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Effect of Progesterone on Broodiness and Egg Production of Turkeys
428
G. A. DONOVAN, W. K. WARDEN AND W. M. REYNOLDS
product as compared with the ration containing fish meal or the one containing several conventional sources of UGF. The third experiment was on the influence of Calorie-protein (C/P) ratio on response to UGF. There was no apparent response to additional UGF at low C/P ratios. Because of the high feed consumption per unit of gain on the low energy diet, the birds probably satisfied their UGF requirements from the low level of these factors in the basal. UGF supplementation was most beneficial with medium C/P ratios. The best 24 week weights resulted from ratios of 30-34, 45-50, and 60-65 for 0-8, 9-16, and 17-24 weeks, respectively. ACKNOWLEDGMENT
The authors are grateful to Messrs. J. D. Berrisford and C. E. Jones, Jr. for the care of the birds, to Dr. J. C. Atkinson
for the statistical analysis of the data, and to Dr. D. F. Chichester for assistance in the preparation of the manuscript. REFERENCES Combs, G. F., G. H. Arscott and H. L. Jones, 1954. Unidentified growth factors required by chicks and poults. Poultry Sci. 33: 71-79. Combs, G. F., and C. S. Shaffner, 1950. Further evidence for an unidentified growth factor required by the poult. Poultry Sci. 29: 623-624. Combs, G. F., G. B. Sweet, H. L. Jones, G. S. Romoser and R. W. Bishop, 1954. Multiplicity of unidentified growth factors required by chicks and poults. Poultry Sci. 33: 1050. Edwards, H. M., R. Dam, L. C. Norris and G. F. Heuser, 1953. Probable identity of unidentified chick growth factors in fish solubles and penicillin mycelium residue. Poultry Sci. 32: 551-554. Schaefer, A. E., R. D. Greene, H. L. Sassaman and S. Wind, 1955. Fermentation meals as a source of unidentified growth factors. Poultry Sci. 34: 851-855. Scott, M. L., and L. S. Jensen, 1952. The effect of antibiotics upon the requirement of turkeys for unidentified vitamins. Poultry Sci. 31: 986-993.
Effect of Progesterone on Broodiness and Egg Production of Turkeys A . VAN TlENHOVEN Agricultural Experiment Station al Cornell University, Ithaca, New York (Received for publication September 23. 1957)
B
ROODINESS in chickens has been interrupted by injection of 25 mg. diethylstilbestrol (Godfrey and Jaap, 1950; Carson et al., 1956) whereas turkeys required 200 mg. for the same effect, according to Blakely et al. (1951). With such massive doses one might expect a detrimental effect on egg production following broodiness because of the well known inhibitory action that estrogens have on pituitary gonadotrophin secretion. No data were reported on this aspect of diethylstilbestrol (D.E.S.) administra-
tion by Blakely el al. (1951) and we, therefore, thought further experimentation was necessary. Various other hormones used in attempts to interrupt broodiness, such as pituitary gonadotrophin (Wodzicki, 1934; Eigemann, 1937) and thyroid hormone (Wodzicki, 1934) or the feeding of a thyroid inhibitor (Eigemann, 1937) were ineffective. Testosterone, although ineffective as an agent to interrupt broodiness, was effective in preventing this behavior pattern (Kosin, 1948); however, at doses which were effec-
PROGESTERONE AND TURKEY BROODINESS
tive in this respect, egg production was adversely affected. The effects of the corpus luteum hormone, progesterone, seem to vary with the dose used and also with the species employed. Riddle and Lahr (1944) were able to induce broody behavior and development of the crop sac gland in ring doves by progesterone pellet implants, while Bates et al. (1935) found that the hormone caused regression of the ovary. Large doses of progesterone given to laying hens have caused cessation of laying and molting (Shaffner, 1955; Adams, 1956; Harris and Shaffner, 1956; Juhn and Harris, 1956). On the other hand progesterone induces premature ovulation (Fraps and Dury, 1953), aids in the maintenance of the exogenous gonadotrophin stimulated turkey (Fraps, 1950), induces precocious egg production of chickens (Nalbandov, 1956) and induces spermatogenesis in pigeon testes (Kar, 1949). The interrupted egg production due to broodiness might, therefore, be alleviated by progesterone through its stimulatory action, directly or indirectly, on the gonads. Experiments were designed to test this possibility. MATERIALS AND METHODS
Empire White hens were housed in breeding pens where daily trapnest records were kept. Each pen contained between 10 and 13 hens. Treatments were assigned at random to the various pens. Diethylstilbestrol (D.E.S.) was given dissolved in sesame oil at a concentration of 25 mg./cc; consecutive injections were given subcutaneously in two equal doses in the skin fold between leg and breast on the first day that broodiness was noted. In the first experiment a distinction was made between "suspected" and "definite" broodiness. In the former case the hen would stay on the nest or, if removed, would reoccupy it; however, on the basis
429
of her laying record she was judged not to have finished her cycle or clutch. A definite broody hen showed the same behavior as described but her laying record indicated that she had laid the last egg of her cycle. In all other experiments, birds were injected when definitely broody. The controls in the estrogen experiment were injected with 8 cc. sesame oil and then placed in broody coops while in the progesterone experiments the hens were placed in broody coops but not injected. We thus did not use any controls in the strict sense of the word, but we compared the effectiveness of the hormones with the method of placing birds in broody coops. The later is a slat bottom coop where the animal receives full feed and water. Progesterone pellets were implanted in the neck at the base of the skull. Single progesterone injections were given subcutaneously in a paste-like material consisting of a mixture of polyglycols.1 RESULTS
In the first series of experiments, summarized in Table 1, it was demonstrated that estrogen failed to interrupt broodiness. Further experimentation with doses as high as 300 mg. D.E.S./hen gave similar negative results. It should also be noted that estrogen injection at the levels used in this experiment strongly suppressed egg production; a phenomenon which is not surprising in view of the inhibitory action of estrogens on gonadotrophin secretion. Preliminary experiments showed that a dose of 10 mg. progesterone administered in a paste was effective while 5 mg. did not 1 Thanks are due to Mr. W. Earl Mattox of Mattox and Moore, Inc. Indianapolis, Indiana, for the generous gift of this material, to Mr. J. Zagata for taking care of the birds. The author also wants to confess his gratitude to Dr. R. A. Monroe for his suggestions regarding the manuscript.
430
A . VAN TlENHOVEN TABLE 1.—Effect
of various treatments of broodiness on duration of broodiness and subsequent egg production Average number of eggs laid 1955-56
Treatment
Estrogen when definitely broody Estrogen when suspected* broody Cooped when suspected* broody Cooped when definitely broody
No. hens
Avg. days broody
19 19 23 23
4.5 6.6 3.8 3.7
14 d. prior to broodiness
14 d. after start broodiness
14 d. after end broodiness
7.6 7.2 8.2 9.2
1.7 2.2 3.2 3.9
3.1 3.3 6.1 7.1
* See text.
seem to influence broodiness. In the experiments reported here, the 10 mg. dose was used. After injection the birds were placed in the pen and only if they were still broody the next afternoon were they placed in a broody coop. For the comparison of the results of the two treatments all data were referred to the individual broody period or periods for hens which had become broody. By broody period is meant the length of time that the hen shows broody behavior when released in the pen. Broody periods are separated by longer or shorter intervals of nonbroody behavior; whether or not eggs are laid during this interval is immaterial for the definition of the term considered. The total number of broody periods observed for each treatment are given in Table 2 which summarizes the results of the experiment. In some cases no eggs were laid between the time of the last broody period and the time of disposal of TABLE 2.—Effect
Treatment
Controls (Broody Coop) Progesterone inj. 10 mg./bird
the hens. These periods have been excluded in the calculations for the last column of Table 2. The results reported in Table 2 show clearly that progesterone interrupted broodiness faster than placing the hens in the broody coop. The difference in duration of broodiness was statistically highly significant. Neither the difference in number of eggs laid in the 14 days after broodiness started nor the interval between start of broody behavior and lay of the first egg was significant (P>0.05). In no case did we observe molting after the progesterone injection as has been reported for chickens (Shaffner, 1955; Adams, 1956; Harris and Shaffner, 1956; Juhn and Harris, 1956). In an uncontrolled trial we found that when the 10 mg. progesterone was given to laying turkey hens, egg laying ceased within 2 days, an observation similar to that found when this hormone is given to laying chickens (Shaffner,
of progesterone on duration of broodiness and subsequent egg production of turkeys
Broody periods*
Eggs during 14 days prior to broodiness
Duration broody period
Eggs during 14 days after broodiness
^ j ™ , sTr l ° ^egg H to\ first
no. 45 57
no. 5.8 7.2
days 3.17 0.37
no. 2.1 2.6
days 11.5t 8.8$
* See text. t 10 broody periods after which no eggs were laid have been excluded. X 14 broody periods after which no eggs were laid have been excluded.
431
PROGESTERONE AND TURKEY BROODINESS
1955; Adams, 1956; Harris and Shaffner, 1956; Juhn and Harris, 1956). Apparently, the progesterone had no deleterious effect on the egg production after broodiness. Probably in the relatively long interval between broodiness and resumption of laying the exogenous progesterone had been excreted. Unfortunately, we know little about the excretion rate of progesterone in birds but in mammals this rate of excretion is very fast (Zarrow et ah, 1954). Because of the favorable effect of progesterone as a therapeutic agent, trials were designed to test the effect of the hormone as a prophylactic agent against the occurrence of broodiness. In pens 1 and 2 (see Table 3) the hens had started to lay during the first week of February. On April 14 the birds in pen 1 were implanted with a 20 mg. pellet. The birds in pens M-U had started egg production during the last week of March. The experimental birds were implanted with progesterone pellets on May 2 and June 6. The results of these experiments are given in Table 3. For pen 2, egg producTABLE 3.—Effect
of progesterone pellets on broodiness and egg production of turkeys Eggs laid
Pen
tion during the experimental period was larger but not significantly so, as tested by the chi square test (Snedecor, 1956). For the other experimental pens we can see that egg production was higher during the experimental than in the pre-experimental period in 1 out of 4 pens in the case of controls, but in 3 out of 4 pens in the case of progesterone treatment. Only in one case (pen T) was the difference highly significant (P<0.01). However, when the total egg production of all experimental pens (N, 0 , R, T) and control pens (M, P, S, U) was considered, the difference was significant (P<0.05). Further evidence that progesterone stimulated egg production is found in the fact that egg production after the first broody period was higher in the experimental than in the control pens (see Table 4). As this table shows, egg production in the experimental pens was also larger before the first broody period. The data were, therefore analyzed by a covariance analysis (Snedecor, 1956) so that adjustment was made for differences in egg production in the pre-broody period. The difference in
Broody periods
Duration
Period
Period
Period
Treatment
Pre-exptl. Exptl. (a) (b)
Diff. (a-b)
Pre-exptl.
Exptl.
Pre-exptl.
Exptl.
C Prog. 20 mg.
no. 466 465
no. 277 308
no. 189 157
no. 11 17
no. 1 5
days 72 72
days 48 48
M P S U
Control Control Control Control
224 213 250 254
214 180 277 251
10 33 -27 3
2 2 0 5
10 10 4 12
42 42 42 42
60 60 60 60
Total
Control
941
922
19
9
36
—
—
Prog. Prog. Prog. Prog.
20mg. 20mg. 20mg. 20mg.
222 248 256 249
242 243 277 307
-20 5 -21 -58
7 6 5 5
8 9 7 6
42 42 42 42
60 60 60 60
Prog. 20mg.
975
1,069
-94
23
30
—
—
1 2
N 0 R T Total
432
A. VAN TlENHOVEN
TABLE 4.—Effect of progesterone on egg production after the first broody period Rate of production Treatment
Hens
Before broody period
After broody period
Controls Progesterone 20 mg. pellet
17
46.6
21.1
32
59.1
33.9
post-broodiness egg production was significant (P<0.05) as revealed by the covariance analysis. These experiments show that in turkeys the effect of progesterone is dependent on the physiological state of the animal. If the bird is broody, progesterone interrupts this pattern of behavior, probably through interference with prolactin secretion by the anterior pituitary. That broodiness and, especially, the urge to sit on the nest is dependent on prolactin has been amply demonstrated (Riddle et al., 1935; Eigemann, 1937; Nalbandov, 1945; Saeki and Tanabe, 1955). This interruption of broodiness by progesterone is, as far as the author is aware, the first time that this phenomenon has been reported. As a matter of fact, Riddle and Lahr (1944) were able to induce broodiness in pigeons by progesterone pellet implantation. In our experiments there is no evidence that progesterone pellets increased the incidence of broodiness over that observed in controls. On the other hand the form in which the hormone is given influences the effect, also, probably because the hormone level in the blood is affected differently. A readily absorbed form (paste) probably corresponding to a relatively high progesterone level in the blood, interrupts egg production when given to laying hens. Although no pituitary bioassays were made it seems reasonable to assume that gonadotrophin secretion was inhibited.
When progesterone is given in a slowly absorbed form (pellet) the level in the blood did not become high enough to inhibit prolactin secretion, but apparently the level was high enough to stimulate the development of the ovaries after broodiness was over. Such a phenomenon of progesterone stimulation of the gonads has been observed by Kar (1949) for male piegons, by Nalbandov (1956) for immature pullets while Fraps (1950) found that progesterone aided in the maintenance of follicles of turkeys stimulated with pregnant mare's serum. The exact pathways by which progesterone affects these physiological processes need to be studied further by correlating the relation of blood progesterone levels with anterior pituitary assays. SUMMARY
Progesterone, 10 mg. per bird, given in a readily absorbed form, interrupts broodiness of turkey hens without affecting egg production. There is evidence that the same dose given to laying hens causes cessation of egg production. Progesterone pellets (20 mg.) implants have no effect on incidence of broodiness but seem to stimulate egg production, especially of hens which have become broody. REFERENCES Adams, J. L., 1956. A comparison of different methods of progesterone administration to the fowl in affecting egg production and molt. Poultry Sci. 35: 323-326. Bates, R. W., E. L. Lahr and 0 . Riddle, 1935. The gross action of prolactin and follicle stimulating hormone on the mature ovary and sex accessories of fowl. Am. J. Physiol. I l l : 361-368. Blakely, R. M., R. W. Anderson and H. I. MacGregor, 1951. The estrogen interruption of broodiness in turkeys. Poultry Sci. 30: 907. Carson, J. R., R. D. Eaton and B. F. Bacon, 1956. Termination of broodiness in the chicken. Storrs Agr. Expt. Sta. Bull. No. 323. Eigemann, M., 1937. Experimentelle Untersuchun-
PROGESTERONE AND TURKEY BROODINESS gen uber die Brutigkeit der Hiihner. Arch. Geflugelk. 11:273-292. Fraps, R. M., 1950. Action of progesterone on the immature avian gonad. Med. Landbouwhogeschool Opzoekstat. Gent. IS: 767-769. Fraps, R. M., and A. Dury, 1943. Occurrence of premature ovulation in the domestic fowl following administration of progesterone. Proc. Soc. Exp. Biol. Med. 52: 346-349. Godfrey, E. F., and R. G. Jaap, 1950. Estrogenic interruption of broodiness in the domestic fowl. Poultry Sci. 29: 356-361. Harris, P. C , and C. S. Shaffner, 1956. Effect of season and thyroidal activity on the molt response to progesterone. Poultry Sci. 35: 11461147. Juhn, M., and P. C. Harris, 1956. Responses in molt and lay of fowl to progestins and gonadotrophins. Proc. Soc. Expt. Biol. Med. 92: 709711. Kar, A. B., 1949. Testicular changes in the juvenile pigeondue to progesterone treatment. Endocrinol. 45: 346-348. Kosin, I. L., 1948. The use of testosterone propionate in controlling broodiness in turkeys. Poultry Sci. 27: 671.
433
Nalbandov, A. V., 1945. A study of the effect of prolactin on broodiness and on cock testes. Endocrinol. 36: 251-258. Nalbandov, A. V., 1956. Effect of progesterone on egg production. Poultry Sci. 35: 1162. Riddle, O., R. W. Bates and E. L. Lahr, 1935. Prolactin induces broodiness in fowl. Am. J. Physiol. I l l : 352-360. Riddle, O., and E. L. Lahr, 1944. On broodiness of ring doves following implants of certain steroid hormones. Endocrinol. 35: 255-260. Saeki, S., and Y. Tanabe, 1955. Changes in prolactin content of fowl pituitary during broody periods and some experiments on the induction of broodiness. Poultry Sci. 34: 909-919. Shaffner, C. S., 1955. Progesterone-induced molt. Poultry Sci. 34: 840-842. Snedecor, G. W., 1956. Statistical Methods, 5th Ed. Iowa State College Press, Ames, Iowa. Wodzicki, K., 1934. Hormonal interruption of broodiness in hens. Nature, 134: 383. Zarrow, M. X., R. L. Shoger and E. A. LazoWasem, 1954. The rate of disappearance of exogenous progesterone from the blood. J. Clin. Endocrinol. 14: 645-651.
The Nutritional Significance of Processed Keratin in Poultry Feeding KENNETH W. MCKERNS 1 AND EDNA RITTERSPORN Research Laboratories, Canada Packers Ltd., Toronto 9, Ontario (Received for publication September 26, 1957)
of the amino acid conONtentTHEof basis keratins given by Graham et al. (1949) and from the amino acid contents of the other dietary ingredients (Almquist, 1952), it is apparent that keratin whether from hoof, horn or feathers, could substitute for a large portion of the soybean oil meal in commercial chick rations without disturbing the amino acid balance of the ration. It would supply arginine and cystine and the low methionine content might be compensated for by 1
Present address: Research Laboratories, American Cyanamid Company, Pearl River, N. Y.
the very high cystine. There has been renewed interest in the last few years in the use of these keratin proteins in animal feeds. Sodium sulfite-treated feather meal was used by Draper (1944) with good growth response in basal diets fed to chicks and rats. It was shown by Binkley and Vasak (1951) that feathers could be made more digestible by steam heating under pressure. Sullivan and Stephenson (1957) found that feathers heated at 35 lbs. steam pressure for 1 hour were a satisfactory replacement for soybean oil meal when added at levels up to 5% of the total ration. Wilder et al. (1953, 1955) also
G. A. DONOVAN, W. K. WARDEN AND W. M. REYNOLDS
product as compared with the ration containing fish meal or the one containing several conventional sources of UGF. The third experiment was on the influence of Calorie-protein (C/P) ratio on response to UGF. There was no apparent response to additional UGF at low C/P ratios. Because of the high feed consumption per unit of gain on the low energy diet, the birds probably satisfied their UGF requirements from the low level of these factors in the basal. UGF supplementation was most beneficial with medium C/P ratios. The best 24 week weights resulted from ratios of 30-34, 45-50, and 60-65 for 0-8, 9-16, and 17-24 weeks, respectively. ACKNOWLEDGMENT
The authors are grateful to Messrs. J. D. Berrisford and C. E. Jones, Jr. for the care of the birds, to Dr. J. C. Atkinson
for the statistical analysis of the data, and to Dr. D. F. Chichester for assistance in the preparation of the manuscript. REFERENCES Combs, G. F., G. H. Arscott and H. L. Jones, 1954. Unidentified growth factors required by chicks and poults. Poultry Sci. 33: 71-79. Combs, G. F., and C. S. Shaffner, 1950. Further evidence for an unidentified growth factor required by the poult. Poultry Sci. 29: 623-624. Combs, G. F., G. B. Sweet, H. L. Jones, G. S. Romoser and R. W. Bishop, 1954. Multiplicity of unidentified growth factors required by chicks and poults. Poultry Sci. 33: 1050. Edwards, H. M., R. Dam, L. C. Norris and G. F. Heuser, 1953. Probable identity of unidentified chick growth factors in fish solubles and penicillin mycelium residue. Poultry Sci. 32: 551-554. Schaefer, A. E., R. D. Greene, H. L. Sassaman and S. Wind, 1955. Fermentation meals as a source of unidentified growth factors. Poultry Sci. 34: 851-855. Scott, M. L., and L. S. Jensen, 1952. The effect of antibiotics upon the requirement of turkeys for unidentified vitamins. Poultry Sci. 31: 986-993.
Effect of Progesterone on Broodiness and Egg Production of Turkeys A . VAN TlENHOVEN Agricultural Experiment Station al Cornell University, Ithaca, New York (Received for publication September 23. 1957)
B
ROODINESS in chickens has been interrupted by injection of 25 mg. diethylstilbestrol (Godfrey and Jaap, 1950; Carson et al., 1956) whereas turkeys required 200 mg. for the same effect, according to Blakely et al. (1951). With such massive doses one might expect a detrimental effect on egg production following broodiness because of the well known inhibitory action that estrogens have on pituitary gonadotrophin secretion. No data were reported on this aspect of diethylstilbestrol (D.E.S.) administra-
tion by Blakely el al. (1951) and we, therefore, thought further experimentation was necessary. Various other hormones used in attempts to interrupt broodiness, such as pituitary gonadotrophin (Wodzicki, 1934; Eigemann, 1937) and thyroid hormone (Wodzicki, 1934) or the feeding of a thyroid inhibitor (Eigemann, 1937) were ineffective. Testosterone, although ineffective as an agent to interrupt broodiness, was effective in preventing this behavior pattern (Kosin, 1948); however, at doses which were effec-
PROGESTERONE AND TURKEY BROODINESS
tive in this respect, egg production was adversely affected. The effects of the corpus luteum hormone, progesterone, seem to vary with the dose used and also with the species employed. Riddle and Lahr (1944) were able to induce broody behavior and development of the crop sac gland in ring doves by progesterone pellet implants, while Bates et al. (1935) found that the hormone caused regression of the ovary. Large doses of progesterone given to laying hens have caused cessation of laying and molting (Shaffner, 1955; Adams, 1956; Harris and Shaffner, 1956; Juhn and Harris, 1956). On the other hand progesterone induces premature ovulation (Fraps and Dury, 1953), aids in the maintenance of the exogenous gonadotrophin stimulated turkey (Fraps, 1950), induces precocious egg production of chickens (Nalbandov, 1956) and induces spermatogenesis in pigeon testes (Kar, 1949). The interrupted egg production due to broodiness might, therefore, be alleviated by progesterone through its stimulatory action, directly or indirectly, on the gonads. Experiments were designed to test this possibility. MATERIALS AND METHODS
Empire White hens were housed in breeding pens where daily trapnest records were kept. Each pen contained between 10 and 13 hens. Treatments were assigned at random to the various pens. Diethylstilbestrol (D.E.S.) was given dissolved in sesame oil at a concentration of 25 mg./cc; consecutive injections were given subcutaneously in two equal doses in the skin fold between leg and breast on the first day that broodiness was noted. In the first experiment a distinction was made between "suspected" and "definite" broodiness. In the former case the hen would stay on the nest or, if removed, would reoccupy it; however, on the basis
429
of her laying record she was judged not to have finished her cycle or clutch. A definite broody hen showed the same behavior as described but her laying record indicated that she had laid the last egg of her cycle. In all other experiments, birds were injected when definitely broody. The controls in the estrogen experiment were injected with 8 cc. sesame oil and then placed in broody coops while in the progesterone experiments the hens were placed in broody coops but not injected. We thus did not use any controls in the strict sense of the word, but we compared the effectiveness of the hormones with the method of placing birds in broody coops. The later is a slat bottom coop where the animal receives full feed and water. Progesterone pellets were implanted in the neck at the base of the skull. Single progesterone injections were given subcutaneously in a paste-like material consisting of a mixture of polyglycols.1 RESULTS
In the first series of experiments, summarized in Table 1, it was demonstrated that estrogen failed to interrupt broodiness. Further experimentation with doses as high as 300 mg. D.E.S./hen gave similar negative results. It should also be noted that estrogen injection at the levels used in this experiment strongly suppressed egg production; a phenomenon which is not surprising in view of the inhibitory action of estrogens on gonadotrophin secretion. Preliminary experiments showed that a dose of 10 mg. progesterone administered in a paste was effective while 5 mg. did not 1 Thanks are due to Mr. W. Earl Mattox of Mattox and Moore, Inc. Indianapolis, Indiana, for the generous gift of this material, to Mr. J. Zagata for taking care of the birds. The author also wants to confess his gratitude to Dr. R. A. Monroe for his suggestions regarding the manuscript.
430
A . VAN TlENHOVEN TABLE 1.—Effect
of various treatments of broodiness on duration of broodiness and subsequent egg production Average number of eggs laid 1955-56
Treatment
Estrogen when definitely broody Estrogen when suspected* broody Cooped when suspected* broody Cooped when definitely broody
No. hens
Avg. days broody
19 19 23 23
4.5 6.6 3.8 3.7
14 d. prior to broodiness
14 d. after start broodiness
14 d. after end broodiness
7.6 7.2 8.2 9.2
1.7 2.2 3.2 3.9
3.1 3.3 6.1 7.1
* See text.
seem to influence broodiness. In the experiments reported here, the 10 mg. dose was used. After injection the birds were placed in the pen and only if they were still broody the next afternoon were they placed in a broody coop. For the comparison of the results of the two treatments all data were referred to the individual broody period or periods for hens which had become broody. By broody period is meant the length of time that the hen shows broody behavior when released in the pen. Broody periods are separated by longer or shorter intervals of nonbroody behavior; whether or not eggs are laid during this interval is immaterial for the definition of the term considered. The total number of broody periods observed for each treatment are given in Table 2 which summarizes the results of the experiment. In some cases no eggs were laid between the time of the last broody period and the time of disposal of TABLE 2.—Effect
Treatment
Controls (Broody Coop) Progesterone inj. 10 mg./bird
the hens. These periods have been excluded in the calculations for the last column of Table 2. The results reported in Table 2 show clearly that progesterone interrupted broodiness faster than placing the hens in the broody coop. The difference in duration of broodiness was statistically highly significant. Neither the difference in number of eggs laid in the 14 days after broodiness started nor the interval between start of broody behavior and lay of the first egg was significant (P>0.05). In no case did we observe molting after the progesterone injection as has been reported for chickens (Shaffner, 1955; Adams, 1956; Harris and Shaffner, 1956; Juhn and Harris, 1956). In an uncontrolled trial we found that when the 10 mg. progesterone was given to laying turkey hens, egg laying ceased within 2 days, an observation similar to that found when this hormone is given to laying chickens (Shaffner,
of progesterone on duration of broodiness and subsequent egg production of turkeys
Broody periods*
Eggs during 14 days prior to broodiness
Duration broody period
Eggs during 14 days after broodiness
^ j ™ , sTr l ° ^egg H to\ first
no. 45 57
no. 5.8 7.2
days 3.17 0.37
no. 2.1 2.6
days 11.5t 8.8$
* See text. t 10 broody periods after which no eggs were laid have been excluded. X 14 broody periods after which no eggs were laid have been excluded.
431
PROGESTERONE AND TURKEY BROODINESS
1955; Adams, 1956; Harris and Shaffner, 1956; Juhn and Harris, 1956). Apparently, the progesterone had no deleterious effect on the egg production after broodiness. Probably in the relatively long interval between broodiness and resumption of laying the exogenous progesterone had been excreted. Unfortunately, we know little about the excretion rate of progesterone in birds but in mammals this rate of excretion is very fast (Zarrow et ah, 1954). Because of the favorable effect of progesterone as a therapeutic agent, trials were designed to test the effect of the hormone as a prophylactic agent against the occurrence of broodiness. In pens 1 and 2 (see Table 3) the hens had started to lay during the first week of February. On April 14 the birds in pen 1 were implanted with a 20 mg. pellet. The birds in pens M-U had started egg production during the last week of March. The experimental birds were implanted with progesterone pellets on May 2 and June 6. The results of these experiments are given in Table 3. For pen 2, egg producTABLE 3.—Effect
of progesterone pellets on broodiness and egg production of turkeys Eggs laid
Pen
tion during the experimental period was larger but not significantly so, as tested by the chi square test (Snedecor, 1956). For the other experimental pens we can see that egg production was higher during the experimental than in the pre-experimental period in 1 out of 4 pens in the case of controls, but in 3 out of 4 pens in the case of progesterone treatment. Only in one case (pen T) was the difference highly significant (P<0.01). However, when the total egg production of all experimental pens (N, 0 , R, T) and control pens (M, P, S, U) was considered, the difference was significant (P<0.05). Further evidence that progesterone stimulated egg production is found in the fact that egg production after the first broody period was higher in the experimental than in the control pens (see Table 4). As this table shows, egg production in the experimental pens was also larger before the first broody period. The data were, therefore analyzed by a covariance analysis (Snedecor, 1956) so that adjustment was made for differences in egg production in the pre-broody period. The difference in
Broody periods
Duration
Period
Period
Period
Treatment
Pre-exptl. Exptl. (a) (b)
Diff. (a-b)
Pre-exptl.
Exptl.
Pre-exptl.
Exptl.
C Prog. 20 mg.
no. 466 465
no. 277 308
no. 189 157
no. 11 17
no. 1 5
days 72 72
days 48 48
M P S U
Control Control Control Control
224 213 250 254
214 180 277 251
10 33 -27 3
2 2 0 5
10 10 4 12
42 42 42 42
60 60 60 60
Total
Control
941
922
19
9
36
—
—
Prog. Prog. Prog. Prog.
20mg. 20mg. 20mg. 20mg.
222 248 256 249
242 243 277 307
-20 5 -21 -58
7 6 5 5
8 9 7 6
42 42 42 42
60 60 60 60
Prog. 20mg.
975
1,069
-94
23
30
—
—
1 2
N 0 R T Total
432
A. VAN TlENHOVEN
TABLE 4.—Effect of progesterone on egg production after the first broody period Rate of production Treatment
Hens
Before broody period
After broody period
Controls Progesterone 20 mg. pellet
17
46.6
21.1
32
59.1
33.9
post-broodiness egg production was significant (P<0.05) as revealed by the covariance analysis. These experiments show that in turkeys the effect of progesterone is dependent on the physiological state of the animal. If the bird is broody, progesterone interrupts this pattern of behavior, probably through interference with prolactin secretion by the anterior pituitary. That broodiness and, especially, the urge to sit on the nest is dependent on prolactin has been amply demonstrated (Riddle et al., 1935; Eigemann, 1937; Nalbandov, 1945; Saeki and Tanabe, 1955). This interruption of broodiness by progesterone is, as far as the author is aware, the first time that this phenomenon has been reported. As a matter of fact, Riddle and Lahr (1944) were able to induce broodiness in pigeons by progesterone pellet implantation. In our experiments there is no evidence that progesterone pellets increased the incidence of broodiness over that observed in controls. On the other hand the form in which the hormone is given influences the effect, also, probably because the hormone level in the blood is affected differently. A readily absorbed form (paste) probably corresponding to a relatively high progesterone level in the blood, interrupts egg production when given to laying hens. Although no pituitary bioassays were made it seems reasonable to assume that gonadotrophin secretion was inhibited.
When progesterone is given in a slowly absorbed form (pellet) the level in the blood did not become high enough to inhibit prolactin secretion, but apparently the level was high enough to stimulate the development of the ovaries after broodiness was over. Such a phenomenon of progesterone stimulation of the gonads has been observed by Kar (1949) for male piegons, by Nalbandov (1956) for immature pullets while Fraps (1950) found that progesterone aided in the maintenance of follicles of turkeys stimulated with pregnant mare's serum. The exact pathways by which progesterone affects these physiological processes need to be studied further by correlating the relation of blood progesterone levels with anterior pituitary assays. SUMMARY
Progesterone, 10 mg. per bird, given in a readily absorbed form, interrupts broodiness of turkey hens without affecting egg production. There is evidence that the same dose given to laying hens causes cessation of egg production. Progesterone pellets (20 mg.) implants have no effect on incidence of broodiness but seem to stimulate egg production, especially of hens which have become broody. REFERENCES Adams, J. L., 1956. A comparison of different methods of progesterone administration to the fowl in affecting egg production and molt. Poultry Sci. 35: 323-326. Bates, R. W., E. L. Lahr and 0 . Riddle, 1935. The gross action of prolactin and follicle stimulating hormone on the mature ovary and sex accessories of fowl. Am. J. Physiol. I l l : 361-368. Blakely, R. M., R. W. Anderson and H. I. MacGregor, 1951. The estrogen interruption of broodiness in turkeys. Poultry Sci. 30: 907. Carson, J. R., R. D. Eaton and B. F. Bacon, 1956. Termination of broodiness in the chicken. Storrs Agr. Expt. Sta. Bull. No. 323. Eigemann, M., 1937. Experimentelle Untersuchun-
PROGESTERONE AND TURKEY BROODINESS gen uber die Brutigkeit der Hiihner. Arch. Geflugelk. 11:273-292. Fraps, R. M., 1950. Action of progesterone on the immature avian gonad. Med. Landbouwhogeschool Opzoekstat. Gent. IS: 767-769. Fraps, R. M., and A. Dury, 1943. Occurrence of premature ovulation in the domestic fowl following administration of progesterone. Proc. Soc. Exp. Biol. Med. 52: 346-349. Godfrey, E. F., and R. G. Jaap, 1950. Estrogenic interruption of broodiness in the domestic fowl. Poultry Sci. 29: 356-361. Harris, P. C , and C. S. Shaffner, 1956. Effect of season and thyroidal activity on the molt response to progesterone. Poultry Sci. 35: 11461147. Juhn, M., and P. C. Harris, 1956. Responses in molt and lay of fowl to progestins and gonadotrophins. Proc. Soc. Expt. Biol. Med. 92: 709711. Kar, A. B., 1949. Testicular changes in the juvenile pigeondue to progesterone treatment. Endocrinol. 45: 346-348. Kosin, I. L., 1948. The use of testosterone propionate in controlling broodiness in turkeys. Poultry Sci. 27: 671.
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Nalbandov, A. V., 1945. A study of the effect of prolactin on broodiness and on cock testes. Endocrinol. 36: 251-258. Nalbandov, A. V., 1956. Effect of progesterone on egg production. Poultry Sci. 35: 1162. Riddle, O., R. W. Bates and E. L. Lahr, 1935. Prolactin induces broodiness in fowl. Am. J. Physiol. I l l : 352-360. Riddle, O., and E. L. Lahr, 1944. On broodiness of ring doves following implants of certain steroid hormones. Endocrinol. 35: 255-260. Saeki, S., and Y. Tanabe, 1955. Changes in prolactin content of fowl pituitary during broody periods and some experiments on the induction of broodiness. Poultry Sci. 34: 909-919. Shaffner, C. S., 1955. Progesterone-induced molt. Poultry Sci. 34: 840-842. Snedecor, G. W., 1956. Statistical Methods, 5th Ed. Iowa State College Press, Ames, Iowa. Wodzicki, K., 1934. Hormonal interruption of broodiness in hens. Nature, 134: 383. Zarrow, M. X., R. L. Shoger and E. A. LazoWasem, 1954. The rate of disappearance of exogenous progesterone from the blood. J. Clin. Endocrinol. 14: 645-651.
The Nutritional Significance of Processed Keratin in Poultry Feeding KENNETH W. MCKERNS 1 AND EDNA RITTERSPORN Research Laboratories, Canada Packers Ltd., Toronto 9, Ontario (Received for publication September 26, 1957)
of the amino acid conONtentTHEof basis keratins given by Graham et al. (1949) and from the amino acid contents of the other dietary ingredients (Almquist, 1952), it is apparent that keratin whether from hoof, horn or feathers, could substitute for a large portion of the soybean oil meal in commercial chick rations without disturbing the amino acid balance of the ration. It would supply arginine and cystine and the low methionine content might be compensated for by 1
Present address: Research Laboratories, American Cyanamid Company, Pearl River, N. Y.
the very high cystine. There has been renewed interest in the last few years in the use of these keratin proteins in animal feeds. Sodium sulfite-treated feather meal was used by Draper (1944) with good growth response in basal diets fed to chicks and rats. It was shown by Binkley and Vasak (1951) that feathers could be made more digestible by steam heating under pressure. Sullivan and Stephenson (1957) found that feathers heated at 35 lbs. steam pressure for 1 hour were a satisfactory replacement for soybean oil meal when added at levels up to 5% of the total ration. Wilder et al. (1953, 1955) also