Responses in Molt and Lay of Fowl to Progestins and Gonadotrophins.

Pc, Harris; Juhn, Mary

doi:10.3181/00379727-92-22588

Cited by 30 publications

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“…Since the gonads are small during the photorefractory state it is probable that feedback from gonadal steroids is low and might lead to increased pituitary gonadotrophin synthesis and the differential release of LH. Support for this comes from reports of progesterone causing moult in turkeys and the domestic fowl and the inhibition of this process by oestrogen and testosterone in the domestic fowl (Juhn and Harris, 1956;Harper and Parker, 1957;Payne, 1972). The exact cause of moult remains to be elucidated but it may be due to a hormone imbalance (Payne, 1972).…”

Section: Discussionmentioning

confidence: 86%

Effect of photoperiod on gonadotrophin concentrations in domestic turkeys

Godden

Scanes

1977

British Poultry Science

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1. Circulating immunoreactive luteinising hormone (LH) and follicle stimulating hormone (FSH) concentrations have been measured during photoperiodically-induced changes in the reproductive state of turkeys. 2. In a period of sexual quiescence on short photoperiods (6L: 18D) LH concentrations were higher during the hours of darkness in both sexes. 3. Transfer to long photoperiods (16L: 8D) stimulated a rapid increase in LH and FSH concentrations. This was maintained for between 2 to 3 months when the concentrations of both gonadotrophins decreased as the birds became photorefractory. 4. Return to short photoperiods had no immediate effect on the concentrations of LH and FSH in females. The concentration of LH was increased during the 3rd week of short photoperiods when the hens were moulting. 5. LH concentrations fluctuated during the ovulatory cycle and were highest about 6 h before ovulation.

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Section: Discussionmentioning

confidence: 86%

Effect of photoperiod on gonadotrophin concentrations in domestic turkeys

Godden

Scanes

1977

British Poultry Science

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“…However, prolactin only interrupted but did not stop egg laying in the quail. Similarly, Juhn and Harris (8) found that, in domestic fowl, prolactin blocked the antagonistic effect of progesterone on egg laying and only temporarily interrupted laying when given alone. Several hormones (e.g., thyroxin, progesterone, growth hormone) injected into laying domestic fowl will stop egg laying ( 9 ) , but these materials may play no role in the termination of ovulation in the natural situation.…”

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confidence: 95%

Effect of Prolactin and Progesterone on Gonads of Breeding California Quail

Jones

1969

Experimental Biology and Medicine

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Although much is known about avian reproductive endocrinology ( 1 ) , the hormonal influences involved in the transition of the sexually active bird (egg laying female, sperm producing male) to the sexually inactive, parental bird are poorly understood. Ever since Riddle and his co-workers found that prolactin stopped egg laying in the domestic fowl and pigeon, produced incubation behavior in hens, and caused collapse of the testes in roosters ( 2 ) , the general opinion has been that this hormone plays a causative role in this transition. However, further work on the same and other species has not always substantiated this opinion (3). Lehrman ( 4 ) and others have implicated progesterone as the hormone which produces incubation behavior in the domestic pigeon, and this hormone also st0p.s egg laying in the domestic fowl if administered early in the ovulatory cycle (1). The purpose of the present study was to determine the effects of prolactin and progesterone on the gonads of breeding California quail (Lophortyx californicus) and to compare these results with those obtained in other bird species.J4ateriaZs and Methods. The 18 quail pairs used in this experiment were yearling or adult birds obtained from Poisal's Rare Bird Farm, Pleasanton, California, in late February, 1965. They were housed as pairs in small ( 2 X 2 X 1 f t ) wire-mesh cages? supplied with food (Purina game chow Layena) and water ad libidurn, and subjected to artificial 1 5 G 9 D photoperiod. The females began laying eggs after about 40 days, and the hormone treatments were begun after each hen had laid approximately 5 eggs. The males were producing sperm at the time of hormone administration or immediately previous to it as indicated by the fertility of their mates' eggs.The pairs were divided into three groups of 6 pairs each: group 1 (control) received 0.2 ml of saline; group 2 received 0.5 mg of progesterone in 0.2 ml of saline; group 3 received 15 IU of prolactin (NIH-P-S8) in 0.2 ml of saline. All injections were administered intramuscularly daily for 12 days at about the fourth hour of light, and a record was kept of eggs laid.After sacrificing the birds on day 13, the ovaries, oviducts, and left testes were fixed in 10% neutral-buffered formalin, blotted dry, and weighed on a Mettler balance. The diameters of the 3 largest ovarian follicles and the length and width of each testis were measured to the nearest 0.1 mm with a dial micrometer. Testis volume was calculated using the formula for the volume of an ellipsoid. The testes were then embedded in paraffin, sectioned at 6 p and stained with Delafield's acid alum-hematoxylin and eosin ; the stage of spermatogenesis was recorded using the criteria of Lewin ( S ) , except that his "early" and LLlate" regression stages were termed stages 6 and 7 in this study. The longest diameters of 30-50 interstial cell nuclei were measured at random under oil immersion with an ocular micrometer. Also, in order to estimate the condition of the gonaduct complex, the height of the epididymidal epithelium...

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“…A small number of new body-feathers and secondaries appeared as early as 3 to 7 d after removal of the old feathers and by day 12 formed brushes; these feathers had probably started to grow before the old feathers were removed. DISCUSSION In view of the growth-rate of new feathers and the time required (somewhat less than 10 d) to produce visible signs of moulting (see also Juhn and Harris, 1956) blood sampling and moult scoring were at intervals appropriate for studying the relationship between hormone concentration and the occurrence of moulting at subsequent observations.…”

Section: Methodsmentioning

confidence: 99%

Role of ovarian steroids in the control of moult induction in laying fowls

Herremans

Decuypere²,

Chiasson³

1988

British Poultry Science

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1. Thirty-five Warren SSL hens were selected on the basis of variation in moulting response following a force-moult at 81 weeks of age. Fourteen hens were from a group which returned to layers mash ad libitum from day 9, while 21 came from a group with dietary restriction prolonged to day 28. Blood samples were taken on days 23 and 36, and hormone concentrations were measured. Moulting was recorded on days 0, 11, 23, 36, 52 and 68. 2. Progesterone (P4) but not oestradiol (E2) inhibited moulting during egg laying and the sharp fall in P4 concentration when laying ceased was a primary factor in the induction of moulting. 3. Thyroxine (T4) concentrations were closely correlated with all criteria of plumage renewal, but not with the onset of moulting. Although T4 was closely correlated with subsequent feather growth it is questionable whether T4 is a primer of moult-induction independent of P4. 4. Feathers which were pulled out required 12 +/- 2 d to be replaced beyond the feather-papillae stage. For remiges this timing was similar regardless of whether hens were moulting or still laying. The timing was similar for remiges and body-feathers in moulting hens, but the reappearance of body-feathers in laying hens was slightly delayed.

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Responses in Molt and Lay of Fowl to Progestins and Gonadotrophins.

Cited by 30 publications

References 0 publications

Effect of photoperiod on gonadotrophin concentrations in domestic turkeys

Effect of photoperiod on gonadotrophin concentrations in domestic turkeys

Effect of Prolactin and Progesterone on Gonads of Breeding California Quail

Role of ovarian steroids in the control of moult induction in laying fowls

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