Ovarian Follicles of New-born Merino Lambs from Genetic Lines which Differ in Fecundity

Rj, Tassell; Jp, Kennedy; Bm, Bindon; Lr, Piper

doi:10.1071/bi9830351

Cited by 17 publications

(11 citation statements)

References 9 publications

(11 reference statements)

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“…However, responses to shortterm lupin supplementation are variable and largely dependent on the ovarian population of antral follicles (Gherardi & Lindsay 1982, Leury et al 1990, Nottle et al 1997, Viñ oles et al 2010b. In ewes, the population of antral follicles is affected by several factors, including genotype and body condition (Tassell et al 1983, Viñ oles et al 1999, and perhaps the perinatal nutritional history of their mother.…”

Section: Introductionmentioning

confidence: 99%

Follicle development, endocrine profiles and ovulation rate in adult Merino ewes: effects of early nutrition (pre- and post-natal) and supplementation with lupin grain

et al. 2014

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In adult ewes, we tested whether ovarian function, including the response to short-term supplementation, was affected by the nutrition of their mothers during the pre-/post-natal period. A 2!2 factorial design was used with nutrition in early life (low or high) and a 6-day supplement (with or without) as factors. All ewes received three prostaglandin (PG) injections 7 days apart, and the supplement (lupin grain) was fed for 6 days from 2 days after the second until the third PG injection. We measured reproductive and metabolic hormones, studied follicle dynamics (ultrasonography), and evaluated granulosa cell numbers, aromatase activity and oestradiol (E 2 ) concentrations in follicular fluid in healthy follicles at days 3 and 7 of supplementation. Ovulation rate was increased by 25% by exposure to high pre-/post-natal nutrition (1.5 vs 1.2; P!0.05), in association with a small decrease in FSH concentrations (PZ0.06) and a small increase in insulin concentrations (PZ0.07). The number of healthy antral follicles was not affected. Acute supplementation increased the number of granulosa cells (3.7G0.2 vs 3.0G0.2 million; P!0.05) in the largest follicle, and the circulating concentrations of E 2 (4.6G0.3 vs 3.9G0.3 pmol/l; P!0.05) and glucose (3.4G0.03 vs 3.3G0.03 mmol/l; P!0.01). Both early life nutrition and acute supplementation appear to affect ovulation rate through changes in glucose-insulin homoeostasis that alter follicular responsiveness to FSH and therefore E 2 -FSH balance.

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Section: Introductionmentioning

confidence: 99%

Follicle development, endocrine profiles and ovulation rate in adult Merino ewes: effects of early nutrition (pre- and post-natal) and supplementation with lupin grain

et al. 2014

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“…3 (1978) reported that 4-week-old Merino lambs contained antral follicles > 1 mm in diameter. On the other hand, newborn Booroola-Merino lambs had fewer antral follicles than did control Merino lambs (Tassell et al, 1983) and 1-month-old Booroola-Assaf ewe lambs had smaller ovaries and fewer antral follicles than did Assaf lambs (Braw-Tal et al, 1988). Our results suggest that the structure of the ovary of the lamb might be influenced by the F gene, although the possibility that other components of the Booroola genotype may be also responsible cannot be excluded.…”

Section: Discussionmentioning

confidence: 99%

“…The reproductive physiology of Booroola-Merino and Booroola-Romney ewes has been exten¬ sively studied during recent years (Bindon et al, 1985a; McNatty . It has been shown that Booroola ewe lambs are characterized by elevated basal plasma FSH concentration between 3 and 6 weeks of age (Findlay & Bindon, 1976;Bindon et al, 1985b) and it has been suggested that differences in ovarian feed-back regulation of FSH, which is known to be operative by this age, is responsible for this phenomenon (Tassell et al, 1983).…”

Section: Introductionmentioning

confidence: 99%

Pituitary response to GnRH and ovariectomy in Booroola-Awassi and Awassi ewe lambs

Braw–Tal

Gootwine²

1989

Reproduction

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Summary. Booroola-Awassi ewe lambs were heterozygous (F + ) for a major gene F, influencing their ovulation rate, while Awassi lambs were non-carriers (++). Basal plasma FSH concentration (mean \ m=+-\ s.e.m.) in Booroola\p=n-\Awassiewe lambs at 4 weeks of age was significantly higher than in Awassi lambs of the same age (5\m=.\06 \m=+-\0\m=.\60and 2\m=.\04\ m=+-\0\m=.\32 ng/ml respectively; P < 0\m=.\001). After GnRH administration, FSH increased from 3\m=.\89 \ m=+-\ 1\m=.\10to 10\m=.\58\m=+-\1\m=.\30 ng/ml in Booroola\p=n-\Awassi (N = 6) and from 1\m=.\87\ m=+-\0\m=.\29to 4\m=.\64\ m=+-\0\m=.\33 ng/ml in Awassi (N = 6) ewe lambs (P < 0\m=.\05). Ovariectomy caused an increase in plasma FSH in Booroola\p=n-\Awassi (N = 4) and Awassi (N = 4) ewe lambs. At 1 week after ovariectomy plasma FSH increased from 5\m=.\96\m=+-\1\m=.\02to 7\m=.\06\m=+-\1\m=.\05 ng/ml in F+ and from 1\m=.\67\m=+-\1\m=.\06to 5\m=.\21\ m=+-\0\m=.\66 ng/ml in ++ ewe lambs, suggesting a stronger negative feed-back effect exerted by the ovaries of Awassi lambs. At 15 weeks after ovariectomy FSH values were similar in Booroola\x=req-\ Awassi (18\m=.\28\ m=+-\1\m=.\96ng/ml) and Awassi (16\m=.\07 \m=+-\ 0\m=.\70ng/ml) lambs. Although the overall pattern of pituitary response to ovariectomy was similar in the F + and ++ ewe lambs, Booroola\p=n-\Awassilambs had small ovaries (132\m=.\5 \m=+-\24\m=.\9 mg) and follicular development did not proceed beyond the preantral stage in 3/4 animals, and Awassi lambs had large ovaries (600\m=.\0\ m=+-\ 233\m=.\9 mg) (P < 0\m=.\05) with many preantral and antral follicles.The present results suggest that (1) the elevated plasma FSH concentration between 3 and 6 weeks of age in Booroola\p=n-\Awassi compared to Awassi ewe lambs might be due to (a) greater responsiveness of the F + pituitary to GnRH and (b) reduced ovarian suppression of FSH release and (2) the ovaries of Booroola\p=n-\Awassilambs, although lacking antral follicles, secrete a factor that controls FSH values. We suggest that differences between the two genotypes can be attributed to the F gene or to other minor genes that came from the Booroola\p=n-\Merinosires used to create the Booroola\p=n-\Awassi progeny.

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“…Interested readers are referred to reports by Bindon (1975Bindon ( , 1984, Piper (1976b, 1977), Piper et al (1976), Piper and Bindon (1983), Tassell et al (1983), Owens et al (1984), Owens et al (1985b), Robertson et al (1984), Bindon et al (1986), Fry et al (1987), Kind et al (1988) and Driancourt et al (1990).…”

Section: Booroola Merino Researchmentioning

confidence: 99%

Bernard Michael Bindon — reproductive physiologist, animal scientist, research leader

Entwistle

Cummins

Hillard

et al. 2006

Aust. J. Exp. Agric.

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This paper is a foreword to a series of papers commissioned on ‘the impact of science on the beef industry’, where the Beef CRC-related collaborative scientific work of Professor Bernard Michael Bindon will be reviewed. These papers will be presented in March 2006, as part of a ‘festschrift’ to recognise his wider contributions to the Australian livestock industries for over 40 years. Bindon’s career involved basic and applied research in many areas of reproductive physiology, genetics, immunology, nutrition, meat science and more recently genomics, in both sheep and cattle. Together with his collaborators, he made large contributions to animal science by improving the knowledge of mechanisms regulating reproductive functions and in elucidating the physiology and genetics of high fecundity livestock. His collaborative studies with many colleagues of the reproductive biology and genetics of the Booroola Merino were amongst the most extensive ever conducted on domestic livestock. He was instrumental in the development of immunological techniques to control ovulation rate and in examining the application of these and other techniques to increase beef cattle reproductive output. This paper tracks his investigations and achievements both within Australia and internationally. In the later stages of his career he was the major influence in attracting a large investment in Cooperative Research Centres for the Australian cattle industry, in which he directed a multi-disciplinary approach to investigate, develop and disseminate science and technology to improve commercial cattle productivity.

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Ovarian Follicles of New-born Merino Lambs from Genetic Lines which Differ in Fecundity

Cited by 17 publications

References 9 publications

Follicle development, endocrine profiles and ovulation rate in adult Merino ewes: effects of early nutrition (pre- and post-natal) and supplementation with lupin grain

Follicle development, endocrine profiles and ovulation rate in adult Merino ewes: effects of early nutrition (pre- and post-natal) and supplementation with lupin grain

Pituitary response to GnRH and ovariectomy in Booroola-Awassi and Awassi ewe lambs

Bernard Michael Bindon — reproductive physiologist, animal scientist, research leader

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