The Recipients' Parity Does Not Influence Their Reproductive Performance Following Non‐Surgical Deep Uterine Porcine Embryo Transfer

With the development of the non‐surgical deep uterine (NsDU) embryo transfer (ET) technology, the commercial applicability of ET in pigs is now possible. There are, nevertheless, many factors that influence NsDU‐ET effectiveness that need to be addressed. The aim of this study was to evaluate the effects of the weaned recipients' parity on fertility and prolificacy following NsDU‐ET. The recipients (n = 120) were selected based on their reproductive history and body condition and grouped into three categories according to their parity: primiparous sows, sows of parity 2 and sows of parities from 3 to 5. Thirty fresh embryos (morulae and unhatched blastocysts) were non‐surgically transferred into one uterine horn of each recipient. It was possible to insert the NsDU‐ET catheter through the cervix along a uterine horn in 98.3% of the recipients. The parity had no influence on the difficulty grade of the insertions or on the percentage of correct insertions. The cervix and uterine wall were not perforated during the insertions, and vaginal discharge was not observed after transfer in any of the recipients. There were no differences in the pregnancy rates (74.8%), farrowing rates (71.2%) or litter sizes (9.6 ± 3.3) between groups. Also, there were no differences between groups regarding to the piglets' birthweights or piglet production efficiency. In conclusion, these results demonstrate that weaned sows from parity 1 to 5 are appropriate to be used as recipients in NsDU‐ET programs, which increase the possibilities for the utilization of ET in the recipient farms.     

Effects of IGF‐1 on In Vitro Culture of Bovine Preantral Follicles are Dose‐Dependent

This study aimed at assessing the effect of different concentrations of the growth factor similar to insulin 1 (IGF‐1) in the development, survival and ultrastructure of the bovine preantral follicles cultured in situ. Fragments of bovine ovarian cortical tissue were cultured during 1 and 7 days in 1 ml of α‐MEM⁺, supplemented with different concentrations of human recombinant IGF‐1 (0, 30, 70 and 100 ng/ml), in an incubator at 37°C and 5% of CO₂ in 24‐well plates with total replacement of the medium every 2 days. Non‐cultured ovarian fragments (control) and ovarian fragments cultured during 1 and 7 days were processed for classic histology, mechanical isolation and electron transmission microscopy (ETM). Parameters such as normality, viability, activation, development, diameter and ultrastructure were evaluated. All statistical analyses were carried out using sas Version 9.2. The results showed that the percentage of follicles morphologically normal in the IGF‐1 30 ng/ml treatment was similar to the fresh control (p > 0.05) both on the day 1 and on the day 7 of in vitro culture. In the viability analysis, the cultured treatments maintained the percentage of viable follicles during the entire culture period (p > 0.05). After 7 days of culture, the IGF‐1 30 ng/ml treatment showed higher percentages of developing follicles (48.33%) than those of the fresh control (22.22%) and the cultured treatments (p < 0.05). Also, after 7 days of culture, IGF‐1 30 ng/ml presented a higher follicular diameter when compared to the control and other concentrations of IGF‐1 tested. Ultrastructurally, the non‐cultured control and IGF‐1 30 ng/ml, after 7 days of culture, showed conserved oocytes, nuclei and organelles. Hence, it is concluded that IGF‐1 30 ng/ml was the most efficient concentration for the development of bovine preantral follicles cultured in vitro.     

Reproductive Performance of Ewes after 5-Day Treatment with Intravaginal Inserts Containing Progesterone in Combination with Injection of Prostaglandin F2α

Three experiments were conducted with a total of 1579 ewes to examine reproductive performance in response to synchronization of oestrus during the breeding season, using controlled internal drug releasing (CIDR-G) inserts in regimens designed to provide high concentrations of circulating progesterone. In experiment 1, treatment with two CIDR-G inserts for 12 days produced conception rate (79%) and prolificacy (1.9) to first service equivalent to breeding at natural oestrus (56% and 2.0, respectively). Pregnancy rates to two service periods were 90 and 79%, respectively. In experiments 2 and 3, progesterone was delivered by a single CIDR-G insert for 5 days in combination with prostaglandin F2alpha (PGF2alpha; 5 mg i.m., twice, 3 h apart) the day before (experiment 2), or at insert removal (experiment 3). The combined treatments improved rates of synchronization of oestrus (p<0.01) by 23 and 20% points, respectively, and pregnancy rates to the first service period by 19 (p<0.05) and 13 (p<0.01) percentage points, respectively, compared to treatment with PGF2alpha alone. It is concluded that the combination of treatment for 5 days with a CIDR-G insert and two injections of 5 mg PGF2alpha, the day before, or the day of insert removal, were effective treatments to obtain high fertility at synchronized oestrus in ewes during the breeding season.     

Daylight effect on melatonin secretion in adult female guanacos (Lama guanicoe)

The wild South American camelids developed a strategy of seasonal reproduction during spring and summer with singleton birth. The photoperiod is one of the factors that may modulate this seasonality where light would be translated into a hormonal signal. This study evaluated the influence of changes in daily light intensity on melatonin concentration in captive guanacos under a long‐day photoperiod (16 hr light/8 hr dark; 33 ‘28′S). Mean melatonin concentration was 28.3 ± 20.3 pg/ml, with a maximum of 52.14 ± 17.19 pg/ml at 23:30 and minimum of 14.29 ± 6.64 pg/ml at 08:30 (p < .001). There was a negative association between light intensity and melatonin concentration (r = ?0.57; p < .001). The results indicate that guanacos respond to variation in daily environmental light with a hormonal response and point to a circannual rhythm as a function of the photoperiod.     

Footwall refrigeration along a detachment fault: implications for the thermal evolution of core complexes

Oxygen isotope compositions of epidote and quartz from chloritic breccias that underlie the detachment fault in the metamorphic core complex of the Whipple Mountains yielded quartz-epidote fractionations that range from 4.1 to 6.4 per mil and increase systematically toward the fault. These fractionations give mean temperatures that decrease from approximately 432 degrees C at 50 meters below the fault to approximately 350 degrees C at 12 meters below the fault. This extreme thermal gradient of 82 degrees C over 38 meters (2160 degrees C per kilometer) is best explained by advective heat extraction by means of circulating surface-derived fluids. Models of lithospheric extension consider only conductive cooling resulting from tectonic denudation and thus require revision to include fluid-induced fault-zone refrigeration.     

First evidence of Kunjin strain of West Nile virus associated with saltwater crocodile (Crocodylus porosus) skin lesions

Recently, the Kunjin strain of West Nile virus (WNV_KUN) has been detected using qRT‐PCR in belly skin lesions of farmed juvenile saltwater crocodiles. This follows an established association between similar lesions and West Nile virus in American alligators. The lesions present as cutaneous lymphohistiocytic aggregates in the dermal layers of both species. While these lesion do not create an obvious defect on the live crocodile, upon tanning the lesion area collapses and does not uptake the dye evenly, thus reducing its aesthetic appeal. As a result, skins are being rejected jeopardising the economic viability of the Australian crocodile industry. Over 50 skin lesions have since been confirmed as WNV_KUN‐positive and preliminary evidence of lesion restructuring is presented. Horizontal transmission of WNV_KUN by mosquitoes is well‐established but other transmission routes, such as ingestion and cloacal shedding, need further evaluation. An infection trial is currently underway to ensure WNV_KUN is the causative agent of these skin lesions.     

Monitoring changes in back fat thickness and its effect on the restoration of ovarian activity and fertility in Bos indicus cows

With the objective of testing the hypothesis if animals with a stable layer of body fat (FAT) during the peripartum have a better chance of becoming pregnant after calving, fifty‐nine multiparous Brahman cows in their last trimester of pregnancy were used. Animals averaged four parturitions and were stocked at a rate of 1.25 animal units per hectare and divided into two groups depending on the time postpartum (dpp) that the intravaginal releasing device CIDR was inserted; Group 1 (<30 dpp; n = 30) received the implant at 25.2 ± 4.21 and withdrawn 9 days later. Group 2 (≥30 dpp; n = 29) received the CIDR at 38.41 ± 5.8. Animals were AI at detected oestrus until 170 dpp and calculated as pregnant at first service or requiring more than one service (1s and >1s), not pregnant but cycling (not pregnant) and those not cycling at all (anestrus). The FAT measurements were taken twice each month from the last trimester of gestation until 96 dpp. The onset of ovarian activity was monitored through blood levels of progesterone (P4) at days 14 and 9 prior to CIDR insertion and days 10, 13, 30 and 33 after CIDR withdrawal. Animals pregnant did not have any major changes in their fat thickness. In contrast, cows pregnant in the group ≥30 dpp had changes in their FAT homoeostasis, and pregnant animals in the 1s and >1s groups did not show differences in dorsal back fat in the last trimester of pregnancy and early postpartum. In contrast, animals not pregnant and in anestrus FAT values decreased considerably after parturition. Overall, fertility was 49%, but 18% of all the animals remained anestrus losing FAT. Thus, animals with adequate metabolic conditions will have a better chance of pregnancy regardless of the time postpartum when the reproductive programme starts.     

Uterine serpin (SERPINA 14) correlates negatively with cytokine production at the foetal–maternal interface but not in the corpus luteum in pregnant dairy heifers experimentally infected with Neospora caninum

This study examines gene expression patterns in dairy heifers experimentally infected with N. caninum during on Day 110 of pregnancy with live foetuses at euthanasia, 42 days later. The study population was constituted of four non‐infected controls and three infected dams. Gene expression was determined on gamma interferon (IFNγ), (Th1 pro‐inflammatory cytokine), interleukin‐4 (IL4) (Th2 pro‐gestation cytokine) or interleukin‐10 (IL10) (T regulatory cytokine) and the serine peptidase inhibitor SERPINA14 in intercaruncular, placental, uterine lymph node (UTLN) and luteal tissue samples. Intercaruncular SERPINA14 expression was negatively correlated with IFNγ expression in cotyledon samples and with IL4 expression in UTLN. No relationships were detected between cytokine gene expression at the foetal–maternal interface and SERPINA14 expression in the luteal samples. Our findings suggest that gene expression of the uterine serpin SERPINA14 correlates negatively with the expression of Th1 and Th2 cytokines at the foetal–maternal interface but not in the corpus luteum.