Publications by authors named "Graeme B Martin"

56 Publications

The ovarian follicle of ruminants: the path from conceptus to adult.

Reprod Fertil Dev 2021 Jul 2. Epub 2021 Jul 2.

This review resulted from an international workshop and presents a consensus view of critical advances over the past decade in our understanding of follicle function in ruminants. The major concepts covered include: (1) the value of major genes; (2) the dynamics of fetal ovarian development and its sensitivity to nutritional and environmental influences; (3) the concept of an ovarian follicle reserve, aligned with the rise of anti-Müllerian hormone as a controller of ovarian processes; (4) renewed recognition of the diverse and important roles of theca cells; (5) the importance of follicular fluid as a microenvironment that determines oocyte quality; (6) the 'adipokinome' as a key concept linking metabolic inputs with follicle development; and (7) the contribution of follicle development to the success of conception. These concepts are important because, in sheep and cattle, ovulation rate is tightly regulated and, as the primary determinant of litter size, it is a major component of reproductive efficiency and therefore productivity. Nowadays, reproductive efficiency is also a target for improving the 'methane efficiency' of livestock enterprises, increasing the need to understand the processes of ovarian development and folliculogenesis, while avoiding detrimental trade-offs as greater performance is sought.
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http://dx.doi.org/10.1071/RD21086DOI Listing
July 2021

Maternal undernutrition during pregnancy and lactation increases transcription factors, ETV5 and GDNF, and alters regulation of apoptosis and heat shock proteins in the testis of adult offspring in the rat.

Reprod Fertil Dev 2021 May;33(7):484-496

Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, L8S 4L8, Canada; and Department of Pediatrics, McMaster University, Hamilton, L8S 4L8, Canada, and Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, L8S 4L8, Canada.

We tested whether changes in Sertoli cell transcription factors and germ cell heat shock proteins (HSPs) are linked to the effects of maternal undernutrition on male offspring fertility. Rats were fed ad libitum with a standard diet (CONTROL) throughout pregnancy and lactation or with 50% of CONTROL intake throughout pregnancy (UNP) or lactation (UNL) or both periods (UNPL). After postnatal Day 21, 10 male pups per group were fed a standard diet ad libitum until postnatal Day 160 when testes were processed for histological, mRNA and immunohistochemical analyses. Compared with CONTROL: caspase-3 was increased in UNP and UNPL (P=0.001); Bax was increased in UNL (P=0.002); Bcl-2 (P<0.0001) was increased in all underfed groups; glial cell line-derived neurotrophic factor (P=0.002) was increased in UNP and UNL; E twenty-six transformation variant gene 5 and HSP70 were increased, and HSP90 was diminished in all underfed groups (P<0.0001). It appears that maternal undernutrition during pregnancy and lactation disrupts the balance between proliferation and apoptosis in germ cells, increasing germ cell production and perhaps exceeding the support capacity of the Sertoli cells. Moreover, fertility could be further compromised by changes in meiosis and spermiogenesis mediated by germ cell HSP90 and HSP70.
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http://dx.doi.org/10.1071/RD20260DOI Listing
May 2021

Periconceptional nutrition with spineless cactus (Opuntia ficus-indica) improves metabolomic profiles and pregnancy outcomes in sheep.

Sci Rep 2021 Mar 30;11(1):7214. Epub 2021 Mar 30.

UWA Institute of Agriculture, University of Western Australia, Crawley, WA, 6009, Australia.

We tested whether periconceptional nutrition with cladodes from the cactus, Opuntia ficus-indica, with or without protein-enrichment, improved the metabolomic profile and reproductive outcomes of adult female sheep. Sixty Rambouillet ewes of similar body weight were randomly allocated among three nutritional treatments that were fed during the breeding period (34 days): Control (Control; n = 20), Opuntia (Opuntia; n = 20) and protein-enriched Opuntia (E-Opuntia; n = 20). There were no effects of treatment on body weight but assessment of urine samples indicated that, for 76 metabolites, the Control and Opuntia groups differed completely (P < 0.05), whereas there was overlap between the Control and E-Opuntia groups. It appears that, in Opuntia-fed and Control-fed sheep, different functional groups are activated leading to changes in the metabolism of glucose, tyrosine, methane, and glycerolipids. Fertility and reproductive rate tended to be higher in the Opuntia (70% and 95%) and E-Opuntia (90% and 110%) groups than in the Control (55% and 65%), and an orthogonal contrast revealed the difference between Control and Opuntia to be significant for both reproductive variables (P < 0.05). We conclude that nutritional supplementation with Opuntia cladodes, with or without protein enrichment, increased fertility rate and reproductive rate of female sheep, without any accompanying increases in body weight. Our observations suggest that the reproductive responses to Opuntia do not simply reflect a response to good nutrition, but might be caused by specific metabolites/metabolomic pathways, perhaps by an activation of the metabolism of glucose, methane, tyrosine and glycerolipids. There are few reports relating these metabolomic compounds with the metabolism of the sheep, let alone with reproductive efficiency. The novelty of these discoveries suggests that we need further research into the mechanisms through which nutrition affects the reproductive system.
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http://dx.doi.org/10.1038/s41598-021-86653-wDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8010085PMC
March 2021

Amino Acids in the Nutrition and Production of Sheep and Goats.

Adv Exp Med Biol 2021 ;1285:63-79

UWA Institute of Agriculture, The University of Western Australia, Crawley, Australia.

In sheep and goats, amino acid nutrition is essential for the maintenance of health and productivity. In this review, we analysed literature, mostly from the past two decades, focusing on assessment of amino acid requirements, especially on the balance of amino acid profiles between ruminal microbial protein and animal production protein (foetal growth, body weight gain, milk and wool). Our aim was to identify amino acids that might limit genetic potential for production. We propose that much attention should be paid to amino acid nutrition of individuals with greater abilities to produce meat, milk or wool, or to nourish large litters. Moreover, research is warranted to identify interactions among amino acids, particularly these amino acids that can send positive and negative signals at the same time.
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http://dx.doi.org/10.1007/978-3-030-54462-1_5DOI Listing
March 2021

Palm oil protects α-linolenic acid from rumen biohydrogenation and muscle oxidation in cashmere goat kids.

J Anim Sci Biotechnol 2020 5;11:100. Epub 2020 Oct 5.

Inner Mongolia Key Laboratory of Animal Nutrition and Feed Science, College of Animal Science, Inner Mongolia Agricultural University, Hohhot, 010018 China.

Background: In ruminants, dietary C18:3n-3 can be lost through biohydrogenation in the rumen; and C18:3n-3 that by-passes the rumen still can be lost through oxidation in muscle, theoretically reducing the deposition of C18:3n-3, the substrate for synthesis of poly-unsaturated fatty acids (n-3 LCPUFA) in muscle. studies have shown that rumen hydrogenation of C18:3n-3 is reduced by supplementation with palm oil (rich in 9 C18:1). In addition, in hepatocytes, studies with neonatal rats have shown that 9 C18:1 inhibits the oxidation of C18:3n-3. It therefore seems likely that palm oil could reduce both rumen biohydrogenation of C18:3n-3 and muscle oxidation of C18:3n-3. The present experiment tested whether the addition of palm oil to a linseed oil supplement for goat kids would prevent the losses of C18:3n-3 and thus improve the FA composition in two muscles, and . To investigate the processes involved, we studied the rumen bacterial communities and measured the mRNA expression of genes related to lipid metabolism in . Sixty 4-month-old castrated male Albas white cashmere kids were randomly allocated among three dietary treatments. All three diets contained the same ingredients in the same proportions, but differed in their fat additives: palm oil (PMO), linseed oil (LSO) or mixed oil (MIX; 2 parts linseed oil plus 1 part palm oil on a weight basis).

Results: Compared with the LSO diet, the MIX diet decreased the relative abuandance of , a bacterial species that is positively related to the proportional loss rate of dietary C18:3n-3 and that has been reported to generate the ATP required for biohydrogenation (reflecting a decrease in the abundance of rumen bacteria that hydrogenate C18:3n-3 in MIX kids). In muscle, the MIX diet increased concentrations of C18:3n-3, C20:5n-3, C22:6n-3, and n-3 LCPUFA, and thus decreased the n-6/n-3 ratio; decreased the mRNA expression of (a gene associated with fatty acid oxidation) and increased the mRNA expression of and (genes associated with n-3 LCPUFA synthesis), compared with the LSO diet. Interestingly, compared to , had greater concentrations of PUFA, greater ratios of unsaturated fatty acids/saturated fatty acids (U/S), and poly-unsaturated fatty acids/saturated fatty acids (P/S), but a lesser concentration of saturated fatty acids (SFA).

Conclusions: In cashmere goat kids, a combination of linseed and palm oils in the diet increases the muscle concentration of n-3 LCPUFA, apparently by decreasing the relative abundance of rumen bacteria that are positively related to the proportional loss rate of dietary C18:3n-3, by inhibiting mRNA expression of genes related to C18:3n-3 oxidation in muscle, and by up-regulating mRNA expression of genes related to n-3 LCPUFA synthesis in muscle, especially in .
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http://dx.doi.org/10.1186/s40104-020-00502-wDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7534170PMC
October 2020

Heat shock protein HSP90 immunoexpression in equine endometrium during oestrus, dioestrus and anoestrus.

Anat Histol Embryol 2021 Jan 10;50(1):50-57. Epub 2020 Aug 10.

Histología y Embriología, Biociencias, Facultad de Veterinaria, Universidad de la República, Montevideo, Uruguay.

Heat shock proteins play a crucial role in cellular development, proliferation, differentiation and apoptosis. Heat shock protein 90 (HSP90) has been localised in the human endometrium, where its immunoexpression changes during the menstrual cycle. Similar studies have not been done for the equid species, so the present study aimed to describe endometrial HSP90 immunoexpression in mare endometrium. Endometrial biopsies were formalin-fixed and paraffin-embedded, and sections were stained with haematoxylin-eosin in preparation for HSP90 immunohistochemistry. Immunostaining and morphometric analyses were performed on the epithelial lining, endometrial glands and connective stroma during oestrus, dioestrus phase and anoestrus period (n = 7 per phase or period). Immunoexpression was localised in the basal region of the epithelial cells lining the lumen. Immunoexpression was greater during oestrus than during either dioestrus or anoestrus. During anoestrus, there was little immunostaining in the endometrium, suggesting that HSP90 is involved in the functional modulation of sex steroid receptors in cyclic mares. Indeed, the function of HSP90 as a chaperone in the folding of proteins, such as steroid receptors, might explain the greater intensity of immunostaining during the oestrus and dioestrus phases, compared the anoestrus period. We conclude that, in the mare, HSP90 plays a role in endometrial function and that further studies are needed to test whether it is important in pathological conditions as endometritis.
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http://dx.doi.org/10.1111/ahe.12598DOI Listing
January 2021

Intake of Spineless Cladodes of During Late Pregnancy Improves Progeny Performance in Underfed Sheep.

Animals (Basel) 2020 Jun 7;10(6). Epub 2020 Jun 7.

Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias, Campo Experimental La Laguna, Matamoros 27440, Coahuila, Mexico.

The present study tested whether feeding ewes during the last third of pregnancy with cladodes of (untreated or protein-enriched), as an alternative to alfalfa hay, would improve milk yield as well as the pre- and post-natal growth of their lambs. Sixty mature Rambouillet ewes and their progeny were randomly allocated among three nutritional treatments: (i) Control, fed alfalfa; (ii) Opuntia, fed untreated cladodes; (iii) E-Opuntia, fed protein-enriched cladodes (pre-treated with urea and ammonium sulphate). Birth weight did not differ among treatments ( > 0.05) but Control ewes produced more milk than both groups of -fed ewes ( < 0.05). However, milk yield was not related to the growth of the progeny ( > 0.05) because lambs from E-Opuntia-fed ewes grew faster ( < 0.01) and were heavier at weaning ( < 0.05) than lambs from the other two groups. We conclude that (with or without protein enrichment) can be used as an alternative to alfalfa hay for feeding ewes during the last third of pregnancy and therefore reduce production costs under extensive conditions in arid and semiarid regions. Moreover, protein-enriched Opuntia appears to improve postnatal lamb growth.
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http://dx.doi.org/10.3390/ani10060995DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7341186PMC
June 2020

Maternal undernutrition during pregnancy and lactation affects testicular morphology, the stages of spermatogenic cycle, and the testicular IGF-I system in adult offspring.

J Dev Orig Health Dis 2020 10 28;11(5):473-483. Epub 2020 Apr 28.

Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Canada.

Maternal undernutrition decreases sperm production in male offspring, possibly through insulin-like growth factor (IGF-I). To test this hypothesis, we fed pregnant Wistar rats ad libitum with a standard diet (CONTROL) or fed 50% of CONTROL intake, either throughout pregnancy (UNP), lactation (UNL, or both (UNPL). After weaning, male offspring (n = 10 per treatment) were fed a standard diet until postnatal day 160, when testes process for histological and molecular analyses. IGF-I immunostaining area and intensity in the testis were greater (P = 0.003) in the UNPL group compared to CONTROL, but lower in the UNP group (P < 0.0001). Levels of IGF-I receptor transcript were lower in the UNPL and UNL groups, compared to CONTROL. There were more Ki-67-positive germ and Sertoli cells, in all underfed groups than in CONTROL. Compared to CONTROL, frequency of spermatogenic cycle stage VII was lower in all underfed groups, and seminiferous tubule diameter was smaller in UNP and UNPL. Plasma FSH concentrations were greater in UNP male offspring compared to all groups (P = 0.05), whereas inhibin B concentrations were greater in UNP (P = 0.01) and UNL (P = 0.003) than in CONTROL or UNPL. Thus, prenatal undernutrition leads to a decrease in testicular IGF-I levels, whereas of pre- and postnatal undernutrition increased testicular IGF-I levels and decreased amounts of IGF-I receptor mRNA in adult offspring. We conclude that maternal undernutrition during pregnancy and lactation leads to long-lasting effects on adult male offspring testicular morphology, spermatogenesis, and IGF-I testicular system.
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http://dx.doi.org/10.1017/S2040174420000306DOI Listing
October 2020

Seventy years of progestagen treatments for management of the sheep oestrous cycle: where we are and where we should go.

Reprod Fertil Dev 2020 Mar;32(5):441-452

Departamento de Produccion y Sanidad Animal, Facultad de Veterinaria, Universidad Cardenal Herrera- Centro de Estudios Universitarios (CEU), CEU Universities, C/ Tirant lo Blanc, 7. 46115 Alfara del Patriarca Valencia, Spain.

Management of the ovine oestrous cycle is mainly based on the use of exogenous hormones to mimic or enhance (progesterone and its analogues) or manipulate (prostaglandin F2α and its analogues) the activity of the corpus luteum, combined with the application of other hormones mimicking the pituitary secretion of gonadotrophins (e.g. equine chorionic gonadotrophin). These protocols have been applied without major change for decades but, now, there are two reasons to reconsider them: (1) our greatly improved knowledge of the dynamics of ovarian physiology, following the application of transrectal ultrasonography, indicates that modification of the protocols may improve fertility yields and (2) increasing concerns about animal health and welfare, food safety and the environmental impact of the treatments, as evidenced by public opinion and therefore market forces. Here, we offer an overview of these issues, introduce an updated protocol and suggest ways for future improvements to the protocols.
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http://dx.doi.org/10.1071/RD18477DOI Listing
March 2020

Age-related declines in ejaculate quality and sperm kinematics vary among strains of Japanese Quail (Coturnix japonica).

Reprod Domest Anim 2020 Jan 4;55(1):64-73. Epub 2019 Dec 4.

School of Agriculture and Environment, Faculty of Science, The University of Western Australia, Crawley, Perth, Australia.

For successful breeding programs, it is important to quantify the useful period of a male's reproductive life and it is often done simply by measurement of semen quality. This information is lacking for Japanese quail so we tested whether there is a decline in ejaculate quality and sperm kinematics with age, and whether the decline varies among strains. Nine males (n = 9) from each of 5 strains (A, B, C, D and E) were subjected to 4 semen collections (n = 16 per male) at 8, 16, 26 and 36 weeks of age. Ejaculate volume, sperm concentration and total sperm per ejaculate were measured, and sperm kinematics were analysed using a Sperm Class Analyser (SCA ). There was a significant effect of age for ejaculate volume, total sperm per ejaculate and per cent medium sperm. The effect of the interaction between age and strain was significant for percent progressive motile sperm, percent rapid sperm, velocity curvilinear, velocity straight line, velocity average path, linearity, straightness and beat cross frequency. Ejaculate volume peaked at Week 26 in all strains, while peak values for sperm concentration and total sperm per ejaculate were observed at Week 16 for most strains. There were declines in percent motile sperm, progressive motile sperm and rapid sperm, and in velocity curvilinear velocity, velocity straight line and velocity average path, by Week 16 for most strains. Linearity declined by Week 26 in some strains, and all strains showed a significant decline in beat cross frequency by that age. In conclusion, the ability of CASA to detect age-related changes in sperm kinematics makes it a valuable tool for identifying the best males and thus improving quail flock fertility. It is essential that breeders understand that age affects both sperm production and sperm kinematics, and that the changes vary with strain.
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http://dx.doi.org/10.1111/rda.13585DOI Listing
January 2020

Pre-pubertal growth, muscle and fat accumulation in male and female sheep-Relationships with metabolic hormone concentrations, timing of puberty and reproductive outcomes.

Reprod Domest Anim 2019 Dec 20;54(12):1596-1603. Epub 2019 Oct 20.

CRC for Sheep Industry Innovation, University of New England, Armidale, NSW, Australia.

Metabolic homeostasis is aligned with changes in growth and body composition, through processes mediated by circulating metabolites and metabolic hormones, and is eventually linked to reproductive success. In the present study with sheep, we determined the relationships among phenotypic and genotypic rates of growth, muscle and fat accumulation, and the circulating concentrations of metabolic and tested for relationships with the timing of puberty and subsequent reproductive outcomes. We used 64 females and 62 males with known phenotypic values for depth of eye muscle (EMD) and fat (FAT) and known Australian Sheep Breeding Values at post-weaning age for live weight (PWT), depth of eye muscle (PEMD) and depth of fat (PFAT). Blood plasma sampled every 20 min for 8 hr via was assayed for growth hormone (GH), insulin-like growth factor I (IGF-I), insulin, leptin, ghrelin, follistatin, glucose and non-esterified fatty acids (NEFA). In males, PWT was positively related to the concentrations of GH, follistatin and glucose, whereas FAT and PFAT were positively related to IGF-I concentrations (p < .01). Testosterone concentration was negatively related to muscle variables (p < .001) and to PFAT (p < .05). In females, the only significant relationship detected was the positive link between EMD and insulin concentrations (p < .05). Reproductive variables were only measured in females. Live weight at first oestrus was related positively to insulin concentration and negatively to GH concentration (p < .05). No other relationships with reproductive variables were significant. The relationships that were detected suggest subtle differences between the sexes in the way their metabolic homeostasis responds to changes in the rates of growth, and muscle and fat accumulation, perhaps due to interference by testosterone in the males.
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http://dx.doi.org/10.1111/rda.13568DOI Listing
December 2019

Corrigendum to "Follicle-stimulating hormone (FSHβ) gene polymorphisms and associations with reproductive traits in Rex rabbit" [Anim. Reprod. Sci. 207 (2019) 36-43].

Anim Reprod Sci 2019 10 3;209:106150. Epub 2019 Sep 3.

Institute of Animal Husbandry and Veterinary Medicine, Shanxi Academy of Agricultural Sciences, Taiyuan 030006, China.

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http://dx.doi.org/10.1016/j.anireprosci.2019.106150DOI Listing
October 2019

Patterns of preoptic-hypothalamic neuronal activation and LH secretion in female sheep following the introduction and withdrawal of novel males.

Reprod Fertil Dev 2019 Oct;31(11):1674-1681

School of Agriculture and Environment, The University of Western Australia, Crawley, WA 6009, Australia; and Corresponding author. Email:

The neuroendocrine response of female sheep to a novel male involves neural activation in the hypothalamus. However, if males are removed, the gonadotrophic signal declines, so the neural activity is likely to change. We examined Fos-immunoreactive (IR) cells in hypothalamic tissues from seasonally anovulatory female sheep exposed to males for 2 or 6h, or for 2h followed by 4h isolation from males. Control females were killed in the absence of male exposure. Male introduction increased LH secretion in all females; male removal was associated with a reduction only in mean and basal LH concentrations. Females exposed to males for 2h had more Fos-IR cells in the arcuate nucleus (ARC), ventromedial nucleus of the hypothalamus (VMH) and organum vasculosum of the lamina terminalis (OVLT) than control females. Fos-IR cells in the preoptic area (POA) were only greater than in control females after 6h exposure to a male. Removal of males decreased the number of Fos-IR cells in the ARC, VMH and OVLT, but not in the POA. Thus, hypothalamic neural activation and LH secretion in female sheep are stimulated by males and decline after male removal. However, activation in the POA persists after removal and may explain the incomplete decline in the LH response.
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http://dx.doi.org/10.1071/RD19079DOI Listing
October 2019

Follicle-stimulating hormone (FSHβ) gene polymorphisms and associations with reproductive traits in Rex rabbits.

Anim Reprod Sci 2019 Aug 29;207:36-43. Epub 2019 May 29.

Institute of Animal Husbandry and Veterinary Medicine, Shanxi Academy of Agricultural Sciences, Taiyuan 030006, China.

Follicle-stimulating hormone (FSH) stimulates granulosa cell proliferation and controls the development and maturation of oocytes. In this study with Rex rabbit, there was exploration of the relationships between reproductive traits and SNPs and haplotypes of FSHβ, and tested whether FSHβ SNPs would segregate between two lines, using 70 females from the White line and 100 females from the Beaver line. Three SNPs (FSH2, FSH30, FSH31) in exon1 and exon3 of FSHβ were strongly associated with reproductive traits in the combined population. For FSH2, the GG variant was associated with greater (P <  0.05) values for total number born (TNB) and number born alive (NBA), compared to those with the TT variant. For FSH30, for the AA variant there was greater (P <  0.05) values for TNB and NBA than with the GG and AG variants. For FSH31, the GG variant was associated with greater (P <  0.05) values for TNB, litter weight at birth (LWB) and litter size at 21 days of age (LS21), than the AG variant, and with greater (P < 0.01) values for NBA than the AG variant. When analyzed separately, FSH2 SNP was associated with LW21 in the Beaver line (P <  0.05), whereas FSH30 and FSH31 SNPs were associated with TNB and NBA in the White line (P <  0.05). It is concluded that genetic variation in FSHβ gene is associated with reproductive traits in the Rex rabbit, therefore, the FSH2, FSH30 and FSH31 SNPs can be used as molecular markers in genetic selection of rabbits.
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http://dx.doi.org/10.1016/j.anireprosci.2019.05.013DOI Listing
August 2019

Pregnancy and Litter Size, But Not Lamb Sex, Affect Feed Intake and Wool Production by Merino-Type Ewes.

Animals (Basel) 2019 May 3;9(5). Epub 2019 May 3.

School of Agriculture and Environment and UWA Institute of Agriculture, The University of Western Australia, Crawley, WA 6009, Australia.

Two experiments (Australia and Mexico) tested whether feed intake (FI) and wool production (WP) are affected by pregnancy (PRG), litter size (LZ), or lamb sex (LS) in Merino-type ewes. In Experiment-1, ewes were either not pregnant (NPR; n = 6), or carrying 1 (PR1; n = 7) or 3 (PR3; n = 11) fetuses, were studied in individual pens. NPR ewes had lower ( < 0.02) FI throughout PRG and lactation (LAC), except around lambing ( < 0.001). Following lambing, FI increased in PRG ewes ( < 0.001) to double the values in NPR ewes. PRG reduced WP ( < 0.001); in PR3, WP was lower than for both PR1 and NPR ( < 0.001). WP decreased during LAC and was lower in ewes rearing lambs than in NPR ewes ( < 0.001). Experiment-2 used 48 pregnant ewes (28 bearing singles and 20 bearing twins). Dam and lamb live weights (LW) and body condition (BC) were recorded from birth to weaning at 60 d, and dam fleece weight (DFW) was measured at weaning (12 months growth). WP was higher in ewes bearing and rearing single lambs than in ewes bearing twins ( < 0.001). DFW was positively ( < 0.01) related to LZ, dam LW, and BC, but not to changes in dam LW during LAC, or to lamb weight at birth or weaning, or LW gain, or LS. In conclusion, FI was affected during PRG and by LZ during LAC, whereas WP was influenced by LZ, but not LS, only during pregnancy.
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http://dx.doi.org/10.3390/ani9050214DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6562602PMC
May 2019

Linseed oil and heated linseed grain supplements have different effects on rumen bacterial community structures and fatty acid profiles in cashmere kids1.

J Anim Sci 2019 Apr;97(5):2099-2113

College of Animal Science, Inner Mongolia Agricultural University, Hohhot, PR China.

This study investigated the effects of dietary supplementation with alternative sources of α-linolenic acid on growth, the composition of rumen microbiota, and the interactions between rumen microbiota and long-chain fatty acid (FA) concentrations, in goat kids. Sixty 4-month-old castrated male Albas white cashmere kids (average BW 18.6 ± 0.1 kg) were randomly allocated among three dietary treatments: (i) basal diet without supplementation (Control), (ii) basal diet supplemented with linseed oil (LSO), (iii) basal diet supplemented with heated linseed grain (HLS). The concentrate:forage ratio was 5:5 and the LSO and HLS treatments provided the kids with similar dietary FA profiles. The diets were fed for 104 d, consisting of 14 d for adaptation followed by 90 d of experimental observation. Treatment did not significantly influence BW, DMI, or bacterial richness or diversity. On the other hand, the relative abundance of bacteria participating in hydrogenation differed significantly among the three groups: the Veillonellaceae and Christensenellaceae were more abundant in LSO kids, Prevotellaceae were more abundant in HLS kids, and the Fibrobacteriaceae were more abundant in Control kids (P < 0.05). Spearman correlation analysis indicated that Ruminobacter, Selenomonas_1, Fretibacterium, Prevotellaceae_UCG-001, Succinimonas, and Ruminococcaceae_NK4A214_group were the genera that participated in hydrogenation of long-chain FAs. HLS-fed kids had a lower relative abundance of Ruminobacter, but a higher abundance of Prevotellaceae_UCG-001 and Fretibacterium than LSO-fed kids. These changes were associated with greater rumen concentrations of C18:3n3 and n-3 PUFA, but lower concentrations of n-6 PUFA and lower n-6/n-3 ratios, in HLS than in LSO-fed kids. In conclusion, feeding kids with HLS increased rumen concentrations of C18:3n3 and n-3 PUFA, but decreased the n-6/n-3 ratio by decreasing the abundance of bacteria that hydrogenate C18:3n3 and increasing the abundance of bacteria that hydrogenate C18:2n6.
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http://dx.doi.org/10.1093/jas/skz079DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6488318PMC
April 2019

The Effects of Diets and Long-term Laboratory Rearing on Reproduction, Behavior, and Morphology of Lucilia cuprina (Diptera: Calliphoridae).

J Med Entomol 2019 04;56(3):665-670

UWA Institute of Agriculture, The University of Western Australia, Crawley, WA, Australia.

The Australian sheep blow fly, Lucilia cuprina (Wiedemann), is commonly reared in the laboratory for many sequential generations on simple, fixed diets, so it can be used in veterinary, medical, and forensic studies. To investigate the effect of diet and long-term laboratory rearing on L. cuprina, flies were fed with two different diets (sugar and milk-sugar) over a year and F1, F6, and F11 generations were used for comparisons based on the number of eggs, attraction to wool and liver, and wing size. The results showed that the number of eggs of gravid flies, and the attractiveness of wool and liver did not differ significantly between diets and generations, but gravid flies were more attracted to wool and liver than non-gravid flies (P < 0.05). Moreover, in the F1 generation, thorax length and wing aspect ratio were significantly longer than in the F6 and F11 generations (P < 0.05), and the wing length was significantly longer than in the F11 generation (P < 0.05). It was concluded that neither diet nor long-term laboratory rearing affect potential fecundity or the behavioral responses of L. cuprina, but the gravidity of flies affects their behavioral response, and long-term laboratory rearing significantly affects fly morphology, apparently explaining a loss in flight performance.
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http://dx.doi.org/10.1093/jme/tjy219DOI Listing
April 2019

The mechanism through which dietary supplementation with heated linseed grain increases n-3 long-chain polyunsaturated fatty acid concentration in subcutaneous adipose tissue of cashmere kids.

J Anim Sci 2019 Jan;97(1):385-397

College of Animal Science, Inner Mongolia Agricultural University, Hohhot, PR China.

The aim of this study was to investigate the effects of dietary supplementation with heated linseed on the fatty acid (FA) composition of the plasma, liver, and subcutaneous adipose tissue (SADT) of Albas white cashmere kids, particularly the effect on n-3 long-chain polyunsaturated FA profiles and the mRNA expression of genes related to lipid metabolism in SADT. Sixty 4-month-old castrated male kids (average BW 18.6 ± 0.1 kg) were selected and randomly allocated into three groups in a randomized block design. Three dietary treatments were used: (1) basal diet without supplementation (Control), (2) basal diet supplemented with linseed oil (LSO), and (3) basal diet supplemented with heated linseed grain (HLS). The diets were fed for 104 d, consisting of 14 d for adaptation followed by 90 d of measurement. Different FA profiles were found in SADT between LSO and HLS. Kids fed HLS had more C18:3n3 (P < 0.0001), C22:6n3 (P = 0.007), and n-3 PUFA (P < 0.0001) and a less (P < 0.0001) n-6/n-3 ratio than LSO kids. These FA differences between LSO and HLS kids were due to the increased expression of elongation of very long chain FA protein 5 (P < 0.0001), delta-6 desaturase (P < 0.0001), and peroxisome proliferator-activated receptor α (P = 0.003) in SADT of HLS kids and was also associated with liver fat metabolism. Together, these results suggest that the consumption of HLS leads to more C22:6n3 than LSO in SADT by increasing liver C22:6n3 content and by increasing SADT mRNA expression of ELOVL5 and FADS2 through promoting PPARα expression.
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http://dx.doi.org/10.1093/jas/sky386DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6313143PMC
January 2019

Behavior and Electrophysiological Response of Gravid and Non-Gravid Lucilia cuprina (Diptera: Calliphoridae) to Carrion-Associated Compounds.

J Econ Entomol 2018 08;111(4):1958-1965

UWA Institute of Agriculture, University of Western Australia, Crawley, WA, Australia.

The Australian blow fly, Lucilia cuprina Wiedmann (Diptera: Calliphoridae), is a major cause of myiasis (flystrike) in Merino sheep in Australia and New Zealand and, as a primary colonizer of fresh carrion, also an important species in forensic investigations. Olfaction is considered the most important cue for insects to rapidly locate carrion over long distances, so the first carrion visitors are predicted to be very sensitive to carrion-related volatile compounds. We studied the responses of the Australian blow fly, Lucilia cuprina, to the carrion-associated compounds dimethyl trisulfide (DMTS), butyric acid, 1-octen-3-ol and indole. We also tested 2-mercaptoethanol, a compound commonly used in fly traps in Australia. We investigated whether responses of the flies are affected by their ovarian status by comparing responses of gravid and non-gravid L. cuprina in electroantennography (EAG) and two-choice laboratory bioassays. All four compounds evoked an EAG response, while only DMTS evoked responses in gas chromatography-mass spectrometry electroantennographic detection (GCMS-EAD) analyses and two-choice bioassays. Gravid flies detected lower doses of the test compounds than non-gravid flies. Our results indicate that DMTS is an important semiochemical for L. cuprina to locate carrion resources, and has potential for use in fly traps for flystrike control. Our observations also suggest that the greater sensitivity of gravid L. cuprina allows them to find fresh carrion quickly to maximize reproductive success by avoiding unsuitable degraded carrion.
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http://dx.doi.org/10.1093/jee/toy115DOI Listing
August 2018

Correlation between objective semen analysis and fertility in Japanese quail.

Theriogenology 2018 Jul 11;115:23-29. Epub 2018 Apr 11.

The UWA Institute of Agriculture, The University of Western Australia, 35 Stirling Highway, Crawley, WA, 6009, Australia.

This study investigated the relationship between sperm kinematics and egg fertility in Japanese quail in an attempt to identify a semen trait that could be used to predict male fertility. Males (n=45) and females (n=180) from five strains (A, B, C, D, E) were used. Ejaculates (n=720) were collected from 8 to 38 weeks of male age. Semen volume and sperm concentration were recorded and sperm motility was analyzed using Sperm Class Analyzer (SCA-CASA). At the time of ejaculate collection, males were allowed to mate with females in order to obtain egg fertility data: percent fertile eggs and the numbers of sperm (Sperm) and sperm-holes (Holes) present on the egg perivitelline membranes. Sperm concentration was positively correlated with ejaculate volume (r=0.35; P < 0.01) and percent fertile eggs (r=0.08; P < 0.05). There were high correlations (P < 0.01) among the sperm kinematic parameters: percent motile (MOT%), percent rapid (Rapid%), percent progressive (PROG%), percent medium (Medium%), velocity curvilinear (VCL), velocity straight line (VSL), and velocity average path (VAP), linearity (LIN%), straightness of trajecotry (STR%) and beat cross frequency (BCF). The strains differed with respect to the correlations for sperm kinematics and egg fertility: Sperm was correlated (P < 0.05) with VSL (r=0.18), VAP (r=0.18), and BCF (r=0.23) for Strain A, with PROG% (r=0.17) for Strain B, and with Medium% (r=0.18) for Strain C. When the data were adjusted for the effects of strain and age, Medium% was correlated with Holes (r=0.36; P < 0.01) and percent fertile eggs (r=0.31; P < 0.01), whereas PROG% was correlated with Sperm (r=0.30; P < 0.01) and Holes (r=0.30; P < 0.01). Males could be ranked into high and low fertility categories based on initial (i.e. Week 8) and the life-time (i.e. Weeks 8-38) data for sperm kinematics and egg fertility. Of the males classified as poorly fertile by Week 8 sperm kinematics, 30% were also confirmed as poor on the basis of life-time sperm kinematics. Of the males classified as poorly fertile by Week 8 egg fertility, 47% were confirmed as poor on the basis of life time-data of egg fertility. We concluded that sperm concentration, Medium%, PROG%, VAP, VSL and BCF are important determinants of egg fertility in quail, and that these relationships depend on genotype.
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http://dx.doi.org/10.1016/j.theriogenology.2018.04.012DOI Listing
July 2018

Phyto-oestrogens affect fertilisation and embryo development in vitro in sheep.

Reprod Fertil Dev 2018 Jul;30(8):1109-1115

School of Agriculture and Environment, The University of Western Australia, Crawley, WA 6009, Australia.

Phyto-oestrogens such as isoflavones are natural compounds that can profoundly affect reproductive function. In the present study, we tested whether including isoflavone compounds (genistein, biochanin A, formononetin) in the maturation medium would affect the outcomes for ovine oocytes in vitro. Each isoflavone compound was evaluated at five concentrations (0, 2.5, 5, 10, 25µgmL-1) and the entire protocol was repeated four times. Cumulus-oocyte complexes were randomly allocated to the treatments, then fertilised and cultured in vitro. Compared with control (0µgmL-1), the lower concentrations of isoflavone (2.5, 5 and 10µgmL-1) had no detectable effect on the rates of cleavage or embryo development, or on embryo total cell counts (TCC). However, the highest concentration (25µgmL-1) of all three isoflavones exerted a variety of effects (P<0.05): genistein decreased cleavage rate, blastocyst rate and blastocyst efficiency (blastocysts produced per 100 oocytes); biochanin A decreased cleavage rate and blastocyst efficiency; and formononetin decreased blastocyst rate and blastocyst efficiency. Biochanin A (25µgmL-1) reduced embryo TCC specifically at the hatched blastocyst stage (P<0.05). We conclude that the presence of isoflavones at 25µgmL-1 during IVM decreases the cleavage rate and inhibits blastocyst hatching.
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http://dx.doi.org/10.1071/RD16481DOI Listing
July 2018

Cellular and molecular responses of adult testis to changes in nutrition: novel insights from the sheep model.

Reproduction 2017 11;154(5):R133-R141

UWA Institute of Agriculture and School of Agriculture and Environment M087, University of Western Australia, Crawley, Australia.

This review explores the cellular and molecular mechanisms that regulate spermatogenesis in the post-pubertal testis that is regressing in response to mild undernutrition, using the sexually mature male sheep as a model. Testis regression leads to reductions in daily sperm production and in the quality of ejaculated spermatozoa (poorer movement, DNA damage). There is also a reduction in spermatogenic efficiency that appears to be caused, at least partially, by increases in germ cell apoptosis. Sertoli cell number does not change with testis regression, although about 1% of Sertoli cells do appear to retain proliferative ability after puberty. On the other hand, Sertoli cell function is disrupted during testis regression, as evidenced by a disorganization of tight junctions and indications that cell differentiation and maturation are reversed. Disrupted Sertoli cell function can explain, at least partially, the increase in germ cell apoptosis and any decrease in the rate of spermatogenesis, the two major contributors to spermatogenic efficiency. These outcomes seem to be mediated by changes in two RNA-based processes: (i) the expression of small non-coding RNAs that are involved in the regulation of Sertoli cell function, spermatogenesis and germ cell apoptosis and (ii) alternative pre-mRNA splicing that affects the regulation of spermatogenesis but does not appear to affect germ cell apoptosis, at least during testis progression induced by undernutrition in the male sheep. These research outcomes can be extended to other animal models and are relevant to issues in human male fertility.
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http://dx.doi.org/10.1530/REP-17-0061DOI Listing
November 2017

Characterizing the reproductive biology of the female pygmy hippopotamus (Choeropsis liberiensis) through non-invasive endocrine monitoring.

Theriogenology 2017 Oct 19;102:126-138. Epub 2017 Jul 19.

School of Animal Biology, University of Western Australia, 35 Stirling Highway, Crawley 6009, Australia; Institute for Breeding Rare and Endangered African Mammals (IBREAM), Edinburgh EH3 6AT, United Kingdom; Mammal Research Institute and Centre for Neuroendocrinology, University of Pretoria, Department of Zoology and Entomology, Pretoria 0084, South Africa; College of Public Health, Veterinary and Medical Sciences, James Cook University, Townsville 4811, Australia.

The pygmy hippopotamus (Choeropsis liberiensis) is endangered in the wild and very little is known about its reproductive biology. In zoological facilities, this species experiences a number of reproductive issues that complicate breeding management, including a high rate of stillbirths and failure of many pairs to reproduce. We conducted a comprehensive study to evaluate reproductive cycles and pregnancy in this species using enzyme immunoassays (EIAs) for fecal hormone metabolite analysis. Fresh fecal samples were collected twice weekly for a one to three year period from 36 female pygmy hippos housed at 24 zoological institutions. Samples were analyzed in three separate laboratories. Three progestogen metabolite EIAs (Pg-diol: 5β-pregnane-3α,20α-diol 3HS:BSA; PdG: pregnanediol-3-glucuronide R13904; mono-P4: Quidel clone 425) and three estrogen metabolite EIAs (E2a: estradiol-17β-OH 17-HS:BSA; E2b: estradiol 17β R0008; E2c: estradiol 17β R4972) accurately reflected reproductive events. Average estrous cycle length was 31.8 ± 7.4 days based on estrogen metabolite peaks and 30.9 ± 7.3 days based on nadir to nadir progestogen metabolite concentrations. Cyclical patterns in both estrogen and progestogen metabolites were detected throughout the year, indicating a lack of seasonality. Estrogen metabolite peaks were also observed during pregnancy and lactation, suggesting that follicular development occurs during both reproductive states. Pregnancy was most reliably demonstrated by elevation in progestogen metabolites (Pg-diol or PdG) in the second half of gestation. Average gestation length based on breeding to calving date was 203 ± 4 days for 15 pregnancies. This comprehensive overview of the reproductive biology of the female pygmy hippo provides valuable data for guiding long-term breeding management for this endangered species and serves as a baseline for future studies addressing the potential influence of social structure, diet, body condition, and other husbandry factors on estrous cycling and reproduction.
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http://dx.doi.org/10.1016/j.theriogenology.2017.07.017DOI Listing
October 2017

Gene polymorphisms associated with temperament.

J Neurogenet 2017 Mar - Jun;31(1-2):1-16. Epub 2017 May 16.

b UWA Institute of Agriculture and School of Animal Biology M082, Faculty of Sciences , University of Western Australia , Crawley , WA , Australia.

When individuals are exposed to stressful environmental challenges, the response varies widely in one or more of three components: psychology, behavior and physiology. This variability among individuals can be defined as temperament. In recent years, an increasing large body of evidence suggests that the dimensions of temperament, as well as personality, psychological disorders and behavioral traits, are influenced by genetic factors, and much of the variation appears to involve variation in genes or gene polymorphisms in the hypothalamic-pituitary-adrenocortical (HPA) axis and the behavior-controlling neurotransmitter networks. Here, we review our current understanding of the probabilistic impact of a number of candidate gene polymorphisms that control temperament, psychological disorders and behavioral traits in animals and human, including the gene polymorphisms related to corticotrophin-releasing hormone (CRH) production and adrenal cortisol production involved in the HPA axis, and a large number of gene polymorphisms in the dopaminergic and serotonergic neurotransmitter networks. It will very likely to assist in diagnosis and treatment of human relevant disorders, and provide useful contributions to our understanding of evolution, welfare and conservation, for animals in the wild and in production systems. Additionally, investigations of gene-gene and gene-environment complex interactions in humans and animals need further clear illustration.
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http://dx.doi.org/10.1080/01677063.2017.1324857DOI Listing
March 2018

Functional changes in mRNA expression and alternative pre-mRNA splicing associated with the effects of nutrition on apoptosis and spermatogenesis in the adult testis.

BMC Genomics 2017 01 10;18(1):64. Epub 2017 Jan 10.

Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, T6G 2P5, Canada.

Background: The effects of nutrition on testis mass in the sexually mature male have long been known, however, the cellular and molecular processes of the testis response to nutrition was not fully understood.

Methods: We tested whether the defects in spermatogenesis and increases in germ cell apoptosis in the testis that are induced by under-nutrition are associated with changes in mRNA expression and pre-mRNA alternative splicing using groups of 8 male sheep fed for a 10% increase or 10% decrease in body mass over 65 days.

Results: We identified 2,243 mRNAs, including TP53 and Claudin 11, that were differentially expressed in testis from underfed and well-fed sheep (FDR < 0.1), and found that their expression changed in parallel with variations in germ cell numbers, testis size, and spermatogenesis. Furthermore, pairs of 269 mRNAs and 48 miRNAs were identified on the basis of target prediction. The regulatory effect of miRNAs on mRNA expression, in combination with functional analysis, suggests that these miRNAs are involved in abnormal reproductive morphology, apoptosis and male infertility. Nutrition did not affect the total number of alternative splicing events, but affected 206 alternative splicing events. A total of 159 genes, including CREM, SPATA6, and DDX4, were differentially spliced between dietary treatments, with functions related to RNA splicing and spermatogenesis. In addition, three gene modules were positively correlated with spermatogenesis-related phenotypic traits and negatively related to apoptosis-related phenotypic traits. Among these gene modules, seven (CFLAR, PTPRC, F2R, MAP3K1, EPHA7, APP, BCAP31) were also differentially expressed between nutritional treatments, indicating their potential as markers of spermatogenesis or apoptosis.

Conclusions: Our findings on significant changes in mRNAs and pre-mRNA alternative splicing under-nutrition suggest that they may partly explain the disruption of spermatogenesis and the increase germ cell apoptosis. However, more research is required to verify their causal effects in regulating spermatogenesis and germ cell apoptosis.
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http://dx.doi.org/10.1186/s12864-016-3385-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5223305PMC
January 2017

A retrospective analysis of mortality in captive pygmy hippopotamus (Choeropsis liberiensis) from 1912 to 2014.

Zoo Biol 2016 Nov 10;35(6):556-569. Epub 2016 Nov 10.

School of Animal Biology, University of Western Australia, Crawley, Australia.

The pygmy hippopotamus (Choeropsis liberiensis) is an IUCN Red List Endangered species (CITES Appendix II) that has been housed in zoological collections since 1912. As wild populations continue to decline throughout the species' range, successful ex situ breeding and management, including an understanding of morbidity and mortality, are of utmost importance. This study is the first comprehensive review of mortality data from the captive population since 1982 and significantly expands on previous analyses. We solicited necropsy reports from 129/187 zoological institutions worldwide that currently or previously held pygmy hippos and received data for 404 animals (177 ♂, 220 ♀, 7 undermined sex), representing 43% of pygmy hippos that have died in captivity. Mortality in neonates was primarily due to perinatal causes (51.8%-stillbirth, failure to thrive, weakness, poor suckling reflex, maternal neglect) or parent-inflicted trauma (28%). Common causes of mortality in adult and geriatric animals included cardiovascular disease (16%), degenerative musculoskeletal conditions (10%), obstructive gastrointestinal disease (9%), and renal insufficiency (13%), sometimes associated with advanced polycystic kidney disease (PKD). Although not the direct cause of mortality, a number of adult and geriatric pygmy hippos were also overweight to obese. Infectious causes of mortality in included leptospirosis and encephalomyocarditis virus, the latter usually presenting as acute death due to cardiovascular demise. This comprehensive overview presents a useful guide for recommendations in preventative veterinary care and for improved husbandry and management of pygmy hippos in captivity. Zoo Biol. 35:556-569, 2016. © 2016 Wiley Periodicals, Inc.
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http://dx.doi.org/10.1002/zoo.21336DOI Listing
November 2016

Modeling the Male Reproductive Endocrine Axis: Potential Role for a Delay Mechanism in the Inhibitory Action of Gonadal Steroids on GnRH Pulse Frequency.

Endocrinology 2016 05 24;157(5):2080-92. Epub 2016 Feb 24.

University of Western Australia Institute of Agriculture and School of Animal Biology (T.R.F., D.B., G.B.M.), School of Medicine and Pharmacology (P.H.R.B.), and Faculty of Engineering, Computing, and Mathematics (P.H.R.B.), The University of Western Australia, Crawley 6009, Australia.

We developed a compartmental model so we could test mechanistic concepts in the control of the male reproductive endocrine axis. Using SAAM II computer software and a bank of experimental data from male sheep, we began by modeling GnRH-LH feed-forward and LH-T feedback. A key assumption was that the primary control signal comes from a hypothetical neural network (the PULSAR) that emits a digital (pulsatile) signal of variable frequency that drives GnRH secretion in square wave-like pulses. This model produced endocrine profiles that matched experimental observations for the testis-intact animal and for changes in GnRH pulse frequency after castration and T replacement. In the second stage of the model development, we introduced a delay in the negative feedback caused by the aromatization of T to estradiol at the brain level, a concept supported by empirical observations. The simulations showed how changes in the process of aromatization could affect the response of the pulsatile signal to inhibition by steroid feedback. The sensitivity of the PULSAR to estradiol was a critical factor, but the most striking observation was the effect of time delays. With longer delays, there was a reduction in the rate of aromatization and therefore a decrease in local estradiol concentrations, and the outcome was multiple-pulse events in the secretion of GnRH/LH, reflecting experimental observations. In conclusion, our model successfully emulates the GnRH-LH-T-GnRH loop, accommodates a pivotal role for central aromatization in negative feedback, and suggests that time delays in negative feedback are an important aspect of the control of GnRH pulse frequency.
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http://dx.doi.org/10.1210/en.2015-1913DOI Listing
May 2016

Finding the Balance: Fertility Control for the Management of Fragmented Populations of a Threatened Rock-Wallaby Species.

Animals (Basel) 2015 Dec 16;5(4):1329-44. Epub 2015 Dec 16.

School of Animal Biology, The University of Western Australia, M092, 35 Stirling Highway, Crawley, WA 6009, Australia.

Populations of Australian marsupials can become overabundant, resulting in detrimental impacts on the environment. For example, the threatened black-flanked rock-wallaby ( Petrogale lateralis lateralis ) has previously been perceived as overabundant and thus 'unwanted' when they graze crops and cause habitat degradation. Hormonally-induced fertility control has been increasingly used to manage population size in other marsupials where alternative management options are not viable. We tested whether deslorelin, a superagonist of gonadotropin-releasing hormone (GnRH), would suppress reproduction in free-living adult female rock-wallabies without adversely impacting body condition. We trapped, synchronised reproduction and allocated female rock-wallabies to a placebo implant (control, n = 22), one (n = 22) or two (n = 20) subcutaneous implants of deslorelin. Females were then recaptured over the following 36 months to monitor reproduction, including Luteinising Hormone levels, and body condition. Following treatment, diapaused blastocysts reactivated in five females and the resulting young were carried through to weaning. No wallabies treated with deslorelin, conceivede a new young for at least 27 months. We did not observe adverse effects on body condition on treated females. We conclude that deslorelin implants are effective for the medium-term suppression of reproduction in female black-flanked rock-wallabies and for managing overabundant populations of some marsupials.
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http://dx.doi.org/10.3390/ani5040414DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4693218PMC
December 2015

Associations between temperament and gene polymorphisms in the brain dopaminergic system and the adrenal gland of sheep.

Physiol Behav 2016 Jan 20;153:19-27. Epub 2015 Oct 20.

UWA Institute of Agriculture and School of Animal Biology, The University of Western Australia, Crawley 6009, Australia. Electronic address:

Sheep of calm or nervous temperament differ in their physiological (cortisol secretion) and behavioural (motor activity) responses to stressors, perhaps due to variation in genes that regulate glucocorticoid synthesis or brain dopamine activity. Using ewes that had been selected over 20 generations for nervous (n=58) or calm (n=59) temperament, we confirmed the presence of a polymorphism in a gene specifically involved in cortisol production (CYP17), and identified polymorphisms in three genes specifically associated with personality and behavioural traits: dopamine receptors 2 and 4 (DRD2, DRD4), and monoamine oxidase A (MAOA). The calm and nervous lines differed in their frequencies of CYP17 SNP628 (single nucleotide A-G mutation at position 628) and DRD2 SNP939 (single nucleotide T-C mutation at position 939), but not for other SNPs detected in DRD2 or MAOA. In a second experiment, we then genotyped a large, non-selected flock of ewes for DRD2 SNP939 and CYP17 SNP628. Responses to the 'arena' and 'isolation box' challenges were associated with the DRD2 SNP939 genotype and the response to ACTH challenge was associated with the CYP17 SNP628 genotype. We conclude that, for sheep, a combination of the DRD2 SNP939 C allele and the CYP17 SNP628 A/A genotype could be used as a genetic marker for nervous temperament, and that a combination of DRD2 SNP939 T/T and CYP17 SNP628 G/G could be used as a genetic marker for calm temperament.
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http://dx.doi.org/10.1016/j.physbeh.2015.10.022DOI Listing
January 2016

Roles of small RNAs in the effects of nutrition on apoptosis and spermatogenesis in the adult testis.

Sci Rep 2015 May 21;5:10372. Epub 2015 May 21.

Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, T6G 2P5, Canada.

We tested whether reductions in spermatozoal quality induced by under-nutrition are associated with increased germ cell apoptosis and disrupted spermatogenesis, and whether these effects are mediated by small RNAs. Groups of 8 male sheep were fed for a 10% increase or 10% decrease in body mass over 65 days. Underfeeding increased the number of apoptotic germ cells (P < 0.05) and increased the expression of apoptosis-related genes (P < 0.05) in testicular tissue. We identified 44 miRNAs and 35 putative piRNAs that were differentially expressed in well-fed and underfed males (FDR < 0.05). Some were related to reproductive system development, apoptosis (miRNAs), and sperm production and quality (piRNAs). Novel-miR-144 (miR-98), was found to target three apoptotic genes (TP53, CASP3, FASL). The proportion of miRNAs as a total of small RNAs was greater in well-fed males than in underfed males (P < 0.05) and was correlated (r = 0.8, P < 0.05) with the proportion of piRNAs in well-fed and underfed males. In conclusion, the reductions in spermatozoal quality induced by under-nutrition are caused, at least partly, by disruptions to Sertoli cell function and increased germ cell apoptosis, mediated by changes in the expression of miRNAs and piRNAs.
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http://dx.doi.org/10.1038/srep10372DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4440528PMC
May 2015
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