Estrogens improve the pregnancy rate in cattle: A review and meta-analysis.

Estrogens have proven to be effective in bovine estrus induction protocols. Considering the extensive use of these products in large-scale estrus synchronization, the primary objective of the present study was to assess their effects on pregnancy rate (PR) using a meta-analysis approach. A total of 797 papers were screened from three major databases (PubMed, Web of Science, Scopus). Sixty-one studies were eligible for inclusion in the meta-analysis. The pregnancy status (success or failure) at 30 days post-insemination was considered as the effect size data. The odds ratios (OR) of PR were evaluated by considering the effects of estrogens in groups with or without estrogen intervention. The impact of estrogen (including factors such as type, dose, and time of administration) and animal characteristics (such as breed, type, and parity) was taken into account when assessing the effectiveness of estrogen response as PR. The results showed an OR of 1.25 (95% CI: 1.15-1.36; P = 0.000) for PR in animals that received estrogen compared to cattle that did not receive estrogen. Estradiol benzoate (OR = 1.3) and estradiol cypionate (OR = 1.2), with doses ranging from 1 to 3 mg (OR = 1.13-1.7), significantly increased the OR of PR. In terms of PR, beef cattle exhibited a higher odds ratio (OR = 1.4; P = 0.000) compared to dairy cattle (OR = 1.1; P = 0.09). The administration of estrogens in the estrus synchronization protocol significantly improved PR in both artificial insemination (OR = 1.2; P = 0.000) and embryo transfer (OR = 1.3; P = 0.033) programs. In summary, incorporating estrogens into estrus induction protocols led to an enhancement of the OR of PR among cattle.

Redox reactions in vitrified-warmed ovary.

BACKGROUNDS: Ovary vitrification is a way for the preservation of fertility in women undergoing chemotherapy and for protecting the valuable or the endangered species. However, cryopreservation of complex tissues, which are composed of different cells and materials, encountered various challenges including oxidative stress damage. OBJECTIVES: This study aimed to evaluate some oxidative stress indices in the vitrified bovine ovaries. METHODS: The pieces of the bovine ovarian cortex (1 × 1 × 1 mm3) were vitrified with final concentrations of ethylene glycol (25%) and glycerol (25%) and 0.5 M sucrose and then, after 48 h, were warmed with descending concentrations (0.5, 0.25, and 0.125 M) of sucrose. The ovaries were processed and some biochemical indicators of oxidative stresses were assayed. RESULTS: Total antioxidant capacity had a 45% decrease after vitrification (P<.0001). This reduction was associated with a 4 times increase in malondialdehyde (P=.0002) and a 53% decrease in superoxide dismutase (P=.0081). The levels of protein carbonyl in vitrified-warmed ovaries were less than in fresh ovaries (P=.0325). Regression analysis showed that the components of oxidative stress indices in vitrified tissues are different from those of fresh tissues. CONCLUSION: An extensive alteration was seen in oxidant/antioxidant balance during vitrification.

Long-lasting canine cardiovascular alterations following bromocriptine induced-estrus.

Bromocriptine (BRM), a dopamine 2 receptor agonist, is a common drug for inducing estrus in dogs. It is also used for the treatment of some endocrine abnormalities and has some cardiovascular consequences in the patients under treatment. The current study aimed to evaluate its effects on the cardiovascular function of dogs during administration and the subsequent induced estrus cycle. Eight non-pregnant female dogs were assigned into control and treatment groups. The control group (n = 3) were dogs that showed proestrus naturally. The treatment group (n = 5) received oral incremental (µg/kg) doses (100 on days 1 and 2, 200 on days 3, 4, and 400 on days 5 until the proestrus expression) of BRM tablets (2.5 mg; Iran-Hormone Co, Iran). The left ventricle function, carotid blood flow indices, and systolic (SAP) and diastolic (DAP) arterial pressure were recorded every two days. The phases of the cycle were determined using a vaginal smear. Peak systolic velocity (PSV), end-diastolic velocity (EDV), and resistance index (RI) had a sharp decline following the administration of BRM (P < 0.05). The carotid PSA, EDV, RI, and pulse index were lower during induced estrus compared to the control (p < 0.05). BRM-induced estrus showed a different pattern of changes compared to the normal cycle from day 9 (p < 0.05) onwards. The cardiovascular effects of BRM remained for days after the termination of administration which may interfere with reproductive functions.

Reproductive cycle and in vitro maturation of canine oocyte: A meta-analysis approach.

Different outcomes of canine in vitro oocyte maturation depend on the phases of the donor's estrus cycle. This study aimed to examine this topic using a meta-analysis approach. From 1765 identified records in three major scientific databases, 145 were selected after the screening, 27 were evaluated for eligibility, and, finally, by removing 3 studies with high heterogeneity, 11 studies were used for the meta-analysis. The anestrus (ANE) phase was the reference for evaluating the luteal (LUT) and follicular (FOL) phases. The effect size data were selected as dichotomous types, and publication bias and heterogeneity were used for the quality assessments. The results showed a higher risk ratio (RR) of meiosis resumption in oocytes from the germinal vesicle stage in the LUT and FOL phases (∼30% more than ANE oocytes). The RR of being oocytes at the germinal vesicle breakdown (GVBD) stage was similar in all three phases. When compared to ANE, the RR of oocytes reaching the metaphase I (MI) stage from GVBD were higher in the FOL and LUT phases (30% and 14%, respectively). Moreover, the rate of oocytes reaching metaphase II (MII) was higher in the FOL and LUT phases (85% and 30%, respectively) than in the ANE phase. Being at an active phase (FOL or LUT phases) increased the rates of transition from the GVBD to MI stages (18%) and the MI to MII stages (48%) as compared with the ANE phase. It was assumed that oocytes in the LUT phase can reach GVBD and MI, whereas oocytes in the FOL phase are more capable of reaching MII than oocytes in anestrus.

Ultrasound monitoring of pregnancy in mini-lop rabbits.

Ultrasound plays a considerable role in human and animal reproduction in terms of early detection of pregnancy, prediction of parturition time, and diagnosis of fetal abnormalities. The present study aimed to evaluate the ultrasound implementation for monitoring of gestation in mini-lop rabbits. Fifteen heads of pubertal does were selected and kept in normal conditions of feeding and temperature. Animals were mated with three bucks from the same breed. The pregnancy monitoring was begun from five days post-mating (dpm) to kindling using a 12.5 MHz ultrasonic transducer. The examinations were performed at fixed dpm for all does (5, 7, 12, 16, 20, and 26). Furthermore, randomly selected does (2-3 does per day; one doe was fixed) were subjected to daily ultrasound examination to estimate the relationship between the ultrasound biometrics with the gestational age (GA) and days to parturition. The pregnancy rate was 80%, and the mean number of live kits at birth was 4.2 in the present study. Based on the ultrasound records, the gestation length can be divided into three tertiles of pregnancy (TOP) in rabbits. The first TOP (0-10 dpm) was monitored by detecting and measuring the gestational sac diameter from 6 to 10 dpm. The 2nd TOP (11-12 dpm) was characterized by detection and measurement of Crown Rump Length and Fetal Heart Rate. From 15 to 20 dpm, bi-parietal diameter and head circumference were positively correlated with the GA (p-value < 0.05). Abdominal circumference and femur length were detectable and measurable during the 3rd TOP (21 dpm-kindling). Pregnancy was detected as early as six dpm with acceptable markers in mini-lop rabbits. Highly significant negative correlations were detected between days to parturition and the sonographic biometrics. Three abnormal fetuses were successfully detected and described, too.

Polyethersulfone/MWCNT nanocomposite scaffold for endometrial cell culture: preparation, characterization, andin vitroinvestigation.

Endometrial cell culture is a method for investigating physiological or pathological conditions or simulatingin vivoconditions for embryo culture. The natural function of the endometrium depends on a polarized epithelium and 3D stromal compartments. The polymer-based scaffolds of simple polyethersulfone (PES), laser scratched PES (PES-LS), and multiwall carbon nanotubes (MWCNT) composited PES (PES-MWCNT) were prepared and used for bovine endometrial cells (bECs) culture. For better investigation of the relationship between physical structure and cell growth behavior, the surface morphologies of the scaffolds were evaluated by atomic force microscopy (AFM) and field emission scanning electron microscopy (FESEM) techniques. Three synthesized membranes (PES, PES-LS, and PES-MWCNT) were evaluated for the cell morphology, viability and, doubling time. Results showed acceptable physical and chemical fabrication of the polymers with no significant differences in the proportions of live cells to primary cultured cells, dead to live cells, and the cell doubling time among groups during the experiment (P > 0.05). Total cell count (live and dead cells) was significantly different on Day 2 among types of polymers. The results showed the comparable potential of the PES-MWCNT membrane for the bECs culture.

Evaluation of oxidant/antioxidant status in serum of sheep experimentally envenomated with Hemiscorpius lepturus scorpion venom.

Scorpion envenomation is a main general health problem in developing countries, especially in tropical and subtropical regions. Hemiscorpius lepturus as a member of the Hemiscorpiidae family is cause of the most scorpion sting lethality in Iran. In the present study, the oxidative stress and antioxidant defense in serum of envenomated sheep with the venom of Hemiscorpius lepturus were investigated. Nine sheep were randomly divided into three groups (three in each). Groups A, B and C received 0.10, 0.05 and 0.01 mg kg-1 of H. lepturus venom subcutaneously, respectively. Blood sampling were performed 30 min before envenomation (control) and 30 min, 1, 2, 3 and 6 hr after envenomation and serum levels of total antioxidant capacity (TAC), malonedialdehyde (MDA) and protein carbonyl (PCO) were determined. The TAC was significantly increased at the doses of 0.10 mg kg-1 (at 3 hr) and 0.05 mg kg-1 (at 6 hr) compared to pre-injection time. However, no significant differences were observed in serum levels of MDA and PCO in different groups. It can be concluded that the dose of 0.01 mg kg-1 of venom had no effect on stress factors of serum, but according to increased level of TAC at the doses of 0.05 and 0.10 and no significant changes in serum levels of MDA and PCO, the oxidative damage has been prevented by the antioxidant defense system response.

Vertical transmission of Theileria lestoquardi in sheep.

This is the first report of an outbreak of Theileria lestoquardi abortion and stillbirth in a mob of 450 ewes in July 2012, during which, approximately 35 late-term ewes lost their fetuses over a 5-day period. A dead ewe and her aborted fetus were transported to the Ahvaz Veterinary Hospital for the diagnostic evaluation. The microbial cultures from the ewe vaginal discharges and fetal abomasal contents and the liver were negative. The blood films of the ewe and her fetus contained Theileria piroplasms and the impression smears from ewe liver and fetal spleen were positive for Theileria Koch blue bodies. The DNA was extracted from the liver and spleen of ewe and her fetus, respectively, and analyzed by polymerase chain reaction (PCR) using specific primers derived from the nucleotide sequences of 18S ribosomal DNA (rDNA) gene of T. lestoquardi. A single fragment of 428-bp fragment was amplified. The PCR product was directly sequenced and the alignment of the sequence with similar sequences in GenBank(®) showed 100% identities with 18S rDNA gene of T. lestoquardi. The present study is the first report of the T. lestoquardi vertical transmission that could be related to the abortion.

Effects of sesame oil on the reproductive parameters of diabetes mellitus-induced male rats.

PURPOSE: The purpose of the present study was to investigate the effect of sesame oil on the reproductive parameters of diabetic male Wistar rats. MATERIALS AND METHODS: The adult male rats in a split plot design were divided into normal (n=10), normal 5% (n=5; 5% sesame oil enriched diet), diabetic (Streptozocin induced diabetes; n=9), diabetic 5% (n=9; 5% sesame oil enriched diet), and diabetic 10% (n=9; 10% sesame oil enriched diet) groups. Diet supplementation continued for 56 days. RESULTS: Sesame oil supplementation did not reduce the plasma glucose concentration of rats in the diabetic groups (p>0.05). The total spermatogonia, spermatocytes, Leydig cells/tubule, and the germ cell to Sertoli cell ratio were lower in the diabetic rats than the normal ones (p<0.05), and with the exception of spermatogonia counts, these values improved by the addition of sesame oil to the diet (p<0.05). The sperm progressive motility and viability were lower in the diabetic rats (p<0.05) and sesame oil supplementation did not improve them. Incorporation of sesame oil into the diet improved the plasma testosterone concentration of the diabetic rats in a dose-dependent manner (p<0.05). CONCLUSIONS: In summary, sesame oil supplementation improved the reproductive parameters of diabetic rats at the levels of the testicular microstructure and function, but was not effective in protecting the epididymal sperm.

The effects of ex vivo cold-storage on cryopreservation of the goat (Caprus hircus) epididymal sperm.

BACKGROUND: There are many studies focused on long or short storage time of epididymal sperm (EPS) of different species. There are limited studies on preservation or cryopreservation of the domestic goat EPS. OBJECTIVE: The aim of the present study was to evaluate the effects of ex vivo cold-storage on freezing of EPS from goat (Capra hircus). MATERIALS AND METHODS: In a split-plot design the caprine testes-epididymides (40 pairs) were divided to 4 storage-time groups equally (0, 24, 48 and 72 h), then subjected to cryopreservation using Bioxell. Sperm parameters were analyzed before and after freezing. RESULTS: Duration of cold-storage as well as freezing at all storage-time points reduced sperm viability and progressive motility while increased sperm tail abnormalities (p<0.0001). Freezing reduced the percentage of cytoplasmic droplets (p<0.0001). The percentage of detached heads was increased at all storage-time points following freezing (p=0.0019), except at time 0 h. CONCLUSION: It can be concluded that cold storage [in refrigerator (4(o)C) for 72 h] of epididymides efficiently protected the goat EPS in terms of progressive motility and viability. However, cold-storage may not protect the goat EPS against cryopreservation with Bioxell.

Effects of Tyrode's solution osmolarities and milk on bull sperm storage above zero temperatures.

BACKGROUND: Control of the medium osmolarity and temperature during long or short time sperm manipulation is essential. OBJECTIVE: The objectives of the present study were to find the effects of different osmolarities of modified Tyrode's solution and milk on the bull sperm during incubation at above zero temperatures. MATERIALS AND METHODS: Semen samples were collected twice from five Najdi bull. Centrifuged and most parts of seminal plasma were removed. First experiment: The concentrated semen were splited into nine aliquots to incubate in three different osmolarities (200, 300 and 400 mOsm) at three temperatures (5, 25 and 39°C) for 15 and 60 min of incubation. Second experiment: The semen samples were splited, mixed with the same volume of whole cow milk (5 and 25°C) and milk with 7% glycerol (5°C) and incubated for 15 and 60 min. RESULTS: Sperm motility severely affected (p<0.05) by incubation at low ionic tension (200 mOsm/l) especially at low temperature (5°C). The impact of low osmolarity on sperm viability can reduce by increasing the incubation temperature to 39°C. The decreased sperm motility, which was induced by lowering osmolarity, was not improved (p>0.05) by increasing temperature during 1 h of incubation. Milk can protect the sperm viability and motility at cool conditions and there is no beneficial effect of glycerol in combination of milk on sperm incubation at above zero temperatures (p<0.05). CONCLUSION: Iso- and hyper-osmotic solutions protect bull sperm motility and viability at 25 and 39°C, while milk can be used for protecting sperm at 5°C.

Effects of chronic heat stress on testicular structures, serum testosterone and cortisol concentrations in developing lambs.

The objective of this study was to investigate the effect of high and moderate summer ambient temperatures on testicular structures and endocrine profile of developing ram lambs. Twenty fall-born ram lambs were randomly divided into two groups: animals were kept outdoor (n=10) under ambient temperature (31-50 degrees C) or maintained indoor (26-32 degrees C) from May to October 2007. Daily maximum ambient temperature was recorded for both environments. Monthly serum testosterone and cortisol concentrations were compared between two groups throughout the experiment. The animals were slaughtered at the end of the study and their testes subjected to histopathology exam. The results showed that maximum outdoor ambient temperature was significantly higher than indoor. There was no difference between two groups on serum testosterone concentration. There was no effect on serum cortisol levels except in August and October. Histolopathological examination revealed a severe testicular degeneration with significant germ line degeneration without any impact on somatic cells. In conclusion, direct exposure of developing lambs during non-breeding season impairs testicular germ cells without significant effect on testicular endocrine function.