Long-term Reproductive Performance Research Articles

Effects of Elective Caesarean Sections in Healthy Near-Term Ewes on Subsequent Reproductive Performance.

Post-surgical reproductive performance following ovine caesarean section has not been well studied. To assess any direct effects of surgical delivery in the absence of confounders such as dystocia or underlying diseases, we studied elective surgery performed in healthy animals for teaching purposes. Four hundred and eleven paired breeding records following vaginal delivery (n = 233), elective caesarean section (n = 122), and subsequent further vaginal deliveries in animals with a history of one prior elective caesarean operation (n = 56) were evaluated retrospectively. The overall subsequent pregnancy rate was 95%. Multivariable statistical analyses did not reveal any significant influence of planned caesarean surgery on subsequent conception, stillbirth, perinatal lamb mortality, lamb birth weights, or the incidence of premature foetal death (mummification and abortion). A significantly higher number of mating attempts was, however, necessary. Also, a significant reduction in litter size was seen in the first pregnancy immediately following a surgical delivery in comparison to animals which had previously only delivered vaginally (p = 0.001), but litter size returned to pre-caesarean levels in further follow-up pregnancies in animals with a history of one elective caesarean section (p = 0.436). Subsequent long-term reproductive performance of sheep following elective caesarean section is thus excellent, and the results encourage retention for breeding.

44 Identification of Vaginal Gene Expression Differences in Gilts Achieving Early or Late Puberty

Abstract A known predictor of reproductive success in swine breeding herds is age at puberty. Early puberty is associated with improved long-term reproductive performance. Additionally, it has been established that vaginal gene expression in gilts changes throughout reproductive development. The hypothesis was that vaginal gene expression was correlated with estrus expression and therefore likelihood of reproductive success. Pre-pubertal gilts (n = 29) were followed from 70 d of age until first estrus or 215 d of age. Vaginal epithelia were collected using a swabbing technique at five key timepoints during reproductive development [70 (on farm arrival), 100 (mid-folliculogenesis), 130, 160 d of age, and first estrus or end of trial]. Boar exposure began on 160 d of age with 15 minutes of fenceline contact at 0700 h daily with trained technicians observing for signs of standing estrus (i.e., erect ears, swollen, pink vulva, allowing back pressure). By 215 d of age, 19 females were classified as expressing estrus early (160 to 181 d), 4 were average (181 to 202), and 6 were late or as anestrus (202 to 215 d). A subset of 5 gilts that expressed estrus early and 5 gilts that expressed estrus late or as anestrus were used for further investigation of vaginal gene expression. Total RNA was isolated from vaginal samples at 3 timepoints (100, 130, and 160 d of age). Samples were sent to a commercial genomic sequencing laboratory for RNA sequencing. Each gene was scaled individually so that all genes were on the same scale for comparison, and the Welch two sample t-test was applied to determine statistical differences. A total of 53 genes were differentially expressed between the early estrus and late estrus or anestrus groups. Data were further screened to identify genes that were expressed in at least 3 gilts in either the early estrus or late estrus group at a given time point; this subset of 26 genes were selected for direct comparison at each time point. At 100 d of age, late estrus gilts had increased expression (P = 0.05) of a gene commonly found in females with polycystic ovary syndrome. At 130 d of age, genes associated with the innate immune response had greater relative expression (P < 0.05) in gilts expressing early estrus. At 160 d of age, genes associated with fat cell deposition had greater relative expression (P < 0.05) in the early estrus expression gilts. Distinct differences in transcripts during reproductive development may be putative biomarkers for detection of early estrus in pre-pubertal females.

PSI-A-9 A Comparison in Vaginal Gene Expression and Circulating Hormone Concentration in Pre-Pubertal Gilts Achieving Puberty at Different Ages

Abstract A known predictor of reproductive success in swine breeding herds is age at puberty. Early puberty is associated with improved long-term reproductive performance and more high-quality offspring. The objective of this study was to compare vaginal gene expression in gilts that achieved estrus early (160 to 181 d of age), average (181 to 202 d of age), late (202 to 215 d of age) and anestrus. Pre-pubertal gilts (n = 13) were followed from 70 d of age until first estrus or 214 ± 1 d. Vaginal epithelia was collected using a swabbing method at five time points during reproductive development [70 (on-farm arrival), 100 (mid-folliculogenesis), 130, 160 (start of boar exposure) d of age and standing estrus or end of trial]. At 140 d of age, females received an indwelling titanium catheter for daily blood collection during boar exposure. Following detected standing estrus, a blood sample was collected every 2 hours for 96 hours to characterize the peak serum concentration of luteinizing hormone that occurs at ovulation. At the conclusion of the trial, 3 gilts displayed early estrus (169 to 171 d of age), 3 gilts were deemed average estrus (194 to 195 d of age), 3 gilts were deemed late estrus (203 to 213 d of age), 3 gilts were deemed anestrus and 1 was identified as having a ‘silent’ estrus after 200 d of age. Total RNA were isolated from vaginal epithelia and relative gene expression insulin-like growth factor-1 (IGF-1), and estrogen receptor (ER)-alpha was quantified by real time RT-PCR, relative to the expression of RPLP0. to D70 was preformed using the PCR package offered in RStudio (version 1.2.5025). There was an increase in ER-alpha expression in the average estrus group (P = 0.03) at 130 d of age. Early estrus females had a greater expression of IGF-1 at 130 d of age compared with anestrus females (P = 0.01). Of the 9 females placed with an indwelling catheter, 2 catheters were nonpatent, and blood sample could not be collected at standing estrus. Of the 7 females where blood sample was collected at standing estrus, all females achieved an luteinizing hormone (LH) peak within 12 h after recorded standing estrus. Identification of key differences in the vaginal epithelium in concert with LH values provides biological evidence that those deemed achieving estrus based on behavior did successfully achieve estrus. These vaginal epithelium differences may serve as putative biomarkers to detect early estrus in pre-pubertal gilts.

Ovarian and Energy Status in Lame Dairy Cows at Puerperium and Their Responsiveness in Protocols for the Synchronization of Ovulation.

The purpose of this study was to assess the ovarian and energy status of multiparous lame dairy cows at the end of puerperium and investigate their responsiveness to estrous synchronization treatment regimens. Initial lameness scoring was performed at 28 ± 5 and 37 ± 5 d post partum, followed by lesion documentation and treatment. Cows were blocked by lameness severity and were randomly allocated to an estrous synchronization treatment regimen with seven days of progesterone supplementation (group LP, n = 26) or with an administration of PGF2α twice, 14 d apart (group LC, n = 26). Non-lame cows served as controls (group C, n = 27) and the same treatment regimen was imposed as that for group LC. Twelve days after estrous presynchronization, an Ovsynch treatment regimen and timed AI were imposed. Ultrasonography of the ovaries and blood sampling for progesterone were used to assess cyclicity status, whereas β-hydroxybutyrate (BHBA) and non-esterified fatty acids (NEFA) were used to assess energy status. Lame cows were to a greater proportion non-cycling (36.5% vs. 11.1%; p = 0.02), had greater overall NEFA concentrations (0.32 ± 0.02 vs. 0.26 ± 0.02 mEq/L; p = 0.02) and a greater incidence of elevated NEFA concentrations (53.9% vs. 29.6%, p = 0.04) compared to control cows. However, no interaction between energy and lameness status was evident regarding non-cycling cows. The percentage of cows responding to the presynchronization, synchronization and ovulating did not differ between groups LP, LC, and C. The first-service conception rate (FSCR) tended to be greater for group C (37.0%) compared to group LP (16.0%; p = 0.08). Long-term reproductive performance did not differ between lame and control cows, although culling rates did (21.2% vs. 0%, respectivly; p = 0.01). The severity of lameness had an effect on culling rates (30.6% vs. 0% for cows with marked vs. moderate lameness; p = 0.01), whereas the type of lesion largely explained poor reproductive performance (FSCR 13.9% vs. 40.0% for cows with claw horn disruptions vs. infectious lesions; p = 0.04). Conclusively, cows that were lame during puerperium are at a greater risk of not cycling irrespective of energy status. Treatment regimens for the synchronization of ovulation seem to be efficient at resuming ovarian cyclicity. Marked lameness was detrimental to survivability, whereas cows with claw horn lesions had compromised reproductive capacity.

170 Associations between postpartum uterine luminal fluid volume and long-term reproductive performance in lactating Holstein dairy cows

170 Associations between postpartum uterine luminal fluid volume and long-term reproductive performance in lactating Holstein dairy cows

279 Identification of Potential Biomarkers of Reproductive Development in Vaginal Gene Expression Associated with Serum Concentrations of Reproductive Hormones at key Periods in Gilt Development

Abstract Early puberty in gilts is associated with long-term reproductive performance. The ability to predict who will achieve early puberty is limited to intensive and invasive collection of serial blood samples to assess reproductive hormones, which is not practical for on-farm use. The objective of this pilot study was to characterize changes in gene expression in the vaginal epithelium related to reproduction during key periods in pubertal development. Pre-pubertal gilts (n =13) in 2 cohorts were followed from 70 d of age until first estrus or 213-215 d of age. Blood and vaginal epithelia were collected at five key timepoints during reproductive development (d70/77, d100/110, d130, d160 and first estrus or end of trial). Total RNA were isolated from vaginal epithelia and relative gene expression of two toll-like receptors (TLR-4 and TLR-5), tacykinin precursor-3 (TAC-3), insulin-like growth factor-1 (IGF-1), and estrogen receptor (ER)-alpha was quantified by real time RT-PCR, relative to the expression of RPLP0. Of the 13 gilts, 3 exhibited estrus early (d169 to 174), 3 were average (d194 to 195), 2 were late (d203 to 213), 3 were deemed anestrus and 2 had a silent estrus (one prior to d160 and one after d200). Statistical analysis of relative expression of each gene relative to 70 d was performed using the PCR package in RStudio (version 1.2.5025). Analysis of gene expression utilized Fisher’s exact t-test for genes TLR-4, TLR-5 and TAC-3, and ANOVA for genes ER-alpha, IGF-1. Expression of IGF-1 and TAC-3 were up-regulated 9-fold and 7-fold, at the start of boar exposure (d 160; P < 0.05). Expression of ER-alpha tended to be upregulated 3-fold at 100 d of age (P = 0.08). Expression of TLR-4 and TLR-5 was not detected for most samples until standing estrus. These transcripts may be putative biomarkers for early estrus detection.

Modelling the reproductive performance of tropical beef herds using long-term experimental grazing data on Urochloa humidicola pastures in the Llanos of Colombia

Long-term reproductive performance of beef breeding herds grazing sown pastures in the neotropical savanna environment of Eastern Colombia (Llanos) is not well documented, while the lifelong reproductive consequences of raising replacement heifers subject to different growth regimes is also intriguing. The study aimed to assess the effects of liveweight (LW), age, and their interaction on conception probabilities of Bos indicus replacement females by analyzing two seven- and eight-years lasting experiments that used commercial Brahman heifers subject initially to different growth rates on Urochloa humidicola pastures. The experiments included two periods, namely the growth period from weaning until 270 kg LW during which heifers were subjected to three stocking rates to attain different rates of gain, and the subsequent reproduction phase subject to common grazing for all growth treatments. The conception data fitted well logistic regressions in which LW and age were the predictor variables during the first two conceptions but the relationship disappeared in subsequent conceptions. Prediction equations compared well with extensive data from northern Australia that showed similar trends. Liveweight of adult cows only increased consistently during pregnancy, but following weaning their LWs returned to the initial low LWs attained at conception. Over the length of the experiments, weaning rates as percentages of calves born were 88% for the two treatments with higher LW gains during the growth period, and 81% for the lowest gaining treatment. Calving intervals were 19-20 months across treatments. It is suggested that the data and equations provided can guide decision making in extensive breeding herds.

173 Identification of Biological Markers to Detect Early Estrus in Pre-Pubertal Gilts

Abstract A proven predictor of reproductive success in swine breeding herds is age at puberty. Early puberty is associated with improved long-term reproductive performance. The objective of this study was to identify biomarkers of reproductive success at key periods in gilt reproductive development. Pre-pubertal gilts (n = 13) in 2 cohorts were followed from 70 d of age until first estrus or 213-215 d of age. Vaginal epithelia were collected using a swabbing technique at 5 key timepoints during reproductive development (70/77, 100/110, 130, 160 d of age, and first estrus or end of trial). Of the 13 gilts, 3 exhibited estrus early (d169 to 171), 2 were average (d 194 to 195), 2 were late (d 203 to 213), 3 were deemed anestrus and 2 had a silent estrus (one prior to d160 and 1 after d200). Total RNA were isolated and relative gene expression measured for RPLP0 (reference gene), TLR-4, TLR-5, IGF-1, ER-alpha and TAC-3 by quantitative real-time RT-PCR. Target genes were those involved with cellular protein function within the reproductive tract (IGF-1) and that prevent infection while allowing fertilization and implantation to occur (toll-like receptors 4 and 5). Gene ER-alpha is essential in the maturation of the female phenotype. Gene TAC-3 is critical for gonadal function. Comparison of relative expression of each gene of interest at different time points relative to 70 d was performed using the PCR package in RStudio (version 1.2.5025). Expression of IGF-1 and TAC-3 were up-regulated 9-fold and 7-fold, respectively, at the start of boar exposure (d 160; P < 0.05). Expression of ER-alpha tended to be upregulated 3-fold at 100 d of age (P = 0.08). Expression of TLR-4 and TLR-5 was not detected for most samples until standing estrus. These transcripts may be putative biomarkers for early estrus detection.

Reduced vitamin supplementation with fat-soluble vitamins A, D, and E added at National Research Council requirements may not be adequate for optimal sow and progeny performance

Objective: To evaluate performance and physiological vitamin status of sows and progeny fed 2 vitamin supplementation levels, industry vs reduced (all vitamins reduced with fat-soluble vitamins added at National Research Council recommendations). Materials and methods: Sows (n = 244) were allotted in a randomized complete block design to 1 of 2 vitamin supplementation levels. At weaning, 765 progeny from a subset of sows were allotted to treatments in a 2 × 2 factorial arrangement of two sow and two nursery vitamin supplementation levels with 15 pens/treatment. Performance and vitamin status of sows and progeny were measured from farrowing to nursery exit. Results: Reduced vitamin supplementation reduced sow lactation feed intake (P = .01), hepatic vitamin A (P = .001), and serum vitamin D (P < .001), but did not affect sow body weight or litter performance. Regardless of vitamin levels fed to the sow, progeny fed reduced levels post weaning had decreased circulating (P < .001) and stored (P = .03) vitamin levels and a reduction in average daily gain (P < .001), average daily feed intake (P < .001), gain:feed ratio (P = .002), and body weight (P < .001) at the end of the nursery period compared to progeny fed industry levels. Implications: Reduced vitamin supplementation reduced sow feed intake without affecting sow or litter performance, but decreased circulating and stored vitamin levels in sows could impact long-term reproductive performance. Reduced vitamin inclusion levels in nursery diets reduced performance and serum vitamin concentrations compared to industry vitamin levels.

O-138 Reproductive performance of women with and without intrauterine adhesions following recurrent dilatation and curettage for miscarriage: long-term follow-up of a randomized controlled trial

Abstract Study question Are the long-term reproductive outcomes following recurrent dilatation and curettage (D&C) for miscarriage in women with identified and treated intrauterine adhesions (IUAs) comparable to women without IUAs. Summary answer Reproductive outcomes in women with identified and treated IUAs following recurrent D&C for miscarriage are impaired compared to women without IUAs. What is known already The Prevention of Adhesions Post Abortion (PAPA) study showed that application of auto-crosslinked hyaluronic acid (ACP) gel, an absorbable barrier in women undergoing recurrent D&C for miscarriage resulted in a lower rate of IUAs, 13% versus 31% (relative risk 0.43, 95% CI 0.22 to 0.83), lower mean adhesion score and significant less moderate to severe IUAs. It is unclear what the impact is of IUAs on long-term reproductive performance. Study design, size, duration This was a follow-up of the PAPA study, a multicenter randomized controlled trial evaluating the application of ACP gel in women undergoing recurrent D&C for miscarriage. All included women received a diagnostic hysteroscopy 8–12 weeks after randomization to evaluate the uterine cavity and for adhesiolysis if IUAs were present. Here, we present the reproductive outcomes in women with identified and treated IUAs versus women without IUAs, 46 months after randomization. Participants/materials, setting, methods Between December 2011 and July 2015, 152 women with a first-trimester miscarriage with at least one previous D&C, were randomized for D&C alone or D&C with immediate intrauterine application of ACP gel. Participants were approached at least 30 months after randomization to evaluate reproductive performance, obstetric and neonatal outcomes and cycle characteristics. Main outcome was ongoing pregnancy. Outcomes of subsequent pregnancies, time to conception and time to live birth were also recorded. Main results and the role of chance In women pursuing a pregnancy, 14/24 (58%) ongoing pregnancies were recorded in women with identified and treated IUAs versus 80/89 (90%) ongoing pregnancies in women without IUAs odds ratio (OR) 0.18 (95% CI 0.06 to 0.50, P-value <0.001). Documented live birth was also lower in women with IUAs; 13/24 (54%) with versus 75/89 (84%) without IUAs, OR 0.22 (95% CI: 0.08 to-0.59, P-value 0.004). The median time to conception was 7 months in women with identified and treated IUAs versus 5 months in women without IUAs (hazard ratio (HR) 0.84 (95% CI 0.54 to 1.33)) and time to conception leading to a live birth 15 months versus 5.0 months (HR 0.54 (95% CI: 0.30 to 0.97)). In women with identified and treated IUAs, premature deliveries were recorded in 3/16 (19%) versus 4/88 (5%) in women without IUAs, P-value 0.01. Complications were recorded in respectively 12/16 (75%) versus 26/88 (30%), P-value 0.001. No differences were recorded in mean birth weight between the groups. Limitations, reasons for caution In the original PAPA study, randomization was applied for ACP gel application. Comparing women with and without IUAs is not in line with the randomization and therefore confounding of the results cannot be excluded. IUAs, if visible during routine hysteroscopy after randomization were removed as part of the study protocol. Wider implications of the findings As IUAs have an impact on reproductive performance, even after hysteroscopic adhesiolysis, primary prevention is essential. Expectative and medical management should therefore be considered as serious alternatives for D&C in women with a miscarriage. In case D&C is necessary, application of ACP gel should be considered. Trial registration number Netherlands Trial Register NTR 3120.

The long-term trend, reproductive performance and colony shifting of the Eurasian Griffon Gyps fulvus in Croatia

The long-term trend, reproductive performance and colony shifting of the Eurasian Griffon Gyps fulvus in Croatia

Parent-of-origin effects of A1CF and AGO2 on testicular germ-cell tumors, testicular abnormalities, and fertilization bias

Testicular tumors, the most common cancer in young men, arise from abnormalities in germ cells during fetal development. Unconventional inheritance for testicular germ cell tumor (TGCT) risk both in humans and mice implicates epigenetic mechanisms. Apolipoprotein B mRNA-editing enzyme complex 1 (APOBEC1) cytidine deaminase and Deadend-1, which are involved in C-to-U RNA editing and microRNA-dependent mRNA silencing, respectively, are potent epigenetic modifiers of TGCT susceptibility in the genetically predisposed 129/Sv inbred mouse strain. Here, we show that partial loss of either APOBEC1 complementation factor (A1CF), the RNA-binding cofactor of APOBEC1 in RNA editing, or Argonaute 2 (AGO2), a key factor in the biogenesis of certain noncoding RNAs, modulates risk for TGCTs and testicular abnormalities in both parent-of-origin and conventional genetic manners. In addition, non-Mendelian inheritance was found among progeny of A1cf and Ago2 mutant intercrosses but not in backcrosses and without fetal loss. Together these findings suggest nonrandom union of gametes rather than meiotic drive or preferential lethality. Finally, this survey also suggested that A1CF contributes to long-term reproductive performance. These results directly implicate the RNA-binding proteins A1CF and AGO2 in the epigenetic control of germ-cell fate, urogenital development, and gamete functions.

Evaluation of pre-breeding reproductive tract scoring as a predictor of long term reproductive performance in beef heifers

In a 7-year longitudinal study 292 Bovelder beef cows in a restricted breeding system in South Africa were observed from 1 to 2 days before their first breeding season, when reproductive tract scoring (RTS, scored from 1 to 5) was performed, until weaning their 5th calves. The objective was to determine whether pre-breeding RTS in heifers is a valid tool to predict long-term reproductive performance. Outcomes measured were failure to show oestrus during the first 24 days of the first 50-day AI season (24-day anoestrus), failure to become pregnant during each yearly artificial insemination (AI) season (reproductive failure), number of days from the start of each AI season to calving, and number of years to reproductive failure. The effect of RTS on each outcome was adjusted for year of birth, pre-breeding age, BW and body condition score (BCS), and for 24-day anoestrus, bull, gestation length, previous days to calving and previous cow efficiency index, the latter two in the case of the 2nd to the 5th calving season. During their first breeding season, heifers with RTS 1 and 2 combined were more likely to be in anoestrus for the first 24 days (OR=3.0, 95% CI 1.5, 6.4, P=0.003), and were also more likely to fail to become pregnant even after adjusting for 24-day anoestrus (OR=2.1, 95% CI 1.1, 3.9, P=0.025), compared to those with RTS 4 and 5 combined. Animals with RTS 1 and 2 combined were at increased risk of early reproductive failure compared to those with RTS 4 and 5 combined (HR=1.4, 95% CI 1.0, 1.9, P=0.045) although RTS was not associated with calving rate or days to calving after the second calving season. Low RTS at a threshold of 1 had consistent specificity of ≥94% for both 24-day anoestrus and pregnancy failure, however its predictive value was lower in the age cohort with a higher prevalence of anoestrus. We conclude that RTS is a valid management tool for culling decisions intended to improve long-term reproductive success in a seasonal breeding system, by excluding heifers that are likely to fail to become pregnant or likely to calve late during their first calving season.

Long-term reproductive performance after surgery for ovarian endometrioma

ObjectiveTo determine the long-term impact of different types of endometrioma surgery on reproductive performance and on age of menopause. Study designThis was a longitudinal observational cohort study of 68 women with previous endometrioma surgery and 68 age- and weight-matched healthy controls. All participants’ hospital records were reviewed and each woman completed a questionnaire and attended an interview. Pregnancy rates were compared between the study and control groups. In the study group, pregnancy rates were compared before and after surgery. ResultsAmongst the 38 women desiring pregnancy after endometrioma surgery, 19 (50%) achieved a spontaneous pregnancy during the follow-up period. This was not significantly different from a pre-operative pregnancy rate of 48% (22/46). Of these 19 patients, four achieved another pregnancy with fertility treatment. An additional eight patients conceived only with the help of fertility treatment, giving an overall long-term post-operative pregnancy rate of 71% (27/38). These results were significantly lower (p=0.0001) than the 98% (57/58) long-term natural pregnancy rate in the control group. Pregnancy rates in patients receiving fertility treatment significantly (p=0.001) increased from 7% (1/15) before surgery to 63% (12/19) post-operatively. In post-menopausal women, the median (quartile) age at menopause was similar in the study (n=9) and control groups (n=6) [48 (45–52) versus 49 (44–52) years, respectively]. ConclusionEndometriomas per se appear to be the main cause of the reduced long-term reproductive performance of the affected patients, with little or no contribution from surgery. Furthermore, endometrioma surgery seems to improve the success rates of fertility treatment.

Developmental Exposure to a Toxic Spill Compromises Long-Term Reproductive Performance in a Wild, Long-Lived Bird: The White Stork (Ciconia ciconia)

Background/ObjectiveExposure to environmental contaminants may result in reduced reproductive success and long-lasting population declines in vertebrates. Emerging data from laboratory studies on model species suggest that certain life-stages, such as development, should be of special concern. However, detailed investigations of long-term consequences of developmental exposure to environmental chemicals on breeding performance are currently lacking in wild populations of long-lived vertebrates. Here, we studied how the developmental exposure to a mine spill (Aznalcóllar, SW Spain, April 1998) may affect fitness under natural conditions in a long-lived bird, the White Stork (Ciconia ciconia).MethodologyThe reproductive performance of individually-banded storks that were or not developmentally exposed to the spill (i.e. hatched before or after the spill) was compared when these individuals were simultaneously breeding during the seven years after the spill occurred (1999–2005).Principal FindingsFemale storks developmentally exposed to the spill experienced a premature breeding senescence compared with their non-developmentally exposed counterparts, doing so after departing from an unusually higher productivity in their early reproductive life (non-developmentally exposed females: 0.5±0.33SE fledglings/year at 3-yr old vs. 1.38±0.31SE at 6–7 yr old; developmentally exposed females: 1.5±0.30SE fledglings/year at 3-yr old vs. 0.86±0.25SE at 6–7 yr old).Conclusions/SignificanceFollowing life-history theory, we propose that costly sub-lethal effects reported in stork nestlings after low-level exposure to the spill-derived contaminants might play an important role in shaping this pattern of reproduction, with a clear potential impact on population dynamics. Overall, our study provides evidence that environmental disasters can have long-term, multigenerational consequences on wildlife, particularly when affecting developing individuals, and warns about the risk of widespread low-level contamination in realistic scenarios.

Breeding dispersal in an isolated population of Spotted Owls Strix occidentalis: evidence for improved reproductive output

Breeding dispersal among territorial species is of interest to population biologists because leaving a territory carries fundamental risks to the dispersing individuals, and this may not outweigh the costs of maintaining the territory. Most studies of breeding dispersal have focused on species inhabiting spatially open populations, in which undetected emigration could impart a negative bias to estimates of dispersal. We studied breeding dispersal in an isolated (spatially closed) population of California Spotted Owl Strix occidentalis occidentalis in southern California for 12 years to assess factors that might correlate with breeding dispersal. Twenty-nine per cent (n = 47) of territorial females and 19% (n = 35) of territorial males dispersed at least once during the study. Annually, 0– 13% of the territorial females and 0–12% of the territorial males dispersed. Among a set of a priori and post hoc models related to breeding dispersal, the top a priori model indicated that birds having higher reproductive output relative to the population average were less likely to disperse. A post hoc model based on an index of territory quality was ranked higher than the top a priori model and indicated that birds occupying higher quality territories were less likely to disperse. These two models were correlated and represented short- and long-term reproductive performance, respectively. Birds that dispersed also failed to fledge young in the year prior to dispersal, but the failure to fledge young did not, by itself, explain dispersal. Because Spotted Owls are long-lived, they may ultimately improve their reproduction by dispersing given that they would have future opportunities to breed over the long term. Birds whose mates are likely to have died tended to improve their reproductive success, whereas the relationship between reproductive success of birds that divorced was less clear. Substantial variation in breeding dispersal was unexplained by our analysis so it is likely that the motivation to disperse was a complex process in this population.

The effect of gilt age at first estrus and breeding on third estrus on sow body weight changes and long-term reproductive performance1

The objective of this trial was to determine the effect of age at first estrus on BW changes and long-term reproductive performance of sows. At approximately 100 d of age, prepubertal C22 gilts (n = 431) were allocated to trial. At a pen average of 140 d of age, gilts began daily direct contact with mature boars to stimulate onset of puberty. Gilts (n = 317, 73%) were recorded as cyclic by 180 d of age (select) and were classified on the basis of age at puberty into 3 puberty groups: 1) early puberty (EP; <153 d of age; n = 85); 2) intermediate puberty (IP; 154 to 167 d of age; n = 140); or 3) late puberty (LP; 168 to 180 d of age; n = 90). Gilts not exhibiting the standing reflex by 180 d of age were considered nonselect (NS; n = 91). Mean day to puberty and age at puberty attainment in each of the classifications were EP: 9.6 +/- 0.5 d and 147.4 +/- 0.5 d; IP: 19.3 +/- 0.5 d and 159.9 +/- 0.3 d; LP: 33.8 +/- 0.7 and 175.7 +/- 0.6 d, respectively. Fewer NS gilts (73.0%) were bred than were EP (97.7%), IP (93.2%), or LP (93.0%) gilts (P < 0.05). Total number of piglets born and born alive were not different between classifications and increased (P < 0.05) over successive parities in EP, IP, and NS gilts. For gilts initially served, there was no effect of puberty group classification on retention in the herd to farrow a third litter, but the rate of fallout per parity tended to be greatest for NS (17.2%) compared with EP (12.4%), IP (15.6%), and LP (14.2%) gilts (P < 0.08). Taken together, these data suggest that the response to a standardized protocol of boar stimulation can identify 50 to 75% of gilts that will have greatest lifetime productivity in the breeding herd. In the known cyclic (select) gilts, BW increased over the productive life of the sow, and EP gilts were lighter than LP gilts at every measured event (P < 0.05). Plasma IGF-1 only differed between puberty groups at d 100 of age (EP: 169.0 +/- 4.4; IP: 157.2 +/- 3.5; LP: 144.0 +/- 4.4 ng/mL), suggesting a mechanism linking IGF-1 status and age at puberty in the present study.

Reproductive Performance after Ectopic Pregnancy

Reproductive performance may be an important variable in treatment selection for unruptured ectopic pregnancy. The impact of treatment choice on reproductive performance is not known. We searched the literature and then tabulated published case reports on laparoscopic salpingostomy, multiple-dose methotrexate, single-dose methotrexate, and expectant management. From this analysis, we are unable to conclude any clinically detectable differences in the efficacy of these four most common treatments for unruptured ectopic pregnancy. Even more recent reports using life tables are inconclusive because the studies are not randomized. We conclude that concern for long-term reproductive performance should not be a factor in selecting between any of these four commonly used treatments for unruptured ectopic pregnancy.

Surgical treatment in polycystic ovary syndrome

The purpose of this review is to provide a critical summary of current knowledge on the role and effectiveness of ovarian surgery in the treatment of polycystic ovary syndrome. Clomiphene citrate is used as a first-line treatment for ovulation induction in infertile anovulatory patients with polycystic ovary syndrome. In clomiphene citrate-resistant women, other treatment modalities such as laparoscopic electrocautery or ovulation induction with gonadotropins have been proposed as alternative therapies. Although gonadotropin treatment and laparoscopic ovarian drilling have demonstrated similar reproductive outcomes, laparoscopic ovarian drilling has some advantages over gonadotropin treatment such as lower cost per pregnancy, improvement in menstrual regularity, and better long-term reproductive performance. On the other hand, knowledge about the pathogenesis of polycystic ovary syndrome has been growing and insulin-sensitizing drugs have gained popularity as a new treatment option. According to current data, metformin has gained popularity as first-line management in clomiphene citrate-resistant women with polycystic ovary syndrome. If ovulation does not occur within several months after treatment with metformin, after the evaluation of all pros and cons related to each treatment, laparoscopic ovarian drilling or gonadotropins may be considered as an effective option according to patient choice.

Habitat quality as a predictor of spatial variation in blue tit reproductive performance: a multi-plot analysis in a heterogeneous landscape

Vertebrate studies have rarely investigated the influence of spatial variation in habitat richness on both short-term (breeding) and long-term (offspring recruitment) reproductive performance using simultaneously multi-patch, multi-habitat type and multi-year approaches at landscape level. Here we present results of such an approach using the influence of two oak tree (Quercus ilex, Q. humilis) species on reproductive performance in Corsican blue tits (Parus caeruleus ogliastrae) as a model system. We found that blue tits breeding in rich broad-leaved deciduous patches consistently laid eggs earlier in the season, and produced larger clutches and more fledglings of higher quality, than those breeding in poor evergreen patches. Also, parents, especially males, were in better physical condition in the broad-leaved deciduous than in the evergreen patches. Surprisingly, estimates of long-term effects of reproduction, such as recruitment rates of locally born offspring, did not differ between the two habitat types. Our results suggest that short-term breeding performance and phenotypic quality of both chicks and parents do not necessarily provide reliable information about contributions to following generations at a scale larger than that of the local study plot. Differences in reproductive performance between the two oak habitat types could not be attributed to density-dependent effects, differences in levels of nest predation, or differences in age structure of the birds. We suggest that habitats that are optimal for breeding are not necessarily optimal for survival after the breeding season.