Timing of growth hormone injections and reproduction in gilts

Gilbertson, Janet A.; Kirkwood, Roy N.; Thacker, P. A.

doi:10.4141/cjas91-087

Cited by 10 publications

(2 citation statements)

References 5 publications

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“…However, plasma LH was reduced in bGHexpressing gilts and boars of line 3607 during sexual maturation compared with nonexpressing control pigs (Guthrie et al, 1991). In contrast, injection of pGH had no significant effect on mean circulating concentrations of LH in pigs (Kirkwood et al, 1988b(Kirkwood et al, , 1989Gilbertson et al, 1991); however, the pulsatile mode of LH release seemed to be slightly attenuated (Gilbertson et al, 1991). Therefore, the theca interna and perhaps the granulosa cells of follicles in bGH-TG or pGH-treated gilts could be less mature and require more time to respond to an injection of PMSG.…”

Section: Discussionmentioning

confidence: 85%

Expression of a bovine growth hormone transgene inhibits pregnant mare's serum gonadotropin-induced follicle maturation in prepuberal gilts

Guthrie

Vg²,

Dj³

et al. 1993

Journal of Animal Science

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Prepuberal gilts were injected with PMSG to determine whether expression of a bovine growth hormone (bGH) transgene inhibited preovulatory maturation of ovarian follicles. Seven transgenic (TG) gilts of line 3706, which expresses a mouse metallothionein-bGH transgene, and eight nontransgenic, control (C) gilts (128 to 147 d old) were injected with PMSG, 12.5 IU/kg BW, 72 h before necropsy. Surface ovarian follicles > or = 1 mm in diameter were counted, measured for diameter, and aspirated for fluid. Follicles were classified morphologically as healthy or atretic and those with follicular fluid estradiol-17 beta > or = 100 ng/mL were classified as estrogenactive (EA). The number of follicles per gilt was 64.3 +/- 6.1 (mean +/- SEM) and did not differ significantly between bGH-TG and C gilts. The PMSG treatment induced growth of large (> 5 mm) follicles in both bGH-TG and C gilts. However, compared with C gilts, bGH-TG gilts had fewer (P < .05) large follicles (5.9 +/- 1.5 vs 18.3 +/- 5.4), a lower proportion of EA large follicles (35 +/- 12.5 vs 69 +/- 13.2%), and in large follicles less (P < .05) estradiol-17 beta (86 +/- 17 vs 350 +/- 69 ng/mL) and androstenedione (300 +/- 33 vs 1,283 +/- 221 ng/mL). Follicular fluid progesterone and inhibin did not differ significantly between bGH-TG and C gilts. The incidence of atresia among small and medium follicles did not differ significantly between bGH-TG and C gilts.(ABSTRACT TRUNCATED AT 250 WORDS)

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Section: Discussionmentioning

confidence: 85%

Expression of a bovine growth hormone transgene inhibits pregnant mare's serum gonadotropin-induced follicle maturation in prepuberal gilts

Guthrie

Vg²,

Dj³

et al. 1993

Journal of Animal Science

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“…Effects of GH on reproductive performance are rather conflicting. Injections of GH to cyclic gilts increased ovulation rate in gilts which ovulated, but also induced anoestrus or suppresses ovulatory response to the gonadotrophic stimulation (Kirkwood et al, 1989;Bryan et al, 1989;Gilbertson et al, 1991). Similarly, transgenic prepuberal gilts which overexpressed GH gene presented a reduced number of large follicles and altered steroidogenesis .…”

Section: Influence Of Nutritional Factors On Ovulation Ratementioning

confidence: 99%

Control of Folliculogenesis and Mechanisms Triggering Alterations in Ovulation Rate in the Pig

Quesnel¹,

Prunier²,

Driancourt

1998

Reprod Domestic Animals

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Chronic administration of growth hormone (GH) to adult chickens exerts marked effects on circulating concentrations of insulin-like growth factor-I (IGF-I), IGF binding proteins, hepatic GH regulated gene I, and hepatic GH receptor mRNA

Radecki

McCann-Levorse

Agarwal

et al. 1997

Endocr

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In young birds, growth hormone (GH) administration has been found to have only a small or even no effect on circulating concentrations of insulin-like growth factor-I (IGF-I). This is in obvious contrast to the situation in mammals. The present study examines the effect of continuous administration of GH in adult male chickens. Plasma concentrations of IGF-I were markedly elevated (2.5-3.0-fold, p < 0.001) in GH-treated chickens. There were also some transient increases in the circulating levels of IGF binding proteins. Adult chickens showed other manifestations of increased responsiveness to GH, including elevated hepatic expression of GH-regulated gene-I (mRNA) with GH treatment (p < 0.05), and a tendency (p < 0.08) for decreased GH-receptor mRNA. In contrast to the changes in circulating concentrations of GH and IGF-I with GH treatment, no changes in plasma concentrations of thyroid hormones, reproductive hormones, glucose, or nonesterified fatty acids were evident.

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Timing of growth hormone injections and reproduction in gilts

Cited by 10 publications

References 5 publications

Expression of a bovine growth hormone transgene inhibits pregnant mare's serum gonadotropin-induced follicle maturation in prepuberal gilts

Expression of a bovine growth hormone transgene inhibits pregnant mare's serum gonadotropin-induced follicle maturation in prepuberal gilts

Control of Folliculogenesis and Mechanisms Triggering Alterations in Ovulation Rate in the Pig

Chronic administration of growth hormone (GH) to adult chickens exerts marked effects on circulating concentrations of insulin-like growth factor-I (IGF-I), IGF binding proteins, hepatic GH regulated gene I, and hepatic GH receptor mRNA

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