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Physiological Disturbance of the Reproductive System in White Leghorn Cockerels Following the Feeding of Enheptin*
Physiological Disturbance of the Reproductive System in White Leghorn Cockerels Following the Feeding of Enheptin* C. B. HUDSON AND J. A. PINO
(Received for publication April 2, 1952)
T
HE efficacy of Enheptin (2-amino, 5-nitrothiazole) in the treatment and prevention of blackhead (infectious enterohepatitis) of turkeys has been demonstrated by DeVolt et al. (1951), Jungherr and Winn (1950), and Waletzky et al. (1950), and others. These investigators reported that, except for a short period of retardation in growth due to depressed feed consumption, no toxic effects were noted. At one time blackhead in chickens was considered to be a benign disease and of no economic importance. After vaccination against fowl pox became a common practice, however, a change was noted. It was observed that, though a flock appeared to be in good health at the time of vaccination, heavy losses were suffered from blackhead. These losses usually began ten days to two weeks after vaccination and continued for ten or more days. This sequence of events can be explained by assuming that the chickens were carriers of the blackhead parasite. Consequently, when the systemic reaction to the vaccine began, the natural defenses of the bird to the blackhead parasite were * Paper of the Journal Series, New Jersey Agricultural Experiment Station, Rutgers University— The State University of New Jersey, Department of Poultry Husbandry.
lowered, permitting rapid invasion of the tissue by the parasite. Later, heavy losses from blackhead began to occur in the absence of any prior history of fowl pox vaccination. This may have been due in part to an increase in virulence of the parasite and in part to the tendency in recent years to rear larger flocks together in a smaller area. Thus, there was need for a drug that would help prevent post-vaccination losses from blackhead as well as losses in natural outbreaks. The drug Enheptin seemed to meet this need and was widely used on poultry flocks in New Jersey during 1951. In the course of routine examination of chickens brought to the Poultry Pathology Laboratory during 1951, increasing incidences of delayed sexual maturity were observed in flocks having a prior history of Enheptin feeding at some time during the growing season. For this reason it was deemed desirable to obtain more reliable information under controlled conditions with respect to the reproductive disturbances resulting from the prophylactic and therapeutic administration of Enheptin. There are no reports in the literature, to the authors' knowledge, which deal with this aspect of Enheptin treatment. This paper presents the results of a preliminary study.
1017
Downloaded from http://ps.oxfordjournals.org/ at FU BerlinFB Humanmedizin on May 8, 2015
Department of Poultry Husbandry, Rutgers University, New Brunswick, N. J.
1018
C. B. HUDSON AND J. A. PINO PROCEDURE
354 lbs. ground yellow corn 200 lbs. ground wheat 200 lbs. ground oats 75 lbs. meat scrap 50 lbs. soybean oil meal 60 lbs. alfalfa leaf meal 301bs.Mico 20 lbs. bone meal 7 lbs. salt 4 lbs. poultry feeding oil, 1.000A, 400D 1,000
To this basic formula was added Enheptin pre-mix at the rate of \ lb. per 100 of feed, giving 0.1% level of 2-amino, 5nitrothiazole in the diet. This diet was fed to the Enheptin group for two weeks and for the third week the Enheptin level was reduced to 0.05% amino nitrothiazole concentration. The control group was fed the all-mash ration without Enheptin. All birds were fed and watered ad libitum. During the second week each cockerel was subjected to artificial ejaculation as practiced for artificial insemination by the method of Burrows and Quinn (1937). This was repeated every other day until the third handling, or two days prior to the termination of the feeding period, when semen was collected and pooled. The Enheptin-fed males failed to produce semen at any time. The control males responded variously in semen production. Two males produced a thin, watery semen; five produced one or two drops of goodquality semen; and one male produced in one ejaculate J cc.
RESULTS
Feed Consumption A total of 45 lbs. of mash was consumed by the control group during the threeweek period (Table 1). The Enheptin fed lot consumed only 18 lbs. of mash during the first two weeks, or about 9 lbs. per week, at which time the Enheptin level was 0.1%. This compares roughly to 15 lbs. per week feed consumption by the control group. In the third week at the Enheptin level of 0.05% the feed consumed by the Enheptin group rose to 14 lbs., which was virtually equivalent to TABLE 1.—Total weekly feed consumption of control and Enheptin-fed cockerels* . ^ot
1st week
2nd week
3rd week
rp . ,
Control Enheptin
14.5 9.0
14.5 9.0
16.0 14.0
45.0 32.0
T
l o m
* 2 amino, 5-nitrothiazole level of 0.1% during 1st two weeks, and 0.05% during 3rd week.
that of the control group. In view of work in progress it is not felt that the reduction in feed intake was sufficient to account for the regression in size and activity of the sexual organs and associated parts. Body Weight The growth rate of the Enheptin lot was somewhat depressed, as shown in
Downloaded from http://ps.oxfordjournals.org/ at FU BerlinFB Humanmedizin on May 8, 2015
Single Comb White Leghorn cockerels 12 weeks of age were randomly divided into two groups of eight each. The birds were individually weighed and comb size (area) of each was taken by measuring the comb at its greatest length and greatest height in centimeters and multiplying these figures. All birds were kept in individual cages and were maintained on an all-mash ration consisting of the following ingredients:
The semen was introduced into six hens also maintained in laying cages. Each hen was inseminated once with 0.1 cc. of the undiluted pooled semen. All eggs laid for one week after the second day following insemination were incubated. At the end of the third week, body weights, comb size and feed consumption data were taken. All birds were slaughtered and their testes weighed. Representative specimens were prepared from each group for histological study.
1019
REPRODUCTION AND ENHEPTIN TABLE 2.—Weight , comb and testes changes in control and Enheptin-
fed White Leghorn cockerels Bird No.
Body wt., start (lb.)
Body wt., finish (lb.)
387 500 484 293 299 489 480 491
2.6 3.1 3.0 3.0 3.1 3.3 2.8 3.5
3.0 3.4 3.6 3.6 3.7 3.8 3.3 4.0
0.4 0.3 0.6 0.6 0.6 0.5 0.5 0.5
45 60 45 71 38 32 60 54
Total Mean
24.40 3.05
28.4 3.55
4.0 0.50
405 50.6
2.8 2.6 3.2 3.0 3.0 2.9 3.0 2.5
3.3 3.0 3.4 3.3 3.3 3.0 3.4 2.5
0.5 0.5 0.2 0.3 0.3 0.1 0.4 0.0
22.9 2.86
25.2 3.15
2.3 0.28
Comb size, start (cm.2)
Gain/ (lb.)
Comb size :, finish (cm.2)
Gain or loss (cm.2)
Testes wt.
21 52 60 20 20 26 24 18
10.Of 20.6 15.7 23.7 5.8 9.6 16.0 16.4
241 30.1
117.8 14.72
(gm.)
Control
Total Mean
Enheptin 69 32 60 60 47 105 57 42 472 59.0
646 80.7 33 18 45 26 25 42 30 28 247 30.9
-36 -14 -15 -34 -22 -63 -27 -14 -225 - 28.1
0.3 0.3 0.2 0.3 0.5 0.4 0.6 0.5 3.1 0.38
* Gains all positive except where preceeded by (—). f Weight of only one testis—no left testis present.
Table 2. The most reasonable explanation, but by no means the only one, for the difference in growth rates between the two groups is the difference in feed consumption. However, this point will be established in current experiments in which paired feeding is being practiced.
surprising to find a great diminution in the testes of the Enheptin-fed males As shown in Table 2, the testes of the control group were more than 40 times as large as
Comb and Testis Size Table 2 shows the severe reduction in size of the secondary sexual character, the comb. The head features, as seen in Figure 1, were typical of castrated or estrogen-treated cockerels. Figure 2 shows normal control males of the same age. Whereas the comb area increased 60% in the control group it decreased about 50% in the Enheptin lot. Since the comb size is a fairly reliable indication of testes size, according to Blyth (1928), Parker et al. (1942) and Jones (1944), it was not
FIG. 1. White Leghorn cockerels fifteen weeks of age at termination of three week Enheptin feeding.
Downloaded from http://ps.oxfordjournals.org/ at FU BerlinFB Humanmedizin on May 8, 2015
101 350 298 369 296 336 482 380
66 112 105 91 58 58 84 72
1020
C. B. H U D S O N AND J. A. P I N O
those of the Enheptin-fed group. Actually the testes of the Enheptin lot had regressed in size even when compared to the normal testis of a 12 week old cockerel. Histology of Testis Although the size of the comb is normally indicative of testes size and sexual development, it does not necessarily indi-
T h e testes of the Enheptin-fed lot as they appear in section are shown in Figure 3. The reduced size of the testes is a reflection of the atrophic condition of the tubules. T h e most striking observation is, of course, the absence of spermatogenesis. The tubules exhibit a single layer of spermatogonial and Sertoli cells a t the basement membrane. I t appears as though
FIG. 3. Testis section of an Enheptin-fed cockerel at termination of three week feeding period. Note atrophy of tubules, absence of spermatogenesis and fibrous interstitial cells. Hematoxylin and eosin. X740 High dry.
Downloaded from http://ps.oxfordjournals.org/ at FU BerlinFB Humanmedizin on May 8, 2015
FIG. 2. Control cockerels of same age as those in Fig. 1.
cate a normally functioning testis. T h e comb size of the male is largely influenced by the sex hormone, androgen, secreted by the Leydig cells of the testes. I t is possible under certain circumstances, as shown by Sturkie et al. (1949), that in spite of the disfunction of tubular elements, hormone secretion of the testis m a y remain apparently normal. Therefore impaired or altered reproductive function as exhibited by comb size and mating behavior should be corroborated by adequate histological procedure.
REPRODUCTION AND E N H E P T I N
1021
an occasional primary spermatocyte has formed b u t there are no advanced stages of sperm formation. The basement membrane is thickened while the interstitial tissue appears more fibrous and condensed. I n the normal testis, Figure 4, the interstitial cells are sparse and less fibrous while the tubules are fat and active. A rlificial
Insemination
Even though the tissue of the testis is subject to histological study, the evidence afforded by microscopic examination is not always a reliable indication of the physiological functioning of this organ, as shown by Sturkie el at. (1949). Previous studies by Sampson and Warren (1939) have shown that semen from young White Leghorn cockerels ten weeks of age was capable of fertilization. I t was necessary in the case a t hand to demonstrate t h a t the control males were pro-
ducing functional spermatozoa before an impairment of the process could be shown in the experimental lot. Of the 21 eggs collected from six hens artificially inseminated with pooled semen from the control males, 15 were fertile, and 13 chicks were hatched. We can say without question, therefore, t h a t the control males were capable of fertilization. DISCUSSION
T h e results as presented obviously raise many questions t h a t must be answered before a complete evaluation of the reproductive disturbance of Enheptin feeding can be made. I t is quite apparent t h a t Enheptin given as described does induce a complete recession of spermatogenesis with an accompanying alteration in secondary sexual characters. Of immediate interest, of course, is the question of duration of effect and the relative influence of dosage level upon the
Downloaded from http://ps.oxfordjournals.org/ at FU BerlinFB Humanmedizin on May 8, 2015
FIG. 4. Testis section of normal cockerel of same age as (hat in Fig. 3. Hematoxylin and eosin. X740 High dry.
1022
NEWS AND NOTES
The nature of this suppression of the spermatogenic and androgenic activity of the testis is at present unknown. Whether the action of Enheptin is directly upon the testicular tissue cannot be stated, however, the question of pituitary involvement certainly presents itself and is to be further investigated. SUMMARY
The feeding of Enheptin (2-amino, 5nitrothiazole) to 12 week old White Leghorn cockerels at a therapeutic level of 0.1% amino thiazole for two weeks followed by a 0.05% level for one week reduced feed intake and retarded growth rate. Testis size was reduced and spermatogenic activity was abolished. Secondary sexual characteristics, the comb and wattles, were regressed and had the appearance of a castrated male. The possible
mode of action of Enheptin is discussed. ACKNOWLEDGMENT The authors are indebted to Dr. Sylvan E. Moulten, of St. Peter's Hospital, New Brunswick, who made the histological preparations of the testes. REFERENCES Burrows, W. H., and J. P. Quinn, 1937. The collection of spermatozoa from the domestic fowl and turkey. Poultry Sci. 16: 19-24. Blyth, J. S. S., 1928. Some observations on the relation between comb growth and gonadic structure in the male domestic fowl. Proc. Roy. Phys. Soc. Edinburg, 21: 175-183. DeVolt, H. M., A. P. Hoist and F. G. Tromba, 1951. The prophylactic action of Enheptin (2-amino, 5-nitrothiazole) on Blackhead (infectious Enterohepatitis) of turkeys. Poultry Sci. 30: 727-729. Jones, D. G., 1944. The relationship between development of the comb, body size and reproductive capacity in White Leghorn males. Thesis, Cornell University, Ithaca, N. Y. Jungherr, E. L., and J. D. Winn, 1950. Field experiments with Enheptin-T on the control of histomoniasis (blackhead) in turkeys. Poultry Sci. 29: 462-165. Parker, J. E., F. F. McKenzie and H. L. Kempster, 1942, Development of the testis and combs of White Leghorn and New Hampshire cockerels. Poultry Sci. 21:35-44. Sampson, F. R., and D. C. Warren, 1939. Sterility in the fowl. Poultry Sci. 15: 413-414. Sturkie, P. D., J. A. Pino, J. L. Weatherwax, A. J. Donnelly and G. M. Dorrance, 1949. Effect of x-rays on fertility in White Leghorn male chickens treated before puberty. Radiology, 52: 112-117. Waletzky, E., J. H. Clark and H. W. Marson, 1950. New chemotherapeutic agents in enterohepatitis (blackhead) of turkeys. Science, 111: 720-721.
NEWS AND NOTES {Continued from page 1016) -WISCONSIN NOTES Gerald E. Annin was appointed Chairman of the Department of Poultry Husbandry, the University of Wisconsin, Madison, in July. He graduated from the University of Missouri with a B.S. in Agriculture
in 1926. He came to the University of Wisconsin in 1927 as Extension Specialist in Poultry. He received a M.S. in Agriculture in 1939 specializing in Cooperative Marketing. Serving chiefly in extension during the past 25 years, Annin has been, at times
(Continued on page 1036)
Downloaded from http://ps.oxfordjournals.org/ at FU BerlinFB Humanmedizin on May 8, 2015
rate of recovery. There is some evidence obtained from poultrymen to the effect that following the therapeutic administration of the drug, recovery in terms of egg laying and fertility takes place in four weeks. This has neither been confirmed nor denied. What the effect of prophylactic treatment would be on the duration or intensity of reproductive disfunction is unknown. As has been noted from the histological evidence, the Sertoli cells and spermatogonia apparently remain healthy but quiescent. It is not illogical to suppose that upon removal of the suppressive influence their activity should be regained.
(Received for publication April 2, 1952)
T
HE efficacy of Enheptin (2-amino, 5-nitrothiazole) in the treatment and prevention of blackhead (infectious enterohepatitis) of turkeys has been demonstrated by DeVolt et al. (1951), Jungherr and Winn (1950), and Waletzky et al. (1950), and others. These investigators reported that, except for a short period of retardation in growth due to depressed feed consumption, no toxic effects were noted. At one time blackhead in chickens was considered to be a benign disease and of no economic importance. After vaccination against fowl pox became a common practice, however, a change was noted. It was observed that, though a flock appeared to be in good health at the time of vaccination, heavy losses were suffered from blackhead. These losses usually began ten days to two weeks after vaccination and continued for ten or more days. This sequence of events can be explained by assuming that the chickens were carriers of the blackhead parasite. Consequently, when the systemic reaction to the vaccine began, the natural defenses of the bird to the blackhead parasite were * Paper of the Journal Series, New Jersey Agricultural Experiment Station, Rutgers University— The State University of New Jersey, Department of Poultry Husbandry.
lowered, permitting rapid invasion of the tissue by the parasite. Later, heavy losses from blackhead began to occur in the absence of any prior history of fowl pox vaccination. This may have been due in part to an increase in virulence of the parasite and in part to the tendency in recent years to rear larger flocks together in a smaller area. Thus, there was need for a drug that would help prevent post-vaccination losses from blackhead as well as losses in natural outbreaks. The drug Enheptin seemed to meet this need and was widely used on poultry flocks in New Jersey during 1951. In the course of routine examination of chickens brought to the Poultry Pathology Laboratory during 1951, increasing incidences of delayed sexual maturity were observed in flocks having a prior history of Enheptin feeding at some time during the growing season. For this reason it was deemed desirable to obtain more reliable information under controlled conditions with respect to the reproductive disturbances resulting from the prophylactic and therapeutic administration of Enheptin. There are no reports in the literature, to the authors' knowledge, which deal with this aspect of Enheptin treatment. This paper presents the results of a preliminary study.
1017
Downloaded from http://ps.oxfordjournals.org/ at FU BerlinFB Humanmedizin on May 8, 2015
Department of Poultry Husbandry, Rutgers University, New Brunswick, N. J.
1018
C. B. HUDSON AND J. A. PINO PROCEDURE
354 lbs. ground yellow corn 200 lbs. ground wheat 200 lbs. ground oats 75 lbs. meat scrap 50 lbs. soybean oil meal 60 lbs. alfalfa leaf meal 301bs.Mico 20 lbs. bone meal 7 lbs. salt 4 lbs. poultry feeding oil, 1.000A, 400D 1,000
To this basic formula was added Enheptin pre-mix at the rate of \ lb. per 100 of feed, giving 0.1% level of 2-amino, 5nitrothiazole in the diet. This diet was fed to the Enheptin group for two weeks and for the third week the Enheptin level was reduced to 0.05% amino nitrothiazole concentration. The control group was fed the all-mash ration without Enheptin. All birds were fed and watered ad libitum. During the second week each cockerel was subjected to artificial ejaculation as practiced for artificial insemination by the method of Burrows and Quinn (1937). This was repeated every other day until the third handling, or two days prior to the termination of the feeding period, when semen was collected and pooled. The Enheptin-fed males failed to produce semen at any time. The control males responded variously in semen production. Two males produced a thin, watery semen; five produced one or two drops of goodquality semen; and one male produced in one ejaculate J cc.
RESULTS
Feed Consumption A total of 45 lbs. of mash was consumed by the control group during the threeweek period (Table 1). The Enheptin fed lot consumed only 18 lbs. of mash during the first two weeks, or about 9 lbs. per week, at which time the Enheptin level was 0.1%. This compares roughly to 15 lbs. per week feed consumption by the control group. In the third week at the Enheptin level of 0.05% the feed consumed by the Enheptin group rose to 14 lbs., which was virtually equivalent to TABLE 1.—Total weekly feed consumption of control and Enheptin-fed cockerels* . ^ot
1st week
2nd week
3rd week
rp . ,
Control Enheptin
14.5 9.0
14.5 9.0
16.0 14.0
45.0 32.0
T
l o m
* 2 amino, 5-nitrothiazole level of 0.1% during 1st two weeks, and 0.05% during 3rd week.
that of the control group. In view of work in progress it is not felt that the reduction in feed intake was sufficient to account for the regression in size and activity of the sexual organs and associated parts. Body Weight The growth rate of the Enheptin lot was somewhat depressed, as shown in
Downloaded from http://ps.oxfordjournals.org/ at FU BerlinFB Humanmedizin on May 8, 2015
Single Comb White Leghorn cockerels 12 weeks of age were randomly divided into two groups of eight each. The birds were individually weighed and comb size (area) of each was taken by measuring the comb at its greatest length and greatest height in centimeters and multiplying these figures. All birds were kept in individual cages and were maintained on an all-mash ration consisting of the following ingredients:
The semen was introduced into six hens also maintained in laying cages. Each hen was inseminated once with 0.1 cc. of the undiluted pooled semen. All eggs laid for one week after the second day following insemination were incubated. At the end of the third week, body weights, comb size and feed consumption data were taken. All birds were slaughtered and their testes weighed. Representative specimens were prepared from each group for histological study.
1019
REPRODUCTION AND ENHEPTIN TABLE 2.—Weight , comb and testes changes in control and Enheptin-
fed White Leghorn cockerels Bird No.
Body wt., start (lb.)
Body wt., finish (lb.)
387 500 484 293 299 489 480 491
2.6 3.1 3.0 3.0 3.1 3.3 2.8 3.5
3.0 3.4 3.6 3.6 3.7 3.8 3.3 4.0
0.4 0.3 0.6 0.6 0.6 0.5 0.5 0.5
45 60 45 71 38 32 60 54
Total Mean
24.40 3.05
28.4 3.55
4.0 0.50
405 50.6
2.8 2.6 3.2 3.0 3.0 2.9 3.0 2.5
3.3 3.0 3.4 3.3 3.3 3.0 3.4 2.5
0.5 0.5 0.2 0.3 0.3 0.1 0.4 0.0
22.9 2.86
25.2 3.15
2.3 0.28
Comb size, start (cm.2)
Gain/ (lb.)
Comb size :, finish (cm.2)
Gain or loss (cm.2)
Testes wt.
21 52 60 20 20 26 24 18
10.Of 20.6 15.7 23.7 5.8 9.6 16.0 16.4
241 30.1
117.8 14.72
(gm.)
Control
Total Mean
Enheptin 69 32 60 60 47 105 57 42 472 59.0
646 80.7 33 18 45 26 25 42 30 28 247 30.9
-36 -14 -15 -34 -22 -63 -27 -14 -225 - 28.1
0.3 0.3 0.2 0.3 0.5 0.4 0.6 0.5 3.1 0.38
* Gains all positive except where preceeded by (—). f Weight of only one testis—no left testis present.
Table 2. The most reasonable explanation, but by no means the only one, for the difference in growth rates between the two groups is the difference in feed consumption. However, this point will be established in current experiments in which paired feeding is being practiced.
surprising to find a great diminution in the testes of the Enheptin-fed males As shown in Table 2, the testes of the control group were more than 40 times as large as
Comb and Testis Size Table 2 shows the severe reduction in size of the secondary sexual character, the comb. The head features, as seen in Figure 1, were typical of castrated or estrogen-treated cockerels. Figure 2 shows normal control males of the same age. Whereas the comb area increased 60% in the control group it decreased about 50% in the Enheptin lot. Since the comb size is a fairly reliable indication of testes size, according to Blyth (1928), Parker et al. (1942) and Jones (1944), it was not
FIG. 1. White Leghorn cockerels fifteen weeks of age at termination of three week Enheptin feeding.
Downloaded from http://ps.oxfordjournals.org/ at FU BerlinFB Humanmedizin on May 8, 2015
101 350 298 369 296 336 482 380
66 112 105 91 58 58 84 72
1020
C. B. H U D S O N AND J. A. P I N O
those of the Enheptin-fed group. Actually the testes of the Enheptin lot had regressed in size even when compared to the normal testis of a 12 week old cockerel. Histology of Testis Although the size of the comb is normally indicative of testes size and sexual development, it does not necessarily indi-
T h e testes of the Enheptin-fed lot as they appear in section are shown in Figure 3. The reduced size of the testes is a reflection of the atrophic condition of the tubules. T h e most striking observation is, of course, the absence of spermatogenesis. The tubules exhibit a single layer of spermatogonial and Sertoli cells a t the basement membrane. I t appears as though
FIG. 3. Testis section of an Enheptin-fed cockerel at termination of three week feeding period. Note atrophy of tubules, absence of spermatogenesis and fibrous interstitial cells. Hematoxylin and eosin. X740 High dry.
Downloaded from http://ps.oxfordjournals.org/ at FU BerlinFB Humanmedizin on May 8, 2015
FIG. 2. Control cockerels of same age as those in Fig. 1.
cate a normally functioning testis. T h e comb size of the male is largely influenced by the sex hormone, androgen, secreted by the Leydig cells of the testes. I t is possible under certain circumstances, as shown by Sturkie et al. (1949), that in spite of the disfunction of tubular elements, hormone secretion of the testis m a y remain apparently normal. Therefore impaired or altered reproductive function as exhibited by comb size and mating behavior should be corroborated by adequate histological procedure.
REPRODUCTION AND E N H E P T I N
1021
an occasional primary spermatocyte has formed b u t there are no advanced stages of sperm formation. The basement membrane is thickened while the interstitial tissue appears more fibrous and condensed. I n the normal testis, Figure 4, the interstitial cells are sparse and less fibrous while the tubules are fat and active. A rlificial
Insemination
Even though the tissue of the testis is subject to histological study, the evidence afforded by microscopic examination is not always a reliable indication of the physiological functioning of this organ, as shown by Sturkie el at. (1949). Previous studies by Sampson and Warren (1939) have shown that semen from young White Leghorn cockerels ten weeks of age was capable of fertilization. I t was necessary in the case a t hand to demonstrate t h a t the control males were pro-
ducing functional spermatozoa before an impairment of the process could be shown in the experimental lot. Of the 21 eggs collected from six hens artificially inseminated with pooled semen from the control males, 15 were fertile, and 13 chicks were hatched. We can say without question, therefore, t h a t the control males were capable of fertilization. DISCUSSION
T h e results as presented obviously raise many questions t h a t must be answered before a complete evaluation of the reproductive disturbance of Enheptin feeding can be made. I t is quite apparent t h a t Enheptin given as described does induce a complete recession of spermatogenesis with an accompanying alteration in secondary sexual characters. Of immediate interest, of course, is the question of duration of effect and the relative influence of dosage level upon the
Downloaded from http://ps.oxfordjournals.org/ at FU BerlinFB Humanmedizin on May 8, 2015
FIG. 4. Testis section of normal cockerel of same age as (hat in Fig. 3. Hematoxylin and eosin. X740 High dry.
1022
NEWS AND NOTES
The nature of this suppression of the spermatogenic and androgenic activity of the testis is at present unknown. Whether the action of Enheptin is directly upon the testicular tissue cannot be stated, however, the question of pituitary involvement certainly presents itself and is to be further investigated. SUMMARY
The feeding of Enheptin (2-amino, 5nitrothiazole) to 12 week old White Leghorn cockerels at a therapeutic level of 0.1% amino thiazole for two weeks followed by a 0.05% level for one week reduced feed intake and retarded growth rate. Testis size was reduced and spermatogenic activity was abolished. Secondary sexual characteristics, the comb and wattles, were regressed and had the appearance of a castrated male. The possible
mode of action of Enheptin is discussed. ACKNOWLEDGMENT The authors are indebted to Dr. Sylvan E. Moulten, of St. Peter's Hospital, New Brunswick, who made the histological preparations of the testes. REFERENCES Burrows, W. H., and J. P. Quinn, 1937. The collection of spermatozoa from the domestic fowl and turkey. Poultry Sci. 16: 19-24. Blyth, J. S. S., 1928. Some observations on the relation between comb growth and gonadic structure in the male domestic fowl. Proc. Roy. Phys. Soc. Edinburg, 21: 175-183. DeVolt, H. M., A. P. Hoist and F. G. Tromba, 1951. The prophylactic action of Enheptin (2-amino, 5-nitrothiazole) on Blackhead (infectious Enterohepatitis) of turkeys. Poultry Sci. 30: 727-729. Jones, D. G., 1944. The relationship between development of the comb, body size and reproductive capacity in White Leghorn males. Thesis, Cornell University, Ithaca, N. Y. Jungherr, E. L., and J. D. Winn, 1950. Field experiments with Enheptin-T on the control of histomoniasis (blackhead) in turkeys. Poultry Sci. 29: 462-165. Parker, J. E., F. F. McKenzie and H. L. Kempster, 1942, Development of the testis and combs of White Leghorn and New Hampshire cockerels. Poultry Sci. 21:35-44. Sampson, F. R., and D. C. Warren, 1939. Sterility in the fowl. Poultry Sci. 15: 413-414. Sturkie, P. D., J. A. Pino, J. L. Weatherwax, A. J. Donnelly and G. M. Dorrance, 1949. Effect of x-rays on fertility in White Leghorn male chickens treated before puberty. Radiology, 52: 112-117. Waletzky, E., J. H. Clark and H. W. Marson, 1950. New chemotherapeutic agents in enterohepatitis (blackhead) of turkeys. Science, 111: 720-721.
NEWS AND NOTES {Continued from page 1016) -WISCONSIN NOTES Gerald E. Annin was appointed Chairman of the Department of Poultry Husbandry, the University of Wisconsin, Madison, in July. He graduated from the University of Missouri with a B.S. in Agriculture
in 1926. He came to the University of Wisconsin in 1927 as Extension Specialist in Poultry. He received a M.S. in Agriculture in 1939 specializing in Cooperative Marketing. Serving chiefly in extension during the past 25 years, Annin has been, at times
(Continued on page 1036)
Downloaded from http://ps.oxfordjournals.org/ at FU BerlinFB Humanmedizin on May 8, 2015
rate of recovery. There is some evidence obtained from poultrymen to the effect that following the therapeutic administration of the drug, recovery in terms of egg laying and fertility takes place in four weeks. This has neither been confirmed nor denied. What the effect of prophylactic treatment would be on the duration or intensity of reproductive disfunction is unknown. As has been noted from the histological evidence, the Sertoli cells and spermatogonia apparently remain healthy but quiescent. It is not illogical to suppose that upon removal of the suppressive influence their activity should be regained.