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The Sites of Calcium and Phosphate Absorption in the Chick1
THE SITES OF CALCIUM AND PHOSPHATE ABSORPTION I N T H E CHICK 1 S. HURWITZ AND A. BAR Department of Animal Science, The Volcani Institute of Agricultural Research, Rehovot, Israel (Received for publication December 4, 1969)
1
Contribution from The Volcani Institute of Agricultural Research, Bet Dagan, Israel. 1969 series No. -E. This work was supported in part by a grant from the United States Department of Agriculture under P.L. 480.
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FIG. 1. Ca/Y-91 (O) and P/Y-91 ( • ) along the intestine of chicks fed yttrium-91-labeled diets.
Calcium, phosphorus and yttrium-91 were analyzed as described previously (Hurwitz and Bar, 1965). The results, presented as mineral/ yttrium-91 ratios and given in Figure 1, indicate a net inflow of calcium into the duodenum. Greatest absorption of calcium occurred between the duodenum and the lower jejunum, but some also continued down to the upper ileum. The lack of change in Ca/Y-91 between the upper and the lower ileum signifies no significant absorption or secretion in this posterior segment. There was no change in the P/Y-91 ratio from feed to the duodenum, followed by a rapid decrease from the duodenum to the upper jejunum, indicating a massive phosphate absorption in the latter segment. No changes were noted in the P/Y91 ratio from the upper jejunum to the lower ileum, indicating no net absorption
324
Downloaded from http://ps.oxfordjournals.org/ at Serials Acq (Law) on May 24, 2015
The nutrition of calcium and phosphorus in the chick has been the subject of numerous investigations. However, the intestinal sites of absorption of those minerals have remained unknown, although some information on the absorption capacity of the various intestinal segments exist from in vitro and in situ experimentation (Hurwitz et al., 1967). Previous work indicated that little absorption of calcium and phosphate in the laying hen occurred beyond the jejunum (Hurwitz and Bar, 1965). Since the laying hen is rather peculiar with regard to its mineral metabolism, it was of interest to determine if those findings were also qualitatively the same in the chick. Yttrium-91 was used as a reference substance in all-vegetable diets containing 1.08% calcium and 0.77% phosphorus, supplied mostly by 0.9% calcium carbonate and 2 . 0 % dicalcium phosphate. The diet was labeled with about 60,uc./kg. of yttrium-91. Thirty-six Cornish X White Rock males, three weeks old, were fed the experimental diet for four days. They were then killed by an intracardial overdose of sodium pentabarbital, and their intestine was separated into the various segments (Figure 1). The contents from each segment (pool from three chicks) were taken for analysis.
325
RESEARCH NOTES ACKNOWLEDGMENT
The technical assistance of Mrs. M. Cotter is gratefully acknowledged. REFERENCES Hurwitz, S., and A. Bar, 1965. Absorption of calcium and phosphorus along the gastrointestinal tract of the laying fowl as influenced by dietary calcium and egg shell formation. J. Nutrition 86: 433-438. Hurwitz, S., H. C. Harrison and H. E. Harrison, 1967. Effect of vitamin D 3 on the in vitro transport of calcium by the chick intestine. J. Nutrition, 91: 319-323.
THE EFFECT OF TIME OF OVIPOSITION IN RELATION TO INSEMINATION ON FERTILITY OF CHICKEN HENS 1 N. P. JOHNSTON 2 AND J. E. PARKER Department of Poultry Science, Oregon Stale University, Corvallis, Oregon 97331 (Received for publication December 9, 1969)
Previous investigations have shown that the percentage of fertile eggs laid following artificial insemination of chicken hens in the morning is lower than that from hens inseminated in the afternoon (Parker, 1945; Bornstein el al., 1960). A generally accepted explanation is that more hens have hard-shelled eggs in their uteri in the morning. Several investigators have reported that fertility of hens with hard-shelled eggs in their uteri at the time of insemination is lower than that from other hens (Moore and Byerly, 1942; Malmstrom, 1943; Parker, 1945; Bornstein el al., 1960). However, more recent results (Parker and Arscott, 1965) showing that fertility from hens inseminated at 9 p.m. was comparable to that of hens inseminated at mid-afternoon are not in 1 Technical Paper No. 2779. Oregon Agricultural Experiment Station. Supported in part by Western Regional Project W-50. 2 Chester M. Wilcox Memorial Scholarship recipient 1966-67.
accord with the above explanation since most of the hens inseminated at 9 p.m. had eggs in their uteri at the time of insemination—many with hard shells. This suggests that not all stages of the hardegg-in-uterus condition are detrimental to fertilization. To gain additional information on the effect of stages of egg formation on fertilization, experiments were initiated to determine the relation of time of oviposition, before and after artificial insemination, on the fertility of hens' eggs. EXPERIMENTAL PROCEDURE Two experiments were conducted, each with three groups of approximately 70 individually-caged White Leghorn pullets that were artificially inseminated at 8 a.m., 4 p.m., and 11:50 p.m. PST on different days. The females were exposed to 14 hours of light per day from 5 a.m. to 7 p.m. The first experiment was conducted in March and the second in April, 1967. Females were artificially inseminated
Downloaded from http://ps.oxfordjournals.org/ at Serials Acq (Law) on May 24, 2015
or secretion in the lower jejunum, or upper ileum. The percentage of absorption, calculated from the mineral/Y-91 ratio in the lower ileum (Hurwitz and Bar, 1965), was 19.5% and 39.9% for calcium and phosphorus, respectively. In summary, most of the absorption of calcium in the 3-week-old chick occurred in the jejunum and possibly some in the ileum. A net secretion of calcium occurred in the duodenum. Phosphate absorption occurred mostly in the upper jejunum.
1
Contribution from The Volcani Institute of Agricultural Research, Bet Dagan, Israel. 1969 series No. -E. This work was supported in part by a grant from the United States Department of Agriculture under P.L. 480.
20
I 16 o 01
-A'
r\
I
'
I
I
-
-
\>——o
£ <
"" _
f\ >— o
"•
•
m
"
c 4 2 fcDuod> «=
•
"•y j
Jejur
I
I
I
20
40
60
-
^
II-
I
80
— -
I 100
120
FIG. 1. Ca/Y-91 (O) and P/Y-91 ( • ) along the intestine of chicks fed yttrium-91-labeled diets.
Calcium, phosphorus and yttrium-91 were analyzed as described previously (Hurwitz and Bar, 1965). The results, presented as mineral/ yttrium-91 ratios and given in Figure 1, indicate a net inflow of calcium into the duodenum. Greatest absorption of calcium occurred between the duodenum and the lower jejunum, but some also continued down to the upper ileum. The lack of change in Ca/Y-91 between the upper and the lower ileum signifies no significant absorption or secretion in this posterior segment. There was no change in the P/Y-91 ratio from feed to the duodenum, followed by a rapid decrease from the duodenum to the upper jejunum, indicating a massive phosphate absorption in the latter segment. No changes were noted in the P/Y91 ratio from the upper jejunum to the lower ileum, indicating no net absorption
324
Downloaded from http://ps.oxfordjournals.org/ at Serials Acq (Law) on May 24, 2015
The nutrition of calcium and phosphorus in the chick has been the subject of numerous investigations. However, the intestinal sites of absorption of those minerals have remained unknown, although some information on the absorption capacity of the various intestinal segments exist from in vitro and in situ experimentation (Hurwitz et al., 1967). Previous work indicated that little absorption of calcium and phosphate in the laying hen occurred beyond the jejunum (Hurwitz and Bar, 1965). Since the laying hen is rather peculiar with regard to its mineral metabolism, it was of interest to determine if those findings were also qualitatively the same in the chick. Yttrium-91 was used as a reference substance in all-vegetable diets containing 1.08% calcium and 0.77% phosphorus, supplied mostly by 0.9% calcium carbonate and 2 . 0 % dicalcium phosphate. The diet was labeled with about 60,uc./kg. of yttrium-91. Thirty-six Cornish X White Rock males, three weeks old, were fed the experimental diet for four days. They were then killed by an intracardial overdose of sodium pentabarbital, and their intestine was separated into the various segments (Figure 1). The contents from each segment (pool from three chicks) were taken for analysis.
325
RESEARCH NOTES ACKNOWLEDGMENT
The technical assistance of Mrs. M. Cotter is gratefully acknowledged. REFERENCES Hurwitz, S., and A. Bar, 1965. Absorption of calcium and phosphorus along the gastrointestinal tract of the laying fowl as influenced by dietary calcium and egg shell formation. J. Nutrition 86: 433-438. Hurwitz, S., H. C. Harrison and H. E. Harrison, 1967. Effect of vitamin D 3 on the in vitro transport of calcium by the chick intestine. J. Nutrition, 91: 319-323.
THE EFFECT OF TIME OF OVIPOSITION IN RELATION TO INSEMINATION ON FERTILITY OF CHICKEN HENS 1 N. P. JOHNSTON 2 AND J. E. PARKER Department of Poultry Science, Oregon Stale University, Corvallis, Oregon 97331 (Received for publication December 9, 1969)
Previous investigations have shown that the percentage of fertile eggs laid following artificial insemination of chicken hens in the morning is lower than that from hens inseminated in the afternoon (Parker, 1945; Bornstein el al., 1960). A generally accepted explanation is that more hens have hard-shelled eggs in their uteri in the morning. Several investigators have reported that fertility of hens with hard-shelled eggs in their uteri at the time of insemination is lower than that from other hens (Moore and Byerly, 1942; Malmstrom, 1943; Parker, 1945; Bornstein el al., 1960). However, more recent results (Parker and Arscott, 1965) showing that fertility from hens inseminated at 9 p.m. was comparable to that of hens inseminated at mid-afternoon are not in 1 Technical Paper No. 2779. Oregon Agricultural Experiment Station. Supported in part by Western Regional Project W-50. 2 Chester M. Wilcox Memorial Scholarship recipient 1966-67.
accord with the above explanation since most of the hens inseminated at 9 p.m. had eggs in their uteri at the time of insemination—many with hard shells. This suggests that not all stages of the hardegg-in-uterus condition are detrimental to fertilization. To gain additional information on the effect of stages of egg formation on fertilization, experiments were initiated to determine the relation of time of oviposition, before and after artificial insemination, on the fertility of hens' eggs. EXPERIMENTAL PROCEDURE Two experiments were conducted, each with three groups of approximately 70 individually-caged White Leghorn pullets that were artificially inseminated at 8 a.m., 4 p.m., and 11:50 p.m. PST on different days. The females were exposed to 14 hours of light per day from 5 a.m. to 7 p.m. The first experiment was conducted in March and the second in April, 1967. Females were artificially inseminated
Downloaded from http://ps.oxfordjournals.org/ at Serials Acq (Law) on May 24, 2015
or secretion in the lower jejunum, or upper ileum. The percentage of absorption, calculated from the mineral/Y-91 ratio in the lower ileum (Hurwitz and Bar, 1965), was 19.5% and 39.9% for calcium and phosphorus, respectively. In summary, most of the absorption of calcium in the 3-week-old chick occurred in the jejunum and possibly some in the ileum. A net secretion of calcium occurred in the duodenum. Phosphate absorption occurred mostly in the upper jejunum.