Uterine Horn Length Research Articles

TO THE QUESTION OF THE TECHNIQUE OF ENDOMETRIAL BIOPSY IN COWS

The article presents the results of studies of morphometric parameters of the reproductive system in cows. It was found that the diameter of the left horn in the bifurcation area significantly exceeds the diameter of the right horn of the uterus. The length of the uterus sections is 28.53% (left) and 29.68% (right) in relation to the total length of the egg ducts. The length of the uterine horns is 34% (left) and 32.52% (right), the body of the uterus is 6.53%, the neck is 2.31%, the vagina is 28.63% - 28.8%. The length of the left ovipositor in cows is less than the right ovipositor by 9.69%, and the length of the left uterine horn exceeded the indicator in the right by 9.53%. The diameter of the left egg duct is expanded in the caudal direction. The right ovipositor is narrowed in the medial area, and has no significant differences in width in the cranial and caudal parts. In the caudal direction, the diameter of the uterine horns increases. At the same time, the width of the left uterine horn is greater than the width of the right one in the middle by 7.33%, and in the caudal by 4.43%. The body and cervix are rectangular in shape. The widest part of the vagina is cranial. The vagina narrows in the caudal direction. The thickness of the wall of the horns and the body of the uterus is uneven. Areas with a thinner wall predominate. The mucous, submucosal and muscular layers of the left uterine horn are inferior by 21.97%, 33.3% and 20.79% to the corresponding indicators in the right uterine horn.

Biometrical and histological study of reproductive organs of indigenous cattle in Bangladesh

Reproductive anatomy is vital for successful reproductive management and has significance for application of assisted reproductive biotechnology. This study was carried out to characterize biometrically and histologically reproductive organs of 50 slaughtered female cattle (<3 years; n=25, 3 to ≤5 years; n=25). The measurements (length, weight and width) of the right segment of the studied reproductive organs were greater compared to the left segment. No significant difference (p>0.05) was observed between left and right ovary length, width and weight within and between age groups. The length of ovaries were 1.92±0.19 cm and 1.95±0.04 cm at <3 years; 2.16±0.21 cm and 2.17±0.19 cm at 3 to ≤5 years; width were 1.09±0.14 cm and 1.17±0.10 cm at <3 years and 1.31±0.10 cm and 1.46±0.11 cm at 3 to ≤5 years and the weight were 1.77±0.41 gm and 2.20±0.57 gm at <3 years; 1.79±0.45 gm and 2.54±0.14 gm at 3 to ≤5 years in the left and right ovaries, respectively. Oviduct length, width and weight did not differ significantly (p>0.05) between the left and right oviducts within and between the age groups. Oviduct length (16.36±0.78 and 17.58±0.97 cm), width (0.21±0.02 and 0.26±0.33 cm) and weight (0.72±0.03 and 0.81±0.11 gm) was found for the right oviduct at <3 years and 3 to ≤5 years and for left oviduct length, width and weight were 16.20±0.65 and 16.64±0.86 cm; 0.19±0.02 and 0.23±0.03 cm; and 0.69±0.04 and 0.79±0.13 gm, at <3 years and 3 to ≤5 years, respectively. However, uterine horn length differed significantly (p<0.05) between age groups in the left (16.18±1.18 vs 27.45±2.98 cm) and the right horn of the uterus (17.45±1.40 cm vs 28.35±2.88 cm). On the other hand, uterine horn width and weight were not differed significantly between the left and right segments within and between the age groups. Uterus body length and weight were significantly (p<0.05) higher at 3 to ≤5 years compared to <3 years old cow. The average weight, length and width of uterine body were 44.40±7.33 gm vs 21.49±5.91 gm; 7.89±0.61 cm vs 5.87±0.43 cm; 3.46±0.27 cm vs 2.76±0.34 cm at <3 years and 3 to ≤5 years, respectively The whole uterus weight was also differed significantly (p<0.05) at <3 years (47.18±14.92 gm) and 3 to ≤5 years (86.07±11.98 gm). Histological studies showed ideal characteristics of cattle oviduct and uterus. In nutshell, the right ovary was larger in length, wider in diameter, and heavier in weight as compared to left one in indigenous cattle of Bangladesh. Bangladesh Journal of Animal Science 51 (4): 169-177

Anatomical distribution of CGRP-containing lumbosacral spinal afferent neurons in the mouse uterine horn.

Sensory stimuli from the uterus are detected by spinal afferent neurons whose cell bodies arise from thoracolumbar and lumbosacral dorsal root ganglia (DRG). Using an in vivo survival surgical technique developed in our laboratory to remove select DRG from live mice, we recently quantified the topographical distribution of thoracolumbar spinal afferents innervating the mouse uterine horn, revealed by loss of immunoreactivity to calcitonin gene-related peptide (CGRP). Here, we used the same technique to investigate the distribution of lumbosacral uterine spinal afferents, in which L5-S1 DRG were unilaterally removed from adult female C57BL/6J mice (N = 6). Following 10–12 days recovery, CGRP immunoreactivity was quantified along the length of uterine horns using fluorescence immunohistochemistry. Relative to myometrial thickness, overall CGRP density in uterine tissues ipsilateral to L5-S1 DRG removal was reduced compared to the DRG-intact, contralateral side (P = 0.0265). Regionally, however, myometrial CGRP density was unchanged in the cranial, mid, and caudal portions. Similarly, CGRP-expressing nerve fiber counts, network lengths, junctions, and the proportion of area occupied by CGRP immunoreactivity were unaffected by DRG removal (P ≥ 0.2438). Retrograde neuronal tracing from the caudal uterine horn revealed fewer spinal afferents here arise from lumbosacral than thoracolumbar DRG (P = 0.0442) (N = 4). These data indicate that, unlike thoracolumbar DRG, lumbosacral spinal afferent nerves supply relatively modest sensory innervation across the mouse uterine horn, with no regional specificity. We conclude most sensory information between the mouse uterine horn and central nervous system is likely relayed via thoracolumbar spinal afferents.

PSVII-3 Evaluation of dietary OmniGen AF supplementation and PG600 injection on reproductive characteristics of gilts

Abstract A cooperative study evaluated effects of supplemental dietary OmniGen AF (OG; Phibro Animal Health Corporation) on reproductive characteristics of gilts. Crossbred gilts (n = 56; initial body weight = 152.3 ± 9.7 kg) were assigned to treatments in a 2 x 2 factorial design [diet (OG or control) and PG600 (Merck Animal Health, El Dora, KS) injection (Yes or No)]. Dietary treatments were: 1) corn-SBM basal diet (control) that met NRC (2012) requirement estimates, or 2) control plus 0.75% OG and were fed 35 to 40 d prior to breeding. A common diet formulation was used by both stations. Gilts were estrous-synchronized by 14-d feeding of Matrix (Merck Animal Health). PG600 injections occurred 24 hours after Matrix withdrawal. Gilts were weighed at breeding and preslaughter (at d 39 to 48 postbreeding) and were euthanized to evaluate reproductive characteristics. There were no OG x PG600 interactions on any response measures (P > 0.15). Mean responses did not differ (P > 0.20) when gilts were fed control or OG diets, respectively, for total uterus weight (6,065 vs. 5,883 g), uterine horn length (129.2 vs. 123.9 cm), ovary weight (9.66 vs. 9.94 g), total corpora lutea (CL) number (25.0 vs. 25.3), individual CL weight (0.41 vs. 0.43 g), total follicular fluid weight (3.17 vs. 3.03 g), individual placenta weight (86.3 vs. 86.4 g), total fetuses (14.2 vs. 13.0), and fetus crown-rump length (7.97 vs. 7.66 cm). Supplementation with OG reduced (P = 0.04) individual placenta fluid volume of gilts (150.6 vs. 115.4 mL). PG600 injection increased (P < 0.001) ovary weight (9.03 vs. 10.57 g), total CL (18.09 vs 32.27) and reduced CL weight (0.46 vs. 0.38 g). The results demonstrated classic PG600 responses on reproductive characteristics but no effects of 0.75% OG supplementation nor an interaction between the two factors.

Gut microbiota contributes to the development of endometrial glands in gilts during the ovary-dependent period

BackgroundThe hyper-prolificacy Meishan gilts achieved a superior endometrial gland development (EGD) than white crossbred gilts during the ovary-independent period (before 60 d of age). Then, the EGD continues under the management of ovary-derived steroid hormones that regulated by gut microbiota (after 60 d of age). However, whether Meishan gilts’ superiority in EGD lasting to the ovary-dependent period (after 60 d of age) and the role of gut microbiota in this period both remain unclear.MethodsMeishan gilts and Landrace x Yorkshire (LxY) gilts were raised under the same housing and feeding conditions until sexual maturity and then we compared their EGD and gut microbiota. Meanwhile, we transplanted fecal microbiota from Meishan gilts to L×Y gilts to explore the role of gut microbiota in EGD. We sampled plasma every 3 weeks and collected the uterus, ovary, liver, and rectal feces after the sacrifice. We then determined the hormone concentrations and expressions of the EGD-related genes. We also profiled the gut microbiota using 16S rDNA sequencing and metabolites of plasma and liver tissue using untargeted metabolomics. Finally, the correlation analysis and significant test was conducted between FMT-shifted gut microbes and EGD-related indices.ResultsMeishan gilts have larger endometrial gland area (P < 0.001), longer uterine horn length (P < 0.01) but lighter uterine horn weight (P < 0.05), a distinctive gut microbiota compared with L×Y gilts. Fecal microbiota transplantation (FMT) increased endometrial gland area (P < 0.01). FMT markedly shifted the metabolite profiles of both liver and plasma, and these differential metabolites enriched in steroid hormone biosynthesis pathway. FMT increased estradiol and insulin-like growth factor 1 but decreased progesterone dynamically. FMT also increased the expression of the EGD-related genes estrogen receptor 1 gene, epithelial cadherin, and forkhead box protein A2. There is a significant correlation between FMT-shifted gut microbes and EGD-related indices.ConclusionSexually matured Meishan gilts achieved a superior EGD than LxY gilts. Meanwhile, gut microbiota contribute to the EGD potentially via regulating of steroid hormones during the ovary-dependent period.

Postpartum Uterine Involution and Embryonic Development Pattern in Chinese Holstein Dairy Cows.

Understanding the postpartum uterine involution pattern and embryonic development could facilitate bovine reproduction management, improve reproductive efficiency, and diagnosis of the reproductive disorder, which would contribute to the success of the dairy business. This study aimed to investigate postpartum uterine involution and embryonic developmental patterns or postconceptional marks of embryonic fetal development in Chinese Holstein dairy cows using B-mode ultrasonography. The results revealed a significant decline in the involution period with an increase of parity and age. The uterine involution period was shorter in multiparous cows when compared with cows with lower parities. Consistently, cows over 4 years old recovered faster than younger cows (2 or 3 years). Besides, the elder cows (over 4 years) had a relatively larger size of resumed cervix uteri and horns. Postpartum uterine involution pattern analysis revealed that the reproductive tract recovered very fast during the first 16 days postpartum for all the parity. Results of postconceptional marks of embryo development revealed a slow increase in diameter of the gravid uterine horn and crown-rump length (CRL) before day 60. In contrast, this increase was dramatic and rapid after the 60th day. We also established two models to estimate gestational age based on gravid uterine horn diameter or CRL. A formula was established to determine the gravid uterine horn size during postconceptional on day 30th–day 90th (r = 0.8714, P < 0.01). In addition, a significant positive correlation between CRL and gestational age (r = 0.98151, P < 0.01) was built. In conclusion, these results illustrated that parity and calving age had significant effects on uterine involution in Chinese Holstein cows. Crown-rump length and gravid uterine horn diameter are both efficient for evaluating the embryo growth. These current findings broaden the understanding of basic reproductive pattern in Chinese Holstein cows and could benefit bovine reproductive management primarily in postpartum and early pregnant cows to reduce the calving interval and avoid periparturient metabolic diseases.

Relationship between Prenatal Characteristics and Body Condition and Endocrine Profile in Rabbits.

Simple SummaryLitter size is an essential trait in rabbit production, and it depends on ovulation rate and embryonic and foetal survival. The period between 8 and 18 d of gestation is critical for foetal survival, as the placenta controls foetal nutrition during this period. Ovulation rate and foetal survival at 12 d of gestation are affected by body condition and metabolic and hormonal profile. Higher foetal survival is related to a higher number of vessels arriving at the implantation site, and may be due to higher available space for the foetus.This study evaluated the relationship between prenatal characteristics and body condition and endocrine profile. A total of 25 non-lactating multiparous females were used. Body condition, measured as body weight and perirenal fat thickness, non-esterified fatty acids (NEFA), leptin, progesterone and 17β-estradiol were recorded at mating and 12 d of gestation. Ovulation rate, number of foetuses, ovary and foetal weight, length and weight of uterine horn, available space per foetus and maternal and foetal placental morphometry were recorded at 12 d of gestation. Ovulation rate showed a positive linear relationship with number of foetuses, ovary weight and NEFA. A negative linear relationship between ovulation rate and perirenal fat thickness and leptin was obtained. Ovulation rate was maximum when body weight and 17β-estradiol were 4.4 kg and 22.7 pg/mL, respectively. Foetal weight showed a positive relationship with perirenal fat thickness and a negative relationship with leptin. An increase in progesterone and NEFA concentration was related to a positive linear increase in number of foetuses and in uterine horn weight. Space available per foetus was affected both by the number of vessels that reach the implantation site and by position of the foetus in the uterine horn. In conclusion, body condition during mating and early gestation should be maintained within an optimal range to ensure the best prenatal characteristics. While 17β-estradiol, NEFA and leptin affected the ovulation rate, progesterone and NEFA affected foetal development. The number of vessels that reach the implantation site determines early foetal survival.

Pregnancy-induced long-term uterine vascular remodeling in the rat

Despite the available research investigating uterine physiology during and immediately following pregnancy, including at the vascular and muscular levels, knowledge of the potential long-term timeline of such changes is limited. Thus, our study sought to investigate the potential long-term changes in uterine vasculature and horn length in the postpartum rat, following delivery and weaning. Female Long-Evans rats (n = 9–11 rats/group/timepoint) were divided into two groups: a pregnant group and an age-matched virgin control group. Rat weight, food consumption and vaginal impedance measurements were recorded throughout the experiment. Rats in the pregnant group were bred and pregnancy was confirmed using ultrasound imaging. The uterus and its vasculature were collected at various timepoints following weaning: 3 (week of weaning), 8–9 and 13 weeks postpartum, and at age-equivalent timepoints in the virgin group, and the diameters of the main uterine artery and vein, and lengths of the mesometrial segmental vessels (MSV) and uterine horns were recorded. The results indicated a significant difference between the previously-pregnant and virgin rats in both internal and external arterial diameters (but not arterial wall thickness), as well as the uterine horn length, 3 weeks postpartum, but not 8–9 and 13 weeks postpartum. Significant differences were observed in both venous diameter and MSV length at all timepoints measured. Placental scars were also observed in previously-pregnant rats at all timepoints measured. Our study highlights the long-term impact of pregnancy on the uterine vasculature and the necessity for consideration of such changes on subsequent pregnancies, as well as pregnancy-related vascular pathologies.

THE IMPACT OF ANIMAL MANAGEMENT TECHNOLOGIES ON THE PHYSICAL AND PHYSIOLOGICAL DEVELOPMENT OF REPLACEMENT GILTS

The paper find out the regularities of physical and physiological development of the replacement young pigs, bred at different housing technologies. The experiment was conducted in OOO “SVK” Krasnogvardeyskiy district (industrial technology) and “SHP Svobodny trud” (traditional technology) of Novoselytsya districts of Stavropol Territory. In order to conduct the experiment on the basis of analogues, the Company selected bipedal pigs (50% large white (CB) + 50% Landrace (L)) aged one month. Each group had 25 pigs. In order to study the development of reproductive organs at the age of 6 and 8 months, a control slaughter of experimental animals was carried out (3 pigs from each group). The live body weight of 6-month-old pigs in OOO “SVK” averaged 110 kg, while in OOO “SHP “Svobodnyy trud” the animals weight was 67-70 kg. At the age of 8 months, the weight of animals in “SHP “Svobodnyy trud” was 103-110 kg, and in OOO “SVK” - 145-150 kg. At the age of 180 days the animal reproductive organs were at the initial stage of development. Only primary follicles of 0.1-0.3 cm in diameter were observed in ovaries weighing 3.1-3.5 g. The bipedal hybrids grown on the intensive technology were inferior to the pigs with the traditional technology of breeding for the development of reproductive organs. They had a lower uterine weight by 9.1%, ovarian weight by 12.9%, and the length of uterine and ovarian horns by 10.9 and 8.6%, respectively. Repair pigs grown according to the traditional technology had ovaries weighing 9.2 g and had fresh yellow bodies. When growing guinea pigs under industrial technology, the rejection of first-pigs amounted to 63.6%, while in the case of animals grown under traditional technology, this indicator was within 26.6%.

Serum Concentrations of AMH and E2 and Ovarian and Uterine Traits in Gilts.

Simple SummaryPoor sow retention is a common issue amongst piggeries that creates excessive wastage. Premature culling is largely attributed to reproductive inadequacy. Thus, it is clear the traditional methods for selecting breeding females are inefficient and early markers of reproductive success are required. The aim of this study was to examine whether circulating levels of anti-Müllerian hormone and oestradiol could be useful indicators of ovarian and uterine traits in young gilts. The findings suggest that at a young age, anti-Müllerian hormone could be used to mark the ovarian reserve. Further research into whether the two hormones could be used to mark uterine capacity is needed.Poor sow retention due to reproductive failure is a common reproductive inefficiency amongst piggeries. This shows that traditional methods of gilt selection are inadequate and a marker of reproductive success is needed. The aim of this study was to determine whether circulating levels of AMH and E2 at D80 and D160 are associated with uterine and ovarian traits at D160. Uterine weight, horn length and horn diameter were measured, and ovarian follicle counts were determined histologically. There was a negative relationship between both D80 and D160 AMH levels and D160 ovarian follicle populations. There was also a positive relationship between D80 E2 levels and uterine capacity in gilts that were pubertal at D160. The findings indicate that D80 and D160 AMH could be used to predict ovarian reserve and that D80 E2 levels may be indicative of uterine capacity in precocial gilts.

The Use of Vagina–Cervix Length Measurement in Evaluation of Future Reproductive Performance of Sows: A Preliminary Study under Commercial Conditions

Simple SummaryAnimal production is focused on maximizing profits with simultaneous animal welfare protection. Thus, discovery of a simple, stress-free method for gilt selection would be an indispensable element for production improvement and would give necessary knowledge for producers. Our data showed that vagina–cervix length measurements could be a good, additional tool to predict a sow’s likely future reproduction efficiency. The advantages for this method are simplicity, speed, and no cost; the measurement is made as an element of the standard insemination procedure without additional stress and in a relatively early stage of life. Consequently, immediately obtained information gives high reliability and effectiveness in gilt selection. The length of the distal part of the internal reproductive tract seems to be related to the length and capacity of uterine horns, which is the most important anatomical property influencing litter size in sows. The aim of this study was to evaluate variation in vagina–cervix length (VCL) in gilts and differences in reproductive performance of sows according to VCL. The study was performed in a commercial farm using 221 gilts introduced into the breeding herd. Females were divided into three groups: (S) short (26.0 ± 2.0 cm, n = 36), (M) medium (31.3 ± 1.46 cm; n = 121), and (L) long VCL (36.0 ± 1.4 cm; n = 42) (p < 0.01). Mean live weight of gilts did not differ significantly among groups. Mean first litter size significantly varied between groups S (10.47 ± 3.01) and L (11.98 ± 2.32) (p = 0.0075) and M (10.67 ± 2.98) and L (p = 0.0054), while there was no significant difference between group S and M. Significant advantage (p = 0.023) was noted in the number of litters obtained from sows in groups L (4.69 ± 3.14), M (3.67 ± 2.71), and S (3.36 ± 2.40), and thus in total life production of sows (p = 0.0054), i.e., the number of piglets born alive. To conclude, the differences in vagina–cervix length in gilts during the first service was associated with significant variability in litter size during the first reproductive cycle, giving an advantage to females with longer VCL. Gilts with longer VCL were culled later and gave significantly more litters. Consequently, their lifetime piglet production was greater than gilts with shorter VCL.

Uterine Characteristics of Prepubertal Gilts at Fixed Body Weight

Abstract Reproduction is one of the most important factors affecting the efficiency of animal production. Within the scope of uterine capacity and other morphometric parameters, the objective of this study was to evaluate the size variability of uterus dissected from prepubertal gilts. The research was conducted on 100 PLW gilts and 100 PL gilts at a pig testing station. After slaughter, the reproductive tract was dissected, and each element was measured and weighed. The obtained results were combined and analyzed in three groups differentiated by uterine capacity: I, II and III. Group I consisted of gilts with a uterine capacity below 115 cm3 (n=69); group II comprised gilts with a uterine capacity between 115 and 175 cm3 (n=85); uterine capacity in group III was above 175 cm3 (n=46). Ontogenesis of the reproductive tract showed great variability with respect to the uterine capacity of gilts of both breeds. Uterine weight with and without ligament was different between the analyzed groups of PLW gilts (P&lt;0.01), and also between the groups of PL gilts (P&lt;0.01; P&lt;0.05). The uterine horns of the PLW gilts in group I were slightly longer than in the PL gilts (90.76 cm vs. 84.20 cm; P&lt;0.05). A slightly higher variability of uterine capacity was observed with respect to the PLW gilts (80.92 cm3 to 243.13 cm3), as compared with the PL gilts (92.61 cm3 to 235.23 cm3). The determined uterine capacity was significantly correlated with all parameters of uterine size (P&lt;0.01), apart from the length of the uterus and cervix in PLW gilts. The proportion between the uterine weight and the length of its horns, which characterizes the thickness of uterine walls, was significantly correlated with the length of uterine horns only in PL gilts (r=0.382**). This study may be used to forecast the potential fertility of related females (littermate gilts and their daughters); it may also be used in sow selection for litter size.

Optimization of Endometrial Decidualization in the Menstruating Mouse Model for Preclinical Endometriosis Research

To induce endometrial decidualization in rodents, an intrauterine oil stimulus can be delivered via the nontraumatic vagina or via the traumatic laparotomy. However, there is considerable variation in amount of decidualization using these inducing methods. Therefore, we studied which oil delivery route could achieve the highest rate of endometrial decidualization along the full length of both uterine horns. To induce decidualization, ovariectomized C57Bl/6J mice were injected with estrogen (100 ng/day; 3 days). A progesterone pellet (5 mg) was implanted subcutaneously, followed by estrogen injections (5 ng/day; 3 days). Oil (20 µL/horn) was injected in the uterus via laparotomy, laparoscopy, or vagina. Four days later, the pellet was removed, followed by hysterectomy after 4 to 6 hours. Endometrial decidualization was evaluated macroscopically and microscopically using hematoxylin and eosin and desmin staining. Furthermore, uterine weight and hormone levels were measured. The proportion of animals with macroscopic bicornuate decidualization was higher after laparoscopic (83%) and laparotomic (89%) injection than after sham injection (11%). Furthermore, macroscopic bicornuate decidualization was significantly higher after laparotomic injection (89%) compared to the vaginal injection (38%). Uterine weight and endometrial surface area were significantly higher in both laparotomy and laparoscopy groups compared to the sham group, while the relative desmin-positive endometrial surface area was only significantly different between the laparotomy and the sham animals. Methods using laparoscopic and laparotomic intrauterine oil injection resulted in a higher amount of decidualized endometrium compared to sham injection, although further optimization is needed to reach full bicornuate decidualization.

Neonatal lactocrine deficiency affects the adult porcine endometrial transcriptome at pregnancy day 13.

Reproductive performance of female pigs that do not receive sufficient colostrum from birth is permanently impaired. Whether lactocrine deficiency, reflected by low serum immunoglobulin immunocrit (iCrit), affects patterns of endometrial gene expression during the periattachment period of early pregnancy is unknown. Here, objectives were to determine effects of low iCrit at birth on the adult endometrial transcriptome on pregnancy day (PxD) 13. On the first day of postnatal life, gilts were assigned to high or low iCrit groups. Adult high (n=8) and low (n=7) iCrit gilts were bred (PxD 0), and humanely slaughtered on PxD 13 when tissues and fluids were collected. The endometrial transcriptome was defined for each group using mRNAseq and microRNAseq. Reads were mapped to the Sus scrofa 11.1 genome build. Mature microRNAs were annotated using miRBase 21. Differential expression was defined based on fold change (≥±1.5). Lactocrine deficiency did not affect corpora lutea number, uterine horn length, uterine wet weight, conceptus recovery, or uterine luminal fluid estrogen content on PxD 13. However, mRNAseq revealed 1157 differentially expressed endometrial mRNAs in high versus low iCrit gilts. Differentially expressed genes had functions related to solute transport, endometrial receptivity, and immune response. Six differentially expressed endometrial microRNAs included five predicted to target 62 differentially expressed mRNAs, affecting similar biological processes. Thus, lactocrine deficiency on the first day of postnatal life can alter uterine developmental trajectory with lasting effects on endometrial responses to pregnancy as reflected at the level of the transcriptome on PxD 13.

Genome-wide association analysis reveals genomic regions on Chromosome 13 affecting litter size and candidate genes for uterine horn length in Erhualian pigs

Litter size has a great impact on the profit of swine producers. Uterine development is an important determinant of reproduction efficiency and could hence affect litter size. Chinese Erhualian pig is one of the most prolific breeds in the world, even though large phenotypic variation in litter size was observed within Erhualian sows. To dissect the genetic basis of the phenotypic variation, we herein conducted genome-wide association studies for total number born and number born alive (NBA) of Erhualian sows. In total, one significant single nucleotide polymorphism (SNP) (P<1.78e−06) and 11 suggestive SNPs (P<3.57e−05) were identified on 10 chromosomes, confirming seven previously reported quantitative trait loci (QTL) and uncovering six QTL for litter size or uterus length. One locus on Sus scrofa chromosome (SSC) 13 (79.28 to 90.43 Mb) harbored a cluster of suggestive SNPs associated with multiparous NBA. The SNP (rs81447100) within this region was confirmed to be significantly (P<0.05) associated with litter size in Erhualian (n=313), Sutai (n=173) and Yorkshire (n=488) populations. Retinol binding protein 2 and retinol binding protein 1 functionally related to the development of uterus were located in a region of 2 Mb around rs81447100. Moreover, four genes related to embryo implantation and development were also detected around other significant SNPs. Taken together, our findings provide a potential marker (rs81447100) for the genetic improvement of litter size not only in Chinese Erhualian pigs but also in European commercial pig breeds like Yorkshire, and would facilitate the final identification of causative variant(s) underlying the effect of SSC13 QTL on litter size.

Nanotechnology-based selection of boar spermatozoa: growth development and health assessments of produced offspring

Abstract The heterogeneous population of spermatozoa within the semen ejaculate influences the sire fertility. The current design of magnetic nanoparticle conjugates allows for selective targeting and removal of non-viable spermatozoa within the semen ejaculate. However, the safe application of this process, termed as nanoselection or nanopurification in previous studies, in food animal production and toxicity concerns has yet to be explored. Here, we assessed the fertility potential of nanoselected boar spermatozoa and the subsequent post-natal growth and health characteristics of resulting offspring. Semen doses were harvested from three fertile boars (n=4 doses per boar) and split in two groups (2 doses/boar). Six semen doses (2 per boar)) were subjected to the targeted depletion of acrosome membrane damaged and apoptotic spermatozoa (nanoselected). Meanwhile, the remaining semen doses (n=6) were maintained in the shipping Styrofoam box (control). The motility characteristics of both control and nanoselected spermatozoa were evaluated before and after nanoselection, followed by their use for double inseminations of six estrus synchronized gilts (2 doses/boar/gilt; 3 gilts /control or nanoselected). In comparison to the controls, the computer-assisted sperm analyzer (Hamilton-Thorne) revealed greater motion characteristics of nanoselected spermatozoa, with a significantly higher proportion of progressive spermatozoa and straightness (P 0.05). Various developmental and health parameters of produced offspring such as hepatic cytochrome P450 enzyme activities, blood glucose and immunoglobulin G concentrations, hematocrit, and white blood cell proportions were similar between and across all pigs (control and nanoselected). In addition, reproductive tracts of females born from nanoselected spermatozoa showed no indication of impaired fertility potential, although a significant shortened uterine horn length was measured (56.3±2.6 cm vs. 64.4±2.2 cm in the control group, P=0.04). In conclusion, findings revealed no obvious perturbations of sperm function following nanoselection, while post-natal growth, development, or health data of derived offspring suggest absence of inflicted sub-lethal toxicities attributable to sperm nanoselection. This study supports the safe use of the proposed nanotechnology-based selection for effective semen handling in terminal line swine production systems.

Effect of Maternal Food Restriction on the Uterus of Female Rats from the First and Second Generation

Postnatal life is affected by changes in fetal development due to adverse events. The present study examined the effect of maternal food restriction on uterine structure and capacity in female rats from the first and second generations (FR1 and FR2) before and after puberty. Pregnant rats were fed ad libitum (Control, C) or maintained under food-restriction conditions (50%FR) during pregnancy. After delivery, all groups were given free access to food. Females from the first generation (FR1) were divided into two subgroups for either uterine dissection or to produce the next generation (FR2). Similar to FR1, FR2 females were exposed to maternal food restriction following the same procedure. FR2 females were also assigned into two subgroups for either uterine dissection or for mating to examine pregnancy outcomes. Uteri from the C, FR1 and FR2 groups were dissected at 4 weeks of age (before puberty) or at 8 weeks of age (after puberty) to evaluate uterine weight and uterine horn length. Tissues were stained with eosin and haematoxylin for examination vialight microscopy. The results showed that food restriction did not affect uterine weight or uterine horn length in FR1 and FR2 females before puberty. However, there were effects of maternal food restriction on uterine weight and length at 8 weeks of age. Uterine weight and uterine horn length were significantly reduced in the FR1 and FR2 groups compared with the values of the controls. This was associated with changes in pregnancy outcomes. Litter size was not affected in the FR1 group; however, litter weight was significantly reduced, leading to an 18% reduction in pup weight at birth. Unlike with FR1 litters, the size of FR2 litters was significantly reduced, leading to a lower degree of pup body weight reduction at birth (only 7%). The gestational length was normal in FR1 females but was significantly decreased in FR2 females. No histopathological changes were observed. These results showed that the uterus was affected by maternal food restriction. It seemed that FR2 females had a different reproductive strategy: they tended to reduce litter size to maintain pup weight at birth. In conclusion, maternal food restriction affects the uteri of the first and second generation. Females from the FR1 and FR2 groups followed different reproductive strategies according to their previous experience with exposure to intrauterine food restriction.

Measures of the ovaries and uterus during development of gilts selected for differences in uterine capacity.

Direct selection for uterine capacity (UC) increased the number of live pigs born. A method to indirectly estimate UC in developing gilts is needed for this trait to be incorporated into commercial selection strategies. We tested the hypothesis that selection for UC alters phenotypic characteristics of the reproductive tract of prepubertal gilts and that these changes could be estimated in live animals using transrectal ultrasound (TRU). Gilts from lines selected for UC and a randomly selected control (CO) line were submitted for TRU at 130, 150, or 170 d of age and harvested 24 h later (n = 10 gilts/line per age). Diameter of the uterine horn was measured (2 to 4 measurements per animal) at TRU. At harvest, measurements of the ovary (height, width, length, weight, and number of visible follicles >1 mm) and uterine horn (weight, length, diameter, and endometrial diameter) were taken. There was no line × age interaction for any of the traits. All ovarian traits increased (P < 0.03) with age. Weight and length of the uterine horn was not different at 130 or 150 d but were increased (P < 0.01) at 170 d of age. Diameter of the uterine horn tended (P = 0.06) to be increased at 170 d compared with 130 or 150 d, but age did not affect (P = 0.38) endometrial diameter. Ovarian weight and width were increased (P < 0.01) and ovarian length and height tended (P = 0.07) to be greater for UC than CO gilts, but the number of visible follicles did not differ. The UC gilts had increased (P < 0.02) weight of uterine horns, which tended (P = 0.09) to be longer than in the CO gilts. Diameter of the uterine horn and the endometrium were greater (P < 0.01) for UC gilts than for CO gilts. Uterine horn diameter measured with TRU was not affected by age or line and was not highly correlated with any of the measured traits. Selection for increased UC results in larger ovaries and uterine horns, but TRU was not useful for estimating these traits in gilts of the age studied.

Examination of the Ovarian Reserve after Generation of Unilateral Rudimentary Uterine Horns in Rats

Objective. The purpose of this experimental rat model study is to evaluate the changes in the ovarian environment after excision of the rudimentary horn. Methods. Ten female Wistar albino rats were used in this study. One cm of right uterine horn length was excised in the first operation. Two months after the first operation, all animals were sacrificed to obtain ovaries for histological examination. Mann-Whitney U test and Student's t-test were used for statistical analysis purposes. Statistical significance was defined as P < 0.005. Results. The number of primordial follicles (P = 0.415), primary follicles (P = 0.959), preantral follicles (P = 0.645), antral follicles (P = 0.328), and Graafian follicles (P = 0.721) was decreased and the number of atretic follicles (P = 0.374) increased in the right ovarian side. Howeve,r this difference was not found to be statistically significant. Conclusion. The results of this experimental rat model study suggest that the excision of rudimentary horn could have negative effects on ipsilateral ovarian functions.

Morphometric Characteristics of the Reproductive System in Polish Large White and Polish Landrace Gilts at 100 Kg Body Weight / Charakterystyka morfometryczna układu rozrodczego loszek wielkiej białej polskiej i polskiej białej zwisłouchej przy masie ciała 100 kg

Abstract The study involved an analysis of the developmental stage of reproductive organs collected at slaughter from 160 gilts (Polish Large White (PLW), n = 80; Polish Landrace (PL), n = 80) at 100 kg body weight. Due to a large variation in slaughter age (140-190 days), three groups of animals were set up: A (less than 160 days), B (160 to 180 days) and C (more than 180 days). PL gilts reached their slaughter weight earlier than PLW gilts (P≤0.05). Uterine weight increased with the age of animals but due to high variability and large deviations from the mean value, statistically significant differences were demonstrated only between gilt groups A and B for both breeds together (120.57 g vs. 148.83 g; P≤0.05). Larger differences related to the age of the gilts were found for cervical length between the groups compared (P≤0.01). The total length of the right and left uterine horns showed a significant increase with age in PLW gilts (P≤0.05). The ratio between uterine weight without ligament and the length of uterine horns (g/cm) was significantly higher in group B than in group A in gilts of both breeds together (P≤0.05), which might indicate thickening of the uterine walls. Uterine capacity was significantly higher in older animals yet due to a large variability of this trait, no significant differences between the groups were shown. The length and diameter of oviducts, the weight of each ovary, their sum and dimensions did not reveal any consistent changes associated with the age or breed of pigs. However, the size of the ovaries determined volumetrically and reported as the volume of ovaries in gilts of both breeds was significantly larger in group B compared with C (P≤0.01). No significant differences related to the studied traits were stated between PLW and PL prepubertal gilts. However, the effect of age on morphometric development of the reproductive system was more pronounced in PLW than in PL gilts.