Smooth muscle electromyography for detecting major alterations in the estrus cycle in rats.

Determining the female animal cycle is crucial in preclinical studies and animal husbandry. Changes in hormone levels during the cycle affect physiological responses, including altered contractility of the visceral smooth muscle. The study aimed to identify estrus and anestrus using smooth muscle electromyographic (SMEMG) measurements, in vivo fluorescent imaging (IVIS) and in vitro organ contractility of the uterus and cecum. The study involved sexually mature female Sprague-Dawley rats, aged 10-12 weeks. The rats received a daily injection of cetrorelix acetate solution for 7 days, while another group served as the control. The animals were subjected to gastrointestinal and myometrial SMEMG. The change in αvß3 integrin activity was measured with IVIS in the abdominal cavity. Contractility studies were performed in isolated organ baths using dissected uterus and cecum samples. Plasma samples were collected for hormone level measurements. A 3-fold increase in spontaneous contraction activity was detected in SMEMG measurements, while a significant decrease in αvß3 integrin was measured in the IVIS imaging procedure. Cetrorelix reduced the level of LH and the progesterone / estradiol ratio, increased the spontaneous activity of the cecum rings, and enhanced KCl-evoked contractions in the uterus. We found a significant change in the rate of SMEMG signals, indicating simultaneous increases in the contraction of the cecum and the non-pregnant uterus, as evidenced by isolated organ bath results. Fluorescence imaging showed high levels of uterine αvß3 integrin during the proestrus-estrus phase, but inhibiting the sexual cycle reduced fluorescence activity. Based on the results, the SMEMG and IVIS imaging methods are suitable for detecting estrus phase alterations in rats.

Access to an outdoor open pack promotes estrus activity in dairy cows.

Dairy cows have a partial preference to access an outdoor deep-bedded pack, but the effects of continuous access to an outdoor area on estrous behaviors has not been studied. Our objective was to investigate if access to an outdoor open deep-bedded pack improves the expression of estrus behaviors. We enrolled 60 lactating Holstein cows directly after calving and followed them each for 12 weeks. Cows were housed in a single freestall pen holding 36 cows at a time, with a dynamic group composition. Half of the cows were randomly assigned to the OUTDOOR treatment; these cows had access to an outdoor open pack via an automated selection gate. INDOOR cows were housed together with OUTDOOR cows but were not allowed outdoor access. All cows were fitted with an automated activity monitor (AAM) 21 ± 3 d before expected calving date. Estrous behaviors (i.e., standing to be mounted and mounting behaviors) were continuously monitored using video, and the intensity of mounting (i.e., the number of standing to be mounted and other mounting behaviors per hour) was calculated per estrus event per cow. Temperature and humidity were monitored by data loggers indoors, and these data were used to calculate the Temperature Humidity Index (THI). Following an alert from the AAM, cows were checked to detect the presence of a dominant preovulatory follicle and an absence of a mature corpus luteum (CL) by rectal ultrasonography following milking, as well as 7 d thereafter to confirm ovulation by the presence of a new CL. A total of 94 estrus events were used in the final analysis. INDOOR cows tended to have a lower mounting intensity with increasing indoor THI, but no such effect was noted for OUTDOOR cows. The total number of cows in estrus positively influenced mounting intensity. OUTDOOR cows had a longer duration of estrus, as measured by the automated monitors, compared with INDOOR cows (12.4 ± 0.7 h versus 9.9 ± 0.8 h). Estrus event number and the total number of cows in estrus were both positively associated with estrus duration. These results indicate that access to an outdoor pack tended to increase mounting behavior for freestall housed dairy cows, especially during periods of elevated THI. We conclude that providing dairy cows access to an outdoor area can help with estrus detection and may thus help improve the reproductive programs on dairy farms.

Influence of early progesterone removal on follicular development, expression of estrus, and pregnancy rates in presynchronized postpartum beef cows.

The objective of this study was to evaluate the impact of early progesterone removal on pregnancy rates to fixed-time artificial insemination (FTAI) in presynchronized beef cows. Postpartum beef cows (n = 882) were randomly assigned to 1 of 2 treatments: 1) 7&7 Synch: cows received a controlled internal drug release insert (CIDR) and a 25-mg injection of prostaglandin F2α on day 0, 100 µg of GnRH on day 7, a second injection of prostaglandin F2α (PG2) at CIDR removal on day 14, and a second injection of GnRH at FTAI 60-66 h after PG2 (day 17); 2) 7&6 Synch: cows received the same treatment as 7&7 Synch; however, CIDR removal occurred in conjunction with PG2 on day 13, while FTAI remained at 60-66 h after CIDR removal (day 16). Ovarian ultrasonography was performed to determine follicle diameter at PG2 and FTAI in a subset of cows (n = 40). Cows exposed to the 7&7 Synch tended to have larger follicle diameter at PG2 compared with 7&6 Synch cows (P = 0.09); however, there were no differences in follicle diameter at FTAI. No differences were determined between treatments for the expression of estrus (7&7 Synch: 61.6 ± 5.30; 7&6 Synch: 54.1 ± 5.45; P = 0.31) or pregnancy rates to FTAI (7&7 Synch: 60.8 ± 3.83; 7&6 Synch: 57.0 ± 3.84; P = 0.42). In conclusion, early removal of progesterone did not impact pregnancy rates in presynchronized beef cows.

Early prediction of oestrus for herd fertility management in cattle and buffaloes - a review.

Oestrus is defined as a period when a female animal exhibits characteristic sexual behaviour in the presence of a mature male. Oestrous manifestation in dairy animals is due to the oestrogen (E2) effect on the central nervous system (CNS). It is a critical issue to be considered on a priority basis. Inefficient oestrous detection reduces the fertility status of the herd. The primary and most reliable indicator of oestrus is standing to be mounted by a bull or another female herd mate, signalling receptivity and the pre-ovulatory state in dairy cattle. Oestrous detection is primarily a management challenge requiring skill and vigilance. To improve the efficiency of oestrous detection in dairy cattle, visual observation is one of the best methods if done three times a day; however, heat detection aids, if combined, give better results. However, techniques like using teaser bulls, tail painting, chin ball markers, ultrasound (USG) examination, hormonal analysis and examination of cervicovaginal mucus (CVM) improve oestrous detection efficiency. Moreover, the changes in production systems have reduced the expression of oestrous behaviour among cows, due to higher oestrogen (E2) metabolism. Therefore, automated systems, such as pedometers, accelerometers and acoustic sensors like infrared thermography (IRT) and image processing, have significantly enhanced reproductive performance by facilitating oestrous detection and optimizing insemination schedules. From this review, we would conclude that oestrous detection alone contributes considerably to the reproductive status of the herd; therefore, applying different methods of oestrous detection reduces the incidence of missed oestrus and improves the fertility status of the herd.

Effect of prostaglandin alone and in combination with trace minerals on the follicular and luteal dynamics, estrus response and pregnancy in sub-estrus buffaloes (Bubalus bubalis).

Sub-estrus is a condition when buffaloes do not display behavioural estrus signs, despite being in estrus and causes a delay in conception and increases the service period. The present study describes the effect of synthetic prostaglandin (PGF2α) alone and in combination with trace minerals on the follicular and corpus luteum (CL) dynamics, serum estradiol (E2) and progesterone (P4) concentration correlating estrus response and pregnancy outcome in sub-estrus buffaloes during the breeding season. A total of 50 sub-estrus buffaloes, identified through ultrasonography (USG) examination, were randomly allocated into three groups, viz. T1 (Synthetic PGF2α, Inj. Cloprostenol 500 µg, i.m, n = 17), T2 (Synthetic PGF2α + Trace mineral supplementation, Inj. Stimvet 1 mL/100 kg body weight, i.m., n = 17) and control (untreated; n = 16). Following treatment, 100% of sub-estrus buffaloes were induced estrus in the T1 and T2 groups, while only 18.75% were induced in the control. The CL diameter and serum P4 concentration were significantly lower at post-treatment, whereas the pre-ovulatory follicle (POF) size and serum E2 concentration were significantly higher in the T1 and T2 groups as compared to the control (p < .05). The buffaloes of the T2 group had a greater proportion of moderate intensities estrus than those of T1. Moreover, the proportion of buffaloes conceived in the T1 and T2 were 41.2% and 52.95%, respectively. The larger POF diameter and higher serum E2 concentration were associated with intense intensity estrus and higher conception rate (66.7%) in sub-estrus buffaloes. Similarly, CL regression rate, POF size and serum E2 concentration were relatively higher in the buffaloes conceived as compared to those not conceived. It is concluded that synthetic PGF2α in combination with trace minerals induces moderate to intense intensities estrus in a greater proportion of sub-estrus buffaloes and increases the conception rate during the breeding season. Moreover, behavioural estrus attributes correlating follicle and luteal morphometry, serum E2 and P4 concentration could be used to optimise the breeding time for augmenting the conception rate in sub-estrus buffaloes.

Effect of a targeted reproductive management program based on automated detection of estrus during the voluntary waiting period on reproductive performance of lactating dairy cows.

The objective of this experiment was to evaluate the effect on reproductive performance of a targeted reproductive management (TRM) program for first postpartum insemination (AI) that prioritized AI at detected estrus (AIE) by providing different intervals for estrus detection based on records of automated estrus alerts (AEA) during the voluntary waiting period (VWP). A secondary objective was to evaluate the association between occurrence of AEA during the VWP and reproductive performance. Lactating Holstein cows (n = 1,260) fitted with neck behavior monitoring sensors for detection of estrus were randomly assigned to a program that used all-timed AI (TAI) for first service (ALL-TAI; n = 632) or a TRM program that prioritized AIE and used TAI only for cows not detected in estrus (TP-AIE; n = 628). Cows in the ALL-TAI treatment received TAI at 76 ± 3 days in milk (DIM) after a Double-Ovsynch protocol. Cows in the TP-AIE treatment were eligible for AIE for 30 ± 3 or 16 ± 3 d after a 49 d VWP if at least one (n = 346) or no (n = 233) AEA were recorded from 15 to 49 DIM. Cows not AIE received TAI after an Ovsynch protocol with progesterone supplementation at 90 ± 3 or 76 ± 3 DIM if the cow had or did not have AEA during the VWP, respectively. Data were analyzed by logistic and Cox's proportional hazard regression. In the TP-AIE treatment, 69.3 % of cows received AIE and more cows with (83.3 %) than without (45.0 %) AEA during the VWP received AIE. Cows in the TP-AIE (69.0 ± 0.7 d) treatment had fewer days from calving to first AI than cows in the ALL-TAI (75.7 ± 0.8 d) treatment. The proportion of cows pregnant by 150 DIM (ALL-TAI = 59.1 % and TP-AIE = 56.0 %) and the hazard ratio (HR) for time to pregnancy (1.0 [95 % confidence interval: 0.9, 1.2]) did not differ between treatments and median days to pregnancy were 102 and 107 for the ALL-TAI and TP-AIE treatments, respectively. Overall, the ALL-TAI (42.3 %) treatment had more first service pregnancies per AI (P/AI) than the TP-AIE (29.0 %) treatment. Cows with AEA during the VWP had greater P/AI (42.5 % vs. 28.9 %), proportion of cows pregnant by 150 DIM (67.4 % vs. 47.0 %), and HR for time to pregnancy (1.6 [1.4, 1.9]) than cows without AEA during the VWP. We conclude that a TRM program that prioritized AIE based on AEA during the VWP led to a similar pregnancy rate and proportion of cows pregnant by mid-lactation than a program that used all-TAI with extended VWP despite fewer P/AI to first service. Also, expression of estrus during the VWP was associated with improved reproductive performance. Thus, AEA during the VWP could be used as a predictor of reproductive potential for TRM of lactating dairy cows.

Effects of short and long - term nutrition and progesterone supplementation on the success of fixed - time artificial insemination in the ewe.

The success of fixed - time artificial insemination (AI) in the ewe is variable due to poor synchrony of estrus. We examined the effects of long-term nutrition (LTN; low, medium, high - 6 months), short-term nutrition (STN; 1.0 M, 1.5 M - 14 days) and progesterone supplementation (P; single pessary, replacement on Day 9) on synchrony and reproductive outcomes. High LTN advanced (P < 0.05) estrus, increased (P = 0.06) pregnancy (range 71.1 - 81.1%) and improved (P < 0.01) litter size (range 1.30 - 1.50). STN increased (P < 0.05) pregnancy (79.0 versus 72.3%) but not litter size or timing of estrus. A LTN x STN interaction (P < 0.01) for time of estrus indicates that the effects of LTN were moderated by STN depending on the level of LTN. Pessary replacement delayed (P < 0.05) the onset of estrus, improved synchrony but did not affect pregnancy or litter size. High LTN increased (P < 0.05) the number of large (≥ 3.8 mm) and medium - size follicles (2.0 - 3.7 mm) but the diameter of large follicles tended to be reduced (P = 0.08) on Day 12. STN did not affect follicle number or size whilst P reduced (P < 0.05) the diameter of large follicles on Day 12 (4.83 versus 5.10 mm) and increased the number of medium - size follicles (3.56 versus 2.74 mm). In conclusion, both LTN and STN are major sources of variability in AI programs whilst pessary replacement has potential to reduce variability.

Combining reproductive outcomes predictors and automated estrus alerts recorded during the voluntary waiting period identified subgroups of cows with different reproductive performance potential.

The objective was to compare differences in reproductive performance for dairy cows grouped based on the combination of data for predictors available during the prepartum period and before the end of the voluntary waiting period (VWP), automated estrus alerts (AEA) during the VWP, and the combination of both factors. In a cohort study, data for AEA and potential predictors of the percentage of cows that receive AI at detected estrus (AIE), pregnancies per AI (P/AI) for first service, and the percentage of cows pregnant by 150 DIM (P150) were collected from -21 to 49 DIM for lactating Holstein cows (n = 886). The association between each reproductive outcome with calving season (cool, warm), calving-related events (yes, no), genomic daughter pregnancy rate (gDPR; high, medium, low), days in the close-up pen (ideal, not ideal), health disorder events (yes, no), rumination time (high or low CV prepartum and high or low increase rate postpartum), and milk yield (MY) by 49 DIM (high, medium, low) were evaluated in univariable and multivariable logistic regression models. Individual predictors (health disorders, gDPR, and MY) associated with the 3 reproductive outcomes in all models were used to group cows based on risk factors (RF; yes, n = 535 or no, n = 351) for poor reproductive performance. Specifically, cows were included in the RF group if any of the following conditions were met: the cow was in the high MY group, had low gDPR, or had at least 1 health disorder recorded. Cows were grouped into estrus groups during the VWP based on records of AEA (estrus VWP [E-VWP], n = 476 or no estrus VWP [NE-VWP], n = 410). Finally, based on the combination of levels of AEA and RF, cows were grouped into an estrus and no RF (E-NoRF, n = 217), no estrus and RF (NE-RF, n = 276), no estrus and no RF (NE-NoRF, n = 134), and estrus and RF (E-RF, n = 259) groups. Cows received AIE up to 31 d after the end of the VWP, and if they did not receive AIE, they received timed AI after an Ovsynch plus progesterone protocol. Logistic and Cox proportional hazard regression compared differences in reproductive outcomes for different grouping strategies. The NoRF (AIE: 76.9%; P/AI: 53.1%; P150: 84.5%) and E-VWP (AIE: 86.8%; P/AI: 44.8%; P150: 82.3%) groups had more cows AIE and higher P/AI and P150 than the RF (AIE: 64.5%; P/AI: 34.9%; P150: 72.9%) and NE-VWP (AIE: 50.0%; P/AI: 38.9%; P150: 72.1%) groups, respectively. When both factors were combined, the largest and most consistent differences were between the E-NoRF (AIE: 91.3%; P/AI: 58.7%; P150: 88.5%) and NE-RF groups (AIE: 47.3%; P/AI: 35.8%; P150: 69.5%). Compared with the whole population of cows or cows grouped based on a single factor, the E-NoRF and NE-RF groups had the largest and most consistent differences with the whole cow cohort. The E-NoRF and NE-RF groups also had statistically significant differences of a large magnitude when compared with the remaining cow cohort after removal of the respective group. We conclude that combining data for AEA during the VWP with other predictors of reproductive performance could be used to identify groups of cows with larger differences in expected reproductive performance than if AEA and the predictors are used alone.

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.

Temporal disposition of pelvic girdle, vagina and vulva in relation to urovagina in cycling and pregnant-postpartum cows.

Urovagina (UV) is less studied in cows. The vaginal contents, constrictor vestibule muscle activity, circulating progesterone, pelvic girdle, vagina and vulva angles were compared on Days 0 and 14 within and between UV (UV group; n = 36) and normal (N group; n = 36) cows. The oestrous duration was compared among the groups. Parameters for various UV severities were also compared. Another set of pregnant-postpartum cows (P-PP group; n = 31) underwent monthly evaluations for UV and the angles from the third month of pregnancy until the second month postpartum. The effect of age, parity and body condition score on UV severities on Day 0, and parity on angles in the P-PP group was evaluated. Different variables were correlated in different groups. The UV group was repeat breeder, exhibited prolonged oestrus and reduced progesterone on Day 14. The latter increased with UV severity on Day 0. On Day 14, severe form of UV was more prevalent. The UV severity increased with parity. In the UV group, a cranioventral pelvic girdle on Day 0 became more cranioventral on Day 14 and was correlated with the vagina moving from a caudodorsal position on Day 0 to a cranioventral position on Day 14. In the P-PP group, the pelvic girdle and vagina remained caudodorsal and UV was undetectable throughout the study. Vagina and vulva displayed a parity-by-month interaction in the P-PP group. To summarize, the UV characteristics were influenced by the oestrous cycle stage, pelvic girdle angles, and parity.

Mucin and salt combination simulate typical fern-like pattern of buffalo saliva smear at estrus.

Estrus detection in buffaloes primarily relies on behavioral and physiological signs. Especially during summer, these signs are less prominent to recognize. Thus, estrus detection is a pronounced challenge within the realm of buffalo husbandry, particularly in the summer. Therefore, a simple and accurate estrus detection method is required for buffalo farmers. The observation of fern-like salivary crystallization patterns is one such simple method to detect estrus in buffaloes, bactrian camels, beagle bitches, and cows. However, the exact mechanism for the formation of typical fern-like is not known. We hypothesized that it might be because of the estrus-specific mucins and salts. To test this hypothesis, we prepared the smears by combining different concentrations of mucin type -2 (MUC2) and -3 (MUC3) with sodium chloride (NaCl). Microscopic examination confirmed that fern-like patterns resulted from a combination of the MUC3 and NaCl produced more realistic fern patterns than that of MUC2 or BSA with salt. To predict possible mucin and salt concentration showing natural fern-like patterns at the estrus stage in buffalo saliva, we constructed a guide tree of artificially generated fern-like patterns using an image analysis online tool. This computation analysis revealed that most of the natural buffalo estrus saliva samples showing typical fern-like patterns clustered in the cluster 2 of the guide tree comprising of 13 clusters. In the cluster 2, MUC3 in combination with the salt concentrations of 100, 150, and 250 mM was commonly found in a close proximity to the natural typical fern-like patterns of saliva smear of buffaloes at estrus. Conclusively, the buffalo saliva at estrus is predicted to have a gel-forming heavily glycosylated protein such as mucin along with at least 100 mM of NaCl. RESEARCH HIGHLIGHTS: Glycoprotein and salts combination replicates fern-like pattern of buffalo saliva at estrus. MUC3 and NaCl salt combination produces more realistic fern-like patterns compared with MUC2 or BSA and salt combination. MUC3 with NaCl at 100, 150, and 250 mM consistently resembled natural estrus saliva fern-like patterns. During estrus, buffalo saliva is expected to contain heavily glycosylated mucin and at least of 100 mM NaCl.

Social effects on behaviorally-scored and pedometer-detected estrus in beef cattle.

The number of cows in estrus often influences estrus behavior; however, the effects of social order are not well documented. This study examined the effects of social order on the expression of behaviorally-scored and pedometer-detected estrus, combined with the effects of the number of cows in estrus. In a herd comprising 13 or 15 beef cattle, cows with orders 1st-7th were defined as dominant and the remaining cows as subordinate. Sole or simultaneous estrus was induced by prostaglandin F2α analog injection and/or intravaginal progesterone treatment. Ovulation timing was determined using ultrasonography at 6-hour intervals. Estrous signs and steps of the cows were recorded 49 h before ovulation using video monitoring and a pedometer, respectively. Among the 59 treated cows, 56 behaviorally-scored estruses (27 sole and 29 simultaneous) were detected. In the sole estrus, 61.5% of the dominant-rank cows had no zero-point period; however, 35.7% of the subordinate-rank cows had that period. The dominant-rank cows in estrus alone had a significantly shorter duration of scored estrus than those in simultaneous estrus (P < 0.05). Among the 50 pedometer-detected estruses (24 sole and 26 simultaneous), the subordinate-rank cows in sole estrus had a shorter interval from estrus onset to ovulation than the dominant-rank cows in simultaneous estrus (P < 0.05). The effects of social order varied in response to the number of cows in estrus, which might have influenced determining the optimal time for artificial insemination.

Social Stress during the Estrus or Luteal Phase in Sheep.

In mammals, progesterone and estrogens affect the stress response. The study aimed to compare the physiological and behavioral responses to the social isolation of ewes during the estrus or luteal phase. Estrous and diestrous ewes (n = 10 and 8 respectively) were individually isolated in a novel place for 10 min. Ewes' behavior was recorded during the test. Cortisol, blood proteins and glucose concentrations, and the skin surface temperature were determined before and after the test. Cortisol increased immediately after the test ended (P = 0.02). Serum total protein (P = 0.02), globulin (P < 0.0001), and plasma glucose (P = 0.006) concentrations were greater in estrus than in the luteal phase. The abdominal skin surface temperature was greater during estrus than during the luteal phase (P = 0.02). Ewes in estrus spent more time standing up immobile than ewes in the luteal phase (P = 0.05). In conclusion, the physiological and behavioral responses changed according to the phase of the estrous cycle. These results highlight the need for future studies focusing on how reproductive status influences the stress response to different management practices in sheep.

Clinical, sonographic and anatomopathological aspects of ovarian teratoma in a heifer / Aspectos clínicos, ultrassonográficos e anatomopatológicos do teratoma ovariano em uma novilha

Teratomas rarely occur in domestic species, especially in cattle. These tumors originate in fetal life and are characterized by rapid growth, which justifies their frequent detection in young animals. This study reported a case of ovarian teratoma in a heifer. On physical examination, the main signs identified were apathy, abdominal distention and tension, empty rumen, and mushy diarrhea. During rectal palpation, a mass was identified in the pelvic region, which was suggestive of cysts on ultrasound examination. The animal underwent laparotomy, followed by euthanasia due to a poor prognosis. At necropsy, a 54 x 43 x 52 cm (length x width x thickness) tumor was observed in the right ovary with multiple cystic areas, in addition to masses associated with multiple adhesions of the intestinal loops and peritonitis. On histopathology, muscle, cartilage, bone, nervous and epithelial tissue, glands, hair with follicles, were identified in the affected ovary. There was mixed inflammation and foci of necrosis observed with a complete absence of ovarian architecture in both the ovaries. Infiltrations were identified in the lymph nodes and mesenteric vessels. Glandular ducts were seen from the serosa to the intestinal mucosa. A locally infiltrative and expansile ovarian teratoma was diagnosed accordingly. It is considered that this kind of tumor can induce abdominal distension and absence of estrus in previously healthy, non-pregnant heifers.

Os teratomas são tumores raros nas espécies domésticas, sobretudo em bovinos. Esses tumores são caracterizados por crescimento rápido e origem durante a vida fetal, o que justifica seu diagnóstico frequente em animais jovens. O presente trabalho relata um caso de teratoma ovariano em uma novilha. No exame físico, os principais sinais identificados foram apatia, distensão e tensão abdominal, rúmen vazio e diarreia pastosa. Durante a palpação retal, uma massa foi identificada na região pélvica. Ao exame ultrassonográfico, a massa era sugestiva de cistos. O animal foi submetido a laparotomia, seguido de eutanásia devido ao mau prognóstico. Na necropsia foi observado um tumor de 54 x 43 x 52 cm (comprimento x largura x espessura) no ovário direito com múltiplas áreas císticas, além de massas associadas à múltiplas aderências das alças intestinais e peritonite. Na histopatologia foram identificados no ovário acometido a presença de tecidos muscular, cartilaginoso, ósseo, nervoso e epitelial, com glândulas, pelos e folículos. Havia inflamação mista e focos de necrose com ausência completa de arquitetura ovariana em ambos os ovários. Infiltrações foram identificadas em linfonodos e vasos mesentéricos. Ductos glandulares foram vistos desde a serosa até mucosa intestinal. Diagnosticou-se um teratoma ovariano localmente infiltrativo e expansivo. Considera-se que este tumor pode induzir distensão abdominal e ausência de estro em novilhas previamente sadias e não gestantes.

Melatonin may prevent or reverse polycystic ovary syndrome in rats

SUMMARY OBJECTIVE To evaluate the ovarian effects of melatonin (Mel) in a rat model of polycystic-ovary-syndrome (PCOS) before and after permanent estrus induction. METHODS Thirty-two adult-female rats with regular estrous cycle were equally divided into four groups: 1) GCtrl - at estrous phase. 2) GPCOS - at permanent-estrous phase. 3) GMel1 - treated for 60 days with Mel (0.4 mg/Kg) during permanent estrus induction and 4) GMel2 - rats with PCOS and treated for 60 days with Mel. After that, the animals were euthanized, and the ovaries were removed and processed for paraffin embedding. Sections were stained with H.E. for histomorphometry or subjected to immunohistochemistry for Ki-67 and cleaved caspase-3 (Casp-3) detections. RESULTS The GPCOS showed lack of corpus luteum and several ovarian cysts, as well as interstitial-like cells. The presence of corpus luteum and a significant increase in primary and antral follicles were observed in Mel-treated groups, which also showed a decrease in the number of ovarian cysts and in the area occupied by interstitial-like cells. These results were more evident in GMel1. The percentage of Ki-67-positive cells was significantly higher in the Mel-treated groups, mainly in the GMel2, as compared to GPCOS. On the other hand, the percentage of Casp-3-positive cells was significantly lower in granulosa cells of GMel1, whereas it was significantly higher in the interstitial-like cells of GMel2, in comparison to GPCOS. CONCLUSION Melatonin administration prevents the permanent estrus state in the PCOS rat model. This effect is more efficient when melatonin is administered before permanent estrus induction.

RESUMO OBJETIVO Avaliar os efeitos ovarianos da melatonina (Mel) em ratas com síndrome dos ovários policísticos (SOP) antes e após a indução do estro-permanente. MÉTODOS Trinta e duas ratas com ciclos estrais regulares foram igualmente divididas em quatro grupos: 1) GCtrl - fase de estro. 2) GSOP - fase de estro-permanente. 3) GMel1 - tratadas por 60 dias com Mel (0,4 mg/kg) durante a indução do estro-permanente e 4) GMel2 - ratas com SOP e tratadas com Mel. Após eutanásia dos animais, os ovários foram processados para inclusão em parafina. Cortes foram corados com H.E ou submetidos à imuno-histoquímica para detecção de Ki-67 e caspase-3 clivada (Casp-3). RESULTADOS O GSOP mostrou ausência de corpos lúteos e vários cistos ovarianos, além de inúmeras células intersticiais. A presença de corpos lúteos e o aumento significativo dos folículos primários e antrais foram observados nos grupos tratados com Mel, os quais também mostraram diminuição no número de cistos ovarianos e na área ocupada pelas células intersticiais. Esses resultados foram mais evidentes no GMel1 do que no GMel2. A porcentagem de células Ki-67 positivas foi significativamente maior no GMel1 e no GMel2, sendo mais evidente no GMel2, em comparação ao GSOP. Por outro lado, a porcentagem de células positivas à Casp-3 foi menor nas células da granulosa do GMel1 e maior nas células intersticiais do GMel2, em comparação ao GSOP. CONCLUSÃO A administração de melatonina previne o estado de estro-permanente em ratas com SOP. Esse efeito é mais eficiente quando a melatonina é administrada após indução do estado de estro-permanente.

Parâmetros reprodutivos após indução de estro com diferentes intervalos de permanência do dispositivo vaginal em cabras Toggenburg acíclicas / Reproductive parameters after induction of estrus with different ranges of the vaginal device in acyclic Toggenburg goats

Este estudo objetivou avaliar o comportamento sexual e a dinâmica ovulatória de cabras da raça Toggenburg após a indução do estro com dispositivo intravaginal de progesterona durante seis, nove e 12 dias de permanência. No momento da inserção do dispositivo e 24 horas antes da retirada do dispositivo, foi administrado 5mg de dinoprost e 200UI de eCG, respectivamente. A dinâmica ovulatória foi acompanhada por ultrassonografia a cada oito horas, enquanto o estro foi observado a cada 12 horas. Todas as cabras apresentaram estro. O intervalo da retirada do dispositivo ao início do estro foi de 29,5 ± 9,6 para G6dias; 34,0 ± 6,0 e 32,4 ± 7,7h, G9dias e G12dias, respectivamente. Igualmente, foi encontrada diferença (P<0,05) entre o G6dias e os outros grupos. A duração do estro diferiu (P<0,05) entre o G6dias (36,0 ± 12,6) e os outros dois grupos (G9dias: 31,2 ± 14,3; G12dias: 33,4 ± 8,6). A taxa de ovulação (81%; 89,5% e; 71,4%), intervalo da retirada do dispositivo à ovulação (50,5 ± 11,4; 46,3 ± 5,9 e; 46,7 ± 8,3), diâmetro do maior folículo (6,6 ± 0,3; 6,6 ± 0,9 e; 6,9 ± 0,8) diâmetro do segundo maior folículo (6,4 ± 0,7; 6,6 ± 0,8 e; 6,8 ± 0,6) e o número de folículos ovulados (1,5 ± 0,6; 1,7 ± 0,6 e 2,0 ± 0,9) para G6dias, G9dias e G12dias, respectivamente, foram semelhantes (P>0,05). Todos os protocolos foram eficientes em induzir o estro sincronizado em cabras da raça Toggenburg, trabalhando em conjunto com a eficiência reprodutiva e produtiva desses animais.(AU)

This study aimed to evaluate the sexual behavior and the ovulatory dynamics of Toggenburg goats after induction of synchronized estrus by an intravaginal progesterone device for six, nine and twelve days. At the device insertion and 24 h before the device removal, 5mg of dinoprost and 200 UI of eCG was administered, respectively. The ovulatory dynamics was assessed by ultrasound every 8 h, while the sexual behavior was observed every 12 h. All goats showed estrus. The intervals from device removal to estrus were 29.5 ± 9.7, 34.0 ± 6.0 and 32.4 ± 7.7h to G6days, G9days and G12days, respectively. Iqually, it was found difference (P<0.05) among G6days and the other groups. The duration of estrus differed (P<0.05) among the G6days (36.0 ± 12.6) and the other two groups (G9days: 31.2 ± 14.3; G12days: 33.4 ± 8.6). The ovulation rate (81.0%; 89.5% and; 71.4%); the interval from device removal to ovulation (50.5 ± 11.4; 46.3 ± 5.9 and; 46.7 ± 8.3), the diameter of the largest follicle (6.6 ± 0.3; 6.6 ± 0.9 and; 6.9 ± 0.8), diameter of the second largest follicle (6.4 ± 0.7; 6.6 ± 0.8 and; 6.8 ± 0.6) and the number of ovulations (1.5 ± 0.6; 1.7 ± 0.6 and; 2.0 ± 0.9) for G6days, G9days and G12days, respectively, were similar (P>0.05). All treatments were effective for the induction of synchronized estrus in Toggenburg goats, working jointly with the reproductive and productive efficiency of these animals.(AU)

Indução do estro em cutias (Dasyprocta leporina) utilizando-se protocolos à base de prostaglandina isolada ou em associação com análogo de GnRH / Estrus induction in agoutis (Dasyprocta leporina) using protocols based on prostaglandin isolated or in association to GnRH analogue

Comparou-se a eficiência de protocolos para indução de estro em cutias. Em cinco fêmeas, foram administradas duas doses de cloprostenol (5µg) com intervalo de nove dias, via intraperitoneal; em outras cinco, administraram-se 30µg de análogo do hormônio liberador de gonadotrofinas (GnRH), via intravulvar, seguidos de 5µg de cloprostenol, via intraperitoneal, após sete dias e, após mais dois dias, nova dose do análogo de GnRH. A cada três dias, a ciclicidade reprodutiva dos animais foi monitorada, por meio de coleta de sangue, para dosagem hormonal, ultrassonografia ovariana e citologia vaginal. Duas das fêmeas que receberam apenas prostaglandina, as quais estavam em fase luteal no início do tratamento, manifestaram o estro aos três e seis dias após a segunda administração da droga. Já nas fêmeas que receberam a prostaglandina associada ao análogo do GnRH, duas que originalmente estavam em fase luteal apresentaram estro aos quatro dias após o tratamento, e uma outra apenas após 10 dias. Não foram evidenciadas diferenças estatísticas quanto à eficiência dos tratamentos (P>0,05). Conclui-se que, de acordo com os protocolos utilizados, o uso da prostaglandina isolada ou em associação com análogo do GnRH para a indução do estro em cutias D. leporina apresenta eficiência limitada às fêmeas que estejam em fase luteal por ocasião do início do tratamento.(AU)

We compared the efficiency of protocols for estrus induction in agoutis. Five females received double intraperitoneal administration of cloprostenol (5µg) on a 2-days interval; other five females were treated with intravulvar administration of 30µg gonadotrophin release hormone analogue (GnRH associated to intraperitoneal administration of 5µg cloprostenol after seven days and a new administration of GnRH analogue after two days. Every 3 days, the agoutis' reproductive cycle was monitored by blood collection for hormonal analysis, ovarian ultrasound and vaginal cytology. Two females, originally in luteal phase, that received isolated prostaglandin presented estrous signs at 3 and 6 days after the second drug administration. From the females that received the association, two that were originally in luteal phase presented estrus at 4 days after treatment, and one other presented estrus only after 10 days. There was no significant statistical difference regarding the efficiency of treatments for estrus induction (P>0.05). We conclude that, according to the protocols tested in the study, the use of isolated prostaglandin or its association to GnRH analogue for estrus induction in D. leporine shows an efficiency limited to the females that were in luteal phase in the beginning of the treatment.(AU)

Expression of proliferating cell nuclear antigen in the endometrium of mares during estrus and at early diestrus / Expressão do antígeno núcleo celular proliferante no endométrio de éguas durante o estro e início do diestro

Immunohistochemical expression of proliferating cell nuclear antigen (PCNA) was evaluated in the endometrium of mares during estrus and at early diestrus. Three samples were collected by endometrial biopsy from 10 mares, on estrus/ second day, in the ovulation day and seven days after the ovulation day. PCNA expression was high in luminal epithelium and low in endometrial glands on samples taken on estrus/second day and on the ovulation day (p 0.05). For samples collected on the seventh day following ovulation, the averaged PCNA immunostaining was higher in glandular epithelium (p 0.05). The study revealed that luminal epithelial cells exhibit higher proliferation during estrus and glandular epithelial cells exhibited higher proliferation during diestrus...

A expressão do antígeno núcleo celular proliferante (ANCP) foi avaliada no endométrio de éguas durante o estro e início do diestro. Em cada uma de dez éguas foram efetuadas biópsias do endométrio em três momentos dos respectivos ciclos reprodutivos: segundo dia do estro, dia da ovulação e sete dias após a ovulação. Nas amostras colhidas no segundo dia do estro e no dia da ovulação, a expressão do ANCP foi elevada no epitélio luminal e baixa nas glândulas endometriais (p 0,05). Nas amostras colhidas no sétimo dia após a ovulação, a média de ANCP imunologicamente corado foi maior no epitélio glandular (p 0,05). O estudo revelou que as células do epitélio luminal apresentaram a maior proliferação durante o estro e que as células epiteliais glandulares apresentaram a maior proliferação durante o diestro...

Study on the vaginal smear of rats submitted to autologous ovarian transplant: impact of remote ischemic preconditioning / Estudo do esfregaço vaginal de ratas submetidas a transplante autólogo de ovário: impacto do precondicionamento isquêmico remoto

PURPOSE: To evaluate the remote ischemic preconditioning (R-IPC) impact on the quality of the ovarian graft by means of vaginal smear of transplanted rats. METHODS: Sixty rats were used divided in six groups: Control; Fresh transplant (TxF); Cryopreserved transplant (TxC); R-IPC; R-IPC + fresh transplant (TxF+R-IPC); R-IPC + cryopreserved transplant (TxC+R-IPC). R-IPC was performed in the common iliac artery. Autologous ovarian tissue was implanted integrally in the retro peritoneum. On the first PO day, vaginal smear collection was daily initiated. After 30 days, the PO day when the estrous cycle was re-initiated was considered for analysis as well as the estrous days and the number of estrous cycles. RESULTS: R-IPC showed a tendency to an early estrus re-initiation (p>0.05) as well as increase the number of cycles in the fresh transplanted group while in the cryopreserved transplant the number of cycles was similar, regardless of the stimulus R-IPC (p>0.05). The animals which had undergone fresh grafts had a longer estrous period than the ones which had undergone cryopreserved grafts, with or without R-IPC (p<0.05). CONCLUSION: R-IPC promoted earlier re-initiation of ovarian activity in the PO and greater estrous frequency, with more consistent results in the fresh grafts than in the cryopreserved ones.

OBJETIVO: Avaliar o impacto do precondicionamento isquêmico remoto (PCI-R) na qualidade do enxerto ovariano através dos esfregaços vaginais dos animais transplantados. MÉTODOS: Foram utilizadas 60 ratas, distribuídas em seis grupos de estudo: Controle; Transplante fresco; Transplante criopreservado; PCI-R; PCI-R + Transplante fresco; PCI-R + Transplante criopreservado. O PCI-R foi realizado na artéria ilíaca comum. O tecido ovariano foi implantado íntegro no retroperiônio. No 1º dia de pós-operatório (PO) foram coletados esfregaços vaginais diariamente. Após 30 dias foram considerados para análise o dia de PO de retorno do estro, assim como o número de dias em estro e de ciclos estrais. RESULTADOS: PCI-R mostrou tendência em reinício mais precoce do cilo estral (p>0,05), assim como aumento no número de cilcos estrais nos grupos com transplante fresco enquanto que no criopreservado o número de ciclos foi semelhante, independente do PCI-R (p>0,05). Os animais que receberam enxertos frescos apresentaram mais dias na fase estro do que os criopreservados, com ou sem PCI-R. CONCLUSÃO: O PCI-R promoveu retorno mais precoce da atividade ovariana no PO e maior freqüência de estro, sendo os resultados mais consistentes nos enxertos frescos do que nos criopreservados.

Determinação do ciclo estral em ratas por lavado vaginal / Determination of estrous cycle in rats by vaginal lavage

Objetivo: determinar as fases do ciclo estral em ratas, utilizando o lavado vaginal, fornecendo a pesquisadores considerações úteis para o seu reconhecimento. Métodos: coleta da secreção vaginal de ratas wistar, por lavado vaginal a fresco, observada em microscópio ótico com objetivas de 10 e 40 vezes, realizada pela manhã, durante dois ciclos completos, em 70 ratas. Resultados: o ciclo estral tem duração média de quatro dias e pode ser dividido em diestro I e II, proestro e estro, os quais podem ser determinados pela distribuição dos tipos celulares no lavado vaginal. Os três tipos celulares que predominam são os leucócitos, células arredondadas nucleadas e células epiteliais cornificadas. Conclusão: o lavado vaginal de ratas constitui um método importante para o estudo das alterações que ocorrem durante o ciclo estral, devido às mudanças abruptas nos níveis de estradiol que ocorrem nas quatro fases do ciclo. A observação é rápida e fácil de ser realizada.