144.Summers, J. D., McConachie, J. D., Slinger, S. J. and Pepper, W. F. (1966). The value of raw unextracted soybeans for laying hens. Poultry Sci. 45: 165–169.CrossRefGoogle Scholar

145.Thornton, P. A.. Moreng, R. E., Blaylock, L. G. and Hartung, T. E. (1956). The effects of dietary protein level on egg production, egg size, egg quality and feed efficiency. Poultry Sci. 35: 1177 (abst).Google Scholar

146.Thornton, P. A. and Whittet, W. (1959). The adequacy of low protein levels for egg product & under various conditions. Poultry Sci. 38: 1255 (abst).Google Scholar

147.Heywang, B. W. and Vavich, M. G. (1965). Comparison of performance of layers fed soybean, glandless or glanded cottonseed meals. Poultry Sci. 44: 1240–1244.Google Scholar

148.Mueller, W. J., (1956). The influence of energy scource, energy–fiber concentration and protein source of the diet on certain egg quality characteristics. Poultry Sci. 35: 1074–1078.Google Scholar

149.Pepper, W. F., Sljnger, S. J. and Ashton, G. C. (1961). The effect of unidentified growth factor sources and restricted feeding on the performance of egg strain chickens. Poultry Sci. 40: 588–597.Google Scholar

150.Wisman, E. L. and Beane, W. L. (1965). Utilization of hatchery by–product meal by the laying hen. Poultry Sci. 44: 1332–1333.Google Scholar

151.Mueller, W. (1967). The effect of two levels of methionine on the biological performance of laying pullets in controlled environments. Poultry Sci. 46: 82–88.Google Scholar

152.Berg, L. R., (1959). Enzyme supplementation of barley diets for laying hens. Poultry Sci. 38: 1132–1139.Google Scholar

153.Berg, L. R., (1961). Effect of adding enzymes to barley diets at different ages of pullets on laying house performance. Poultry Sci. 40: 34–39.Google Scholar

154.Griminger, P. and Scott, H. M. (1954). The effect of different cereals on feed efficiency egg quality and shell thickness. Poultry Sci. 33: 1217–1219.Google Scholar

155.Bearse, G. E. and Berg, L. R. (1955). The effect of varying levels of aureomycin on the performance of young laying chickens. Poultry Sci. 34: 1180 (abst).Google Scholar

156.Donaldson, W. E. and Gordon, G. D. (1960). The effect of 3% added animal fat on laying hen performance. Poultry Sci. 39: 583–587.Google Scholar

157.March, B. E. and Biely, J. (1963). The effects of dietary fat and energy levels on the performance of caged laying birds. Poultry Sci. 42: 20–24.CrossRefGoogle Scholar

158.Anderson, G. J., Petersen, C. F., Wiese, A. C. and Lampman, C. E. (1957). The effect of high level vitamin supplementation of high and low energy rations on egg production and egg shell quality. Poultry Sci. 36: 1369–1376.Google Scholar

159.Carlson, C. W., (1959). An observation with glucosamine and other additives in a diet for laying hens. Poultry Sci. 38: 1193–1194.(alst).Google Scholar

160.Gilbreath, J. C., Welch, Q. B., Waggoner, R. E. and Morrison, R. D. (1960). The effect of trifluoperazine and reserpine on reproductive efficiency in chickens. Poultry Sci. 39: 735–739.Google Scholar

161.Gilbreath, J. C., Garvin, L. F. and Welch, Q. B. (1959). Effect of orally administered reserpine on egg production and quality. Poultry Sci. 38: 535–538.Google Scholar

162.Heywang, B. W., (1965). The effect of the tranquilizer reserpidine on caged White Leghorn layers during hot weather in a semi-arid subtropical climate. Poultry Sci. 44: 1270–1273.Google Scholar

163.Casey, J. M., Gilbreath, J. C. and Morrison, R. D. (1963). Turkey reproduction as influenced by reserpine administered during growth. Poultry Sci. 42: 637–641.Google Scholar

164.Thomas, J. M., Nakaue, H. S. and Reid, B. L. (1966). Effect of increasing dietary levels of acetyl-salicylic acid on performance and cecal microbial counts of White Leghorn pullets. Poultry Sci. 45: 1313–1317.Google Scholar

165.Asmundson, V. S. and Pinsky, P. (1935). The effect of the thyroid on the formation o the hen's eggs. Poultry Sci. 14: 99–104.Google Scholar

166.Berg, L. R. and Bearse, G. E. (1948). The effect of iodinated casein and thiouracil on the performance of White Leghorn pullets. Poultry Sci. 27: 653.Google Scholar

167.Berg, L. R. and Bearse, G. E. (1951). Effect of iodinated casein and thiouracil on the performance of laying birds. Poultry Sci. 30: 21–28.Google Scholar

168.Vicente Trujillo, F., (1970). The effect of methionine, thiouracil, dienestrol diacetate and thyroprotein on development and prevention of fatty liver in laying pullets. World's Poultry Sci. J. 26: 483 (abst).Google Scholar

169.Wilson, W. O., (1949). High environmental temperatures as affecting the reaction of laying hens to iodized casein. Poultry Sci. 28: 581–592.Google Scholar

170.Gabuten, A. R. and Shaffner, C. S. (1954). A study of the physiological mechanisms affecting specific gravity of chicken eggs. Poultry Sci. 33: 47–53.Google Scholar

171.Godfrey, G. F., (1949). The effect of feeding thyroprotein on egg shell quality and hatchability. Poultry Sci. 28: 867–873.Google Scholar

172.Gutteridge, H. S. and Novikoff, M. (1947). The effect of natural and synthetic vitamins D₂ and D₃ and of thyroprotein on egg shell quality. Poultry Sci. 26: 210–212.Google Scholar

173.Gutteridge, H. S. and Pratt, J. M. (1946). The effect of vitamin D₂ and D₃ in fish oils and of iodo–casein on shell quality. Poultry Sci. 25: 89–91.Google Scholar

174.Hoffmann, E. and Wheeler, R. S. (1948). The value of thyroprotein in starting, growing and laying rations. IV. Effect on the egg production, shell quality, and body weight of year-old pullets during hot weather. Poultry Sci. 27: 609–612.Google Scholar

175.Savage, J. E., Turner, C. W., Kempster, H. L. and Hogan, A. G. (1952). The effects of vitamin B₁₂ and thyropotein on egg production, egg weight, shell quality and hatchability. Poultry Sci. 31: 22–31.Google Scholar

176.Hutt, F. B. and Gowe, R. S. (1948). On the supposed effect of iodocasein upon egg production. Poultry Sci. 27: 286–293.Google Scholar

177.Howes, J. R., (1969). Egg shell calcification and sodium retention. Poultry Sci. 48: 1822 (abst).Google Scholar

178.Adams, J. L., Casida, L. E. and McGibbon, W. H. (1951). Some characteristics of eggs from estrogen–fed pullets. Poultry Sci. 30: 694–700.Google Scholar

179.Brahmakshatriya, R. D., Snetsinger, D. C. and Waibel, P. E. (1968). Effects of exogenous estrogen and/or androgen on performance, egg shell characteristics and blood plasma changes in White Leghorn hens. Poultry Sci. 47: 1657 (abst).Google Scholar

180.Brahmakshatriya, R. D., Snetsinger, D. C. and Waibel, P. E. (1969). Effects of exogenous estrogen and/or androgen on performance, egg shell characteristics and blood plasma changes in laying hens. Poultry Sci. 48: 444–451.Google Scholar

181.Herrick, R. B. and Adams, J. L. (1955), Effect of exogenous gonadal hormones on Single Comb White Leghorn pullets. Poultry Sci. 34: 1362–1367.Google Scholar

182.Polin, D. and Sturkie, P. D. (1959). The decrease of plasma non–diffusible calcium levels in starved laying hens in relationship to shell deposition and estrogen. Poultry Sci. 38: 166–170.CrossRefGoogle Scholar

183.Carlson, C. W., (1957). Some effects of arsanilic acid and/or penicillin upon egg production. Poultry Sci. 36: 1070–1075.Google Scholar

184.Boone, M. A., Richey, D. J. and Morgan, C. L. (1957). Effects of antibiotics on egg production when chickens are naturally infected with chronic respiratory disease. Poultry Sci. 36: 1340–1344.Google Scholar

185.Chin, G. and Brant, A. W. (1953). Egg quality and aureomycin. Poultry Sci. 32: 875–876.Google Scholar

186.Sizemore, J. R., Lillier, J., Denton, C. A. and Bird, H. R. (1953). Influence of aureomycin in the chick diet upon subsequent reproductive performance of laying hens. Poultry Sci. 32: 618–624.Google Scholar

187.Nikolaiczuk, N., (1966). Buquinolate toxicity in growing pullets and laying hens. Poultry Sci. 45: 1110–1111. (abst).Google Scholar

188.Stephens, J. F., Barnett, B. D. and Butters, H. E. (1966). Effect of buquinolate on growth and egg production of White Leghorn pullets. Poultry Sci. 45: 1127 (abst).Google Scholar

189.Stephens, J. F., Barnett, B. D. and Butters, H. E. (1967). Effect of buquinolate on growth and egg production of White Leghorn pullets. Poultry Sci. 46: 203–206.Google Scholar

190.Heywang, B. W. and Vavich, M. G. (1959). The effect of high levels of an antibiotic on egg weight and shell quality during hot weather. Poultry Sci. 38: 999–1003.CrossRefGoogle Scholar

191.Krueger, W. F., Wahid, Md. A. and Quisenberry, J. H. (1966). The effect of sulfaquinoxaline and chlorotetracycline in combination on fertility and hatchability of chicken eggs. Poultry Sci. 45: 1098 (abst).Google Scholar

192.Robblee, A. R. and Clandinin, D. R. (1964). Potentiation of chlorotetracycline in laying chickens. Poultry Sci. 43: 462–466.Google Scholar

193.Guenthner, E. and Carlson, C. W. (1964). Antibiotics in laying diets. Poultry Sci. 43: 1324 (abst).Google Scholar

194.Boone, M. A. and Barnett, B. D. (1963). The effect of furadroxyl on laying hens. Poultry Sci. 42: 1257 (abst).Google Scholar

195.Francis, D. W. and Shaffner, C. S. (1956). An investigation of the morphological change in young chickens and the reroductive performance of adult chickens fed furazolidone or nitrofurozone. Poultry Sci. 35: 1371–1381.CrossRefGoogle Scholar

196.McClung, M. R., (1961). Influence of furazolidone on performance in laying hens. Poultry Sci. 40: 1429 (abst).Google Scholar

197.Stiles, P. G., (1962). The effect of furazolidone on egg production, egg quality, fertility and hatchability under commercial farm conditions. Poultry Sci. 41: 1336–1338.Google Scholar

198.Weiss, H. S., (1957). Further comments on the effect of nicarbazin on the egg. Poultry Sci. 36: 589–591.Google Scholar

199.Boone, M. A. and Barnett, B. D. (1965). The effect of nidroxyzone and nihydrozone on laying hens. Poultry Sci. 44: 514–519.Google Scholar

200.Petersen, C. F., Sauter, E. A., Conrad, D. H. and Anderson, G. J. (1958). The influence of penicillin in the diet of White Leghorn hens upon production and shell quality of eggs. Poultry Sci. 37: 796–801.Google Scholar

201.Marusich, W. L., Ogrinz, E., Brand, M. and Mitrovic, M. (1969). Safety and compatibility of sulfadimethoxine potentiated mixture (Ro 5–0013), a new broad spectrum coccidiostat–antibacterial, in chickens. Poultry Sci. 48: 217–222.Google Scholar

202.Waldroup, P. W. and Harms, R. H. (1961). Potentiation of tetramycin II. Evaluation of low dietary calcium in laying hen diets. Avian Dis. 5: 409–414.Google Scholar

203.Eoff, H. J., Davies, R. E., Ferguson, T. M. and Couch, J. R. (1962). Studies on the influence of terephthalic acid and broad spectrum antibiotics on egg production and egg shell coloration in caged layers. Poultry Sci. 41: 1036–1041.Google Scholar

204.Becker, W. A. and Bearse, G. E. (1962). Sulfanilamide, specific gravity of eggs and an interaction. Poultry Sci. 41: 198–200.Google Scholar

205.Benesch, R., Barron, N. S. and Mawson, C. A. (1944). Carbonic anhydrase, sulfonamides and shell formation in the domestic fowl. Nature 153: 138–139.Google Scholar

206.Bernard, R. and Genest, P. (1945). Sulfonamides and egg shell formation in the domestic fowl. Science 101: 617–618.Google Scholar

207.Genest, P. and Bernard, R. (1945). Rev. Can, Biol. 4: 172–192. Quoted in Bernard, R. and P. Genest, (1945): Sulfonamides and egg shell formation in the domestic fowl. Science 101: 617–618.Google Scholar

208.Gutowska, M. S. and Mitchell, C. A. (1945). Carbonic anhydrase in the calcification of the egg shell. Poultry Sci. 24: 159–167.Google Scholar

209.Hinshaw, W. R. and McNeil, E. (1943). Experiments with sulfanilamide for turkeys. Poultry Sci. 22: 291–294.Google Scholar

210.Mehring, A. L. Jr., Titus, H. W. and Brumbaugh, J. H. (1955). Effects of two sulfonamides on the formation of egg shells. Poultry Sci. 34: 1385–1389.Google Scholar

211.Scott, H. M., Jungherr, E. and Matterson, L. D. (1944). The effect of feeding sulfanilamide to the laying fowl. Poultry Sci. 23: 446–453.Google Scholar

212.Fry, J. L. and Wilson, H. R. (1967). Studies of dietary piperazine, phenothiazine, and dibutyltin dilaurate. 2. Yolk mottling and other egg quality characteristics. Poultry Sci. 46: 319–322.Google Scholar

213.Peardon, D. L., Haberman, W. O., Marr, J. E., Garland, F. W. Jr. and Wilcke, H. L. (1965). The effects of piperazine, phenothiazine and Di-N-butylin dilaurate combinations on chicken egg production and egg quality in chickens. Poultry Sci. 44: 413–424.Google Scholar

214.Helbacka, N. V., Quigley, G. D. and Shaffner, C. S. (1958). The effect of malathion on egg quality. Poultry Sci. 37: 728–729.Google Scholar

215.Berg, L. R., Bearse, G. E. and Hamilton, C. M. (1947). The effect of Newcastle diseaae on egg production and egg quality. Poultry Sci. 26: 614–622.Google Scholar

216.Biswal, G. and Morrill, C. C. (1954). The pathology of the reproductive tract of laying pullets affected with Newcastle disease. Poultry Sci. 33: 880–897.Google Scholar

217.Clegg, R. E. and Mueller, C. D. (1951). Calcium metabolism during Newcastle disease. Poultry Sci. 30: 157–158.Google Scholar

218.Fraps, R. M., (1965). Twenty–four hour periodicity in the mechanism of pituitary gonadotrophin release for follicular maturation and ovulation in the chicken. Endocrinol. 77: 5–18.Google Scholar

219.Lorenz, F. W. and Newlon, W. E. (1944). Influence of avian pneumoencephalitis on subsequent egg quality. Poultry Sci. 23: 193–198.Google Scholar

220.Quinn, J. P., (1950). Effect of Newcastle disease on egg quality. Poultry Sci. 29: 776.Google Scholar

221.Quinn, J. P., Brant, A. W. and Thompson, C. H. Jr. (1956). Effect of a naturally occurring outbreak of Newcastle disease on egg quality and production. Poultry Sci. 35: 3–10.Google Scholar

222.Broadfoot, D. I. and Smith, W. M. (1954). Effects of infectious bronchitis in laying hens on egg production, per cent unsettable eggs and hatchability. Poultry Sci. 33: 653–654.Google Scholar

223.Crinion, R. A. P., (1969). Egg quality following infectious bronchitis at an early age. Poultry Sci. 48: 1799–1800.(abst).Google Scholar

224.Gordeuk, S. Jr., and Bressler, G. O. (1950). Infectious bronchitis: Its effect on rate of egg production and egg quality. Penn. Agric. Expt. Sta. Prog. Report. No. 36.Google Scholar

225.Hill, R. W. and Lorenz, F. W. (1956). Studies on egg changes following avian respiratory disease. Poultry Sci. 35: 409–417.Google Scholar

226.Sevoian, M. and Levine, P. P. (1957). Effects of infectious bronchitis on the reproductive tracts, egg production and egg quality of laying chickens. Avian Dis. 1: 136–164.Google Scholar

227.Taylor, L. W., Gunns, C. A., Grau, C. R. and Lepkovsky, S. (1953). Effect of a respdtory disease on reproduction. Poultry Sci. 32: 129–137.Google Scholar

228.Vanroekel, H., Bulis, K. L., Clarke, M. K., Olesiuk, O. M. and Sperling, F. G. (1950). Infectious bronchitis. Massachusetts Agr. Expt. Sta. Bull. No. 460: 1–47.Google Scholar

229.Vanroekel, H., Clarke, M. K., Bullis, K. L., Olesiuk, O. M. and Sperling, F. G. (1951). Infectious bronchitis. Am. J. Vet. Res. 12: 140–146.Google Scholar

230.Carson, J. R., Eaton, R. D. and Luginbuhl, R. E. (1954). The effect of injections of an oil suspension of tetramycin on egg production and egg quality in hens affected with chronicyrespiratory disease. Poultry Sci. 33: 589–596.Google Scholar

231.Quinn, J. P. and Thompson, C. H. Jr., (1952). Effect of Newcastle disease live–virus vaccination of immature White Leghorn pullets on subsequent egg quality. Poultry Sci. 31: 695–699.Google Scholar

232.Vanroekel, H., Olesiuk, O. M., and Peck, H. A. (1952). Chronic respiratory disease in chickens. Am. J. Vet. Res. 13: 252–259.Google Scholar

233.Raggi, L. G., Brownell, J. R. and Stewart, G. F. (1961). Effects of infectious laryngotracheitis virus on egg production and quality. Poultry Sci. 40: 134–140.Google Scholar

234.Broadfoot, D. I., Pomeroy, B. S. and Smith, W. M. Jr. (1954). Effects of infectious bronchitls on egg production. J. Am. Vet. Med. Assoc. 124: 128–130.Google Scholar

235.Cecil, H. C., Bitman, J., Harris, S. J., and Fries, G. F., (1969). DDT–induced decrease in egg shell calcium. Poultry Sci. 48: 1794–1795 (abst).Google Scholar

236.Kondra, P. A., Sell, J. L. and McKirdy, J. A. (1964). The effect of thalidomide on reproduction in the hen. Poultry Sci. 43: 1420–1425.Google Scholar

237.Mills, N. Jr., Helbacka, N. V. and Creek, R. D. (1969). The effect of a high level of lithium carbonate on egg shell formation of laying hens. Poultry Sci. 48: 1766–1767.Google Scholar

238.Mueller, W. J., (1962). Carbonic anhydrase, diuretics and egg shell formation. Poultry Sci. 41: 1792–1796.Google Scholar

239.Naber, E. C. and Sunde, M. L. (1965). The effect of beta–aminopropinitrile on calcium metabolism in the laying hen. Poultry Sci. 44: 1402 (abst).Google Scholar

240.Swanson, M. H., Waibel, P. E., Helbacka, N. V. and Johnson, E. L. (1956). The effects of arasan on shell egg quality. Poultry Sci. 35: 92–495.Google Scholar

241.Waibel, P. E., Pomeroy, B. S. and Johnson, E. L. (1955). Effect of arasan–treated corn on laying hens. Science 121: 401–402.Google Scholar

242.Smith, A. H., Hage, T. J., Julian, L. M. and Redmond, D. M. (1956). The effect of X–irridiation of the oviduct on egg production and egg quality in the fowl. Poultry Sci. 35: 539–545.Google Scholar

243.Adams, A. W., Emerick, R. J. and Carlson, C. W. (1966). Effects of nitrate and nitrite in the drinking water on chicks, poults and laymg hens. Poultry Sci. 45: 1215–1222.Google Scholar

244.Fuller, H. L. and Morris, G. K. (1962). A study. of the effects of ethylene dibromide fumigant components on egg production. Poultry Sci. 41: 645–654.Google Scholar

245.Siddigui, S. M. and Fry, J. L. (1963). Studies with warfarin on the incidence of blood spots and relation to prothrombin time, egg quality and mortality of laying hens. Poultry Sci. 42: 1125–1130.Google Scholar

246.O'neil, J. B. and Rae, W. J. (1965). Ergot tolerance in chicks and hens. Poultry Sci. 44: 1404 (abst).Google Scholar

247.Scott, H. A., (1970). Reported in: Anderson, G. B., T. C. Carter and R. M. Jones, (1970). Some factors affecting the incidence of cracks in hen's egg shells. Br. Poultry Sci. 11: 103–116.Google Scholar

248.Wood–GUSH, D. G. M. and Gilbert, A. B. (1969). Observations on the laying behaviour of hens in battery cages. Br. Poultry Sci. 10: 29–36.Google Scholar

249.Anderson, G. B., Carter, T. C. and Jones, R. M. (1970). Some factors affecting dynamic fracture of egg shells in battery cages. In Factors Affecing Egg Gradmg. Ed. Gordon, R. F. and Edinburgh, B. M., Oliver, and Boyd, .Google Scholar

250.Blount, W. P., (1951). Hen Batteries. London, Bailliere, Tindall and Cox.Google Scholar

251.Blount, W. P., (1966). Comments on the Brambell Committee Report. London British Oil and Cake Mills Ltd.Google Scholar

252.Dorminey, R. W., Jones, J. E. and Wilson, H. R. (1965). Influence of cage size and frightening on incidence of bod checked eggs. Poultry Sci. 44: 307–308.Google Scholar

253.Elson, H. A., (1968). Quoted in: H. A. Elson, (1969). The relationship between cage floor design and shell quality. World's Poultry Sci. J. 25: 145 (abst).Google Scholar

254.Elson, H. A., (1969). The relationship betwecn cage floor design and shell quality. World's Poultry Sci. J. 25: 145 (abst).Google Scholar

255.Querner, H. and Tuller, R. (1966). Brooding of pullets and keeping of laying hens in different cage systems compared with brooding and keeping on floor. World's Poultry Sci. J. 23: 53 (abst).Google Scholar

256.Tower, B. A., Roy, E. P. and Olinde, A. J. (1969). The performance of layers confined in single versus colony cages: A four–year summary. Poultry Sci. 48: 1883 (abst).Google Scholar

257.Wilson, H. R. and Jones, J. E. (1964). The effects of crowding on cage layer performance. 61st. Ann. Proc. Assoc. of Soc. Agr. Workers, Inc. p. 280.Google Scholar

258.Blount, W. P., (1968). Intensive livestock farming. London, Heinemann.Google Scholar

259.Olsen, M. W. and Lucas, L. M. (1963). Special floor reduces egg breakage in turkey laying cages. Poultry Sci. 42: 43–45.Google Scholar

260.Berg, R. W. and Shoffner, R. N. (1966). Space requirements for turkey breeder hens. Poultry Sci. 45: 1070 (abst).Google Scholar

261.Funk, E. M., Froning, G., Grotts, R., Forward, J. and Kinder, Q. (1958). Quality of eggs laid by caged layers. Missouri Agr. Expt. Sta. Bull. 658: 1–8.Google Scholar

262.Johnson, H. S. and Zindel, H. C. (1962). Comparisons between pullets housed in cages, on a slatted floor and on a litter floor. Quarterly Bulletin (Mich. Agr. Expt. Sta.) 45: 2–16.Google Scholar

263.Timmons, D. P., Durfee, W. K. and McClung, W. R. (1961). Performance of caged layers in the northeast under moderate cost housing conditions. Poultry Sci. 40: 1465 (abst).Google Scholar

264.Magruder, N. D. and Nelson, J. W. (1965). Long term studies of the effect of slatted floor versus litter on laying performance. Poultry Sci. 44: 1395 (abst).Google Scholar

265.Wilson, H. R., Jones, J. E. and Dorminey, R. W. (1967). Performance of layers under various cage regimes. Poultry Sci. 46: 422–425.Google Scholar

266.Charles, D. R. and Payne, C. G. (1966). The influence of graded levels of atmospheric ammonia on chickens. II. Effects on the performance of laying hens. Br. Poultry Sci. 7: 189–198.Google Scholar

267. Helbacka, N. V., Casterline, J. L. Jr. and Smith, C. J. (1963). The effect of high CO₂ atmosphere on the laying hen. Poultry Sci. 42: 1082–1084.Google Scholar

268.Lee, C. E., Scholes, J. C. and Henry, C. L. (1944). The effect of “free choice” grain feeding on egg production, feed consumption, body weight and egg quality. Poultry Sci. 23: 360–370.Google Scholar

269.Macintyre, T. M. and Jenkins, M. H. (1955). Effect of different feeding methods on the efficiency of egg production. Poultry Sci. 34: 376–383,Google Scholar

270.Macintyre, T. M. and Gardiner, E. E. (1961). The effect of restricting the feed intake of confinement reared pullets on future performance. Poultry Sci. 40: 1425 (abst).Google Scholar

271.Berg, L. R. and Bearse, G. W. (1946). The changes in egg quality resulting from force molting White Leghorn yearling hens. Poultry Sci. 25: 396 (abst).Google Scholar

272.Berg, L. R. and Bearse, G. E. (1947). The changes in egg quality resulting from force molting White Leghorn yearling hens. Poultry Sci. 26: 414–418.Google Scholar

273.Hansen, R. S., (1960). The effect of methods of forced molting on reproductive performance of chickens. Poultry Sci. 39: 1057 (abst).Google Scholar

274.Bearse, G. E., Jennings, R. C. and Morris, T. R. (1967). The effects of inducing rest in White Leghorn hens with I. C. I. compound 33828. Poultry Sci. 46: 1233 (abst).Google Scholar

275.Hansen, R. S., (1966). The effect of frequency of rests (forced molts) on hen performance and egg quality. Poultry Sci. 45: 1089 (abst).Google Scholar

276.Marble, D. R., (1962). The effects of extended production and forced molt on albumen and shell quality. Poultry Sci. 41: 1662 (abst).Google Scholar

277.Noles, R. K., (1966). Subsequent production and egg quality of forced molted hens. Poultry sci. 45: 50–57.Google Scholar

278.Swanson, M. H., Bell, D. D. and Little, T. M. (1969). Effect of feeding program during a forced molt on subsequent production. Poultry Sci. 48: 1881 (abst).Google Scholar

279.Horst, P. and Petersen, J. (1968). Investigations on the influence of forced moulting of of hens on performance and egg quality. World's Poultry Sci. J. 24: 283 (abst).Google Scholar

280.Mehner, A. and Torges, H. G. (1967). The effect of force moulting and of different temperatures on body weight, laying performance and egg quality of Leghorn pullets. World Poultry Sci. J. 23: 261 (abst).Google Scholar

281.Mehner, A. and Torges, H. G. (1967). Egg quality characteristics before and after laying pause in New Hampshire hens. World's Poultry Sci. J. 23: 55–56 (abst).Google Scholar

282.Cooper, J. B. and Barnett, B. D. (1966). Cannibalism control treatments and egg shell thickness. Poultry Sci. 45: 1423–1424.Google Scholar

283.Marks, H. L., and Siegel, P. B. (1960). The influence of dubbing on various production characteristics. Poultry Sci. 39: 1091–1097.Google Scholar

284.Marks, H. L. and Lucas, L. M. (1967). The influence of early photoperiod lengths on birds maintained under “short days”. Poultry Sci. 46: 1589–1590.Google Scholar

285.King, D. F., (1962). Egg production of chickens raised and kept in darkness. Poultry Sci. 41: 1499–1503.Google Scholar

286.Siegel, H. S. and Beane, W. L. (1963). Photoperiod length and shell thickness in laying fowl. Poultry Sci. 43: 1361–1362 (abst).Google Scholar

287.Shutze, J. V., Matson, W. E. and McGinnis, J. (1961). Influence of different photo–periods during brooding and rearing on subsequent productive characteristics in chicken. Poultry Sci. 40: 1604–1611.Google Scholar

288.Stiles, P. G. and Dawson, L. E. (1961). The effect of physical disturbance, sound and light, on the incidence of blood spots and other egg quality factors. Poultry Sci. 40: 189–195.Google Scholar

289.Asmundson, V. S., Kratzer, F. H., Moses, B. D. (1951). Relation of all–night light to egg quality in turkeys. Poultry Sci. 30: 546–548.Google Scholar

290.Bennion, N. L. and Warren, D. C. (1933). Temperature and its effect on egg size in the domestic fowl. Poultry Sci. 12: 69–82.Google Scholar

291.Froning, G. W. and Funk, E. M. (1958). Seasonal, variation in quality of eggs laid by caged layers and their sisters on the floor. Poultry Sci. 37: 215–223.Google Scholar

292.Helbacka, N. V. and Casterline, J. L. Jr. (1963). Plasma CO₂ capacity of laying hens. Poultry Sci. 42: 450–451.Google Scholar

293.Pfost, R. E., (1960). Decline of interior egg quality as affected by the season of the year and the age of the hen. Poultry Sci. 39: 1284 (abst).Google Scholar

294.Quinn, J. P., (1963). Estimates of some genetic parameters of egg quality. Poultry Sci. 42: 792–793.Google Scholar

295.Warren, D. C., Conrad, R., Schumacher, A. E. and Avery, T. B. (1950) Effects of fluctuating environment on laying hens. Kansas Agr. Expt Sta. Tech. Bull. 68.Google Scholar

296.Wilhelm, L. A., (1940). Some factors affecting variations in egg shell quality. Poultry Sci. 19: 246–253.Google Scholar

297.Wilhelm, L. A. and Heiman, V. (1938). The seasonal variations in interior egg quality on new laid eggs. Washington Agr. Expt. Sta. Tech. Paper 358.Google Scholar

298.Strain, J. H. and Johnson, A. S. (1957). Seasonal, strain and hatch effects on egg quality traits. Poultry Sci. 36: 539–546.Google Scholar

299.Baskett, R. G., Dryden, W. H. and Hale, R. W. (1937). Investigations on the strength of hen eggs. J. Min. Agric. N. Ire. 5: 132–142.Google Scholar

300.Carmon, L. G. and Huston, T. M. (1965). The influence of environmental temperature upon egg components of domestic fowl. Poultry Sci. 44: 1237–1240.Google Scholar

301.Funk, E. M., Froning, G., Grotts, R., Forward, J. and Cotterill, O. (1958). Seasonal variation in egg quality. Missouri Res. Bull, 659.Google Scholar

302.Miller, M. W. and Bearse, G. E. (1934). Phosphorus requirements of laying hens. Washington Agr. Expt. Bull, 306.Google Scholar

303.Mueller, C. D., Avery, T. B., Smith, H. D. and Clegg, R. E. (1951). Effects of controlled light and temperature for laying hens. Poultry Sci. 30: 679–686.Google Scholar

304.O'niel, J. B., and Rae, W. J. (1952). Changes in specific gravity of eggs during the laying year. Sci. Agr. 32: 185–189.Google Scholar

305.Jenkins, N. K. and Tyler, C. (1960). Changes in egg shell thickness and white and yolk weight and composition over a period of a year. J. Agric. Sci. 55: 323–331.Google Scholar

306.Tyler, C. and Geake, F. H. (1964). Egg shell strength and its relationship to thickness with particular reference to individuality in the domestic hen. Br. Poultry Sci. 5: 3–18.Google Scholar

307.Campos, A. C., Wilcox, F. H. and Shaffner, C. S. (1960). The influence of fast and slow rises in ambient temperature on production traits and mortality of laying pullets. Poult. Sci. 39: 119–129.Google Scholar

308.Charles, D. R., Payne, C. G. and Lamming, G. F. (1963). Atmospheric ammonia and the performance of laying hens. University of Nottingham, School of Agric. Report, 93–100. Quoted in: Payne, C. G., (1966). Environmental temperature and egg production in Physiology of the domestic Fowl. Edited by: Horton-Smith, C., and Amoroso, E. C., Oliver, and Boyd, .Google Scholar

309.Conrad, R. M., (1939). The effect of high temperature on the blood calcium of the laying hen. Poultry Sci. 18: 327–329.Google Scholar

310.El-Boushy, A. R., Simons, P. C. M. and Wiertz, G. (1968). Structure and ultrastructure of the hen's egg shell as influenced by environmental temperature, humidity and vitamin C additions. Poultry Sci. 47: 456–467.Google Scholar

311.Mather, F. B., Epling, G. P. and Thornton, P. A. (1962). The microscopic structure of the egg shell matrix as influenced by shell thickness and environmental temperature. Poultry Sci. 41: 963–970.Google Scholar

312.Mueller, W. J., (1959). The effect of environmental temperature and humidity on the calcium balance and serum calcium of laying pullets. Poultry Sci. 38 1296–1301.Google Scholar

313.Mueller, W. J., (1966). Effect of rapid temperature changes on acid–base balance and shels quality. Poultry Sci. 45: 1109 (abst).Google Scholar

314.Thornton, P. A., (1962). Tyrosine, protein and ascorbic acid effects on egg shell thickness from chickens subjected to heat stress. Poultry Sci. 41: 1832–1835.Google Scholar

315.Warren, D. C. and Schnepel, R. L. (1940). The effect of air temperatures on egg shell thickness in the fowl. Poultry Sci. 19: 67–72.Google Scholar

316.Huston, T. M., (1958). The influence of high environmental temperature on egg size, shell quality and albumen height of domestic fowl. Poultry Sci. 37: 1213–1214 (abst).Google Scholar

317.Huston, T. M. and Carmon, J. L. (1961). The influence of high environmental temperature on specific gravity and albumen quality of hen eggs. Poultry Sci. 40: 1060–1062.Google Scholar

318.Campos, A. C., Wilcox, F. H. and Shaffner, C. S. (1962). The influence of fast and slow drops in ambient temperature on egg production traits. Poultry Sci. 41: 856–865.Google Scholar

319.Welter, J. F., Boone, M. A. and Barnett, B. D. (1967). The effects of temperature stress on subsequent egg production of the fowl. Poultry Sci. 46: 646–650.Google Scholar

320.Mueller, W. J., Maw, A. J. G. and Buss, E. G. (1960). The influence of season and age of layers on egg weight, shape index, albumen quality and shell thickness. Poultry Sci. 39: 854–860.Google Scholar

321.Brunson, C. C. and Godfrey, G. F. (1953). The relationship of egg shape, egg weight, specific gravity and 21-day incubation weight–loss to hatchability of broad-breasted bronze turkey eggs. Poultry Sci. 32: 846–849.Google Scholar

322.Johnson, A. S. and Merritt, E. S. (1955). Heritability of albumen height and specific gravity of eggs from White Leghorns and Barred Rocks and the correlations of these traits with egg production. Poultry Sci. 34: 578–587.Google Scholar

323.Noles, R. K. and Tindell, D. (1967). Observations on the inter–relationships of egg quality traits and their association with season, age and strain of bird. Poultry Sci. 46: 943–952.Google Scholar

324.O–niel, H. S. and Rae, W. J. (1951). Changes in specific gravity of the egg during the laying year. Sci Agric. 34: 185–189.Google Scholar

325.Paul, H. S. and Snetsinger, D. C. (1969). Dietary calcium and phosphorus and variation in plasma alkaline phosphatase activity in relationship to physical characteristics of egg shells. Poultry Sci. 48: 241–251.Google Scholar

326.Pope, C. W., Watts, A. B., Williams, E. and Brunson, C. C. (1960). The effect of the length of time in production and stage of egg formation on certain quality measurements and blood constituents of laying hens. Poultry Sci. 39: 1427–1431.Google Scholar

327.Burmester, B. R., (1940). A study of the physical and chemical changes of the egg during its passage through the lsthmus and uterus of the hen's oviduct. J. Exp. Zool. 84: 445–500.Google Scholar

328.Berg, L. R. (1945). The relationship of clutch position and time interval between eggs to egg shell quality. Poultry Sci, 24: 555–563.Google Scholar

329.Burrows, W. H. and Byerly, T. C. (1942). Premature expulsion of eggs by hens following injection of whole posterior pituitary preparations. Poultry Sci. 21: 416–421.Google Scholar

330.Gilbert, A. B. and Lake, P. E. (1963). The effect of oxytocin and vasopressin on oviposition in the domestic hen. J. Physiol. Lond. 169: 52–53.Google Scholar

331.Tanaka, K. and Nakajo, S. (1962). Participation of neurohypophyseal hormone in oviposition in the hen. Endocrin. 70: 453–458.Google Scholar

332.Opel, H. (1965). Failure of neurohypophysectomy to reduce egg shell thickness in chickens Poultry Sci. 44: 1135–1136.Google Scholar

333.Carter, T. C., (1970). The hens egg: Some factors affecting deformation in statically loaded shells. Br. Poultry Sci. 11: 15–38.Google Scholar

334.Jaap, R. G. and Muir, F. V. (1968). Erratic oviposition and egg defects in broiler–type pullets. Poultry Sci. 47: 417–423.CrossRefGoogle Scholar

335.Huston, T. M. and Nalbandov, A. V. (1953). Neurohumoral control of the pituitary in the fowl. Endocrinol. 52: 149–156.Google Scholar

336.Koga, O., (1967). Nervous control of egg formation in the hen. II. The effect of a thread in the oviduct of the laying hen on egg production. Japan Poultry Sci. 4: 8–16.Google Scholar

337.Lake, P. E. and Gilbert, A. B. (1964). The effect on egg production of a foreign object in the lower oviduct regions of the domestic hen. Res. Vet. Sci. 5: 39–45.Google Scholar

338.Sykes, A. H., (1953). Premature oviposition in the hen. Nature 172: 1098–1099.Google Scholar

339.Sykes, A. H., (1962). Effect of a uterine irritant on egg formation in the fowl. J. Reprod. Fert. 9: 214–217.Google Scholar

340.Hewitt, E. A., (1939). The physiology of the reproductive system of the fowl. J. Am. Vet. Med. Assoc. 95: 201–210.Google Scholar

341.Opel, H., (1967.) Effects of brain piqure on the first and second ovipositions of the hen's 2-egg sequence. Proc. Soc. Expt. Biol. Med. 125: 627–630.Google Scholar

342.Sturkie, P. D. and Lin, Y. C. (1966). The effects of sodium pentobarbital on oviposition in the hen. Poultry Sci. 45: 851–852.Google Scholar

343.Polin, D. and Sturkie, P. D. (1955). Prevention of premature oviposition and shell–less eggs with ephedrine. Poultry Sci. 34: 1169–1170.Google Scholar

344.Sturkie, P. D., Weiss, H. S. and Ringer, R. K. (1954). Effects of injections of acteylcholine and ephedrine upon components of the hens egg. Poultry Sci. 33: 18–24.Google Scholar

345.Weiss, H. S., (1951). The effect of neuromimetic drugs on egg formation. Ph.D. Thesis, Rutgers University, New Jersey.Google Scholar

346.Weiss, H. S. and Sturkie, P. D. (1952). Time of oviposition as affected by neuromimetic drugs. Poultry Sci. 31: 227–231.Google Scholar