Pre-partum changes in the plasma concentrations of progesterone, relaxin, prostaglandin F-2  and 13,14-dihydro-15-keto prostaglandin F-2  in meclofenamic acid-treated sows

Gooneratne, A. D.; Bryant‐Greenwood, Gillian D.; Walker, Felicity M. Maule; Nottage, Helen M.; Hartmann, PE

doi:10.1530/jrf.0.0680033

Cited by 16 publications

(7 citation statements)

References 27 publications

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“…The nature of the signal initiating the release of relaxin is unlikely to come from the uterus, since the timing of the surge of relaxin was identical in both hysterectomized sows and sows in late pregnancy (Anderson, Adair, Stromer & McDonald, 1983). These data, together with the findings of Gooneratne, Bryant-Greenwood, Maule-Walker et al (1983) and Randall, Taverne, Challis et al (1986), question the role of uterine PGF2a as the natural and initial luteolytic agent (First & Bosc, 1979). It has therefore been suggested that small amounts of intra-luteal PG (Rothchild, 1981;Patek & Watson, 1983) may be responsible for the regression of the corpus luteum and thus may not be detected in the peripheral circulation by conventional radioimmunoassay.…”

Section: Discussionmentioning

confidence: 98%

Initiation of parturition and lactation in the sow: effects of delaying parturition with medroxyprogesterone acetate

Whitely

Hartmann²,

Willcox³

et al. 1990

Journal of Endocrinology

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The synthetic progestagen, medroxyprogesterone acetate (MPA), was administered to sows in late pregnancy with the objective of slightly delaying the time of farrowing and thereby providing more marked associations between hormonal changes and the termination of pregnancy, and the initiation of farrowing and lactation in this species. MPA was administered orally (140 mg, twice daily) to eight sows in late pregnancy on days 112, 113 and 114 of gestation. Parturition was then induced to occur on day 116 by injecting 200 micrograms cloprostenol i.m. on day 115 of gestation. The peripartum changes in the plasma concentrations of progesterone, cortisol, oestradiol-17 beta, relaxin, prolactin, lactose and 13,14-dihydro-15-keto prostaglandin F2 alpha (PGFM) were measured in these sows together with a group of untreated sows. The gestational length for the MPA-treated sows (116.3 +/- 0.3 days, mean +/- S.E.M.) was significantly (P less than 0.01) greater compared with the untreated sows (114.9 +/- 0.3 days). Plasma progesterone declined earlier (P less than 0.05) with respect to the time of parturition in the treated sows compared with the untreated group. With respect to the timing of parturition, the time at which maximal concentrations of relaxin were attained and the timing of the subsequent decline were earlier in the MPA-treated sows. In both groups of sows, the concentration of relaxin increased before the decline in plasma progesterone. In the untreated sows, the concentration of PGFM increased either slightly before or at the same time as the decline in plasma progesterone, whereas in sows treated with MPA, progesterone concentrations began to decline before any significant increase in the plasma concentration of PGFM. The profiles of cortisol, oestradiol-17 beta and PGFM were similar in both groups of sows. In both groups of sows, the timing of the initial increase in the concentration of plasma prolactin coincided with a similar rise in plasma lactose (P less than 0.01). Plasma progesterone either declined earlier or at the same time as the rise in plasma lactose (P less than 0.01) in the treated group of sows only. We conclude that since the prepartum changes in the concentration of progesterone and relaxin occurred before significant changes in the concentration of PGFM in the MPA-treated sows, the nature of the luteolytic factor and the mechanism by which it exerts its action remains obscure. The higher concentration of lactose in the mammary secretion at birth in the MPA-treated sows compared with the untreated group suggested that lactogenesis was initiated earlier with respect to parturition following MPA treatment.(ABSTRACT TRUNCATED AT 400 WORDS)

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Section: Discussionmentioning

confidence: 98%

Initiation of parturition and lactation in the sow: effects of delaying parturition with medroxyprogesterone acetate

Whitely

Hartmann²,

Willcox³

et al. 1990

Journal of Endocrinology

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“…Results from the present study indicate no association between plasma estradiol and birth intervals and therefore do not support a role for loss of placental estrogen as a mechanism for the prolonged last birth interval. Large amounts of prostaglandin F 2␣ are released from the uterus during and after parturition (Gooneratne et al, 1983;Watts et al, 1988;Lundin-Schiller et al, 1996). Both the endometrium and placenta are likely to be sources of prostaglandin.…”

Section: Discussionmentioning

confidence: 99%

Proportion of the litter farrowed, litter size, and progesterone and estradiol effects on piglet birth intervals and stillbirths

Vallet

Miles

Brown–Brandl

et al. 2010

Animal Reproduction Science

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Stillbirth in swine ranges from 2 to 9%, resulting in a significant loss of piglets. Previous studies clearly indicate a relationship between prolonged birth intervals and stillbirth, but factors influencing birth intervals are not fully known. To characterize birth intervals and stillbirth, farrowing was recorded during three farrowing seasons. Blood samples were collected on d 110 and d 113 of gestation, and were assayed for progesterone and estrogen. Relationships between estrumate (cloprostenol sodium, an analogue of prostaglandin F(2alpha)) usage, litter size, proportion of the litter farrowed, progesterone and estrogen concentrations, birth intervals, and stillbirth were analyzed using regression analysis. A clear relationship between birth intervals and stillbirth was observed. Stillbirth rate was unaffected by birth intervals of <1 h, and increased (P < 0.01) for birth intervals >1 h. A significant negative association between litter size and birth intervals was observed (P < 0.01). Birth intervals were unaffected by proportion of the litter farrowed until the last piglet in the litter, whose birth interval increased dramatically (1.5-fold; P < 0.01). Stillbirth rates increased as proportion of the litter farrowed increased, and a dramatic increase in stillbirth occurred for the last piglet in the litter. Neither d 110 nor 113 plasma progesterone concentrations were associated with litter size, birth intervals, or stillbirth rates. Curvilinear relationships were present between d 110 or 113 plasma estradiol concentrations and litter size. However, neither d 110 nor 113 estradiol concentrations were associated with birth intervals or stillbirth rates. These results indicate that (1) birth intervals greater than 1 h are associated with increased stillbirth; (2) larger litter size reduces birth intervals; (3) the last piglet in the litter has both a prolonged birth interval and increased risk of stillbirth; (4) plasma progesterone before farrowing does not influence birth intervals or stillbirth; and (5) plasma estradiol does not influence birth interval or stillbirth, despite a positive relationship between litter size and plasma estradiol. An understanding of the effects of litter size and proportion of the litter farrowed on birth intervals might be exploited to decrease stillbirth in piglets.

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“…The reason for the effect on stillbirth is unclear but may be due to the conversion of essential fatty acids to prostaglandins, leukotrienes, and thromboxanes (Kremmyda et al, 2011). Prostaglandins affect farrowing onset and uterine contractility (First and Bosc, 1979;Gooneratne et al, 1983). Leukotrienes affect lung function, particularly in response to disease (McCarthy and Weinberg, 2012).…”

Section: Gromega + Zincmentioning

confidence: 99%

Effect of essential fatty acid and zinc supplementation during pregnancy on birth intervals, neonatal piglet brain myelination, stillbirth, and preweaning mortality1,2

Vallet

Rempel

Miles

et al. 2014

Journal of Animal Science

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Omega fatty acids and zinc contribute to physiological pathways that could affect the farrowing process, stillbirth, preweaning mortality, and postweaning return to estrus. To determine effects of omega fatty acids and zinc on these reproductive traits, gilts were mated and fed either a control diet, a diet supplemented with 1.09% Gromega, a diet supplemented with 0.07% zinc sulfate, or a diet supplemented with both Gromega and zinc sulfate from d 80 of gestation until farrowing. Farrowings were video recorded to obtain birth intervals for each piglet, and the number of live and stillborn piglets was recorded. On d 1 after farrowing, piglets were weighed, and the smallest piglet in each litter was sacrificed. A blood sample was collected to measure the immunoglobulin immunocrit ratio, and brain, cerebellum, brain stem, full and empty stomach (to calculate stomach content weight), and heart weights were recorded. Because myelination of specific brain regions may affect preweaning mortality, brain stem, cerebellum, and spinal cord tissues were measured for content of myelin basic proteins and myelin lipids. For remaining piglets, survival to weaning and weaning weights were recorded. Results indicated a weak positive correlation (r = 0.23, P < 0.05) between immunocrit values and brain stem high molecular weight myelin basic protein. There was also a Gromega × zinc supplementation interaction (P < 0.05) on brain stem high molecular weight myelin basic protein in which the combined treatment was greater than the control or each supplement alone. Zinc treatment decreased stillbirth rate during prolonged farrowing and subsequent preweaning survival of low birth weight piglets. Gromega increased overall stillbirth rate and increased the stillbirth rate during prolonged farrowing. There were no relationships between myelin measurements and preweaning survival. In conclusion, combined Gromega and zinc supplementation appeared to improve myelination, but zinc alone improved stillbirth and preweaning survival.

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Pre-partum changes in the plasma concentrations of progesterone, relaxin, prostaglandin F-2 and 13,14-dihydro-15-keto prostaglandin F-2 in meclofenamic acid-treated sows

Cited by 16 publications

References 27 publications

Initiation of parturition and lactation in the sow: effects of delaying parturition with medroxyprogesterone acetate

Initiation of parturition and lactation in the sow: effects of delaying parturition with medroxyprogesterone acetate

Proportion of the litter farrowed, litter size, and progesterone and estradiol effects on piglet birth intervals and stillbirths

Effect of essential fatty acid and zinc supplementation during pregnancy on birth intervals, neonatal piglet brain myelination, stillbirth, and preweaning mortality1,2

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