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Relation of Time of Day of Artificial Insemination to Fertility and Hatchability of Hens’ Eggs
Relation of Time of Day of Artificial Insemination to Fertility and Hatchability of Hens' Eggs JESSE E. PARKER* University of Tennessee Agricultural Experiment Station, Knoxville, Tennessee (Received for publication, October 23, 1944)
* Poultry husbandman, North Dakota Agricultural Experiment Station, Fargo since May 1944.
$
314
was only 32.6 percent when insemination was made while a hard-shell egg was in the uterus, and 70 percent if a membranous egg was in the oviduct. Percentages of fertility were calculated on the basis of eggs produced in a 10-day period subsequent to insemination. The author is not acquainted with any work on the relation of time of day of insemination to the hatchability ot fertilized eggs. EXPERIMENTAL PROCEDURE
Artificial inseminations were made in three groups of battery-confined Rhode Island Red pullets, with reference to time of day. One group was inseminated between 6:30 and 7:00 a.m., another at noon, and the third between 5:30 and 6:00 p.m., Central Standard Time. All inseminations were made with 0.1 c.c. of mixed semen; semen from the same males being used with all three groups. The hens were inseminated one time, and the percentages of fertility and of hatchability of fertile eggs were determined on the basis of the number of uncracked eggs laid during a period covering the second to fourteenth day, inclusive, following insemination. Just after insemination the hens were examined by anal palpation with the index finger. Notation was made as to whether a hard-shell egg, soft-shell egg, or no egg was observed in the repro-
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C l N C E artificial insemination, as a ^ method of fertilizing hens' eggs, is being used by many research workers and some poultry breeders, the relation of time of day of insemination to fertility and hatchability of eggs should be of interest. Moore and Byerly (1942) showed that the percentage of fertile eggs laid when hens were inseminated while a hard-shell egg was in the uterus was lower than when inseminations were accomplished with hens that had just laid or with hens that had no egg in the oviduct. Results of their studies suggest that for highest fertility, hens should not be inseminated in the early part of the day, since at that time a large percentage of them would have a hard-shell egg in the oviduct. Gracewski and Scott (1943) observed that under natural mating conditions fertility was increased when males were permitted to run in the breeding pen only during the afternoon. When matings were restricted to the forenoon, the resulting fertility was even lower than when the matings were not restricted. They interpreted their results as confirming Malmstrom's conclusion that a membranous egg in tlie oviduct at the time of mating enhances the possibility of fertilization. Malmstrom (1943) observed that fertility
F E R T I L I T Y AND H A T C H A B I L I T Y OF H E N S ' E G G S ,
315
TABLE 1.—Relation of time of day of artificial insemination to fertility and hatchability Fertility
Time of insemination
Hens inseminated
Eggs incubated
Morning Noon Afternoon
35 36 36
293 297 279
Weighted mean
Unweighted mean
Weighted mean
Unweighted mean
50.9 71.7 77.8
49.0 71.4 76.8
79.9 79.8 91.7
80.0 78.8 86.6
RESULTS
The data in Table 1 show that a pronounced reduction in fertility resulted when hens were inseminated in the morn-
ing. Hens inseminated in the late afternoon produced a slightly higher percentage of fertile eggs than those inseminated at noon, but the difference was not statistically significant (Table 2). Hatchability of fertilized eggs was significantly higher in the afternoon-inseminated group than in the morning or noon group. With a view to finding some explanation for the observed differences in fertility and hatchability, data on time of laying and the results of the oviducal examination in the three groups were summarized (Table 3). It is noted that a large percentage of the hens in the morning-inseminated group laid after insemination, and hence had a hard-shell egg in the uterus; whereas, in the two other groups only a few laid after insemination or had hardshell eggs. A comparison oi the noon group
-Results of chi-square tests for significance of differences based on weighted averages
Comparisons
^vISiT^
Significance
Differences infertility: 1. Morning vs. afternoon inseminations 2. Morning vs. noon inseminations 3. Noon vs. afternoon inseminations 4. Laid before vs. laid after insemination 5. Laid neither before nor after vs. laid after insemination 6. Soft egg vs. hard egg in uterus 7. No egg vs. hard egg in uterus 8. Soft egg vs. no egg in uterus
45.0 27.1 2.8 74.0 42.9 58.1 48.0 2.9
+ + + + + +
Differences in hatchability: 9. Morning vs. afternoon inseminations 10. Noon vs. afternoon inseminations 11. Laid before vs. laid after insemination 12. Laid neither before nor after vs. laid after insemination 13. Soft egg vs. hard egg in uterus 14. Soft egg vs. no egg in uterus 15. No egg vs. hard egg in uterus
10.9 12.5 5.2 4.8 7.4 5.0 0.8
+ + + + + +
Downloaded from http://ps.oxfordjournals.org/ by guest on April 13, 2015
ductive tract. Records were also kept as to whether the hens laid before or after they were inseminated on the day of insemination. Two experiments were conducted: one on December 29, 30, and 31, 1942, and the other on March 9, 10, and 12, 1943. Artificial lights were not used. A total of 107 inseminations were made and 869 eggs were incubated in* the two experiments. To simplify the tabulation of results, and because the observations were similar in most respects, the data from the two experiments are combined for presentation in this paper.
TABLE 2.-
Hatchability
316
JESSE E. PARKER TABLE 3.—Data on time of laying and oviducal examination
Hens inseminated
T i m e of insemination
E g g laying on d a y of insemination Before insemination
After insemination
N o egg
5 22 30
23 4 0
12 22 15
35 36 36
Morning Noon Afternoon
E x a m i n a t i o n of oviduct Soft
egg
Hardshell egg
0 10 18
23 4 3
TABLE 4.—Relation of time of laying and kind of egg in oviduct at time of insemination to fertility and hatchability Kind of egg in oviduct Egg laying on day of insemination
Laid before insemination Laid after Insemination
Soft egg
No egg .
Hard egg
Fertil- HatchFertil- HatchFertil- HatchFertil- HatchHens Eggs ity ability Hens Eggs ity ability Hens Eggs ity ability Hens Eggs ity ability No.
No.
%
%
No.
No.
* 36
295
73.6
81.6
21
182
_
—
—
70.2
86.4
7
59
82.6
28
241
_
Laid neither before nor after insemination
13
84
Total
49
379
72.8
%
%
No.
78.0
91.5
— — —
—
27
81.4
85.4
3
78.8 | 90.0 | 30
No.
%
%
No.
No.
%
%
57
477
75.3
85.5
27
226
42.0
75.8
42.0
75.8
23
78.3
94.4
23
166
75.3
87.2
249
45.4
78.8
107
869
66.6
84.3
226
Downloaded from http://ps.oxfordjournals.org/ by guest on April 13, 2015
and the afternoon group with respect to with a hard-shell egg in the oviduct at observed presence or absence of hard- or time of insemination were only 45 percent soft-shell egg in the oviduct shows that a fertile; whereas, those from hens in which greater number of the noon group had no no egg or a soft egg was observed were 73 egg in the oviduct, and a greater number and 79 percent fertile, respectively. The of the afternoon group had a soft-shell two latter percentages indicate that hens egg in the oviduct at the time of insemina- were more easily fertilized when a soft egg was in the oviduct than when no egg tion. The relation of time of laying on day of was observed. The difference, however, insemination to subsequent fertility and did not prove to be significant (Table 2). hatchability is shown in Table 4. The per- Fertile eggs from hens with a soft egg in centages of fertility and hatchability were the oviduct at time of insemination similar in the group that laid before in- hatched significantly better than those semination and in the group that laid from hens with no egg or with a hard-shell neither before nor after insemination; but egg in the oviduct at time of insemination. in the group that laid after insemination, The small difference between the hatchaboth fertility and hatchability were lower bility percentages of the no-egg group and than in the other two groups. The differ- the hard-egg group was not significant. ences between the hatchability percentSince fertility is reduced by inseminaages were not as great as the differences tion of hens just before they lay, when a between the fertility percentages, but in hard-shell egg is in the oviduct, it is not both cases the differences were statis- surprising that the percentage fertility tically significant (Table 2). ' was low when hens were inseminated in Table 4 also shows that eggs from hens the morning. About two-thirds of the
FERTILITY AND HATCHABILITY OF H E N S ' EGGS
DISCUSSION
The results of these experiments indicate that higher fertility and hatchability might be obtained in breeding pens or flocks if the males were allowed to mate with the females only in the afternoons during the hatching season. So far as fertility is concerned, the results obtained are in agreement with those reported by Gracewski and Scott (1943), Moore and Byerly (1942), and Malmstrom (1943). The observation that hatchability was increased when hens were inseminated in the late afternoon is interesting and has important implications. This increased hatchability has been shown to be related to the fact that the larger percentage of hens have a soft or membranous egg in the lower region of the reproductive system late in the day. No definite explanation of this relationship is offered. Could it be that the oviducal environment concurrent with earlier stages of egg-shell formation so affect the spermatozoa as to
determine the fate of the embryos resulting from the union of these spermatozoa with ova? SUMMARY
In experiments with three groups of hen artificially inseminated, one in the early morning, one at noon, and one in the late afternoon, it was observed that fertility was lowest in the morning group and highest in afternoon group. Hatchability of fertile eggs was significantly higher in the afternoon group. Time of laying with respect to insemination was found to affect both fertility and the hatchability of fertile eggs. Hens that laid after insemination, but on the same day, had lower fertility and hatchability than hens that laid before insemination or those that laid neither before nor after. Percentages of fertility and hatchability in the two latter groups were very nearly the, same. Hens observed by anal palpation to have a hard-shell egg in the uterus at time of insemination produced a lower percentage of fertile eggs than those with no egg or with a soft egg in the posterior region of the oviduct. Both fertility and hatchability were highest in the soft-egg group. The results of these investigations indicate that it is possible to increase hatchability as well as fertility by restricting the mating of chickens to the afternoons. REFERENCES
Gracewski, J. J., and H. M. Scott, 1943, The influence of time of mating on fertility. Poultry Sci. 22:264-265. Malmstrom, M. V., 1943. Factors influencing fertility in the domestic fowl. Master's thesis—Univ. Conn. Moore, 0 . K., and T. C. Byerly, 1942. Relation of time of insemination to percent fertility. Poultry Sci. 21:253-255.^
Downloaded from http://ps.oxfordjournals.org/ by guest on April 13, 2015
morning-inseminated group laid following insemination and had a hard-shell egg in the oviduct at time of insemination (Table 3). The increase in the percentage of fertility of the afternoon-inseminated hens over that of hens inseminated at noon was probably influenced by the facts that a larger percentage of them had a soft egg in the oviduct at time of insemination and none of them laid just after insemination. Both conditions have been shown to have a favorable influence on fertility. The fact that eggs from hens with a soft egg in the oviduct at time of insemination hatched better than those from other groups offers an explanation as to why hatchability was greatest when hens were inseminated in the afternoon, as a greater percentage of hens had soft eggs in their oviducts.
317
* Poultry husbandman, North Dakota Agricultural Experiment Station, Fargo since May 1944.
$
314
was only 32.6 percent when insemination was made while a hard-shell egg was in the uterus, and 70 percent if a membranous egg was in the oviduct. Percentages of fertility were calculated on the basis of eggs produced in a 10-day period subsequent to insemination. The author is not acquainted with any work on the relation of time of day of insemination to the hatchability ot fertilized eggs. EXPERIMENTAL PROCEDURE
Artificial inseminations were made in three groups of battery-confined Rhode Island Red pullets, with reference to time of day. One group was inseminated between 6:30 and 7:00 a.m., another at noon, and the third between 5:30 and 6:00 p.m., Central Standard Time. All inseminations were made with 0.1 c.c. of mixed semen; semen from the same males being used with all three groups. The hens were inseminated one time, and the percentages of fertility and of hatchability of fertile eggs were determined on the basis of the number of uncracked eggs laid during a period covering the second to fourteenth day, inclusive, following insemination. Just after insemination the hens were examined by anal palpation with the index finger. Notation was made as to whether a hard-shell egg, soft-shell egg, or no egg was observed in the repro-
Downloaded from http://ps.oxfordjournals.org/ by guest on April 13, 2015
C l N C E artificial insemination, as a ^ method of fertilizing hens' eggs, is being used by many research workers and some poultry breeders, the relation of time of day of insemination to fertility and hatchability of eggs should be of interest. Moore and Byerly (1942) showed that the percentage of fertile eggs laid when hens were inseminated while a hard-shell egg was in the uterus was lower than when inseminations were accomplished with hens that had just laid or with hens that had no egg in the oviduct. Results of their studies suggest that for highest fertility, hens should not be inseminated in the early part of the day, since at that time a large percentage of them would have a hard-shell egg in the oviduct. Gracewski and Scott (1943) observed that under natural mating conditions fertility was increased when males were permitted to run in the breeding pen only during the afternoon. When matings were restricted to the forenoon, the resulting fertility was even lower than when the matings were not restricted. They interpreted their results as confirming Malmstrom's conclusion that a membranous egg in tlie oviduct at the time of mating enhances the possibility of fertilization. Malmstrom (1943) observed that fertility
F E R T I L I T Y AND H A T C H A B I L I T Y OF H E N S ' E G G S ,
315
TABLE 1.—Relation of time of day of artificial insemination to fertility and hatchability Fertility
Time of insemination
Hens inseminated
Eggs incubated
Morning Noon Afternoon
35 36 36
293 297 279
Weighted mean
Unweighted mean
Weighted mean
Unweighted mean
50.9 71.7 77.8
49.0 71.4 76.8
79.9 79.8 91.7
80.0 78.8 86.6
RESULTS
The data in Table 1 show that a pronounced reduction in fertility resulted when hens were inseminated in the morn-
ing. Hens inseminated in the late afternoon produced a slightly higher percentage of fertile eggs than those inseminated at noon, but the difference was not statistically significant (Table 2). Hatchability of fertilized eggs was significantly higher in the afternoon-inseminated group than in the morning or noon group. With a view to finding some explanation for the observed differences in fertility and hatchability, data on time of laying and the results of the oviducal examination in the three groups were summarized (Table 3). It is noted that a large percentage of the hens in the morning-inseminated group laid after insemination, and hence had a hard-shell egg in the uterus; whereas, in the two other groups only a few laid after insemination or had hardshell eggs. A comparison oi the noon group
-Results of chi-square tests for significance of differences based on weighted averages
Comparisons
^vISiT^
Significance
Differences infertility: 1. Morning vs. afternoon inseminations 2. Morning vs. noon inseminations 3. Noon vs. afternoon inseminations 4. Laid before vs. laid after insemination 5. Laid neither before nor after vs. laid after insemination 6. Soft egg vs. hard egg in uterus 7. No egg vs. hard egg in uterus 8. Soft egg vs. no egg in uterus
45.0 27.1 2.8 74.0 42.9 58.1 48.0 2.9
+ + + + + +
Differences in hatchability: 9. Morning vs. afternoon inseminations 10. Noon vs. afternoon inseminations 11. Laid before vs. laid after insemination 12. Laid neither before nor after vs. laid after insemination 13. Soft egg vs. hard egg in uterus 14. Soft egg vs. no egg in uterus 15. No egg vs. hard egg in uterus
10.9 12.5 5.2 4.8 7.4 5.0 0.8
+ + + + + +
Downloaded from http://ps.oxfordjournals.org/ by guest on April 13, 2015
ductive tract. Records were also kept as to whether the hens laid before or after they were inseminated on the day of insemination. Two experiments were conducted: one on December 29, 30, and 31, 1942, and the other on March 9, 10, and 12, 1943. Artificial lights were not used. A total of 107 inseminations were made and 869 eggs were incubated in* the two experiments. To simplify the tabulation of results, and because the observations were similar in most respects, the data from the two experiments are combined for presentation in this paper.
TABLE 2.-
Hatchability
316
JESSE E. PARKER TABLE 3.—Data on time of laying and oviducal examination
Hens inseminated
T i m e of insemination
E g g laying on d a y of insemination Before insemination
After insemination
N o egg
5 22 30
23 4 0
12 22 15
35 36 36
Morning Noon Afternoon
E x a m i n a t i o n of oviduct Soft
egg
Hardshell egg
0 10 18
23 4 3
TABLE 4.—Relation of time of laying and kind of egg in oviduct at time of insemination to fertility and hatchability Kind of egg in oviduct Egg laying on day of insemination
Laid before insemination Laid after Insemination
Soft egg
No egg .
Hard egg
Fertil- HatchFertil- HatchFertil- HatchFertil- HatchHens Eggs ity ability Hens Eggs ity ability Hens Eggs ity ability Hens Eggs ity ability No.
No.
%
%
No.
No.
* 36
295
73.6
81.6
21
182
_
—
—
70.2
86.4
7
59
82.6
28
241
_
Laid neither before nor after insemination
13
84
Total
49
379
72.8
%
%
No.
78.0
91.5
— — —
—
27
81.4
85.4
3
78.8 | 90.0 | 30
No.
%
%
No.
No.
%
%
57
477
75.3
85.5
27
226
42.0
75.8
42.0
75.8
23
78.3
94.4
23
166
75.3
87.2
249
45.4
78.8
107
869
66.6
84.3
226
Downloaded from http://ps.oxfordjournals.org/ by guest on April 13, 2015
and the afternoon group with respect to with a hard-shell egg in the oviduct at observed presence or absence of hard- or time of insemination were only 45 percent soft-shell egg in the oviduct shows that a fertile; whereas, those from hens in which greater number of the noon group had no no egg or a soft egg was observed were 73 egg in the oviduct, and a greater number and 79 percent fertile, respectively. The of the afternoon group had a soft-shell two latter percentages indicate that hens egg in the oviduct at the time of insemina- were more easily fertilized when a soft egg was in the oviduct than when no egg tion. The relation of time of laying on day of was observed. The difference, however, insemination to subsequent fertility and did not prove to be significant (Table 2). hatchability is shown in Table 4. The per- Fertile eggs from hens with a soft egg in centages of fertility and hatchability were the oviduct at time of insemination similar in the group that laid before in- hatched significantly better than those semination and in the group that laid from hens with no egg or with a hard-shell neither before nor after insemination; but egg in the oviduct at time of insemination. in the group that laid after insemination, The small difference between the hatchaboth fertility and hatchability were lower bility percentages of the no-egg group and than in the other two groups. The differ- the hard-egg group was not significant. ences between the hatchability percentSince fertility is reduced by inseminaages were not as great as the differences tion of hens just before they lay, when a between the fertility percentages, but in hard-shell egg is in the oviduct, it is not both cases the differences were statis- surprising that the percentage fertility tically significant (Table 2). ' was low when hens were inseminated in Table 4 also shows that eggs from hens the morning. About two-thirds of the
FERTILITY AND HATCHABILITY OF H E N S ' EGGS
DISCUSSION
The results of these experiments indicate that higher fertility and hatchability might be obtained in breeding pens or flocks if the males were allowed to mate with the females only in the afternoons during the hatching season. So far as fertility is concerned, the results obtained are in agreement with those reported by Gracewski and Scott (1943), Moore and Byerly (1942), and Malmstrom (1943). The observation that hatchability was increased when hens were inseminated in the late afternoon is interesting and has important implications. This increased hatchability has been shown to be related to the fact that the larger percentage of hens have a soft or membranous egg in the lower region of the reproductive system late in the day. No definite explanation of this relationship is offered. Could it be that the oviducal environment concurrent with earlier stages of egg-shell formation so affect the spermatozoa as to
determine the fate of the embryos resulting from the union of these spermatozoa with ova? SUMMARY
In experiments with three groups of hen artificially inseminated, one in the early morning, one at noon, and one in the late afternoon, it was observed that fertility was lowest in the morning group and highest in afternoon group. Hatchability of fertile eggs was significantly higher in the afternoon group. Time of laying with respect to insemination was found to affect both fertility and the hatchability of fertile eggs. Hens that laid after insemination, but on the same day, had lower fertility and hatchability than hens that laid before insemination or those that laid neither before nor after. Percentages of fertility and hatchability in the two latter groups were very nearly the, same. Hens observed by anal palpation to have a hard-shell egg in the uterus at time of insemination produced a lower percentage of fertile eggs than those with no egg or with a soft egg in the posterior region of the oviduct. Both fertility and hatchability were highest in the soft-egg group. The results of these investigations indicate that it is possible to increase hatchability as well as fertility by restricting the mating of chickens to the afternoons. REFERENCES
Gracewski, J. J., and H. M. Scott, 1943, The influence of time of mating on fertility. Poultry Sci. 22:264-265. Malmstrom, M. V., 1943. Factors influencing fertility in the domestic fowl. Master's thesis—Univ. Conn. Moore, 0 . K., and T. C. Byerly, 1942. Relation of time of insemination to percent fertility. Poultry Sci. 21:253-255.^
Downloaded from http://ps.oxfordjournals.org/ by guest on April 13, 2015
morning-inseminated group laid following insemination and had a hard-shell egg in the oviduct at time of insemination (Table 3). The increase in the percentage of fertility of the afternoon-inseminated hens over that of hens inseminated at noon was probably influenced by the facts that a larger percentage of them had a soft egg in the oviduct at time of insemination and none of them laid just after insemination. Both conditions have been shown to have a favorable influence on fertility. The fact that eggs from hens with a soft egg in the oviduct at time of insemination hatched better than those from other groups offers an explanation as to why hatchability was greatest when hens were inseminated in the afternoon, as a greater percentage of hens had soft eggs in their oviducts.
317