Secretion of Luteinizing Hormone During a Forced Molt in Turkey Hens

Bacon, Wayne L.; Long, David P.

doi:10.3382/ps.0751579

Cited by 26 publications

(10 citation statements)

References 15 publications

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“…Therefore, an increase of the yolk T deposition in moulted HET but not LET quails may refer to a higher responsiveness of the HET than LET lines to rejuvenation processes either at the central or peripheral level or both. For example, a resumption of laying is accompanied by cell proliferation and apoptosis mediated remodelling of the anterior pituitary (Chowdhury and Yoshimura, 2002) and an increase of the plasma LH associated with increased LH pulse frequency (Bacon and Long, 1996).…”

Section: Discussionmentioning

confidence: 99%

Genetic differences in yolk testosterone levels influence maternal hormone deposition in the second laying cycle in Japanese quails

Zeman

Škrobánek

Okuliarova

2013

Comparative Biochemistry and Physiology Part A: Molecular &

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Section: Discussionmentioning

confidence: 99%

Genetic differences in yolk testosterone levels influence maternal hormone deposition in the second laying cycle in Japanese quails

Zeman

Škrobánek

Okuliarova

2013

Comparative Biochemistry and Physiology Part A: Molecular &

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“…Concentrations of plasma LH in turkey hens were measured by RIA [20]. The LH RIA used reagents provided by John Proudman (USDA, Beltsville, MD).…”

Section: Hormone Assay and Data Analysismentioning

confidence: 99%

Circadian Rhythm of the Preovulatory Surge of Luteinizing Hormone and Its Relationships to Rhythms of Body Temperature and Locomotor Activity in Turkey Hens1

Yang

Morgan²,

Kirby³

et al. 2000

Biology of Reproduction

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Simultaneous measurements of plasma LH, body temperature, and locomotor activity were made in laying turkey hens and are reported. Blood samples were remotely collected using a jugular cannula system, and body temperature and locomotor activity were remotely monitored using a radiotelemetry system in freely moving laying turkeys. Under a photoschedule of 14L:10D, the period for preovulatory surges of LH was 25.7 +/- 0.4 h while the periods for peak body temperature and onset of sustained locomotor activity were 24.9 +/- 0.4 and 25.7 +/- 0.5 h, respectively. During exposure to constant light, the periods for preovulatory surges of LH, peak body temperature, and onset of sustained locomotor activity increased to 27.9 +/- 0.9, 26.7 +/- 0.7, and 27.4 +/- 0.7 h, respectively. With the 14L:10D photoschedule, initiation of LH surges was restricted to the scotophase, but after 8 days of constant light, initiation of LH surges had dispersed throughout the 24-h subjective day and night. With constant light, the amplitude of the peak body temperature rhythm decreased, while the duration of the locomotor activity rhythm became broadened and, in some birds, disorganized. Peak body temperature and onset of locomotor activity rhythms and LH surges did not coincide, even though peak body temperature, onset of locomotor activity, and LH surges had similar periods. It is concluded that 1) the photoschedule influences the periods of the LH surge, peak body temperature, and onset of locomotor activity; and 2) a specific or direct relationship between the rhythms of LH surge, body temperature, and locomotor activity remains to be determined in laying turkey hens.

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“…Concentrations of LH were measured by RIA as previously described [29] using 100 l plasma for each duplicate. The intraassay and interassay coefficients of variation (CV) determined with a pool plasma (mean, 3.33 ng/ml) were 5.9% and 6.3%, respectively.…”

Section: Lh P 4 and E 2 Assaysmentioning

confidence: 99%

Interval Between Preovulatory Surges of Luteinizing Hormone Increases Late in the Reproductive Period in Turkey Hens1

Liu¹,

Long²,

Bacon³

2002

Biology of Reproduction

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In turkey hens, the egg production rate is relatively high early during a reproductive period, but declines as the period progresses. Among lines with different egg production potential, the interval between preovulatory surges of LH is the primary determinant of the egg production rate. The main objective of this study was to determine whether the decline in egg production rate late during an egg production period is also associated with a difference in the interval between LH preovulatory surges. A group of photosensitive turkey hens (Early) were photostimulated with continuous light (24L:0D) at 40 wk of age to induce egg laying, and serial blood samples were collected after about 3 wk of egg production. A second group of hens (Late) were housed in floor pens and photostimulated with 14L:10D at 40 wk of age for a normal 36-wk reproduction period and were then switched to 24L:0D lighting for 2 wk before collection of serial blood samples. Continuous light photostimulation was used for at least 2 wk before and during serial blood sampling to avoid potential masking effects of diurnal lighting on the interval between LH surges. The Early (n = 12) and Late (n = 16) hens were cannulated 3 days before being serially bled hourly for 10 days. The mean interval between preovulatory surges of LH was shorter in the Early hens than in the Late hens (26.1 +/- 2.5 h and 34.7 +/- 3.9 h, respectively). The intra-hen LH surge interval coefficient of variation was lower in the Early hens than in the Late hens (7.2% and 18.6%, respectively). The inter-hen LH surge interval coefficient of variation was similar in the Early and Late hens (9.5% and 11.2%, respectively). The incidence of blind surges of LH (those not retrospectively associated with ovipositions) was not different between Early and Late laying hens (8.4% +/- 15.2% and 7.3% +/- 14.6%, respectively). In conclusion, in turkey hens, longer intervals and greater intra-hen variation between LH surges were associated with a poorer rate of egg production late in the reproductive period relative to early in the reproductive period.

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Secretion of Luteinizing Hormone During a Forced Molt in Turkey Hens

Cited by 26 publications

References 15 publications

Genetic differences in yolk testosterone levels influence maternal hormone deposition in the second laying cycle in Japanese quails

Genetic differences in yolk testosterone levels influence maternal hormone deposition in the second laying cycle in Japanese quails

Circadian Rhythm of the Preovulatory Surge of Luteinizing Hormone and Its Relationships to Rhythms of Body Temperature and Locomotor Activity in Turkey Hens1

Interval Between Preovulatory Surges of Luteinizing Hormone Increases Late in the Reproductive Period in Turkey Hens1

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