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Magnesium Nutriture of the Hen: Influence on Retention of Magnesium, Calcium, and Nitrogen, and on Ration Metabolizable Energy Value1
SPERM VIABILITY AND FERTILITY
dead sperm ratios were not reflected in the fertility experiment.
1437
to semen used for inseminating hens within a half hour. ACKNOWLEDGEMENTS
SUMMARY
Support for this research was received from the Ontario Department of Agriculture and Food and the National Research Council of Canada Operating Grant A1970. The authors gratefully acknowledge the cooperation and assistance of Dr. J.W. Macpherson in conducting these studies and reviewing the manuscript. REFERENCES Blackshaw, A. W., 1958. The effect of glycerol on supra-vital staining of spermatozoa. Australian Vet. J. 34: 71-76. Brown, K. I., 1966. Some factors affecting storage of turkey semen. Ohio Res. Summ. 17, Ohio Agr. Res. and Dev. Center, Wooster, Ohio. Cooper, D. M., and J. C. Rowell, 1958. Relations between fertility, embryonic survival and some semen characteristics in the chicken. Poultry Sci. 37: 699-707. Hackett, A. J., and J. W. Macpherson, 1965. Some staining procedures for spermatozoa. A review. Can. Vet. J. 6: 55-62. Harper, J. A., 1955. The effect of holding time of turkey semen on fertilizing capacity. Poultry Sci. 34: 1289-1291.
Magnesium Nutriture of the Hen: Influence on Retention of Magnesium, Calcium, and Nitrogen, and on Ration Metabolizable Energy Value1 J. L. SELL Animal Science Department, North Dakota State University, Fargo, North Dakota 58102 (Received for publication March 10, 1969)
M
AGNESIUM (Mg) deficiency has been described for many animal species including chicks (Almquist, 1942; and Gardiner et al, 1960), ducks (Van 1 Published with the approval of the Director of the North Dakota Agricultural Experiment Station as Journal Article No. 186, Project H-7-26.
Reen and Pearson, 1953) and laying hens (Sell et ah, 1967). Signs of this deficiency include impaired reproduction, hypomagnesemia, anorexia and death. Despite considerable data describing clinical manifestations of Mg deficiency, little information is available concerning mineral and nitrogen balance, or utilization of di-
Downloaded from http://ps.oxfordjournals.org/ at Oakland University on July 1, 2015
Eosin nigrosin was estimated to be a more satisfactory stain than bromphenol blue-nigrosin or Congo red-nigrosin for differentiating between the degrees of viability of sperm on the basis of trials with chicken semen, using a total of 72 counts each comprised of 100 sperm. The proportion of stained turkey sperm, using eosin nigrosin on 144 counts each comprised of 100 sperm, was increased during four hours of storage. A collection temperature of 30° C. produced a lower proportion of stained sperm than 15°C. while fewer stained sperm were encountered with a holding temperature of 15°C. as opposed to 30°C. during four hours of storage. However, the use of the same collection and storage temperatures in a fertility experiment with 84 turkey females revealed a significant drop in fertility only in the comparison of semen, stored for five hours at 15°C. and 30°C,
1438
J. L. SELL
METHODS AND MATERIALS
Twenty-four, White Leghorn hens, 28 weeks of age and laying at a rate of 60% or more during the preceding week, were selected for the experiment. Two hens were assigned at random to each of twelve wire-mesh metabolism cages. The shifting-type metabolism cages of Lockhart et al. (1963) were used to minimize contamination of excreta with feed and feathers. This device allowed hens access to feed for a 15 minute period during each successive 45 minute cycle. The hens were allowed 2 weeks to adapt to these conditions prior to beginning the experiment. The low-Mg basal ration contained the following, expressed as a percent of the total ration: sucrose, 49.7; soybean protein2, 21.6; soybean oil, 6.0; solka floe3, 10.47; calcium carbonate (reagent grade), 2 Nutrition Biochemical Corporation, Cleveland, Ohio 44128. 3 Solka floe, BW-40, Brown Company, 277 Park Avenue, New York, New York 10017.
7.39; monobasic calcium phosphate (reagent grade), 1.83; vitamin-mineral premixes, 2.33 (Hajj and Sell, 1969); chromic oxide, 0.30; DL-methionine, 0.21; and choline chloride (99%), 0.17. This ration contained 52 p.p.m. Mg, 3.2 percent Ca and 17.4 percent protein by analysis. Chromic oxide was included in the ration as an index material. During a 6-week, pre-experimental period, all hens were fed the above ration to which sufficient magnesium sulfate was added to give 500 p.p.m. of Mg in the ration. Distilled water was supplied ad libitum. Four magnesium levels were tested. These levels were 52, 170, 270 and 370 p.p.m., by analysis, and were obtained by varying the amount of magnesium sulfate in the basal diet at the expense of an equal weight of solka floe. Each of the 4 ration treatments was assigned to hens in 3 metabolism cages. Based upon previous experience, it was anticipated that Mg deficiency would develop within 10 to 14 days in hens fed the ration containing 52 p.p.m. Mg. Therefore, collection of excreta from all hens commenced 10 days after start of the trial. Collections were made for 3 successive, 3-day intervals, with each 3-day collection handled separately for laboratory analysis. At the end of the final collection period, blood samples were obtained from all hens by heart probe and serums harvested. Feed consumption and egg production data were recorded during the experiment. Ration and excrement samples were dried at 65°C. for 48 hours in an air convection oven, ground and stored in sealed containers until analyses were performed. Nitrogen was determined by the macroKjeldahl procedure and heats of combustion were measured in an adiabatic calorimeter. Weighed samples of excreta and rations
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etary energy as related to Mg status of chickens. Marked disturbances in calcium (Ca) metabolism due to Mg deficiency have been observed in several species (Aikawa, 1963). Bunce et al. (1963) reported that dietary protein and Mg were interrelated in a manner whereby the Mg requirement of chicks and rats increased as dietary protein level increased. Mazzocco et al. (1966) found that rats fed a Mg deficient ration suffered from aminoaciduria and retained less dietary nitrogen than their counterparts fed a ration supplemented with Mg. The experiment reported herein was conducted to determine the effect of Mg deficiency in the laying hen on the utilization of dietary Ca, Mg and nitrogen, and the metabolizable energy value of the ration.
1439
M A G N E S I U M NUTRITTJRE OF THE H E N
TABLE 1.—Feed consumption, egg production and concentration of Ca and Mg in the serum as influenced by ration Mg level Dietary Mg (p.p.m.) 52 170 270 370 Standard error of the mean 1
Hen-day feed consumption (g.) 79al
81" 100b 94 b + 2.4
(%)
Serum Ca (mg./lOO ml.)
Serum Mg (mg./lOO ml.)
25.O 40.5 b 53.4" 76.2" + 3.7
24.0» 27.3 b 27.4 b 21.8" + 0.7
0.58" 1.49b 2.38" 2.36° + 0.10
H.D. egg production
Means within an item not followed by the same superscript letter are significantly different (P<0.05).
Metabolizable energy values for the rations were calculated according to the procedure of Hill and Anderson (1958). The d a t a were subjected to statistical analysis (Snedecor, 1956) and multiple range comparisons (Duncan, 1955). RESULTS AND DISCUSSION
Hen-day feed consumption during the 9-day collection interval was significantly ( P < 0 . 0 5 ) less for hens fed rations containing 52 or 170 p.p.m. Mg than for hens fed 270 or 370 p.p.m. Mg (Table 1). R a t e 4 Perkin-Elmer Model 303 Atomic Absorption Spectrophotometer, Perkin-Elmer Corporation, Norwalk, Connecticut.
of egg production was directly related to concentration of Mg in the ration with hens fed 370 p.p.m. Mg producing at a relatively high rate. T h e findings are consistent with those of Hajj and Sell (1969) except t h a t they did not observe an adverse effect on egg production as long as Mg comprised 255 p.p.m. or more of the ration. I n the current study, 270 p.p.m. M g failed to support a high rate of egg production even though feed consumption was in a normal range. T h e effects of ration t r e a t m e n t on serum Ca concentration were not consistent (Table 1). Calcium concentration in serum was reduced significantly ( P < 0 . 0 5 ) when the lowest and highest levels of M g were fed as compared with the 2 intermediate levels. An explanation for these results was not apparent from the d a t a collected. Hajj (1968) observed a decrease in serum Ca concentration of Mg deficient hens only after severe anorexia developed. By the end of the trial, serum Mg concentration was very low for hens fed 170 p.p.m. or less Mg confirming previous findings of Cox and Sell (1967) and Sell et al. (1967). T h e nutrient utilization data were consistent from one, 3-day collection period to another. Therefore, the data collected over the total 9-day interval were pooled for presentation.
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were washed for 24 hours at 550°C. T h e residue of each sample was washed into a 110 ml. digestion flask with 10 ml. of perchloric acid digestion mixture (Bolin and Lockhart, 1960) and the flask contents heated until oxidation of chromic oxide was complete. T h e digest was diluted to flask volume with distilled water, and chromic oxide concentration determined colorimetrically. An aliquot of the diluted digest was further diluted with appropriate amounts of lanthanum chloride solution and distilled water, preparatory for Mg and Ca analysis. Magnesium and Ca concentrations in the digests and in serum samples were determined by atomic absorption spectrophotometry. 4
1440
J. L. SELL
as well as difference in the physiological status of the hens used. The metabolizable energy value of the ration was not changed by Mg deficiency (Table 2). I t is well known that Mg plays a key role in energy metabolsim in the body. Hajj and Sell (1969) found that the rate of oxidative phosphorylation in livers of hens fed a ration containing 55 p.p.m. was less than one-half that of hens fed 455 p.p.m. Mg. However, it appears that the derangement of energy metabolism within the body as induced by Mg deficiency in the current study was not great enough to measurably affect the ability of the hens to derive energy from the ration. Percent retention of Mg was lowest in hens fed the ration containing 52 p.p.m. Mg and highest in those fed 170 p.p.m. Retention decreased slightly with each further increment of Mg above 170 p.p.m. The very low retention of Mg by hens fed the ration containing 52 p.p.m. may reflect poor availability of the Mg contained in the basic ingredients or it may reflect an inability of the hen to conserve absorbed Mg. There is only meager evidence on these points, but research such as that conducted by McCance and Widdowson (1939), Aikawa, (1958) and Bartley et al. (1961) indicates that very little
TABLE 2.—Retention of nitrogen, Ca and Mg, and ration metabolizable energy as influenced by ration Mg level
Dietary Mg (p.p.m.) 52 170 270 370 Standard error of the mean
N retention
Ca retention
(%)
(%)
43.3" 1 46.4* 47.6* 44.4* + 2.3
41.1" 42.3» 39.7" 44.6" + 3.2
Ration metabolizable energy (Kcal./g.) 3.134" 3.138" 3.176" 3.172" + 0.021
Mg retention
(%) 10.3" 58.7° 53.2 b ° 46. Sb + 3.0
Means within an item not followed by the same superscript letter are significantly different (P<0.05).
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There were no significant effects of ration Mg level on percent nitrogen retention (Table 2) in spite of the marked decrease in feed consumption and productivity of hens fed low-Mg rations. Mazzocco et al. (1966) observed marked aminoaciduria and increased excretion of nitrogen in the urine of Mg deficient rats. Nitrogen retention also was reduced in these rats, although the magnitude of decrease was not statistically significant. Mazzocco et al. (1966) concluded that Mg deficiency leads to deranged protein metabolism with a concomitant decrease in utilization of dietary protein. If this occurred in the hens, the magnitude of change was too small to be detected in the present study. Percent Ca retention was not affected noticeably by ration Mg level. Taylor and Kirkley (1967) found that hens retained over 50% of their dietary Ca during periods of lay as contrasted to only 17% during non-laying periods. A similar relationship was not observed in the current experiment. Hens fed 52 p.p.m. Mg continued to retain a relatively high proportion of ingested Ca even though they had ceased to produce eggs during the last 6 days of the experiment. These conflicting observations were probably the result of differences in quantitative intake of Ca
1441
MAGNESIUM NUTRITURE OF THE H E N
20
10
20 30 Mg Consumed (mg/day/hen)
40
- & •
FIG. 1. Retention of Mg by the laying hen as related to amount of Mg consumed. The points represent individual observations and the solid line represents the regression of Mg retained on intake of Mg (Y=0.5414X-1.004).
(Mg) deficiency in the laying hen on the utilization of dietary Mg, calcium (Ca), nitrogen and energy was determined. Magnesium deficiency developed in hens fed rations containing 270 p.p.m. or less Mg as evidenced by significantly ( P < 0.05) reduced egg production. Feeding rations containing 52 or 170 p.p.m. Mg also resulted in decreased feed consumption and hypomagnesemia but did not affect the retention of dietary Ca or nitrogen. Metabolizable energy value of the ration was not affected by Mg deficiency. Retention of dietary Mg from semi-purified rations, in which most of the Mg was supplied by supplemental magnesium sulfate, was greater than 50%. These findings are discussed in relation to the potential availability of Mg supplied by ingredients of practical laying hen rations. ACKNOWLEDGEMENTS
SUMMARY The influence of dietary magnesium
The author gratefully acknowledges the technical assistance of Robert L.
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endogenous Mg is excreted in the feces by non-ruminant animals. Also, animals fed Mg deficient rations excreted very little Mg in the urine. Assuming that the hen handles Mg in a manner similar to other species, it would appear that the low retention of Mg by hens fed the 52 p.p.m. Mg rations was due to low availability of Mg for absorption. This low retention also explains the extremely rapid development of Mg deficiency in hens as reported by Sell et al. (1967) when a similar low-Mg ration was fed. A linear relationship existed between the quantity of Mg retained and the amount ingested (Figure 1). However, it is doubtful if this linear relationship would continue when larger amounts of Mg were consumed. The upper level of intake of Mg in this trial (34 to 35 mg./hen/day) has been shown to be the minimum requirement of the hen for overall reproduction performance (Hajj and Sell, 1969), and intakes in excess of 35 to 40 mg. of Mg per day would probably cause excretion of increasing proportions of the Mg consumed. Since these data for dietary Mg retention were obtained by feeding magnesium sulfate in a semi-purified ration, they should be viewed with caution. Attempts to extend these relatively high retention values to practical rations might not be justified, particularly since Gunther and Lenkeit (1964) found that high producing hens fed a ration containing 1900 p.p.m. Mg from natural ingredients retained only 6 to 9% of the Mg consumed. Also, their hens showed a slight, but consistent, negative Mg balance. Further studies designed to determine the availability of Mg from practical feedstuffs for poultry as well as other animals is needed.
1442
J. L. SELL
Johnson and Rikka Lunde in carrying out this study. REFERENCES
NEWS AND NOTES {Continued from page 1413) bilities and just the hugeness of the whole display. I don't believe anybody could realize the opportunities that are available in this industry without seeing these exhibits. "This trip to the Junior Fact Finding Conference will really be something I will remember the rest of my life. I can't remember ever being so affected by anything before. It strengthened my desire to get more of an education and maybe go into some phase of poultry, such as in public relations. I plan to major in some form of agriculture and after this trip, it doesn't look like anything could beat the poultry industry."
Terry expressed his thanks to those who made his trip possible: Yell County Farm Bureau, Aikansas Valley Industries, Production Credit Association, the Arkansas Poultry Federation, and also Delano Robberson, F.F.A. Advisor at Plain view, the group's chaperon in Kansas City, Garlen T. Willis, his F.F.A. advisors, and his parents, Mr. and Mrs. Marvin Sullivan. Donna Harding of Mount Olivet, Kentucky, and Sally Kloepping of Lexington, Nebraska, placed second and third. They each received a pen and desk set. The Junior Fact Finding Conference, held in con-
{Continued on page 1452)
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Aikawa, J. K., E. L. Rhoades and G. S. Gordon, 1958. Urinary and fecal excretion of orally administered Mg28. Proc. Soc. Exp. Biol. Med. 98: 29-31. Aikawa, J. K., 1963. The Role of Magnesium in Biologic Processes. C. C Thomas, Springfield, 111. Almquist, H. J., 1942. Magnesium requirement of the chick. Proc. Soc. Exp. Biol. Med. 49:544-545. Bartley, J. C , E. F. Reber, J. W. Yusken and H. W. Norton, 1961. Magnesium balance study in pigs three to five weeks of age. J. An. Sci. 20: 137-141. Bolin, D. W., and W. C. Lockhart, 1960. The use of perchloric acid as a sole oxidizing reagent for organic matter and chromium oxide. Proc. North Dakota Acad. Sci. 14: 102-105. Bunce, G. E., P. G. Reeves, T. S. Oba and H. E. Sauberlich, 1963. Influence of the dietary protein level on the magnesium requirement. J. Nutr. 79: 220-226. Cox, A. C , and J. L. Sell, 1967. Magnesium deficiency in the laying hen. Poultry Sci. 46: 675680. Duncan, D. B., 1955. Multiple range and multiple F tests. Biometrics, 11: 1-42. Gardiner, E. E., J. C. Rogler and H. E. Parker, 1960. Magnesium requirement of the chick. Poultry Sci. 39:1111-1115. Gunther, V. K., and W. Lenkeit, 1964. Langfristige untersuchengen uber den calcium-phosphor-und magnesium umstaz der legehenne. Feitschrift
Tierphysiol, Tierernahrung and Fultermiltelkunde, 19: 265-291. Hajj, R. N., 1968. Magnesium requirement and metabolism of the laying hen. Unpublished Ph.D. Thesis, Library, North Dakota State University, Fargo, North Dakota. Hajj, R. N., and J. L. Sell, 1969. Magnesium requirement of the laying hen for reproduction. J. Nutr. 97: 441-448. Hill, F. W., and D. L. Anderson, 1958. Comparison of metabolizable and productive energy determined with chickens. J. Nutr. 64: 587-604. Lockhart, W. C , R. L. Bryant and D. W. Bolin, 1963. A shifting type metabolism pen. Bulletin, North Dakota Farm Research 23: 16-19. Mazzocco, V. E., G. Lizarralde, E. B. Flink and J. E. Jones, 1966. Generalized aminoaciduria in the magnesium deficient rat. Proc. Soc. Exp. Biol. Med. 123:403^08. McCance, R. A., and E. M. Widdowson, 1939. Fate of calcium and magnesium after intravenous administration to normal persons. Biochem. J. 33: 523-531. Sell, J. L., R. Hajj, A. Cox and W. Guenter, 1967. Effect of magnesium deficiency in the hen on egg production and hatchability of eggs. Brit. Poultry Sci. 8: 55-64. Snedecor, G. W., 1956. Statistical Methods, Iowa State University Press. Ames, Iowa. Taylor, T. G., and J. Kirkley, 1967. The absorption and excretion of minerals by laying hens in relation to egg shell formation. Brit. Poultry Sci. 8: 289-295. Van Reen, R., and P. B. Pearson, 1953. Magnesium deficiency in the duck. J. Nutr. 51: 191-203.
dead sperm ratios were not reflected in the fertility experiment.
1437
to semen used for inseminating hens within a half hour. ACKNOWLEDGEMENTS
SUMMARY
Support for this research was received from the Ontario Department of Agriculture and Food and the National Research Council of Canada Operating Grant A1970. The authors gratefully acknowledge the cooperation and assistance of Dr. J.W. Macpherson in conducting these studies and reviewing the manuscript. REFERENCES Blackshaw, A. W., 1958. The effect of glycerol on supra-vital staining of spermatozoa. Australian Vet. J. 34: 71-76. Brown, K. I., 1966. Some factors affecting storage of turkey semen. Ohio Res. Summ. 17, Ohio Agr. Res. and Dev. Center, Wooster, Ohio. Cooper, D. M., and J. C. Rowell, 1958. Relations between fertility, embryonic survival and some semen characteristics in the chicken. Poultry Sci. 37: 699-707. Hackett, A. J., and J. W. Macpherson, 1965. Some staining procedures for spermatozoa. A review. Can. Vet. J. 6: 55-62. Harper, J. A., 1955. The effect of holding time of turkey semen on fertilizing capacity. Poultry Sci. 34: 1289-1291.
Magnesium Nutriture of the Hen: Influence on Retention of Magnesium, Calcium, and Nitrogen, and on Ration Metabolizable Energy Value1 J. L. SELL Animal Science Department, North Dakota State University, Fargo, North Dakota 58102 (Received for publication March 10, 1969)
M
AGNESIUM (Mg) deficiency has been described for many animal species including chicks (Almquist, 1942; and Gardiner et al, 1960), ducks (Van 1 Published with the approval of the Director of the North Dakota Agricultural Experiment Station as Journal Article No. 186, Project H-7-26.
Reen and Pearson, 1953) and laying hens (Sell et ah, 1967). Signs of this deficiency include impaired reproduction, hypomagnesemia, anorexia and death. Despite considerable data describing clinical manifestations of Mg deficiency, little information is available concerning mineral and nitrogen balance, or utilization of di-
Downloaded from http://ps.oxfordjournals.org/ at Oakland University on July 1, 2015
Eosin nigrosin was estimated to be a more satisfactory stain than bromphenol blue-nigrosin or Congo red-nigrosin for differentiating between the degrees of viability of sperm on the basis of trials with chicken semen, using a total of 72 counts each comprised of 100 sperm. The proportion of stained turkey sperm, using eosin nigrosin on 144 counts each comprised of 100 sperm, was increased during four hours of storage. A collection temperature of 30° C. produced a lower proportion of stained sperm than 15°C. while fewer stained sperm were encountered with a holding temperature of 15°C. as opposed to 30°C. during four hours of storage. However, the use of the same collection and storage temperatures in a fertility experiment with 84 turkey females revealed a significant drop in fertility only in the comparison of semen, stored for five hours at 15°C. and 30°C,
1438
J. L. SELL
METHODS AND MATERIALS
Twenty-four, White Leghorn hens, 28 weeks of age and laying at a rate of 60% or more during the preceding week, were selected for the experiment. Two hens were assigned at random to each of twelve wire-mesh metabolism cages. The shifting-type metabolism cages of Lockhart et al. (1963) were used to minimize contamination of excreta with feed and feathers. This device allowed hens access to feed for a 15 minute period during each successive 45 minute cycle. The hens were allowed 2 weeks to adapt to these conditions prior to beginning the experiment. The low-Mg basal ration contained the following, expressed as a percent of the total ration: sucrose, 49.7; soybean protein2, 21.6; soybean oil, 6.0; solka floe3, 10.47; calcium carbonate (reagent grade), 2 Nutrition Biochemical Corporation, Cleveland, Ohio 44128. 3 Solka floe, BW-40, Brown Company, 277 Park Avenue, New York, New York 10017.
7.39; monobasic calcium phosphate (reagent grade), 1.83; vitamin-mineral premixes, 2.33 (Hajj and Sell, 1969); chromic oxide, 0.30; DL-methionine, 0.21; and choline chloride (99%), 0.17. This ration contained 52 p.p.m. Mg, 3.2 percent Ca and 17.4 percent protein by analysis. Chromic oxide was included in the ration as an index material. During a 6-week, pre-experimental period, all hens were fed the above ration to which sufficient magnesium sulfate was added to give 500 p.p.m. of Mg in the ration. Distilled water was supplied ad libitum. Four magnesium levels were tested. These levels were 52, 170, 270 and 370 p.p.m., by analysis, and were obtained by varying the amount of magnesium sulfate in the basal diet at the expense of an equal weight of solka floe. Each of the 4 ration treatments was assigned to hens in 3 metabolism cages. Based upon previous experience, it was anticipated that Mg deficiency would develop within 10 to 14 days in hens fed the ration containing 52 p.p.m. Mg. Therefore, collection of excreta from all hens commenced 10 days after start of the trial. Collections were made for 3 successive, 3-day intervals, with each 3-day collection handled separately for laboratory analysis. At the end of the final collection period, blood samples were obtained from all hens by heart probe and serums harvested. Feed consumption and egg production data were recorded during the experiment. Ration and excrement samples were dried at 65°C. for 48 hours in an air convection oven, ground and stored in sealed containers until analyses were performed. Nitrogen was determined by the macroKjeldahl procedure and heats of combustion were measured in an adiabatic calorimeter. Weighed samples of excreta and rations
Downloaded from http://ps.oxfordjournals.org/ at Oakland University on July 1, 2015
etary energy as related to Mg status of chickens. Marked disturbances in calcium (Ca) metabolism due to Mg deficiency have been observed in several species (Aikawa, 1963). Bunce et al. (1963) reported that dietary protein and Mg were interrelated in a manner whereby the Mg requirement of chicks and rats increased as dietary protein level increased. Mazzocco et al. (1966) found that rats fed a Mg deficient ration suffered from aminoaciduria and retained less dietary nitrogen than their counterparts fed a ration supplemented with Mg. The experiment reported herein was conducted to determine the effect of Mg deficiency in the laying hen on the utilization of dietary Ca, Mg and nitrogen, and the metabolizable energy value of the ration.
1439
M A G N E S I U M NUTRITTJRE OF THE H E N
TABLE 1.—Feed consumption, egg production and concentration of Ca and Mg in the serum as influenced by ration Mg level Dietary Mg (p.p.m.) 52 170 270 370 Standard error of the mean 1
Hen-day feed consumption (g.) 79al
81" 100b 94 b + 2.4
(%)
Serum Ca (mg./lOO ml.)
Serum Mg (mg./lOO ml.)
25.O 40.5 b 53.4" 76.2" + 3.7
24.0» 27.3 b 27.4 b 21.8" + 0.7
0.58" 1.49b 2.38" 2.36° + 0.10
H.D. egg production
Means within an item not followed by the same superscript letter are significantly different (P<0.05).
Metabolizable energy values for the rations were calculated according to the procedure of Hill and Anderson (1958). The d a t a were subjected to statistical analysis (Snedecor, 1956) and multiple range comparisons (Duncan, 1955). RESULTS AND DISCUSSION
Hen-day feed consumption during the 9-day collection interval was significantly ( P < 0 . 0 5 ) less for hens fed rations containing 52 or 170 p.p.m. Mg than for hens fed 270 or 370 p.p.m. Mg (Table 1). R a t e 4 Perkin-Elmer Model 303 Atomic Absorption Spectrophotometer, Perkin-Elmer Corporation, Norwalk, Connecticut.
of egg production was directly related to concentration of Mg in the ration with hens fed 370 p.p.m. Mg producing at a relatively high rate. T h e findings are consistent with those of Hajj and Sell (1969) except t h a t they did not observe an adverse effect on egg production as long as Mg comprised 255 p.p.m. or more of the ration. I n the current study, 270 p.p.m. M g failed to support a high rate of egg production even though feed consumption was in a normal range. T h e effects of ration t r e a t m e n t on serum Ca concentration were not consistent (Table 1). Calcium concentration in serum was reduced significantly ( P < 0 . 0 5 ) when the lowest and highest levels of M g were fed as compared with the 2 intermediate levels. An explanation for these results was not apparent from the d a t a collected. Hajj (1968) observed a decrease in serum Ca concentration of Mg deficient hens only after severe anorexia developed. By the end of the trial, serum Mg concentration was very low for hens fed 170 p.p.m. or less Mg confirming previous findings of Cox and Sell (1967) and Sell et al. (1967). T h e nutrient utilization data were consistent from one, 3-day collection period to another. Therefore, the data collected over the total 9-day interval were pooled for presentation.
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were washed for 24 hours at 550°C. T h e residue of each sample was washed into a 110 ml. digestion flask with 10 ml. of perchloric acid digestion mixture (Bolin and Lockhart, 1960) and the flask contents heated until oxidation of chromic oxide was complete. T h e digest was diluted to flask volume with distilled water, and chromic oxide concentration determined colorimetrically. An aliquot of the diluted digest was further diluted with appropriate amounts of lanthanum chloride solution and distilled water, preparatory for Mg and Ca analysis. Magnesium and Ca concentrations in the digests and in serum samples were determined by atomic absorption spectrophotometry. 4
1440
J. L. SELL
as well as difference in the physiological status of the hens used. The metabolizable energy value of the ration was not changed by Mg deficiency (Table 2). I t is well known that Mg plays a key role in energy metabolsim in the body. Hajj and Sell (1969) found that the rate of oxidative phosphorylation in livers of hens fed a ration containing 55 p.p.m. was less than one-half that of hens fed 455 p.p.m. Mg. However, it appears that the derangement of energy metabolism within the body as induced by Mg deficiency in the current study was not great enough to measurably affect the ability of the hens to derive energy from the ration. Percent retention of Mg was lowest in hens fed the ration containing 52 p.p.m. Mg and highest in those fed 170 p.p.m. Retention decreased slightly with each further increment of Mg above 170 p.p.m. The very low retention of Mg by hens fed the ration containing 52 p.p.m. may reflect poor availability of the Mg contained in the basic ingredients or it may reflect an inability of the hen to conserve absorbed Mg. There is only meager evidence on these points, but research such as that conducted by McCance and Widdowson (1939), Aikawa, (1958) and Bartley et al. (1961) indicates that very little
TABLE 2.—Retention of nitrogen, Ca and Mg, and ration metabolizable energy as influenced by ration Mg level
Dietary Mg (p.p.m.) 52 170 270 370 Standard error of the mean
N retention
Ca retention
(%)
(%)
43.3" 1 46.4* 47.6* 44.4* + 2.3
41.1" 42.3» 39.7" 44.6" + 3.2
Ration metabolizable energy (Kcal./g.) 3.134" 3.138" 3.176" 3.172" + 0.021
Mg retention
(%) 10.3" 58.7° 53.2 b ° 46. Sb + 3.0
Means within an item not followed by the same superscript letter are significantly different (P<0.05).
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There were no significant effects of ration Mg level on percent nitrogen retention (Table 2) in spite of the marked decrease in feed consumption and productivity of hens fed low-Mg rations. Mazzocco et al. (1966) observed marked aminoaciduria and increased excretion of nitrogen in the urine of Mg deficient rats. Nitrogen retention also was reduced in these rats, although the magnitude of decrease was not statistically significant. Mazzocco et al. (1966) concluded that Mg deficiency leads to deranged protein metabolism with a concomitant decrease in utilization of dietary protein. If this occurred in the hens, the magnitude of change was too small to be detected in the present study. Percent Ca retention was not affected noticeably by ration Mg level. Taylor and Kirkley (1967) found that hens retained over 50% of their dietary Ca during periods of lay as contrasted to only 17% during non-laying periods. A similar relationship was not observed in the current experiment. Hens fed 52 p.p.m. Mg continued to retain a relatively high proportion of ingested Ca even though they had ceased to produce eggs during the last 6 days of the experiment. These conflicting observations were probably the result of differences in quantitative intake of Ca
1441
MAGNESIUM NUTRITURE OF THE H E N
20
10
20 30 Mg Consumed (mg/day/hen)
40
- & •
FIG. 1. Retention of Mg by the laying hen as related to amount of Mg consumed. The points represent individual observations and the solid line represents the regression of Mg retained on intake of Mg (Y=0.5414X-1.004).
(Mg) deficiency in the laying hen on the utilization of dietary Mg, calcium (Ca), nitrogen and energy was determined. Magnesium deficiency developed in hens fed rations containing 270 p.p.m. or less Mg as evidenced by significantly ( P < 0.05) reduced egg production. Feeding rations containing 52 or 170 p.p.m. Mg also resulted in decreased feed consumption and hypomagnesemia but did not affect the retention of dietary Ca or nitrogen. Metabolizable energy value of the ration was not affected by Mg deficiency. Retention of dietary Mg from semi-purified rations, in which most of the Mg was supplied by supplemental magnesium sulfate, was greater than 50%. These findings are discussed in relation to the potential availability of Mg supplied by ingredients of practical laying hen rations. ACKNOWLEDGEMENTS
SUMMARY The influence of dietary magnesium
The author gratefully acknowledges the technical assistance of Robert L.
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endogenous Mg is excreted in the feces by non-ruminant animals. Also, animals fed Mg deficient rations excreted very little Mg in the urine. Assuming that the hen handles Mg in a manner similar to other species, it would appear that the low retention of Mg by hens fed the 52 p.p.m. Mg rations was due to low availability of Mg for absorption. This low retention also explains the extremely rapid development of Mg deficiency in hens as reported by Sell et al. (1967) when a similar low-Mg ration was fed. A linear relationship existed between the quantity of Mg retained and the amount ingested (Figure 1). However, it is doubtful if this linear relationship would continue when larger amounts of Mg were consumed. The upper level of intake of Mg in this trial (34 to 35 mg./hen/day) has been shown to be the minimum requirement of the hen for overall reproduction performance (Hajj and Sell, 1969), and intakes in excess of 35 to 40 mg. of Mg per day would probably cause excretion of increasing proportions of the Mg consumed. Since these data for dietary Mg retention were obtained by feeding magnesium sulfate in a semi-purified ration, they should be viewed with caution. Attempts to extend these relatively high retention values to practical rations might not be justified, particularly since Gunther and Lenkeit (1964) found that high producing hens fed a ration containing 1900 p.p.m. Mg from natural ingredients retained only 6 to 9% of the Mg consumed. Also, their hens showed a slight, but consistent, negative Mg balance. Further studies designed to determine the availability of Mg from practical feedstuffs for poultry as well as other animals is needed.
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J. L. SELL
Johnson and Rikka Lunde in carrying out this study. REFERENCES
NEWS AND NOTES {Continued from page 1413) bilities and just the hugeness of the whole display. I don't believe anybody could realize the opportunities that are available in this industry without seeing these exhibits. "This trip to the Junior Fact Finding Conference will really be something I will remember the rest of my life. I can't remember ever being so affected by anything before. It strengthened my desire to get more of an education and maybe go into some phase of poultry, such as in public relations. I plan to major in some form of agriculture and after this trip, it doesn't look like anything could beat the poultry industry."
Terry expressed his thanks to those who made his trip possible: Yell County Farm Bureau, Aikansas Valley Industries, Production Credit Association, the Arkansas Poultry Federation, and also Delano Robberson, F.F.A. Advisor at Plain view, the group's chaperon in Kansas City, Garlen T. Willis, his F.F.A. advisors, and his parents, Mr. and Mrs. Marvin Sullivan. Donna Harding of Mount Olivet, Kentucky, and Sally Kloepping of Lexington, Nebraska, placed second and third. They each received a pen and desk set. The Junior Fact Finding Conference, held in con-
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Aikawa, J. K., E. L. Rhoades and G. S. Gordon, 1958. Urinary and fecal excretion of orally administered Mg28. Proc. Soc. Exp. Biol. Med. 98: 29-31. Aikawa, J. K., 1963. The Role of Magnesium in Biologic Processes. C. C Thomas, Springfield, 111. Almquist, H. J., 1942. Magnesium requirement of the chick. Proc. Soc. Exp. Biol. Med. 49:544-545. Bartley, J. C , E. F. Reber, J. W. Yusken and H. W. Norton, 1961. Magnesium balance study in pigs three to five weeks of age. J. An. Sci. 20: 137-141. Bolin, D. W., and W. C. Lockhart, 1960. The use of perchloric acid as a sole oxidizing reagent for organic matter and chromium oxide. Proc. North Dakota Acad. Sci. 14: 102-105. Bunce, G. E., P. G. Reeves, T. S. Oba and H. E. Sauberlich, 1963. Influence of the dietary protein level on the magnesium requirement. J. Nutr. 79: 220-226. Cox, A. C , and J. L. Sell, 1967. Magnesium deficiency in the laying hen. Poultry Sci. 46: 675680. Duncan, D. B., 1955. Multiple range and multiple F tests. Biometrics, 11: 1-42. Gardiner, E. E., J. C. Rogler and H. E. Parker, 1960. Magnesium requirement of the chick. Poultry Sci. 39:1111-1115. Gunther, V. K., and W. Lenkeit, 1964. Langfristige untersuchengen uber den calcium-phosphor-und magnesium umstaz der legehenne. Feitschrift
Tierphysiol, Tierernahrung and Fultermiltelkunde, 19: 265-291. Hajj, R. N., 1968. Magnesium requirement and metabolism of the laying hen. Unpublished Ph.D. Thesis, Library, North Dakota State University, Fargo, North Dakota. Hajj, R. N., and J. L. Sell, 1969. Magnesium requirement of the laying hen for reproduction. J. Nutr. 97: 441-448. Hill, F. W., and D. L. Anderson, 1958. Comparison of metabolizable and productive energy determined with chickens. J. Nutr. 64: 587-604. Lockhart, W. C , R. L. Bryant and D. W. Bolin, 1963. A shifting type metabolism pen. Bulletin, North Dakota Farm Research 23: 16-19. Mazzocco, V. E., G. Lizarralde, E. B. Flink and J. E. Jones, 1966. Generalized aminoaciduria in the magnesium deficient rat. Proc. Soc. Exp. Biol. Med. 123:403^08. McCance, R. A., and E. M. Widdowson, 1939. Fate of calcium and magnesium after intravenous administration to normal persons. Biochem. J. 33: 523-531. Sell, J. L., R. Hajj, A. Cox and W. Guenter, 1967. Effect of magnesium deficiency in the hen on egg production and hatchability of eggs. Brit. Poultry Sci. 8: 55-64. Snedecor, G. W., 1956. Statistical Methods, Iowa State University Press. Ames, Iowa. Taylor, T. G., and J. Kirkley, 1967. The absorption and excretion of minerals by laying hens in relation to egg shell formation. Brit. Poultry Sci. 8: 289-295. Van Reen, R., and P. B. Pearson, 1953. Magnesium deficiency in the duck. J. Nutr. 51: 191-203.