Breeding and reproductive behaviour of the neo-tropical opossum, Didelphis marsupialis insularis, Allen 1902 under captive conditions

Developing a captive breeding system for the widely hunted Caribbean species of opossum Didelphis marsupialis insularis can greatly aide in the management and conservation of this species in the neo-tropics. Although this species possesses ideal traits for captive breeding in this region (tolerance to high heat and humidity, high reproductive rate, and resistance to disease), challenges due to its aggressive behaviour and limited information on its breeding behaviour have prevented a system from being developed for this species. The present study describes a breeding system, and the reproductive behaviour of this species under captive conditions. Six (1 male; 5 females) adult opossums were maintained and managed for breeding over a ten (10) month period. Pouch litter sizes averaged 5±2.5 with a range of 2 to 8. Gestation length was found to be 13.25±0.96 days and 4 litters (n=23) were successfully weaned at 11-13 weeks. It was found that the male D. m. insularis exhibits behaviours of interest that can serve as indicators for receptivity of the female, and overall, that this species can be successfully reared and bred under captive conditions in the neo-tropics.

Effects of Litter Size and Parity on Farrowing Duration of Landrace × Yorkshire Sows

Litter size has increased and farrowing duration has also prolonged in recent years. The aim of this study was to analyze the effect of litter size and parity on farrowing duration (FAR) to estimate the possibility of selecting a short farrowing duration. We recorded 32,200 parturitions of 8420 Landrace × Yorkshire sows, determined farrowing duration, litter size, parity, gestation length. Results showed that total number of born (TNB) and parity obeyed a cubic (p = 0.0004, p = 0.004) relationship while number born alive (NBA) and number born dead (NBD) obeyed a linear (p = 0.0239, p = 0.0035) relationship with FAR. Gestation length obeyed a linear (p = 0.02) relationship with FAR. FAR of sows with stillbirth was longer than that of sows without stillbirth. Stillbirth rate increased rapidly from about 2% to 4%, especially when FAR was over 240 min. FAR gradually prolonged with the parities. FAR of 7th parity sows was longer than that of 1st~6th parity sows (p < 0.05), but different parity sows had little difference in the same FAR interval except for gilts. Results indicated it was possible and necessary to consider FAR into pig breeding without worrying about decreasing of live litter size or negative effect of parity if FAR was shorter than 300 min.

Factors affecting gestation length in small sized breeds of dogs.

A large variation in the gestation length can be expected when the gestation is calculated from the day of mating to birth. The present study was designed to assess the influence of different factors like litter size, breed, parity and age on gestation length in bitches. A total of 89 small sized bitches of different breeds having different age, parity and body weight, were selected for the study. The mean age, body weight and parity of the animals included in the present study were 3.00 ± 0.15 years (1 to 8 years), 9.9 ± 0.25 Kg (6 to 15kg) and 1.14 ± 0.10 (0-4th parity) respectively. The mean gestation lengths observed in different small sized breeds were 60.68 ± 0.55, 59.82 ± 0.54, 60.78 ± 1.74, 58.83 ± 1.35 and 58.17 ± 0.74 in the Pug, Beagle, Dachshund, French Bulldog and the Spitz, respectively. The mean litter size in the study was 4.34 ± 0.13 with a range of 2-8. The mean gestational length in animals having ? 3 litter size was 60.83 ± 0.64 days and 59.90 ± 0.43 days in animals having >3 litter size. Age limit of the animals ranged from 1 to 8 years with a mean of 3 ± 0.15 years. The mean gestation length in bitches aged ?3 years was 60.21 ± 0.23 days (n=63) and this was 60.15 ± 0.3 (n=26) days in bitches in the >3 years group. Mean gestational length observed in nulliparous bitches was 60.86 ± 0.4 days (n=29), while in multiparous bitches it was 59.90 ± 0.5 days (n=60). From the present investigation it could be concluded that no significant difference exists in gestational length between different breeds, litter size, age group and parity.

Mutant alleles differentially shape fitness and other complex traits in cattle

Mutant alleles (MAs) that have been classically recognised have large effects on phenotype and tend to be deleterious to traits and fitness. Is this the case for mutations with small effects? We infer MAs for 8 million sequence variants in 113k cattle and quantify the effects of MA on 37 complex traits. Heterozygosity for variants at genomic sites conserved across 100 vertebrate species increase fertility, stature, and milk production, positively associating these traits with fitness. MAs decrease stature and fat and protein concentration in milk, but increase gestation length and somatic cell count in milk (the latter indicative of mastitis). However, the frequency of MAs decreasing stature and fat and protein concentration, increasing gestation length and somatic cell count were lower than the frequency of MAs with the opposite effect. These results suggest bias in the mutations direction of effect (e.g. towards reduced protein in milk), but selection operating to reduce the frequency of these MAs. Taken together, our results imply two classes of genomic sites subject to long-term selection: sites conserved across vertebrates show hybrid vigour while sites subject to less long-term selection show a bias in mutation towards undesirable alleles.

Perinatal complications and maximising lamb survival in an adolescent paradigm characterised by premature delivery and low birthweight

The competition for nutrients in overnourished and still-growing adolescent sheep negatively impacts gestation length, colostrum supply and lamb birthweight, all of which may affect neonatal morbidity and survival to weaning. Herein perinatal complications and the requirement for supplementary feeding were analysed in relation to gestational-intake, and the degree of premature delivery and prenatal growth-restriction exhibited. Pregnancies were established by embryo transfer and the mean/standard deviation (SD) gestation length and birthweight of the optimally-fed control group (n = 100) was used to define early delivery and reduced birthweight categories (1.5 and 3.0 SDs below the control mean for each aspect). Control lambs were largely delivered at term (94%), and had a normal birthweight (92%), while very preterm (≤139days, 18.5%) and preterm delivery (140-142days, 54.8%), extremely low birthweight (ELBW; females ≤2838g and males ≤3216g, 21.1%) and low birthweight (LBW; females 2839 to ≤4001g and males 3217 to ≤4372g, 32.2%), were common in the overnourished group (n = 270, P<0.001). Accordingly, overnourished dams were more likely to lamb without assistance while the incidence of major dystocia was greater in controls. Initial lamb vigour at birth was independent of gestational-intake, delivery or birthweight category but both ELBW and very premature lambs required more assistance with feeding in the first 24h postnatal, primarily reflecting low colostrum availability. Indeed, relative to normal, ELBW lambs had a greater risk of experiencing mismothering, and enhanced likelihood of requiring supplementary feeding throughout the neonatal period (P<0.001). ELBW lambs also had a greater possibility of respiratory issues at birth (P<0.01) and renal complications (P<0.001), while very preterm delivery was associated with an increased risk of gastrointestinal tract problems (P<0.01). In spite of these complications, all-cause mortality was low (5.4%) suggesting that our proactive neonatal care regime can overcome many of the issues associated with extreme prematurity and low birthweight.

Metabolomic fingerprinting of pig seminal plasma identifies in vivo fertility biomarkers

Background Metabolomic approaches, which include the study of low molecular weight molecules, are an emerging -omics technology useful for identification of biomarkers. In this field, nuclear magnetic resonance (NMR) spectroscopy has already been used to uncover (in) fertility biomarkers in the seminal plasma (SP) of several mammalian species. However, NMR studies profiling the porcine SP metabolome to uncover in vivo fertility biomarkers are yet to be carried out. Thus, this study aimed to evaluate the putative relationship between SP-metabolites and in vivo fertility outcomes. To this end, 24 entire ejaculates (three ejaculates per boar) were collected from artificial insemination (AI)-boars throughout a year (one ejaculate every 4 months). Immediately after collection, ejaculates were centrifuged to obtain SP-samples, which were stored for subsequent metabolomic analysis by NMR spectroscopy. Fertility outcomes from 1525 inseminations were recorded over a year, including farrowing rate, litter size, stillbirths per litter and the duration of pregnancy. Results A total of 24 metabolites were identified and quantified in all SP-samples. Receiver operating characteristic (ROC) curve analysis showed that lactate levels in SP had discriminative capacity for farrowing rate (area under the curve [AUC] = 0.764) while carnitine (AUC = 0.847), hypotaurine (AUC = 0.819), sn-glycero-3-phosphocholine (AUC = 0.833), glutamate (AUC = 0.799) and glucose (AUC = 0.750) showed it for litter size. Similarly, citrate (AUC = 0.743), creatine (AUC = 0.812), phenylalanine (AUC = 0.750), tyrosine (AUC = 0.753) and malonate (AUC = 0.868) levels had discriminative capacity for stillbirths per litter; and malonate (AUC = 0.767) and fumarate (AUC = 0.868) levels for gestation length. Conclusions The assessment of selected SP-metabolites in ejaculates through NMR spectroscopy could be considered as a promising non-invasive tool to predict in vivo fertility outcomes in pigs. Moreover, supplementing AI-doses with specific metabolites should also be envisaged as a way to improve their fertility potential.

Social Organisation, Ecology and Reproduction in the Sanje Mangabey (Cercocebus Sanjei) in the Udzungwa Mountains National Park, Tanzania

<p>Understanding of the biology of threatened species is central to effective planning for sustainable management of wildlife. The Sanje mangabey, Cercocebus sanjei of Udzungwa Mountains National Park in Tanzania is under pressure from increasinghuman hunting, and habitat loss threatens its long-term survival. This thesis endeavoured to document the socio-biological and ecological aspects of this little-known species in a small habituated group of 62 individuals within the Mwanihana forest in Udzungwa Mountains National Park. I studied the social organisation, size and age-sex composition of one group by following and monitoring of the Sanje mangabeys over a six-month period. I also investigated the spatial-temporal interactions and associations between age and sex classes within a group. I assessed the Sanje mangabey's ranging and movementpatterns and monitored its reproductive behaviour by examining female sexual skin swellings and relationships between sexual swellings and sexual behaviour. Further, I investigated the species feeding habits and influences of seasonal parameters (rainfall and temperature) upon reproduction, feeding ecology and behaviour of this species. The Sanje mangabey social organisation is structured in a hierarchy characterised by dominance according to the sex and age of individuals. The study group was composed of individuals of all sexes and age classes; newborn babies, juveniles, sub adults and adults, males and females. Adult males were generally dominant overfemales and males of lower age. Males showed more agonistic behaviours to juveniles than did females and there were stable linear dominance hierarchies among individuals across the sexes (Landau's dominance index, h' =0.92, p =0.0281) and a high directional consistency index, DC =0.91) for both sexes. The linearity indices 'h' were 0.84, P= 0.041, DC = 0.94 and 0.93, P = 0.0382, DC = 0.94) for males and females, respectively. Individuals spent about 8% on average of day grooming each other and the rate of grooming differed across and within sexes and age classes. There was a significant relationship between duration of the initiator's first grooming episode and subsequent reciprocation by the receiver in all age classes (P < 0.05). The independent effects of total grooming duration of the initiator also showed a significant difference and predicted total grooming duration of the recipient (P =0.0001). However, there was no evidence for grooming to be directed towards higher ranking Sanje mangabeys. The Sanje mangabey's home range was 301 hectares and exhibited a mean daily range of 1760 metres within the Mwanihana forest. The rangeand movement patterns of this species differed significantly between seasons of the year. During the dry season (no rain) the group covered larger distances (P = 0.001) between forest patches and moved significantly faster (P = 0.001) than during wet (rain) season. The Sanje mangabey is omnivorous, feeding on plant material, invertebrates and vertebrates such as lizards. There were marked influences of temperature and rainfall on the feeding patterns. Mangabeys utilised the arboreal layer (>16m high) during cool and wet periods and were observed feeding mostly on the ground resources during hot and dry periods. The reproductive potential and social behaviour of theSanje mangabey, however, did not vary with the different seasons of the year. Sanje mangabeys have a mean swelling cycle length of 32.1 +/- 2.4 days. Individual females showed differences in swelling duration (F =12.43, P = 0.043) and noevidence of group variation in cycle length (H= 30.2, DF = 6, P < 0.05) was seen. Maximum swelling lasted for 4.4 +/- 0.9 days on average and detumescence was 14.7 +/- 3.9 days. The mean menses length was 3 +/- 0.2 days (n = 3). Most cycling females, showed days with regular swellings of both sizes. The gestation length averaged 173days and the interval between birth and resumption of the swelling cycle was observed to be 184 days. The sexual skin swellings appear to be sexually attractive signals of female reproductive condition. Although mating occurred in all stages of the female cycle, a peak was observed during maximum swelling size and breakdown. These findings illustrate the utility of sex swellings as signals used by males to determine reproductive condition.</p>

Social Organisation, Ecology and Reproduction in the Sanje Mangabey (Cercocebus Sanjei) in the Udzungwa Mountains National Park, Tanzania

<p>Understanding of the biology of threatened species is central to effective planning for sustainable management of wildlife. The Sanje mangabey, Cercocebus sanjei of Udzungwa Mountains National Park in Tanzania is under pressure from increasinghuman hunting, and habitat loss threatens its long-term survival. This thesis endeavoured to document the socio-biological and ecological aspects of this little-known species in a small habituated group of 62 individuals within the Mwanihana forest in Udzungwa Mountains National Park. I studied the social organisation, size and age-sex composition of one group by following and monitoring of the Sanje mangabeys over a six-month period. I also investigated the spatial-temporal interactions and associations between age and sex classes within a group. I assessed the Sanje mangabey's ranging and movementpatterns and monitored its reproductive behaviour by examining female sexual skin swellings and relationships between sexual swellings and sexual behaviour. Further, I investigated the species feeding habits and influences of seasonal parameters (rainfall and temperature) upon reproduction, feeding ecology and behaviour of this species. The Sanje mangabey social organisation is structured in a hierarchy characterised by dominance according to the sex and age of individuals. The study group was composed of individuals of all sexes and age classes; newborn babies, juveniles, sub adults and adults, males and females. Adult males were generally dominant overfemales and males of lower age. Males showed more agonistic behaviours to juveniles than did females and there were stable linear dominance hierarchies among individuals across the sexes (Landau's dominance index, h' =0.92, p =0.0281) and a high directional consistency index, DC =0.91) for both sexes. The linearity indices 'h' were 0.84, P= 0.041, DC = 0.94 and 0.93, P = 0.0382, DC = 0.94) for males and females, respectively. Individuals spent about 8% on average of day grooming each other and the rate of grooming differed across and within sexes and age classes. There was a significant relationship between duration of the initiator's first grooming episode and subsequent reciprocation by the receiver in all age classes (P < 0.05). The independent effects of total grooming duration of the initiator also showed a significant difference and predicted total grooming duration of the recipient (P =0.0001). However, there was no evidence for grooming to be directed towards higher ranking Sanje mangabeys. The Sanje mangabey's home range was 301 hectares and exhibited a mean daily range of 1760 metres within the Mwanihana forest. The rangeand movement patterns of this species differed significantly between seasons of the year. During the dry season (no rain) the group covered larger distances (P = 0.001) between forest patches and moved significantly faster (P = 0.001) than during wet (rain) season. The Sanje mangabey is omnivorous, feeding on plant material, invertebrates and vertebrates such as lizards. There were marked influences of temperature and rainfall on the feeding patterns. Mangabeys utilised the arboreal layer (>16m high) during cool and wet periods and were observed feeding mostly on the ground resources during hot and dry periods. The reproductive potential and social behaviour of theSanje mangabey, however, did not vary with the different seasons of the year. Sanje mangabeys have a mean swelling cycle length of 32.1 +/- 2.4 days. Individual females showed differences in swelling duration (F =12.43, P = 0.043) and noevidence of group variation in cycle length (H= 30.2, DF = 6, P < 0.05) was seen. Maximum swelling lasted for 4.4 +/- 0.9 days on average and detumescence was 14.7 +/- 3.9 days. The mean menses length was 3 +/- 0.2 days (n = 3). Most cycling females, showed days with regular swellings of both sizes. The gestation length averaged 173days and the interval between birth and resumption of the swelling cycle was observed to be 184 days. The sexual skin swellings appear to be sexually attractive signals of female reproductive condition. Although mating occurred in all stages of the female cycle, a peak was observed during maximum swelling size and breakdown. These findings illustrate the utility of sex swellings as signals used by males to determine reproductive condition.</p>

Service Sire Effects on Body Condition Score, Milk Production, and Rebreeding of Mixed-Aged Dairy Cows Bred to Angus and Hereford Bulls—A Case Study in New Zealand

Beef-breed bulls are used in dairy herds to produce a calf of greater value for finishing than calves sired by dairy bulls. There is limited research about which beef-breed bulls are most appropriate, and whether any negative impact on cow performance in terms of milk production and rebreeding should be considered. The aim of this case study was to compare the body condition score, milk production, and rebreeding performance of mixed-aged dairy cows bred to a selection of Angus and Hereford beef-breed bulls. Body condition score, post-calving live weight, milk production, rebreeding performance, and survival of 952 mixed-aged dairy cows artificially bred to 65 Angus and Hereford bulls were compared. There was no effect of service sire on post-calving live weight, days in milk, milk production, or inter-calving intervals of mixed-aged cows. Service sire had an effect on the calving day due to differences in gestation length (p < 0.001), although this did not translate into an effect on days in milk. A longer gestation length negatively influenced pregnancy rates, and greater birth weight of the calf negatively influenced survival to rebreeding (p < 0.05), indicating the potential for an effect of service sire. Selection of beef-breed service sires for dairy cows should include emphasis on lighter calves and shorter gestation lengths. The general absence of the service sire effect on the parameters measured in this study indicated that any of the service sires used in this experiment would be appropriate for use over dairy cows.

A trans-national examination of the impact of the COVID-19 pandemic on abortion requests through a telemedicine service

BackgroundThe COVID-19 pandemic is limiting access to reproductive healthcare worldwide. Substantial research gaps remain regarding the impact of the pandemic on access to abortion care.MethodsWe performed a cohort analysis of abortion requests made through the telemedicine abortion service Women on Web (WoW) between 18 March 2020 and 4 May 2020. We used binary logistic regression analyses to test the association between COVID-19 as a reason for the help request and reporting having had an ultrasound to determine gestation and/or use of contraception. A subanalysis of Italy, Argentina, Malaysia and the United Arab Emirates (UAE) was executed to explore differences between countries.ResultsOf requests made during the study period, 43.5% (n=1972) were COVID-19-related. A negative association was found with having had an ultrasound to determine gestation length and COVID-19-related requests. Italy had the highest percentage (66.5%, n=117) of COVID-19-related requests in the subanalysis, followed by Argentina (55.3%, n=68), Malaysia (51.9%, n=41) and the UAE (44.4%, n=75).ConclusionsAlmost half the women and pregnant people having an abortion through WoW reported experiencing obstacles to abortion care because of COVID-19. Abortion guidelines should be updated to permit abortion services via telemedicine. This is especially urgent during the ongoing pandemic.