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Relationship between Number of Sperm Inseminated and Fertility of Turkey Hens at Various Stages of Productiona
Relationship Between Number of Sperm Inseminated and Fertility of Turkey Hens at Various Stages of Production 1 T. J. SEXTON Animal Physiology and Genetics Institute, Agricultural Research Service, Beltsville, Maryland 20705 (Received for publication November 29, 1976) ABSTRACT Hens were inseminated weekly for 20 weeks with diluted (1:4) semen containing either 200, 100, 50 or 20 million sperm. A relationship of the number of sperm inseminated to stages of production and fertility existed only with a weekly insemination dose of 50 million sperm in which fertility was significantly lower at both the early and late stages of egg production. The physiological significance of the decline in fertility late in the season is discussed. Poultry Science 56:1054-1056, 1977 INTRODUCTION Investigators disagree considerably on the number of sperm required per insemination for maximum fertility in the turkey. For example, Parker (1946) reported that high levels of fertility can be achieved with weekly inseminations of undiluted semen containing 45 million sperm whereas Lorenz (1950) estimated that 200 million sperm were required. Similarly, reports for achieving maximum levels of fertility with diluted semen vary — 12, 39 and 90 million sperm per weekly insemination (van Tienhoven and Steel, 1957; Brown, 1970; Sexton, 1976). These reported differences are probably due to many factors, as discussed by Sexton (1976), and the one that has received little attention is the influence of stage of egg production. The present study was undertaken to determine the relationship of the number of sperm inseminated to the fertility of turkey hens throughout the breeding season. MATERIALS AND METHODS Pooled semen samples were collected from at least 5 Medium White males. The samples were diluted 1 part semen to 4 parts extender
a Mention of a trade name, proprietary product, or specific equipment does not constitute a guarantee or warranty by the U.S. Department of Agriculture and does not imply its approval to the exclusion of other products that may be suitable. 1 Minnesota Turkey Growers Association, St. Paul, Minnesota 55114. 2 Applied Genetic Laboratory, Omaha, Nebraska 68127.
within 15 min. of collection. Two commercially available extenders were used: Minnesota Turkey Semen Extender (MTGA) 1 and the Universal Medium (UM) 2 . The samples were then held at 5 C. for 30 min. while motility and cell concentration were determined by conventional methods (Sexton, 1976). In experiment # 1 , 100 Medium White hens were used simultaneously in 5 treatment groups; 20 hens were assigned per treatment. Each hen was inseminated weekly for 20 wk. with either 200, 100, 50 or 20 million sperm. Undiluted semen from the same pooled samples served as a control. In experiment #2, 15 hens in the later stages of production were inseminated the first week with 200 million sperm. During the remaining 7 week period, the following treatments were applied to each of 4 groups: a) no inseminations (measure duration of fertility), b) weekly insemination of undiluted semen containing 200 million sperm or c) weekly insemination of semen diluted in MTGA or UM containing 50 million sperm. Eggs were collected daily, stored at 15°C. and incubated within 7 days. Fertility was determined by candling on Day 7 of incubation. Significance of the data was determined by analysis of variance and differences between treatment means were assessed by the LSD test. RESULTS AND DISCUSSION A relationship existed between fertility and stage of egg production only when the weekly insemination dose contained 50 million sperm (Table 1). The lowered fertility during the early stage of production is probably attributed to an
1054
RESEARCH NOTES
1055
TABLE 1. — Relationship of the number of sperm inseminated to fertility of hens at various stages of egg production3Weeks in egg production 11- -15
6-10
1-5
Sperm number inseminated (10 6 /week)
M
U
M
U
Control 0 200 100 50 20
96 91 90 79* 44*
88 87 71* 46* 36*
89 87 90 94 74*
94 89 89 87 72*
M 88 89 100 93 42*
16--20i U
M
U
90 90 91 91 71*
87 88 95 68* 38*
92 90 95 62* 75*
Semen was diluted 1:4 with either Minnesota Turkey Semen Extender (M) or the Universal Medium (U). Hens were inseminated with .05 cc of undiluted semen containing approximately 275 million sperm. * Significantly lower than the controls in the same column, (P<.05).
i n c o m p l e t e filling of t h e sperm storage glands, whereas t h e decline in fertility during t h e latter stages is less explainable. A t t e m p t s t o increase fertility of hens in t h e later stages b y multiple inseminations were unsuccessful (Table 2). Similarly, Harper and A r s c o t t ( 1 9 6 9 ) r e p o r t e d t h a t changing from a 3 t o 2 week insemination interval m a d e little difference in t h e p a t t e r n of seasonal decline in fertility. Van Krey et al. ( 1 9 6 7 ) concluded t h a t late seasonal decline in fertility was t h e result of n o n - r e t e n t i o n of s p e r m a t o z o a within t h e u t e r o vaginal storage sites. This n o n - r e t e n t i o n of sperm m a y explain w h y multiple inseminations of hens in t h e later stages of p r o d u c t i o n did n o t increase fertility t o t h e levels (90+%) achieved in t h e early stages (Table 2). It is interesting t o n o t e in T a b l e 2 t h a t fertility of hens in their 23rd thru 2 8 t h week of p r o d u c t i o n inseminated with 5 0 million sperm
per weekly dose was equal t o t h a t of t h e control birds inseminated with 2 0 0 million sperm per weekly insemination dose. This finding m a y be related t o t h e observation by Van Krey and Leighton ( 1 9 7 0 ) t h a t fewer sperm containing glands were present in hens of p o o r fertility t h a n in hens of high fertility and m a y t h u s suggest t h a t , regardless of t h e n u m b e r of sperm deposited in t h e vagina of hens during their later stages of p r o d u c t i o n , fewer cells can be stored and t h e result is lower fertility levels. REFERENCES Brown, K. I., 1970. Effect of sperm numbers and interval of insemination on fertility in turkeys. Ohio Ag. Res. Dev. Ctr. Res. Summary, 47:7—10. Harper, J. A., and G. H. Arsott, 1969. Seasonal decline in fertility of turkey eggs. Poultry Sci. 48:2109-2113. Lorenz, F. W., 1950. Onset and duration of fertility in turkeys. Poultry Sci. 29:20—26. Parker, J. E., 1946. Relation of amount of semen used in artificial insemination of turkeys to fertility.
TABLE 2. — Relationship of the number of sperm inseminated to the fertility of bens in the late stages of egg production
Extender
Sperm inseminate/ week(10 6 ) a
20-22
23-25
26-28
None — Control A None — Control B Minnesota extender Universal medium
b 200 50 50
73 71 76 78
•53* 78 80 81
9* 83 83 80
Weeks in egg production
All hens were inseminated the first week with 200 million sperm. Hens received only the initial (a) insemination and were not inseminated thereafter. 'Significantly lower than all other treatments in the same column, (P<.05).
1056
SEXTON
Bimonthly Bull. North Dakota Ag. Exp. Sta. 8:8-9. Sexton, T. J., 1976. Studies on the dilution of turkey semen. Br. Poultry Sci. 17:179-184. Van Krey, H. P., and A. T. Leighton, 1970. Sperm gland populations, oviduct homogenates and late season declines in fertility. Poultry Sci. 49:1447.
Van Krey, H. P., A. T. Leighton and L. M. Potter, 1967. Sperm gland populations and late seasonal declines in fertility. Poultry Sci. 46:1332. van Tienhoven, A. and R. G. D. Steel, 1957. The effect of different diluents and dilution rates on fertilizing capacity of turkey semen. Poultry Sci. 36:473-479.
a Mention of a trade name, proprietary product, or specific equipment does not constitute a guarantee or warranty by the U.S. Department of Agriculture and does not imply its approval to the exclusion of other products that may be suitable. 1 Minnesota Turkey Growers Association, St. Paul, Minnesota 55114. 2 Applied Genetic Laboratory, Omaha, Nebraska 68127.
within 15 min. of collection. Two commercially available extenders were used: Minnesota Turkey Semen Extender (MTGA) 1 and the Universal Medium (UM) 2 . The samples were then held at 5 C. for 30 min. while motility and cell concentration were determined by conventional methods (Sexton, 1976). In experiment # 1 , 100 Medium White hens were used simultaneously in 5 treatment groups; 20 hens were assigned per treatment. Each hen was inseminated weekly for 20 wk. with either 200, 100, 50 or 20 million sperm. Undiluted semen from the same pooled samples served as a control. In experiment #2, 15 hens in the later stages of production were inseminated the first week with 200 million sperm. During the remaining 7 week period, the following treatments were applied to each of 4 groups: a) no inseminations (measure duration of fertility), b) weekly insemination of undiluted semen containing 200 million sperm or c) weekly insemination of semen diluted in MTGA or UM containing 50 million sperm. Eggs were collected daily, stored at 15°C. and incubated within 7 days. Fertility was determined by candling on Day 7 of incubation. Significance of the data was determined by analysis of variance and differences between treatment means were assessed by the LSD test. RESULTS AND DISCUSSION A relationship existed between fertility and stage of egg production only when the weekly insemination dose contained 50 million sperm (Table 1). The lowered fertility during the early stage of production is probably attributed to an
1054
RESEARCH NOTES
1055
TABLE 1. — Relationship of the number of sperm inseminated to fertility of hens at various stages of egg production3Weeks in egg production 11- -15
6-10
1-5
Sperm number inseminated (10 6 /week)
M
U
M
U
Control 0 200 100 50 20
96 91 90 79* 44*
88 87 71* 46* 36*
89 87 90 94 74*
94 89 89 87 72*
M 88 89 100 93 42*
16--20i U
M
U
90 90 91 91 71*
87 88 95 68* 38*
92 90 95 62* 75*
Semen was diluted 1:4 with either Minnesota Turkey Semen Extender (M) or the Universal Medium (U). Hens were inseminated with .05 cc of undiluted semen containing approximately 275 million sperm. * Significantly lower than the controls in the same column, (P<.05).
i n c o m p l e t e filling of t h e sperm storage glands, whereas t h e decline in fertility during t h e latter stages is less explainable. A t t e m p t s t o increase fertility of hens in t h e later stages b y multiple inseminations were unsuccessful (Table 2). Similarly, Harper and A r s c o t t ( 1 9 6 9 ) r e p o r t e d t h a t changing from a 3 t o 2 week insemination interval m a d e little difference in t h e p a t t e r n of seasonal decline in fertility. Van Krey et al. ( 1 9 6 7 ) concluded t h a t late seasonal decline in fertility was t h e result of n o n - r e t e n t i o n of s p e r m a t o z o a within t h e u t e r o vaginal storage sites. This n o n - r e t e n t i o n of sperm m a y explain w h y multiple inseminations of hens in t h e later stages of p r o d u c t i o n did n o t increase fertility t o t h e levels (90+%) achieved in t h e early stages (Table 2). It is interesting t o n o t e in T a b l e 2 t h a t fertility of hens in their 23rd thru 2 8 t h week of p r o d u c t i o n inseminated with 5 0 million sperm
per weekly dose was equal t o t h a t of t h e control birds inseminated with 2 0 0 million sperm per weekly insemination dose. This finding m a y be related t o t h e observation by Van Krey and Leighton ( 1 9 7 0 ) t h a t fewer sperm containing glands were present in hens of p o o r fertility t h a n in hens of high fertility and m a y t h u s suggest t h a t , regardless of t h e n u m b e r of sperm deposited in t h e vagina of hens during their later stages of p r o d u c t i o n , fewer cells can be stored and t h e result is lower fertility levels. REFERENCES Brown, K. I., 1970. Effect of sperm numbers and interval of insemination on fertility in turkeys. Ohio Ag. Res. Dev. Ctr. Res. Summary, 47:7—10. Harper, J. A., and G. H. Arsott, 1969. Seasonal decline in fertility of turkey eggs. Poultry Sci. 48:2109-2113. Lorenz, F. W., 1950. Onset and duration of fertility in turkeys. Poultry Sci. 29:20—26. Parker, J. E., 1946. Relation of amount of semen used in artificial insemination of turkeys to fertility.
TABLE 2. — Relationship of the number of sperm inseminated to the fertility of bens in the late stages of egg production
Extender
Sperm inseminate/ week(10 6 ) a
20-22
23-25
26-28
None — Control A None — Control B Minnesota extender Universal medium
b 200 50 50
73 71 76 78
•53* 78 80 81
9* 83 83 80
Weeks in egg production
All hens were inseminated the first week with 200 million sperm. Hens received only the initial (a) insemination and were not inseminated thereafter. 'Significantly lower than all other treatments in the same column, (P<.05).
1056
SEXTON
Bimonthly Bull. North Dakota Ag. Exp. Sta. 8:8-9. Sexton, T. J., 1976. Studies on the dilution of turkey semen. Br. Poultry Sci. 17:179-184. Van Krey, H. P., and A. T. Leighton, 1970. Sperm gland populations, oviduct homogenates and late season declines in fertility. Poultry Sci. 49:1447.
Van Krey, H. P., A. T. Leighton and L. M. Potter, 1967. Sperm gland populations and late seasonal declines in fertility. Poultry Sci. 46:1332. van Tienhoven, A. and R. G. D. Steel, 1957. The effect of different diluents and dilution rates on fertilizing capacity of turkey semen. Poultry Sci. 36:473-479.