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Force Molting (Interruption of Egg Laying) in White Leghorn Hens by the Use of Enheptin (2-Amino, 5-Nitrothiazole)
Force Molting (Interruption of Egg Laying) in White Leghorn Hens by the Use of Enheptin (2-Amino, 5-Nitrothiazole) J O H N A. P I N O
Rutgers University, New Brunswick, New Jersey (Received for publication August 18, 1954)
A
and to observe post-treatment reproductive performance. PROCEDURE AND RESULTS The plan of the test was quite simple. Three pens of White Leghorn hens, 20 months of age, having been hatched the previous year in March, were treated as follows beginning November 2: Pen 33—Forty-three birds. Used as a control pen. It was continued on the previous regime receiving an all-mash diet designated N. J. #11.* Artificial light from 4 a.m. to 8 a.m. Pen 34—Forty-seven birds. Received N. J. #11 plus 0.10 percent Enheptin in the diet from November 2 to November 9 and 0.05 percent Enheptin in the diet from November 10 to 16 after which time it received N. J. #11 without drug. Artificial light was given from 4 a.m. to 8 a.m. Pen 36—Forty-five birds. All-mash N . J. #11. November 2 and 3 received no feed or Paper of the Journal Series, New Jersey Agricultural Experiment Station, Rutgers University—The State University of New Jersey, Department of Poultry Husbandry, New Brunswick. * N. J. #11 formula: Ground yellow corn 710 lbs. Soybean oil meal 100 Meat scrap 150 Alfalfa meal 120 Steamed bone meal 40 fMico concentrate 60 Salt 7 Feeding oil 8 }Bi2-antibiotic feed supplement 5 Ground wheat 400 Ground oats 400 t Mico concentrate, a mineral supplement manufactured by the Limestone Products Corp., Newton, N. J. % To furnish 9 grams of antibiotic (aureomycin or equivalent) and 9 milligrams of vitamin Bis activity per ton of feed.
540
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FORCE molt to the husbandman means to make hens stop egg laying. This is accomplished with variations in severity by radical diet changes, fasting, and darkness. The object of this practice is to switch the period of productivity in order to accrue later advantages. A procedure for causing molt is described in the Washington Extension Bulletin 323 (1947). It has been shown by Berg and Bearse (1947) that force molting results in the improvement of egg quality characteristics when comparing "just prior" and "after" molt eggs. The force-molted hens were not able to recover the level of pullet-year egg quality characteristics. Van der Meulen (1939) reporting on hormonal control of molt was able to force the molt by oral doses of desiccated pig thyroid. He showed that induced hyperthyroidism precipitates molt and interrupts egg production, the duration of which varies with the season. Previous reports by Hudson and Pino (1952) and Pino and Hudson (1953) have shown that the oral administration of the drug Enheptin (2-amino, 5-nitrothiazole) at dietary levels of 0.1 percent to White Leghorn chickens will completely suppress reproductive activity and cause precipitous molting. It is now evident, Pino et al. (1954), that the sexual suppression is in some way the result of interference with the secretion of pituitary gonadotropic hormone. The present study was conducted to observe the effectiveness of the drug Enheptin in forcing hens to molt
541
FORCE MOLTING BY ENHEPTIN water. November 17 to 30 a restricted feed intake. No artificial light between November 2 to December 7 after which time lights were given from 4 a.m. to 8 a.m.
FEED CONSUMPTION AND BODY WEIGHT
Feed consumption during the critical period of force molting is shown in Table 1. TABLE 1.—Average weekly per bird feed intake1 {Estimated from record of total feed consumption per pen)
EGG PRODUCTION Period
Pen 33 control lb.
Pen 34 drug treated lb.
Nov. 2 - 9 10-16 17-23 24-30 Dec. 1- 7 8-15
1.95 2.08 1.85 1.83 2.00 2.05
1.16* 0.92* 0.89 1.80 1.84 1.92
Pen 36 force molted lb. 1.48* 1.84 1.21* 0.95* 1.75 1.85
1 Feed consumption for each pen prior to the periods shown in the table was essentially the same. * Indicates treatment periods.
It may be noted that pen 34 (the drug treated pen) suffered a severe drop in feed intake for 3 weeks after which time rapid recovery to normal feed intake was established. More recent data (unpublished) indicate that the treatment period with drug, in order to stop production, need not be as long as in this experiment. This would shorten the period of reduced feed intake and probably lessen the weight loss. For the period November 17 to 30, pen
Egg production is plotted in Figure 1. The precipitous decline and rapid ascent of production shown by pens 34 and 36 TABLE 2.—Number of individual birds {in percent) which laid any eggs during periods shown* Figures in parentheses represent actual pen production during same period in percent hen days Pen 33
Pen 34
1- 7 8-14 15-21 22-31
78 (52.8) 72 (47.5) 78 (50.8) 74(43.7)
81 (51.3) 81 (41.6) 83 (45.9) •1(41.7)
1- 7 8-14
67 (43.5) 61 (35.8)
85 (46.2) 43 (13.9)
15-21 22-30
59 (33.5) 61 (35.9)
1- 7 8-14 15-21 22-31 1- 7 8-14 15-21 22-31 1- 7 8-14 15-21 22-28
55 56 51 50 54 58 51 68 65 65 55 55
Period October
November
December
January
February
(27.8) (26.8) (27.2) (26.8) (27.5) (26.3) (23.4) (30.0) (33.3) (31.6) (22.7) (21.2)
Pen 36 76 70 67 72
1
0(0) 0(0) 4 (2.4) 11 (8.3) 38 (18.9) 77 (35.8) 85 (49.3) 93 (44.1) 91 (45.7) 91 (45.1) 93 (55.4) 93 (61.1) 88 (47.5) 72 (49.5)
(48.8) (41.2) (42.8) (39.5)
67 (33.1) 47 (25.0) 42 (23.3) 27 (9.7) 9 (3.2) 9 (3.2) 19 (8.3) 49 (21.6) 79 (41.5) 87 (47.1) 91 (46.1) 81 (39.5) 73 (38.2) 76 (42.1) 80(34.5) 58 (31.2)
* Mortality from October 1, 1953, to February 28, 1954, was pen 33t 6 birds; pen 34, 4 birds; pen 36, 2 birds, f Dotted lines indicate period of treatment.
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Each pen was a 10'X20' unit. All were located in the same building and were adjacent to one another except that pens 34 and 36 were separated by a solid board partition and one empty pen of equivalent size. Each of the three groups was kept intact as of the preceding five months. Their performance during that time was essentially identical. Birds in all pens were trapnested daily.
36 was limited to approximately the same feed intake which pen 34 experienced during the previous 2 weeks. Although pen 36 was given no feed or water for two days at the beginning of the test, this was not sufficient to interrupt egg production completely. Body weight loss varied considerably among individuals within each pen. Whereas 90 percent of the birds in both pens 34 and 36 lost from 0.1-2.0 lb., 79 percent of the birds in the control pen lost weight varying between 0.1-2.1 lb. The extent of weight loss of individual birds in the control pen was just as great as in the other two pens. However, when uniform molting is induced, the extent of body weight loss is more impressive. The precise relationship which drug administration has to weight loss is under current study.
J. A. PINO
P. 33
> o z
O
o
o UJ
z < ->
FIG. 1. Egg production calculated on a hen-day basis. Pen 33, control; pen 34, Enheptin treated November 2-16; pen 36, feed restricted.
are striking when compared to the control pen. Of interest are the data shown in Table 2. In pen 33 there were at all times a large percentage of birds in production. A scrutiny of the trapnest records shows that the individuals comprising those in production do not remain the same. Some birds are going out of production, others are coming into production. MOLT
All birds were examined periodically for degree of molt. It was found that at the time treatment was initiated, some of the birds in each group had already begun to molt. While individuals molted sporadically in the control pen, the drug treated birds uniformly shed profusely, regardless of the stage of molt they already were in when treatment began. Rapid molting of the majority of individuals was observed in the feed restricted force-molted pen
(pen 36). In this pen the treatment seemed to occasion the molt of non-molting birds but did not affect molting birds. FERTILITY AND HATCHABILITY
Two test hatches were conducted. Three males were placed in each pen and rotated between pens every fifth day until all males had spent equivalent time in each pen. The first setting, which followed the treatment period by 59 days, showed little difference in fertility and hatchability, as shown in Table 3. At that time production in the drug-treated pen (pen 34) was rapidly climbing. As a result more chicks were obtained from this pen. The second setting showed a marked improvement in fertility and hatchability in the drug-treated and feed restricted pens. During the second test hatch, pen 34 produced an average of 3.67 chicks per hen
Downloaded from http://ps.oxfordjournals.org/ at Oakland University on June 10, 2015
P R O D U C T I O N
ASSOCIATION NOTICE TABLE 3.—Fertility and hatchability of all eggs produced from force molted hens—P. 33 Control, 41 hens; P. 34 Enheplin treated, 46 hens; P. 36 Feed Restricted, 43 hens Eggs Pen produced and set 33 34 36
59 99 86
33 34 36
90 206 170
Fert
-*
% fert. Hatched hatchf
First Hatcht 45 76.3 79 79.8 68 79.1 Second Hatch§ 70 77.8 195 94.7 148 87.1
39 64 59
66.1 64.6 68.6
56 169 138
62.2 . 82.0 81.2
543
explain the action of Enheptin. It has been shown, Pino et al. (1954) that gonadotropic hormone activity is apparently inhibited by Enheptin whereas thyrotropic activity is not affected. It is apparent from these observations that the endocrine mechanisms controlling molt and egg production are related. REFERENCES
while pens 33 and 36 produced 1.37 and 3.21 chicks per hen respectively. SUMMARY
Hens administered the drug Enheptin (2-amino, 5-nitrothiazole) in the diet stop egg production within 7 to 10 days. There is marked shedding of feathers from all regions of the body. It was been observed (data unpublished) that there is greater individual variability in extent and duration of feather loss with decreasing dietary concentrations of drug. The period of non-productivity for individual birds seems to be related to the duration of molt. The mechanisms by which the drug Enheptin causes molting is not known. Van der Meulen's (1939) theory of cyclic periodicity in pituitary output of gonadotropic and thyrotropic hormones could
Since original preparation of this paper, the following reports have appeared: Robblee, A. R., and D. R. Clandinin, 1954. The use of Enheptin for the induction of moult in yearling hens. Poultry Sci. 33: 1078. Shaffner, C. S., 1954. Progesterone induced molt. Poultry Sci. 33: 1079-1080. Shaffner, C. S., 1954. Feather papilla stimulation by progesterone. Science, 120: 345.
ASSOCIATION NOTICE Guest attendance at the annual meeting is limited to guests invited by the Executive Committee upon recommendation or request by an Active Member of the Association. It is important that all requests be in the hands of the Secretary-Treasurer, C. B. Ryan, Department
of Poultry Husbandry, Texas A and M College System, College Station, Texas, at least 30 days prior to the annual meeting. Persons wishing to invite guests please comply with the deadline requirement. This ruling does not apply to the family of a member.
Downloaded from http://ps.oxfordjournals.org/ at Oakland University on June 10, 2015
* Apparent (candled) fertility at 7 days of incubation. t Hatch of total eggs set. X Eggs saved for 4 days beginning December 31, 59 days from start of treatment. § Eggs saved for 7 days beginning January 4, 63 days from start of treatment.
Berg, L., and G. E. Bearse, 1947. The changes in egg quality resulting from force molting White Leghorn yearling hens. Poultry Sci. 26: 414-418. Hudson, C. B., and J. A. Pino, 1952. Physiological disturbance of the reproductive system in White Leghorn cockerels following the feeding of Enheptin. Poultry Sci. 31: 1017-1022. Pino, J. A., and C. B. Hudson, 1953. Duration of sexual retardation in S. C. White Leghorn pullets and cockerels following Enheptin (2-Amino, 5-Nitrothiazole) feeding. Poultry Sci. 32: 650655. Pino, J. A., L. S. Rosenblatt and C. B. Hudson, 1954, Inhibition of pituitary gonadotropic hormone secretion by Enheptin (2-Amino, 5-Nitrothiazole). Proc. Soc. Exp. Biol. Med. 87:201-207. The Poultry Council of the State College of Washington, 1947. Summer force molting of hens for commercial egg production. State College of Washington Agricultural Extension Bull. 323. Van der Meulen, J. B., 1939. Hormonal regulation of molt and ovulation. Proceedings Seventh World's Poultry Congress and Exposition, pp. 109-112.
Rutgers University, New Brunswick, New Jersey (Received for publication August 18, 1954)
A
and to observe post-treatment reproductive performance. PROCEDURE AND RESULTS The plan of the test was quite simple. Three pens of White Leghorn hens, 20 months of age, having been hatched the previous year in March, were treated as follows beginning November 2: Pen 33—Forty-three birds. Used as a control pen. It was continued on the previous regime receiving an all-mash diet designated N. J. #11.* Artificial light from 4 a.m. to 8 a.m. Pen 34—Forty-seven birds. Received N. J. #11 plus 0.10 percent Enheptin in the diet from November 2 to November 9 and 0.05 percent Enheptin in the diet from November 10 to 16 after which time it received N. J. #11 without drug. Artificial light was given from 4 a.m. to 8 a.m. Pen 36—Forty-five birds. All-mash N . J. #11. November 2 and 3 received no feed or Paper of the Journal Series, New Jersey Agricultural Experiment Station, Rutgers University—The State University of New Jersey, Department of Poultry Husbandry, New Brunswick. * N. J. #11 formula: Ground yellow corn 710 lbs. Soybean oil meal 100 Meat scrap 150 Alfalfa meal 120 Steamed bone meal 40 fMico concentrate 60 Salt 7 Feeding oil 8 }Bi2-antibiotic feed supplement 5 Ground wheat 400 Ground oats 400 t Mico concentrate, a mineral supplement manufactured by the Limestone Products Corp., Newton, N. J. % To furnish 9 grams of antibiotic (aureomycin or equivalent) and 9 milligrams of vitamin Bis activity per ton of feed.
540
Downloaded from http://ps.oxfordjournals.org/ at Oakland University on June 10, 2015
FORCE molt to the husbandman means to make hens stop egg laying. This is accomplished with variations in severity by radical diet changes, fasting, and darkness. The object of this practice is to switch the period of productivity in order to accrue later advantages. A procedure for causing molt is described in the Washington Extension Bulletin 323 (1947). It has been shown by Berg and Bearse (1947) that force molting results in the improvement of egg quality characteristics when comparing "just prior" and "after" molt eggs. The force-molted hens were not able to recover the level of pullet-year egg quality characteristics. Van der Meulen (1939) reporting on hormonal control of molt was able to force the molt by oral doses of desiccated pig thyroid. He showed that induced hyperthyroidism precipitates molt and interrupts egg production, the duration of which varies with the season. Previous reports by Hudson and Pino (1952) and Pino and Hudson (1953) have shown that the oral administration of the drug Enheptin (2-amino, 5-nitrothiazole) at dietary levels of 0.1 percent to White Leghorn chickens will completely suppress reproductive activity and cause precipitous molting. It is now evident, Pino et al. (1954), that the sexual suppression is in some way the result of interference with the secretion of pituitary gonadotropic hormone. The present study was conducted to observe the effectiveness of the drug Enheptin in forcing hens to molt
541
FORCE MOLTING BY ENHEPTIN water. November 17 to 30 a restricted feed intake. No artificial light between November 2 to December 7 after which time lights were given from 4 a.m. to 8 a.m.
FEED CONSUMPTION AND BODY WEIGHT
Feed consumption during the critical period of force molting is shown in Table 1. TABLE 1.—Average weekly per bird feed intake1 {Estimated from record of total feed consumption per pen)
EGG PRODUCTION Period
Pen 33 control lb.
Pen 34 drug treated lb.
Nov. 2 - 9 10-16 17-23 24-30 Dec. 1- 7 8-15
1.95 2.08 1.85 1.83 2.00 2.05
1.16* 0.92* 0.89 1.80 1.84 1.92
Pen 36 force molted lb. 1.48* 1.84 1.21* 0.95* 1.75 1.85
1 Feed consumption for each pen prior to the periods shown in the table was essentially the same. * Indicates treatment periods.
It may be noted that pen 34 (the drug treated pen) suffered a severe drop in feed intake for 3 weeks after which time rapid recovery to normal feed intake was established. More recent data (unpublished) indicate that the treatment period with drug, in order to stop production, need not be as long as in this experiment. This would shorten the period of reduced feed intake and probably lessen the weight loss. For the period November 17 to 30, pen
Egg production is plotted in Figure 1. The precipitous decline and rapid ascent of production shown by pens 34 and 36 TABLE 2.—Number of individual birds {in percent) which laid any eggs during periods shown* Figures in parentheses represent actual pen production during same period in percent hen days Pen 33
Pen 34
1- 7 8-14 15-21 22-31
78 (52.8) 72 (47.5) 78 (50.8) 74(43.7)
81 (51.3) 81 (41.6) 83 (45.9) •1(41.7)
1- 7 8-14
67 (43.5) 61 (35.8)
85 (46.2) 43 (13.9)
15-21 22-30
59 (33.5) 61 (35.9)
1- 7 8-14 15-21 22-31 1- 7 8-14 15-21 22-31 1- 7 8-14 15-21 22-28
55 56 51 50 54 58 51 68 65 65 55 55
Period October
November
December
January
February
(27.8) (26.8) (27.2) (26.8) (27.5) (26.3) (23.4) (30.0) (33.3) (31.6) (22.7) (21.2)
Pen 36 76 70 67 72
1
0(0) 0(0) 4 (2.4) 11 (8.3) 38 (18.9) 77 (35.8) 85 (49.3) 93 (44.1) 91 (45.7) 91 (45.1) 93 (55.4) 93 (61.1) 88 (47.5) 72 (49.5)
(48.8) (41.2) (42.8) (39.5)
67 (33.1) 47 (25.0) 42 (23.3) 27 (9.7) 9 (3.2) 9 (3.2) 19 (8.3) 49 (21.6) 79 (41.5) 87 (47.1) 91 (46.1) 81 (39.5) 73 (38.2) 76 (42.1) 80(34.5) 58 (31.2)
* Mortality from October 1, 1953, to February 28, 1954, was pen 33t 6 birds; pen 34, 4 birds; pen 36, 2 birds, f Dotted lines indicate period of treatment.
Downloaded from http://ps.oxfordjournals.org/ at Oakland University on June 10, 2015
Each pen was a 10'X20' unit. All were located in the same building and were adjacent to one another except that pens 34 and 36 were separated by a solid board partition and one empty pen of equivalent size. Each of the three groups was kept intact as of the preceding five months. Their performance during that time was essentially identical. Birds in all pens were trapnested daily.
36 was limited to approximately the same feed intake which pen 34 experienced during the previous 2 weeks. Although pen 36 was given no feed or water for two days at the beginning of the test, this was not sufficient to interrupt egg production completely. Body weight loss varied considerably among individuals within each pen. Whereas 90 percent of the birds in both pens 34 and 36 lost from 0.1-2.0 lb., 79 percent of the birds in the control pen lost weight varying between 0.1-2.1 lb. The extent of weight loss of individual birds in the control pen was just as great as in the other two pens. However, when uniform molting is induced, the extent of body weight loss is more impressive. The precise relationship which drug administration has to weight loss is under current study.
J. A. PINO
P. 33
> o z
O
o
o UJ
z < ->
FIG. 1. Egg production calculated on a hen-day basis. Pen 33, control; pen 34, Enheptin treated November 2-16; pen 36, feed restricted.
are striking when compared to the control pen. Of interest are the data shown in Table 2. In pen 33 there were at all times a large percentage of birds in production. A scrutiny of the trapnest records shows that the individuals comprising those in production do not remain the same. Some birds are going out of production, others are coming into production. MOLT
All birds were examined periodically for degree of molt. It was found that at the time treatment was initiated, some of the birds in each group had already begun to molt. While individuals molted sporadically in the control pen, the drug treated birds uniformly shed profusely, regardless of the stage of molt they already were in when treatment began. Rapid molting of the majority of individuals was observed in the feed restricted force-molted pen
(pen 36). In this pen the treatment seemed to occasion the molt of non-molting birds but did not affect molting birds. FERTILITY AND HATCHABILITY
Two test hatches were conducted. Three males were placed in each pen and rotated between pens every fifth day until all males had spent equivalent time in each pen. The first setting, which followed the treatment period by 59 days, showed little difference in fertility and hatchability, as shown in Table 3. At that time production in the drug-treated pen (pen 34) was rapidly climbing. As a result more chicks were obtained from this pen. The second setting showed a marked improvement in fertility and hatchability in the drug-treated and feed restricted pens. During the second test hatch, pen 34 produced an average of 3.67 chicks per hen
Downloaded from http://ps.oxfordjournals.org/ at Oakland University on June 10, 2015
P R O D U C T I O N
ASSOCIATION NOTICE TABLE 3.—Fertility and hatchability of all eggs produced from force molted hens—P. 33 Control, 41 hens; P. 34 Enheplin treated, 46 hens; P. 36 Feed Restricted, 43 hens Eggs Pen produced and set 33 34 36
59 99 86
33 34 36
90 206 170
Fert
-*
% fert. Hatched hatchf
First Hatcht 45 76.3 79 79.8 68 79.1 Second Hatch§ 70 77.8 195 94.7 148 87.1
39 64 59
66.1 64.6 68.6
56 169 138
62.2 . 82.0 81.2
543
explain the action of Enheptin. It has been shown, Pino et al. (1954) that gonadotropic hormone activity is apparently inhibited by Enheptin whereas thyrotropic activity is not affected. It is apparent from these observations that the endocrine mechanisms controlling molt and egg production are related. REFERENCES
while pens 33 and 36 produced 1.37 and 3.21 chicks per hen respectively. SUMMARY
Hens administered the drug Enheptin (2-amino, 5-nitrothiazole) in the diet stop egg production within 7 to 10 days. There is marked shedding of feathers from all regions of the body. It was been observed (data unpublished) that there is greater individual variability in extent and duration of feather loss with decreasing dietary concentrations of drug. The period of non-productivity for individual birds seems to be related to the duration of molt. The mechanisms by which the drug Enheptin causes molting is not known. Van der Meulen's (1939) theory of cyclic periodicity in pituitary output of gonadotropic and thyrotropic hormones could
Since original preparation of this paper, the following reports have appeared: Robblee, A. R., and D. R. Clandinin, 1954. The use of Enheptin for the induction of moult in yearling hens. Poultry Sci. 33: 1078. Shaffner, C. S., 1954. Progesterone induced molt. Poultry Sci. 33: 1079-1080. Shaffner, C. S., 1954. Feather papilla stimulation by progesterone. Science, 120: 345.
ASSOCIATION NOTICE Guest attendance at the annual meeting is limited to guests invited by the Executive Committee upon recommendation or request by an Active Member of the Association. It is important that all requests be in the hands of the Secretary-Treasurer, C. B. Ryan, Department
of Poultry Husbandry, Texas A and M College System, College Station, Texas, at least 30 days prior to the annual meeting. Persons wishing to invite guests please comply with the deadline requirement. This ruling does not apply to the family of a member.
Downloaded from http://ps.oxfordjournals.org/ at Oakland University on June 10, 2015
* Apparent (candled) fertility at 7 days of incubation. t Hatch of total eggs set. X Eggs saved for 4 days beginning December 31, 59 days from start of treatment. § Eggs saved for 7 days beginning January 4, 63 days from start of treatment.
Berg, L., and G. E. Bearse, 1947. The changes in egg quality resulting from force molting White Leghorn yearling hens. Poultry Sci. 26: 414-418. Hudson, C. B., and J. A. Pino, 1952. Physiological disturbance of the reproductive system in White Leghorn cockerels following the feeding of Enheptin. Poultry Sci. 31: 1017-1022. Pino, J. A., and C. B. Hudson, 1953. Duration of sexual retardation in S. C. White Leghorn pullets and cockerels following Enheptin (2-Amino, 5-Nitrothiazole) feeding. Poultry Sci. 32: 650655. Pino, J. A., L. S. Rosenblatt and C. B. Hudson, 1954, Inhibition of pituitary gonadotropic hormone secretion by Enheptin (2-Amino, 5-Nitrothiazole). Proc. Soc. Exp. Biol. Med. 87:201-207. The Poultry Council of the State College of Washington, 1947. Summer force molting of hens for commercial egg production. State College of Washington Agricultural Extension Bull. 323. Van der Meulen, J. B., 1939. Hormonal regulation of molt and ovulation. Proceedings Seventh World's Poultry Congress and Exposition, pp. 109-112.