Influence of increasing dietary calcium and magnesium levels on performance, mineral metabolism, and egg mineral content of laying hens.

The effects of increasing dietary magnesium level from .17 to .77% and calcium level from 3 to 4.2% for laying hens over a 7-week period was investigated. Increasing either dietary magnesium or calcium level had no significant effect (P greater than .05) on feed consumption, egg production, egg weight, or egg shell deformation. Increasing dietary magnesium level had no significant effect on calcium retention, although there was a significant (P less than .01) reduction in the percentage of magnesium retained. Egg shell calcium content was significantly (P less than .01) reduced and shell magnesium significantly (P less than .05) increased in response to increase in dietary magnesium content. Increasing dietary magnesium level also significantly (P less than .01) reduced bone calcium and zinc contents while concomitantly increasing bone magnesium levels. Bone ash and calcium were significantly (P less than .05) increased and bone magnesium reduced when the calcium content of the diet was increased. Plasma calcium was significantly (P less than .01) increased in dietary calcium level and significantly decreased with increased dietary magnesium. The converse was true for plasma magnesium in response to increases in dietary calcium and magnesium. Significant positive correlations were observed between mineral contents of diet and bone, bone and plasma, and plasma and shell. A negative correlation was observed between shell magnesium level and egg shell quality as assessed by deformation. An antagonistic relationship seems to exist between calcium and magnesium, and this is discussed in relation to skeletal integrity and egg shell quality.

[1]  K. G. Reichmann,et al.  Influence of dietary calcium and phosphorus on metabolism and production in laying hens. , 1977, British poultry science.

[2]  M. Ellis,et al.  The effect of feeding magnesium-enriched diets on the quality of the albumen of stored eggs , 1977, British Journal of Nutrition.

[3]  D. Roland,et al.  The Effect of Increased Dietary Calcium on Hens Chosen for Their Ability to Produce Eggs with High and Low Specific Gravity , 1977 .

[4]  A. W. Adams.  Magnesium Sulfate Effects on Three Strains of Egg Type Hens , 1976 .

[5]  S. Leeson,et al.  Calcium and phosphorus requirements of the laying hen. , 1976, Poultry science.

[6]  M. Sunde,et al.  Dietary calcium levels in pre-lay and lay diets in Leghorn pullets. , 1975, Poultry science.

[7]  J. Stafford,et al.  Magnesium metabolism in the laying fowl. , 1973, British poultry science.

[8]  M. L. Scott,et al.  The Calcium Requirements of Laying Hens and Effects of Dietary Oyster Shell Upon Egg Shell Quality , 1971 .

[9]  Candlish Jk.  The formation of mineral and organic matrix of fowl cortical and medullary bone during shell calcification. , 1971 .

[10]  R. Clegg,et al.  Influence of calcium in laying rations on shell quality and interior quality of eggs. , 1968, Poultry science.

[11]  T. Taylor,et al.  The absorption and excretion of minerals by laying hens in relation to egg shell formation. , 1967 .

[12]  G. W. Mcward.  Magnesium tolerance of the growing and laying chicken. , 1967 .

[13]  S. Hurwitz,et al.  ABSORPTION OF CALCIUM AND PHOSPHORUS ALONG THE GASTROINTESTINAL TRACT OF THE LAYING FOWL AS INFLUENCED BY DIETARY CALCIUM AND EGG SHELL FORMATION. , 1965, The Journal of nutrition.

[14]  R. Schraer,et al.  CALCIUM METABOLISM AND SKELETAL DYNAMICS OF LAYING PULLETS. , 1964, The Journal of nutrition.

[15]  I. Macintyre,et al.  Inter-relation of calcium and magnesium absorption. , 1962, Clinical science.