Animal reproduction science

Publisher: Elsevier Masson

Current impact factor: 1.51

Impact Factor Rankings

2016 Impact Factor Available summer 2017
2014 / 2015 Impact Factor 1.511
2013 Impact Factor 1.581
2012 Impact Factor 1.897
2011 Impact Factor 1.75
2010 Impact Factor 1.721
2009 Impact Factor 1.563
2008 Impact Factor 1.89
2007 Impact Factor 1.739
2006 Impact Factor 2.186
2005 Impact Factor 2.136
2004 Impact Factor 1.41
2003 Impact Factor 1.286
2002 Impact Factor 1.681
2001 Impact Factor 1.196
2000 Impact Factor 1.08
1999 Impact Factor 0.813
1998 Impact Factor 1.105
1997 Impact Factor 0.93
1996 Impact Factor 0.838
1995 Impact Factor 0.709
1994 Impact Factor 0.855
1993 Impact Factor 0.678
1992 Impact Factor 0.701

Impact factor over time

Impact factor

Additional details

5-year impact 1.86
Cited half-life 7.90
Immediacy index 0.19
Eigenfactor 0.01
Article influence 0.47
ISSN 1873-2232

Publisher details

Elsevier Masson

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  • Classification

Publications in this journal

  • [Show abstract] [Hide abstract]
    ABSTRACT: Throughout cryopreservation, sperm are exposed to major osmotic challenges. Only intact membranes of sperm cells are able to regulate these volumetric changes, which can be determined by the hypo-osmotic swelling test (HOS test). Correlations between the HOS test and conventional semen variables are inconsistent. Therefore, the objectives of this study were 1) to examine relationships between HOS test results and standard semen variables before freezing and after thawing and 2) to evaluate the prognostic value of the HOS assessments on post-thaw quality of dog semen. Semen of 35 dogs was collected and analysed before freezing and after thawing following a 7-day freeze-thaw interval. Conventional semen variables such as sperm cell motility, membrane integrity morphology were evaluated and the HOS test was conducted with results from this test being recorded. In fresh semen the HOS test was positively correlated with progressive motility of sperm cells: r = 0.52, sperm cell membrane integrity: r = 0.50 and normal sperm cell morphology: r = 0.46 (P < 0.05). In frozen-thawed semen, the data obtained with the HOS test were positively correlated with progressive sperm cell motility: r = 0.67 and membrane integrity: r = 0.86 (P < 0.05). The data obtained with the HOS test in fresh semen were positively correlated with sperm cell membrane integrity: r = 0.50 normal sperm cell morphology: r = 0.55 and data from the HOS test (r = 0.43; P < 0.05) with frozen-thawed semen. For the prediction of individual cryopreservation capacity, results from assessment of the fresh semen variables of good and poor semen quality were statistically compared. Based on these results, it is not possible to predict the quality of frozen-thawed dog semen using the HOS test.
    No preview · Article · Jan 2016 · Animal reproduction science
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    ABSTRACT: The Insulin-Like Growth Factor 1 has an important role in reproduction, foetal development and growth. It regulates the secretion of gonadotrophin releasing hormone, stimulates ovarian function and steroidogenesis. The present study was conducted to characterise the 5′ flanking region of goat IGF1 gene, ascertain ovarian expression of the IGF1gene, detect SNPs and assess the association with prolificacy in the two indigenous goat breeds of South India viz., low prolific Attappady Black and high prolific Malabari. The 5′ flanking region of IGF1 gene was PCR amplified, cloned and sequenced from both breeds. Genotyping was performed in 277 goats from the two genetic groups using the PCR-Single Strand Conformational Polymorphism (SSCP) and the expression of the IGF1 gene in the ovary was analysed by quantitative real time PCR. The 5′ flanking region of the IGF1 gene was 601 bp long and located at 450 bp upstream of the start codon. Sequence exhibited 97% to 99% similarity with that of the sheep, cattle and sika deer IGF1 genes. Three genotypes, PP, PQ and QR were observed at this locus with the frequency of 0.62, 0.30 and 0.08, respectively. Sequencing of the representative PCR products from each genotype revealed two SNPs, g.224A>G and g.227C>T. The population was found to be in Hardy-Weinberg disequilibrium at both loci. Statistical results indicated that these loci were associated with litter size (P ≤ 0.05). However, no significant difference was found in the expression of the IGF1 gene in the ovaries of the two goat breeds. These results suggest the significant influence of the IGF1 gene on prolificacy in goats and identified SNPs would benefit the selection of prolific animals in future breeding programs.
    No preview · Article · Jan 2016 · Animal reproduction science
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    ABSTRACT: The present study tested whether progesterone supplementation six days before estrus synchronization with PGF2α increases pregnancy per artificial insemination (P/AI), and reduces the incidence of twin births. Seven hundred and eighty three first-service dairy cows were synchronized with two injections of PGF2α 14 days apart, starting on day 35 postpartum. Six days before the second PGF2α injection, cows were treated either with a progesterone-releasing intravaginal device (PRID) and an intramuscular injection of 500 mg of progesterone (group P4; n = 387) or served as control (n = 396) and did not receive the PRID or the progesterone injection. Cows were inseminated 12 hours after estrus. Pregnancy was diagnosed 40 to 45 days later by transrectal palpation. Progesterone administration improved (p < 0.05) the percentage of cows detected in estrus in multiparous [(192/255) 75.2% vs (161/267) 60.2%], but not in primiparous cows [93/132 (70.4%) vs 90/129 (69.7%)]. Progesterone treatment increased P/AI in multiparous [53/192 (27.6%) vs 27/161 (16.7%)] but not in primiparous cows [25/93 (26.8%) vs 29/90 (32.2%)]. The incidence of twin births was lower (p = 0.07) in cows treated with progesterone [1/74 (1%)] than in the control group [4/53 (7%)]. It is concluded that progesterone administration before estrus synchronization with PGF2α in first service dairy cows improves estral response and increases P/AI in multiparous, but not in primiparous cows, and decreases the incidence of twin births.
    No preview · Article · Jan 2016 · Animal reproduction science
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    ABSTRACT: Expression of estrus after PG and before fixed-time AI has been reported to change the uterine environment, increase accessory sperm numbers, fertilization rates, and overall embryo survival. Thus, expression of estrus can strongly impact overall pregnancy success. Because of variation in percentage of beef females detected in estrus and number of animals per study, it can be difficult to detect a significant effect of estrus on pregnancy success. Thus, a meta-analysis was conducted using data from 10,116 beef females in 22 studies that utilized variations of the 5 most common fixed-time AI protocols (CO-Synch, 7-d CO-Synch + CIDR, 5-d CIDR, PG 6-d CIDR, and the 14-d CIDR protocols) to examine the effect of detection in standing estrus on subsequent fixed-time AI pregnancy success. A random-effects model was used to combine the studies/herds. The overall model indicated a positive effect of estrus on conception rates with cows detected in estrus before fixed-time AI having a 27% greater (P < 0.05; 95% CI = 22% to 32%) conception rate compared with those not detected in estrus. Next we determined factors that influenced expression of estrus. Data were available on 547 cows synchronized with a CIDR based fixed-time AI protocols and observed for estrus before AI during 2 to 4 breeding seasons. Analysis of these cows indicated that days postpartum (P = 0.22) did not impact estrous expression. In contrast, BCS influenced estrous expression (P = 0.04) with cows in a BCS of ≤ 4 (51 ± 5%) having decreased expression of estrus compared to cows with a BCS > 4 (≥ 70 ± 4%). Initiation of estrous cycles before the breeding season also influenced estrous expression (P = 0.03), with anestrous cows having greater expression of estrus compared with estrus-cycling cows (78 ± 5% vs. 70 ± 5%, respectively). In conclusion, among all currently recommended fixed-time AI protocols, cows detected in estrus before fixed-time AI had improved conception rates, with BCS and estrus-cycling status having the greatest influence on expression of estrus.
    No preview · Article · Jan 2016 · Animal reproduction science

  • No preview · Article · Jan 2016 · Animal reproduction science
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    ABSTRACT: The aim of the present study was to explore proteome changes in rainbow trout (Oncorhynchus mykiss) fertilized eggs as an effect of triploidization heat-shock treatment. Eggs and milt were taken from eight females and six males. The gametes were pooled to minimize the individual differences. After insemination, the eggs were incubated at 10 °C for 10 min. Half of the fertilized eggs were then subjected to heat shock for 10 min submerged in a 28 °C water bath to induce triploidy. The remainder were incubated normally and used as diploid controls. Three batches of eggs were randomly selected from each group and were incubated at 10–11 °C under the same environmental conditions in hatchery troughs until the fry stage. Triplicate samples of 30 eggs (10 eggs per trough) from each group were randomly selected 1.5 h post-fertilization for proteome extraction. Egg proteins were analyzed using two-dimensional electrophoresis (2-DE) and MALDI-TOF/TOF mass spectrometry. Based on the results from the statistical analyses, 15 protein spots were found to decrease significantly in abundance in heat-shock treated group and were selected for identification. Out of 15 protein spots showing altered abundance, 14 spots were successfully identified. All of the egg proteins identified in our study were related to vitellogenin (vtg). Decreased abundance of vitellogenin in heat-shock treated eggs in our study may either be explained by (i) higher utilization of vtg as an effect of increased cell size in triploids or (ii) changed metabolism in response to heat-shock stress and (iii) diffusion of vtg through chorion due to incidence of egg shell damage. Decreased abundance of vitellogenin in heat-shock treated eggs was associated with reduced early survival rates and lowered growth performance of triploid fish.
    No preview · Article · Jan 2016 · Animal reproduction science
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    ABSTRACT: Propagation of bovine spermatogonial stem cells (SSCs) from the cryopreserved testicular tissue is essential for the application of SSCs-related techniques. To explore the appropriate conditions for in vitro culture of bovine spermatogonia (containing putative SSCs), Sertoli cell monolayer and serum concentration were set as two main control factors. Morphological examination showed that the intactness and structure of adult bovine testicular tissue were well maintained after cryopreservation. The enriched bovine spermatogonia were large round CD9 and promyelocytic leukemia zinc finger protein (PLZF) positive cells, with high nucleocytoplasmic ratios and multiple types including single, paired-, aligned-cells or grape cluster-like colonies in vitro. In Sertoli cell co-culture system, bovine spermatogonia attached quickly and proliferated obviously faster than those in the system without Sertoli cells. Serum-free media was no good for the attachment and proliferation of bovine spermatogonia. When 2.5%, 5% and 10% fetal bovine serum (FBS) was employed in the media, spermatogonia attached easily and divided quickly to form paired-, chained-cells or grape cluster-like colonies with comparable percentages in all groups. However, the contaminated somatic cells proliferated robustly in groups containing 5% and 10% FBS. Together, bovine spermatognia isolated from cryopreserved adult testis tissue express CD9 and PLZF, can survive and proliferate conspicuously in Sertoli cell co-culture system, and low serum provides an optimal condition for the survival and proliferation of bovine spermatogonia because of avoiding the rapid growth of testis somatic cells.
    No preview · Article · Jan 2016 · Animal reproduction science
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    ABSTRACT: Piwil1 mediates spermatogenesis and ensures stable cell division rates in germline cells in mammals. However, the involvement of Piwil1 in poultry spermatogenesis and meiosis is poorly understood. In the present study, we used TaqMan RT-qPCR to characterize Piwil1 mRNA expression in different types of spermatogenic cells, including primordial germ cells (PGCs), spermatogonial stem cells (SSCs), spermatogonia cells (Sa), tetraploid cells (Tp), round sperm cells (Rs), mature sperm, and in PGCs treated with retinoic acid. Our results revealed that Piwil1 is differentially expressed during spermatogenesis in chicken. Compared to PGCs, SSCs, Tp, and Sa, Rs cells presented the highest Piwil1 mRNA expression levels. Retinoic acid significantly upregulated Piwil1 and Stra8 mRNA expression as well as Piwil1 levels in chicken PGCs. In addition, retinoic acid induced PGCs to progress through all the meiotic stages, eventually leading to haploid cell formation, which was determined using flow cytometry and western blot analysis. Taken together, our results showed that during spermatogenesis, Piwil1 was first expressed at low levels in germ stem cells, PGCs, and SSCs. Its expression levels increased during later meiosis stages. Finally, no expression was detected in mature sperm after meiosis. Treatment of PGCs with retinoic acid further demonstrated that Piwil1 plays a key role in meiosis during chicken spermatogenesis.
    No preview · Article · Jan 2016 · Animal reproduction science
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    ABSTRACT: Ovarian activity, which is mainly controlled by follicle-stimulating hormone and luteinizing hormone, is vital to successful reproduction and maintaining reproductive efficiency in livestock. To determine if the regulation of follicular-luteal transition occurs at the post-transcriptional level in hircine ovaries, the expression patterns of small RNAs in the ovarian tissues of Anhui white goats in the follicular and luteal phases were analyzed using Solexa sequencing. In total, 1039 miRNAs were co-expressed in the two libraries, and 278 and 469 miRNAs were specifically expressed in the hircine ovaries during the follicular and luteal phases, respectively. A total of 43 potential novel miRNAs were predicted in the two libraries. GO annotation and KEGG pathway analysis were applied to analyze the target genes of all miRNAs predicted in the two libraries. The highly and differentially expressed miRNAs included miR-26-5p, miR-145-5p, miR-145, miR-145a-5p, miR-125a-5p, miR-320d, and miR-320c, which may participate in follicular-luteal transition. Five co-expressed miRNAs, of which 2 were differentially expressed between the two libraries, were randomly selected to validate the expression pattern using RT-PCR, and the results were consistent with the Solexa sequencing data. Our present results help to clarify the roles of miRNAs in the regulation of follicular-luteal transition in goat ovaries, which may further enhance the reproductive efficiency of commercially important animals in the future.
    No preview · Article · Jan 2016 · Animal reproduction science
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    ABSTRACT: Using a high-throughput optical tracking technique that is based on partially-coherent digital in-line holography, here we report a detailed analysis of the statistical behavior of horse sperms' three-dimensional (3D) swimming dynamics. This dual-color and dual-angle lensfree imaging platform enables us to track individual 3D trajectories of ∼1,000 horse sperms at sub-micron level within a sample volume of ∼9 μL at a frame rate of 143 frames per sec (FPS) and collect thousands of sperm trajectories within a few hours for statistical analysis of their 3D dynamics. Using this high-throughput imaging platform, we recorded >17,000 horse sperm trajectories that can be grouped into six major categories: irregular, linear, planar, helical, ribbon, and hyperactivated, where the hyperactivated swimming patterns can be further divided into four sub-categories, namely hyper-progressive, hyper-planar, hyper-ribbon, and star-spin. The large spatio-temporal statistics that we collected with this 3D tracking platform revealed that irregular, planar, and ribbon trajectories are the dominant 3D swimming patterns observed in horse sperms, which altogether account for >97% of the trajectories that we imaged in plasma-free semen extender medium. Through our experiments we also found out that horse seminal plasma in general increases sperms' straightness in their 3D trajectories, enhancing the relative percentage of linear swimming patterns and suppressing planar swimming patterns, while barely affecting the overall percentage of ribbon patterns.
    No preview · Article · Jan 2016 · Animal reproduction science
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    ABSTRACT: The present study was designed to examine whether an estrus induction with gonadotropins could affect luteal P4 synthesis in early pregnant gilts. Sixteen prepubertal gilts received 750 IU of PMSG and 500 IU of hCG 72 h later. Prepubertal gilts in the control group (n = 17) were observed daily for estrus behavior. All gilts were inseminated in their first estrus. Corpora lutea (CLs) were collected on days 10, 12 and 15 of pregnancy and analyzed for (1) the mRNA and protein expression of steroidogenic acute regulatory protein (StAR), cytochrome P450 family 11 subfamily A polypeptide 1 (CYP11A1), and 3β-hydroxysteroid dehydrogenase (3βHSD); (2) the tissue concentration of P4; and (3) the mRNA expression of luteinizing hormone receptor (LHR) and estrogen receptors (ESR1 and ESR2). Additionally, P4 concentration was analyzed in blood serum of all animals. PMSG/hCG injections to induce estrus decreased mRNA expression of StAR, CYP11A1 and 3βHSD on day 10 and CYP11A1 on day 12 of pregnancy compared with the control group, while CYP11A1 and 3βHSD proteins were down-regulated on day 10 in the hormonally-treated gilts. Concentrations of P4 in luteal tissue and blood serum were also lower in animals after gonadotropin-induced estrus. In contrast, LHR and ESR1 mRNA expression was greater in PMSG/hCG-treated than control gilts on day 15 of gestation. In conclusion, induction of estrus with a PMSG/hCG protocol in prepubertal gilts impaired expression of the luteal P4 synthesis system. Low P4 content may, in turn, induce local mechanisms involving LHR and ESR1 expression to support CL function.
    No preview · Article · Jan 2016 · Animal reproduction science
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    ABSTRACT: Biosafety issue associated with the risk of pathogenic contamination of cryopreserved semen is a common concern because of associated declines in sperm quality, storage period and disease transmission. This study was conducted to evaluate the effects of methods of semen collection on sperm quality and bacterial composition of post-thawed semen of silver barb (Barbodes gonionotus). Semen collection methods consisted of four treatments: (1) hand-stripping of abdomen without rinsing of urogenital area with water, (2) hand-stripping of abdomen after rinsing of urogenital area with water, (3) catheterization without rinsing of urogenital area with water and (4) catheterization after rinsing of urogenital area with water. Semen diluted with calcium-free Hank's balanced salt solution containing 10% dimethylsulfoxide (DMSO) was frozen at a freezing rate of −8 °C min−1 before plunging in liquid nitrogen. Post-thawed semen collected by catheterization after rinsing urogenital area had the lowest bacterial number, about 2-log reduction of total heterotrophic, Gram negative and pseudomonad bacteria, compared with the other three collection treatments. However, percentages of motile and viable sperm were not significantly (P > 0.05) different among treatments. This method eliminated Flavobacterium aquatile, Bacillus megaterium, Kocuria varians, Staphylococcus haemolyticus and Aeromonas media in cryopreserved semen. This is the first report demonstrating the effects of semen collection methods on bacteriological quality of frozen-thawed fish semen.
    No preview · Article · Jan 2016 · Animal reproduction science
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    ABSTRACT: As demonstrated by some authors, the type of analyzing chamber can greatly influence the results of computer-assisted sperm analysis (CASA). This study aimed to compare three of the disposable chamber types currently available on the market and to determine whether the CASA output may be significantly different among them. The semen from five Fleckvieh bulls was analyzed by CASA using three different disposable chambers: Leja (20 μm), MofA (20 μm) and Minitube (20 μm), at three different time points: immediately after filling the chamber, at 6 min, and also at 12 min after filling. Sperm concentration was also determined using the Nucleocounter® NC-100™ device and the hemocytometer as standard methods. The results showed higher values in terms of total and progressive sperm motility for MofA compared to the other two chambers immediately after filling (p < 0.05), but higher values for Leja and Minitube after 6 and 12 min (p < 0.05). All three disposable chambers offered lower values for sperm concentration compared to standard methods (Leja: 68.4 ± 4.9 × 106/mL; MofA: 80.8 ± 9.6 × 106/mL; Minitube: 67.3 ± 5.4 × 106/mL; Nucleocounter: 86.5 × 106/mL; Hemocytometer: 84.0 × 106/mL). We conclude that for rapid analyses the MofA chambers provide superior results when compared to the other types that we tested. However, when the analysis requires a longer duration, the Minitube type, and especially the Leja type provide a greater degree of confidence. Further, for determining sperm concentration we think that examiners would be more accurate using the Nucleocounter or the hemocytometer and should make use of CASA only when the other methods are not available.
    No preview · Article · Jan 2016 · Animal reproduction science
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    ABSTRACT: Disease prevention is a key aspect in developing cryopreservation procedures for fish sperm and in improving the reproductive biotechnology for commercially important aquatic species. The purpose of this study was to evaluate the effects of an antibiotic supplementation (0.25% penicillin–streptomycin, PS and 0.25% penicillin–gentamicin, PG) on sperm motility and viability, bacterial profile and fertilization capacity of cryopreserved silver barb (Barbodes gonionotus) semen. The experimental protocol involved three treatments: addition of PS alone; addition of PG alone; and no addition of antibiotics (Control). Semen samples were frozen and cryostored for 12-mo. Administration of 0.25% PS significantly (P < 0.05) improved sperm motility and viability and reduced (P < 0.05) total heterotrophic bacteria, gram negative bacteria and pseudomonads bacteria in cryopreserved semen. Post-thawed semen treated with 0.25% PS did not contain contaminating bacteria including Bacillus subtilis subsp. inaquosorum, Bacillus safensis, Aeromonas punctata subsp. caviae, Serratia plymuthica, Pseudomonas azotoformans and Pseudomonas sp. Post-thawed semen supplemented with 0.25% PG showed degenerative changes in motility and viability of sperm. Eggs fertilized with 0.25% PS or antibiotic-free cryopreserved semen had similar fertilization rates, lower (P < 0.05) than those of fresh semen. Incorporation of 0.25% PS was suitable for cryopreservation of silver barb semen based on the presence of good quality of post-thawed sperm and elimination of bacterial contaminants: B. subtilis subsp. inaquosorum, B. safensis, A. punctata subsp. caviae, Ser. plymuthica, P. azotoformans and Pseudomonas sp. This is the first study to investigate the antibiotic effect on the number of bacteria and their profile in cryopreserved semen of fish.
    No preview · Article · Jan 2016 · Animal reproduction science
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    ABSTRACT: The aim of this study was to evaluate the uterine blood supply and endometrial vessel architecture, during the equine estrous cycle. Narrow Band Imaging (NBI) hysteroscopy was used for evaluating changes in the endometrial vasculature during the estrous cycle [six mares, d 0 (representing the day of ovulation), d 6 and 11 in four locations]. In addition, endometrial biopsy samples were used for immunodetection of markers for angiogenesis (Vascular Endothelial Growth Factor A, its receptor 2, as well as angiopoietin-2 and its receptor-tyrosine-kinase Tie2) during the estrous cycle (three mares, d 0, 5 and 10; one biopsy per mare). Detailed analysis of hysteroscopic images revealed an increase in the vascular density from estrus towards diestrus. In contrast, microscopic specimens prepared from biopsies revealed no evidence for changes in the endometrial vessel number during the estrous cycle. Studies on expression of angiogenesis markers indicated that cyclic changes in the endometrial vascular density observed by NBI-hysteroscopy were not due to formation of new vessels. It is concluded that vessels are involved in blood supply of a smaller area during diestrus, facilitating better distribution of nutrients during this phase.
    No preview · Article · Jan 2016 · Animal reproduction science
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    ABSTRACT: Gonadal soma-derived factor (gsdf) is a teleost- and gonad-specific growth factor involved in early germ cell development. The red spotted grouper, Epinephelus akaara, as a protogynous hermaphrodite, provides a novel model for understanding the mechanisms of sex determination and differentiation in teleosts. In the present study, a 2307-bp long gsdf gene was cloned from E. akaara and there was further analysis of its tissue distribution and gonadal patterns of gene expression during the female phase and sex change developmental stages. The cellular localization of gsdf at the late transitional developmental stage was also analyzed. In addition, the concentrations of serum sex steroid hormones (E2, 11-KT and DHP) were determined. The gsdf transcripts were exclusively localized in the gonad. During the female phase at an early developmental stage, when the ovotestis contained mainly oogonia and primary growth oocytes, the gsdf mRNA was relatively more abundant. The relative abundance of gsdf decreased, however, and the lesser amount was sustained with the advancement of oocyte development. During the transitional phase, the relative abundance of gsdf mRNA increased slightly at the early developmental stage and there were further increases in relative abundance in the late developmental stage, and the gsdf transcripts were observed in the Sertoli cells surrounding early developing spermatogonia. Among the sex steroids, 11-KT concentrations were positively correlated with amount of gsdf mRNA during sex change. These results suggest that gsdf could have roles in regulating pre-meiotic germ cell proliferation and be involved in sex change in E. akaara.
    No preview · Article · Dec 2015 · Animal reproduction science
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    ABSTRACT: The objective was to compare the conception rates for FTAI and in vitro embryo production between Nelore cows with different antral follicle counts (AFC=number of follicles ≤3mm in diameter in the ovaries). Nelore cows (n=547) were subjected to ovulation synchronization. Randomly during the estrous cycle (D0), cows received an intravaginal device containing 1.9g P4 (CIDR(®)) and 2mg BE (Estrogin(®)), IM. When the device was removed (D8), the cows received 500μg PGF2α (Ciosin(®)), 300IU eCG (Novormon(®)) and 1mg EC (ECP(®)), IM. All cows were inseminated 48h after P4 device removal. Antral follicles ≥3mm were counted using an intravaginal microconvex transducer (D0), and the cows were assigned to high (G-High, ≥25 follicles, n=183), intermediate (G-Intermediate, 16-20 follicles, n=183) or low AFC groups (G-Low, ≤10 follicles, n=181). In another experiment, COCs were retrieved by OPU from Nelore cows (n=66), which were assigned to groups according to oocyte production: G-High (n=22, ≥40 oocytes), G-Intermediate (n=25, 18-25 oocytes) or G-Low (n=19, ≤7 oocytes). All COCs from the same cow were cultured individually (maximum of 25 COCs per drop) and then in vitro fertilized using thawed frozen sperm (2×10(8)/dose) from a Nelore sire of known fertility. The data were analyzed using a Kruskal-Wallis and a Chi-square test (P≤0.05). There was no difference in the conception rates after FTAI between Nelore cows with high, intermediate or low AFC (51.9 vs. 48.6 vs. 58.6%). The number of viable embryos was 18.4±6.7 (G-High), 6.1±3.6 (G-Intermediate) and 0.6±0.7 (G-Low; P<0.05). Therefore, AFC had no influence on the conception rates for FTAI; however, Nelore cows with high oocyte production exhibited better in vitro embryo production.
    No preview · Article · Dec 2015 · Animal reproduction science