Relationships between Luteinizing Hormone, Follicle-Stimulating Hormone and Prolactin Secretion and Ovarian Follicular Development in the Weaned Sow1

Foxcroft, G. R.; Shaw, H. J.; Hunter, M. G.; Booth, P. J.; Lancaster, Richard

doi:10.1095/biolreprod36.1.175

Cited by 68 publications

(34 citation statements)

References 6 publications

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“…Our data do not show any effect of these body reserves on any characteristics of gonadotrophin feedback exerted by the ovaries on the pituitary release of LH and FSH. Similarly, lower FSH concentrations were observed in lactating sows with higher plasma oestradiol [26] as well as negative correlations between plasma FSH measured during lactation or within 48 hours after weaning and follicular characteristics (diameter of 10 biggest follicles, follicular fluid oestradiol, aromatase activity) measured 48 hours after weaning [12]. In addition, negative relationships between plasma oestradiol and inhibin on the one hand and plasma FSH on the other hand were observed on the days after weaning [38].…”

Section: Discussionmentioning

confidence: 76%

Influence of feed intake during pregnancy and lactation on fat body reserve mobilisation, plasma leptin and reproductive function of primiparous lactating sows

et al. 2001

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-From day 23 of pregnancy, 24 gilts received either a medium (M, n = 16) or a high (H, n = 8) level of feeding calculated to meet 115% or 190% of energy for maintenance, respectively. During lactation, all H sows were fed ad libitum (H-AL) whereas M sows were fed either ad libitum (M-AL, n = 8) or were restricted (M-RE, n = 8) to the amount of feed ingested by H-AL sows. Increased feed intake during pregnancy increased live weight, backfat thickness, and estimated body lipid and protein on days 4 and 25 of lactation (P < 0.05). It also resulted in lower feed intake and higher lipid mobilisation during lactation (P < 0.05) without a detrimental influence on milk production. Activities of malic enzyme and glucose-6-phosphate dehydrogenase from neck fat samples were higher in H than M sows on day 4 (P < 0.05). They decreased during lactation in H sows (P < 0.05). Mean diameter of adipocytes decreased during lactation in the 3 groups (P < 0.05) but did not differ between groups on days 4 and 25. Plasma leptin on days 4, 11, 18 and 25 was higher in H than in M sows (P < 0.05) but was not influenced by lactational feed intake. Neither measured characteristics of gonadotrophin secretion on day 22, nor of ovarian activity on day 26, were significantly influenced by the level of feeding during pregnancy or lactation.

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Section: Discussionmentioning

confidence: 76%

Influence of feed intake during pregnancy and lactation on fat body reserve mobilisation, plasma leptin and reproductive function of primiparous lactating sows

et al. 2001

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“…Weaning between 3 and 5 weeks pp results in an immediate and transient increase in LH mean levels and pulsatility (Parvizi etal, 1976; Van de Wiel etal, 1978;Shaw and Foxcroft, 1985;Armstrong et al, 1986b). From (Stevenson et al, 1981; Edwards and Foxcroft, 1983a;Foxcroft et al, 1987), whereas others have reported that FSH concentrations rise after weaning (Cox and Britt, 1982a;Shaw and Foxcroft, 1985). In fact, individual profiles of plasma FSH differ considerably between sows with a significant increase immediately after weaning in some animals and no variation in others (Foxcroft et al, 1987; Guingand, unpublished data).…”

Section: Energetic Balance and Circulating Metabolitesmentioning

confidence: 99%

“…In sows with a normal return to oestrus, plasma oestradiol-17[3 rises significantly within 24&horbar;48 h after weaning (Rojanasthien, 1988;Prunier etal, 1994). In follicular fluids, relatively high concentrations of oestradiol-17(3 and testosterone are present 48 h after weaning (Foxcroft et al, 1987). Concentrations of inhibin in plasma and follicular fluids rise progressively during the first 2 d following weaning (Trout et al, 1992).…”

Section: Ovarian Activitymentioning

confidence: 99%

“…Two days after weaning, theca and granulosa binding of hCG increases with stage of follicular development (Foxcroft et al, 1987). During lactation, the ovaries are responsive to gonadotrophins since it is possible to induce ovulation by exogenous gonadotrophins or GnRH during lactation (see review by Rojanasthien et al, 1988).…”

Section: Ovarian Responsiveness To Gonadotrophinsmentioning

confidence: 99%

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Endocrine bases of lactational anoestrus in the sow

Quesnel¹,

Prunier²

1995

Reprod. Nutr. Dev.

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Summary ― Parturition in the sow is followed by a period of anovulation which is prolonged by lactation. Follicular development and luteinizing hormone (LH) secretion are depressed during the last month of pregnancy. After parturition, LH secretion increases but is again inhibited by the establishment of lactation. Lactating sows are submitted to stimuli originating from the young, whose intensity culminates 3-14 d post-partum (pp), and to high nutrient requirements for milk production. The

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“…(experimental treatments). At the end of incubation, cells were sedimented by centrifugation at 1000 g for 10min and medium was stored at -20°C until estimation of net progesterone accumulation by radioimmunoassay (Foxcroft et al, 1987). The intra-and interassay coefficients of variation were 5-3 and 15-8%, respectively; assay sensitivity was 20 pg per tube.…”

Section: Introductionmentioning

confidence: 99%

Effect of prostaglandins on luteal function during early pregnancy in pigs

Więsak

Hunter²,

Foxcroft³

1992

Reproduction

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Summary. Luteal cells were obtained by digestion of luteal tissue of cyclic (day 12) and early pregnant (days 12, 20 and 30) pigs. Suspensions of the dispersed luteal cells (5 x 104 cells ml \m=-\1) were incubated for 2 h in minimum essential medium (MEM) alone (control) and MEM with different concentrations of prostaglandin FF2\ g=a\(PGF2\g=a\) and PGE2 (0\m=.\01,0\m=.\1,1, 10, 100 and 1000 ng ml \m=-\1) and luteinizing hormone (LH) 100 and 1000 ng ml\m=-\1, or with combinations of LH+ PGF2\g=a\and LH + PGE2. Net progesterone production was measured in the incubation media by direct radioimmunoassay.The overall response pattern of the luteal cells to exogenous hormones on day 12 of the oestrous cycle and pregnancy differed (P < 0\m=.\5) from treatment on day 20 and 30 of pregnancy. In general progesterone production was higher (P < 0\m=.\5) and the response to PGF2\g=a\ and PGE2 treatment was most obvious on day 12 of the oestrous cycle and pregnancy. Overall, PGF2\g=a\ stimulated progesterone production in a dosedependent manner (P < 0\m=.\05). The response to PGE2 was of a quadratic nature (P < 0\m=.\05) in which the lowest and the highest doses of PGE2 were associated with a greater production of progesterone than were the intermediate doses. Treatment of luteal cells with PGF2\g=a\ + LH or PGE2 + LH caused overall inhibition (P < 0\m=.\05) of progesterone production compared with treatment with each hormone alone. This interaction was not affected by the dose of LH used.These findings indicate that PGF2\g=a\ and PGE2 are involved in the autocrine control of corpus luteum function.

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Relationships between Luteinizing Hormone, Follicle-Stimulating Hormone and Prolactin Secretion and Ovarian Follicular Development in the Weaned Sow1

Cited by 68 publications

References 6 publications

Influence of feed intake during pregnancy and lactation on fat body reserve mobilisation, plasma leptin and reproductive function of primiparous lactating sows

Influence of feed intake during pregnancy and lactation on fat body reserve mobilisation, plasma leptin and reproductive function of primiparous lactating sows

Endocrine bases of lactational anoestrus in the sow

Effect of prostaglandins on luteal function during early pregnancy in pigs

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