Progesterone Injection and Egg Production in Turkey Hens1

Abstract

An arrest in laying associated with either a polyovarian follicle (POF) or a polycystic ovarian follicle (PCOF) syndrome has been reported in turkey hens photostimulated at an early age with a constant-light photoperiod. Hens expressing the POF or PCOF syndrome had stopped laying for several weeks, but the ovary contained an increased number of mature-size and larger follicles (POF hens), which were cystic (PCOF) in some of the hens. Hens with the POF or PCOF syndrome had plasma progesterone (P(4)) concentrations that were relatively high and without surges. We hypothesized that high plasma P(4) concentrations may block ovulatory surges of LH but not the growth or maintenance of hierarchical follicles leading to development of the POF or PCOF syndrome in turkey hens. In the first six studies, hens were photostimulated with either a 14L:10D or a 24L:0D photoperiod and, after laying for 1-38 wk, were then injected daily for up to 14 days with P(4) (up to 1.50 mg kg(-1) day(-1)) and necropsied. At all ages, the oviposition rate was reduced at a P(4) dosage of 0.17 mg kg(-1) day(-1). With dosages of 0.33 mg kg(-1) day(-1) or greater, however, ovipositions stopped in most hens within approximately 2 days. For hens laying for less than 15 wk, oviductal weight and number of hierarchical follicles of P(4)-injected hens were not different from control vehicle-injected hens, but the numbers of mature, cystic, and atretic follicles were increased. For hens laying for 38 wk, when treated with P(4), oviductal weight and number of hierarchical follicles decreased, but number of atretic follicles increased. No effect of photoperiod was found on egg production, oviductal weight, or follicle number, and none of the hens developed POF or PCOF syndrome in these experiments. Two additional experiments were conducted with hens early in the reproductive period that had been photostimulated with 14L:10D or 24L:0D and injected with P(4) (0.33 mg kg(-1) day(-1)) for 10 or 12 days but not necropsied until 3 wk after the last injection. Most of the hens photostimulated with the 24L:0D photoperiod and injected with P(4), and a few of the hens photostimulated with the 14L:10D photoperiod and injected with P(4), had developed the PCOF syndrome when necropsied. The hens with the PCOF syndrome had high levels of P(4) when necropsied. From these studies, we concluded that the PCOF syndrome can be induced early in the reproduction period by photostimulating turkey hens with a 24L: 0D photoperiod, injecting them for 10 to 12 days with P(4) at a dosage of 0.33 mg kg(-1) day(-1), and then waiting 3 wk for the PCOF syndrome to develop.

Characterization of gene expression in the hypothalamo-pituitary-gonadal axis during the preovulatory surge in the turkey hen

“…Those data are in direct contrast with the current findings for the turkey, where a decrease in GNRHR mRNA and a two-fold increase in FSHB mRNA were observed. Several key functional differences have been established between chicken and turkey HPG axis progesterone feedback activity for ovulation to occur that may be contributing to the inconsistencies of pituitary mRNA expression between species (Bacon and Liu, 2004).…”

Plasma Farming: Non-Thermal Dielectric Barrier Discharge Plasma Technology for Improving the Growth of Soybean Sprouts and Chickens

“…Serum growth hormone and insulin-like growth factor 1 which contribute to improve the energy metabolism and protein synthesis for muscle and bone growth in poultry [80,81], thyroid hormones which play an important role skeletal muscle differentiation and growth [82], testosterone which increases the synthesis of myofibril and sarcoplasmic proteins and stimulates skeletal muscle ATP concentration and energy metabolism [83], and ATP levels were significantly increased in plasma-treated chickens; these metabolic improvements were found to be mediated by the regulation of demethylation levels in the skeletal muscle and thyroid gland [19]. However, next-generation chickens which were obtained from plasma direct-treated parents had no significant differences in the hatching rate, average daily gain, length of tibia, and concentrations of serum hormones (including growth hormone, thyroid hormones, insulin-like growth factor 1, and testosterone) and ATP, because their mothers had no significant changes in the female reproductive capacity (including the serum estradiol and progesterone levels which regulate egg production and quality [84][85][86], egg-laying rate, and egg weight) following the plasma treatment [20]. Hens primarily determine the development of offspring embryos and the postnatal growth [87].…”

Molecular cloning and characterization of pigeon (Columba liva) ubiquitin and ubiquitin-conjugating enzyme genes from pituitary gland library

“…For example, prolactin is secreted from the anterior pituitary at a high level at the onset of egg laying in chickens and quail 5-7. Estradiol, progesterone, latinizing hormone (LH) and follicle-stimulating hormone (FSH) are the most important hormones involved in regulating ovulation 8,9. Growth hormone and thyroid-stimulating hormone-subunit mRNA increase as embryonic development proceeds 10.…”