Gut microbiota affects the estrus return of sows by regulating the metabolism of sex steroid hormones

Background Sex hormones play important roles in the estrus return of post-weaning sows.Previous studies have demonstrated a complex and bi-directional regulation between sex hormones and gut microbiota.However,the extent to which the gut microbiota affects estrus return of post-weaning sows is largely unknown.Results In this study,we first screened 207 fecal samples from well-phenotyped sows by 16S rRNA gene sequencing and identified significant associations between microbes and estrus return of post-weaning sows.Using metagenomic sequencing data from 85 fecal samples,we identified 37 bacterial species that were significantly associated with estrus return.Normally returning sows were characterized by increased abundances of L.reuteri and P.copri and decreased abundances of B.fragilis,S.suis,and B.pseudolongum.The changes in gut microbial composition significantly altered the functional capacity of steroid hormone biosynthesis in the gut microbiome.The results were confirmed in a validation cohort.Significant changes in sex steroid hormones and related compounds were found between normal and non-return sows via metabolome analysis.An integrated analysis of differential bacterial species,metagenome,and fecal metabolome provided evidence that normal return-associated bacterial species L.reuteri and Prevotella spp.participated in the degradation of pregnenolone,progesterone,and testosterone,thereby promoting estrogen biosynthesis.Furthermore,the microbial metabolites related to sow energy and nutrient supply or metabolic disorders also showed relationships with sow estrus return.Conclusions An integrated analysis of differentially abundant bacterial species,metagenome,and fecal metabolome revealed the involvement of L.reuteri and Prevotella spp.in sow estrus return.These findings provide deep insight into the role of gut microbiota in the estrus return of post-weaning sows and the complex cross-talk between gut microbiota and sex hormones,suggesting that the manipulation of the gut microbiota could be an effective strategy to improve sow estrus return after weaning.

Synchronization of Estrus in Sheep in Different Seasons

[Objectives] The aim was to improve and stabilize the estrus synchronization of local sheep in Xinjiang during the breeding season and non-breeding season. [Methods]The data of estrus rate and estrus concentration time were analyzed by different hormone treatment programs. [Results]eding season,whether PMSC was used did not affect the estrus of sheep when sponge and PG were used（ P 〉 0. 05）. Estrus was concentrated in 36-48 h after sponge plugs were removed,and the estrus rate in this period accounted for 74. 19% of the total. In non-breeding season,the estrus rate in the sponge plug plus PGF treatment was only56. 12%,significantly lower than that（ 90. 43%） in the sponge plug plus PG plus PMSG treatment（ P 〈 0. 01）. The estrus was also concentrated in 36-48 h after sponge plugs were removed. The estrus rate at this stage was 67. 42%,accounting for 82. 8% of the total. In breeding season,the estrus rate in sheep injected with333 IU of PMSG（ 81. 96%） was significantly lower than those of sheep injected with 500（ 90. 25%） and 750 IU（ 95. 3%）（ P 〈 0. 05）. [Conclusions] This study provides a theoretical basis for the production enterprises to save a lot of manpower and material resources.

Effects of Ficus asperifolia on normal rat estrus cyclicity

Objective:To evaluate Ficus asperifolia(Moraceae)(F.asperifolia)effecting on regular estrus cycle of Wistar rats.Methods:Air-dried fruits of F.asperifolia were extracted using water.Prior to the test,vaginal smear was monitored daily for a 3-week period to select females with normal(regular)estrous cycle.Those with regular estrus cycle weighing between 150-170 g were randomized into three sets of 15 animals each.Each set was then divided into three groups:Group 1(control)was orally administered with distilled water(10 mL/kg body weight)once a day for 1 week starting from the proestrus stage.Groups 2 and 3 were respectively treated with 100and 500 mg/kg body weight of the plant aqueous extract.The two other sets of 15 animals each were similarly treated as the first set for 3 weeks and 6 weeks respectively.Estrus cycle pattern was monitored before and during plant extract application whereas lipid profile,ovary,uterus and liver growth indices were determined at the end of each treatment.Results:F.asperifolia did not disrupt(0%)the order of appearance of normal estrus cycle stages,namely,proestrus,estrus,metestrus and diestrus.Short-term treatment(1 week duration)exhibited high frequency of appearance of proestrus and estrus stages while mid-(3 weeks)and long-term(6 weeks)treatments revealed constancy in the frequency of all stages irrespective to animal groups.The plasma and organ lipid profile,as well as ovary,uterus and liver growth remained unchanged when compared to distilled water-treated animals.Following long-term administration of plant extract(6 weeks),no adverse effect was noticed.Conclusions:Our data partially support the use of F.asperifolia in common medicine.

Identification Effects of Pedometer on Estrus of Holstein Cows during Peak Lactation Period

[Objective]The paper was to discuss identification effects of pedometer on estrus of Holstein cows during peak lactation period. [Method]The estrus of Holstein cows during peak lactation period were identified by manual observation and pedometer monitoring. [Result]Compared with manual observation,the detection rate of estrus in Holstein cows using pedometer monitoring was increased by 24. 01%,which reduced the labor cost and enhanced accuracy rate. [Conclusion]The research could provide reliable basis for estrus identification of cows.

Estrus Synchronization and Artificial Insemination with Fresh and Chilled Semen in Assaf Ewes

This paper aims to study the efficiency of two short-term progestagen (FGA vs. MAP) + eCG treatments in estrus synchronization and artificial insemination (AI) with fresh or chilled semen in Assaf ewes fertility rate. All ewes received a subcutaneous implant of exogenous melatonin 45 days before been treated with short-term progestagens + eCG. By June 1st, ewes were divided in two groups: half was treated with an intravaginal sponge impregnated with 20 mg of FGA and the other half with an intravaginal sponge impregnated with 60 mg of MAP. Progestagen treatments lasted for 6 days. At sponge withdraw, all ewes were injected with 750 IU of eCG. Ovarian activity was assessed by plasmatic progesterone levels before and after progestagens + eCG treatment. Semen was collected by electro ejaculation and extended with Andromed? or OviXcell?. AI was performed 55 hours after eCG administration with fresh or chilled semen. During AI several factors were assessed: vagina mucosa color and lubrication, external cervical Os type, cervical mucous viscosity, semen deposition place and seminal cervix outflow. Semen was deposited as deep as possible without distress or trauma cervix mucosa. All Assaf ewes presented cyclic activity before progestagen + eCG treatments (2nd fortnight of May). Short-term progestagen + eCG treatments were equally efficient (100.0%). About 76.5% of Assaf ewes were pregnant 41 days after AI. Fertility rate was influenced by external Os type, semen deposition place and seminal cervix outflow. However, this rate was not conditioned by vaginal color or lubrication, cervical mucus viscosity, semen preservation technic and semen extender.

Effect of short-term gavage of ethanolic extract of cogon grass (Imperata cylindrica L) root on the ovarian activity and estrus behavior of female mice

Objective:To assess the effect of short-term gavage of ethanolic extract of Imperata cylindrica L root on the ovarian activity and estrus behavior of female mice.Methods:Eighteen virgin female ddY mice,8 to 10 weeks of age,weighing 22-25 g with regular estrus cycle,were divided into three groups.Group 1 received 0.5%carboxymethylcellulose,whereas Groups 2 and 3 received the ethanolic extract of Imperata cylindrica L root at 90 and 115 mg/kg body weight(b.w.)per day by gavage for 20 days,respectively.All of the groups were checked before 9 a.m.daily for vaginal cytology to determine the estrus phase.On day 21,the mice were sacrificed to collect serum samples to quantify the concentrations of reproductive hormones using enzyme-linked immunosorbent assay and to determine changes in the reproductive organs based on their reproductive organ weight,histomorphology,and histomorphometry of ovarium and uterus.Results:The reproductive organ weight in the treatment groups was similar compared with that in the control group.The 90 mg/kg b.w.treatment group showed an increase in corpus luteum number when compared with the control group,with few degenerated follicles and diminished oocytes.Moreover,the 115 mg/kg b.w.treatment group showed fewer primordial and primary follicles and an increase in corpus luteum number and a prolonged diestrus phase compared to the control and 90 mg/kg b.w.treatment groups.The histomorphology examination of the uterus showed that the thickness of myometrium and epithelium in the treated animals was similar to the control group.In addition,there was a significant decrease in follicle-stimulating hormone level in the 115 mg/kg b.w.treatment group(P<0.05).Conclusions:Short-term gavage of ethanolic extract of Imperata cylindrica L root reduces the follicle-stimulating hormone serum level and folliculogenesis.

Efficacy of anti-microbial agents on vaginal microorganisms and reproductive performance of synchronized estrus ewes

Objective:To isolate and identify microflora and fungal species at different phases during estrus synchronization of ewes and estimate their prevalence;compare the effectiveness of antimicrobial administration to intravaginal sponge on the changes in the vaginal micro-organisms and reproductive performance.Methods: Sixty Egyptian ewes were allocated into three equal groups (G: 1, 2 and 3). G1 was inserted with vaginal sponge containing medroxy-progesterone acetate and served as control;without antimicrobial additive. The other two groups were treated as G1, but sponges were previously injected with ciprofloxacin (G2), while sponges of G3 were injected with ciprofloxacin and clotrimazole. Vaginal swabs were collected from each treated ewe, prior sponge insertion, at sponge withdrawal and 48 h later for microbiological investigation and bacterial count. On the day of sponge removal, 300 IU/eCG was administered for each treated ewe. The identified bacterial strains before sponge insertion were tested for sensitivity with antimicrobial disks.Results:Bacterial isolates before sponge insertion were more sensitive to ciprofloxacin. Frequencies of ewes in estrus;the interval from sponge withdrawal to onset estrus and the duration of estrus were statistically similar among treated groups. The pregnancy rate in G2 (100%) was higher than G1 (66.7%) and G3 (82.4%). The total bacterial count before sponge insertion was similar between all treatments and increased significantly in all groups on the day of sponge withdraw. The prevailing bacteria on D0, D14 and 48 h after sponge removal for all treated groups wereStaphylococcus spp. followed byEscherichia coli. Regarding to fungus species, percentages of isolation increased from 5% (before sponge insertion) to 100.00% and 88.89% at sponge withdraw for G1 and G2, respectively. In G3, the fungus was declined from 10% (before sponge insertion) to 5% (at sponge removal).Conclusions:The concomitant treatments by antimicrobial to the vaginal sponge which used for estrus synchronization in ewes can improve reproductive performance.

Evaluation of two methods of estrus synchronization of cattle in Chad

The results of an artificial insemination experiment carried out in the suburban area of N’Djamena are here reported. Two methods of synchronization (Norgestomet combination/estradiol/PGF2a/PMSG and PGF2a only) were used with Chadian zebu and crossed breeds in 2007 and 2008. Females were inseminated after induction of estrus with semen of French Normand breed. The fertility rate was low with PGF2a (29.41%). The results obtained with the combination of several hormones were better (66.66%). The survival rates of crossbreeds were particularly low, 40% in 2007 and 33.33% in 2008, mainly due to the traditional management of the herd and the lack of technical support. The insemination cost of a cow was 39,550 F CFA in 2007 with PGF2a and 59,200 F CFA in 2008 with the method consisting of combining of four hormones. The cost of producing a calf in those two years was very high, 134,470 F CFA in 2007 and 118,400 F CFA in 2008.

Variations in Reproductive Hormones during Estrus Cycle in Local Beef Cattle from Jilin of China

[ Objective] To provide a theoretical basis for improving reproductive efficiency of domestic beef cattle in Jilin of China. [ Method] China Red Steppe cattle, Yanbian yellow cattle and Simmental cattle in Jilin Province were used for detection. The levels of progesterone （P4）, estradiol （ E2 ）, follicle-stimulating hormone （FSH） and luteinizing hormone （LH） in serum and urine during estrus cycle were determined. [ Result] The levels of P4 and E2 were significantly different between pregnant cattle and non-pregnant cattle on Day 21 post estrus （ P 〈 0.01 ）. The level of LH on estrus day was significantly different from that on the other days of estrus cycle （ P 〈 0.05）. [ Conclusion] It is feasible to detect P4 level for diagnosis of estrus and eady pregnancy in beef cattle.

Estrus Grouping in Sheep Treated with Melengestrol Acetate （MGA）

In Mexico the predominant sheep production system is the semi-extensive with grazing during the day and stanchion afternoon and night. Sheep herd are usually small, approximately 10 to 75 heads. The objectives of these systems are savings and marketing of lambs. Meat is the main economic product of this kind, the breeding is long, which do not control the delivery dates and ages of the sheep are not uniform, affecting the demand for the local market （for the months of June and December）. Therefore the aim of this work was implement a technology that allows the grouping of the estrus and therefore group deliveries for batches of uniform lambs. This technology was designed to suppress the estrus and heifers growth promoter of feedlots, this technology is melengestrol acetate （MGA） which is a synthetic progesterone oral administration that it is easy to manage in the food or alone, economic that it does not represent any risk for sheep females of abortive type, evaluating the effect of the MGA on rate of estrus and gestation in sheep. Work developed in the municipality of Charo from Michoac^in State, M6xico, 20 hair sheep divided in two groups of 10 female, group one treated with MGA and group tow was the whitens. 100% of the sheep treated with a dose of 0.45 mg MGA/head/day for 17 days orally, presented estrus grouped in 5-10 days; however only 50% of the sheep of the witness group presented estrus. In the experimental group there was a rate of 70% with a gestation difference time of no more than ten days gestation and witness group 50%. The MGA is an efficient alternative for the producer of sheep when administered 0.45 mg MGA/head/day for 17 days because inhibits the estrus and once withdrawn treatment manifests estrus synch with which get a rate of gestation elevated by natural riding.

Study of Estrus Cow Serum （ECS） in Maturation Media on in vitro Maturation Rate of Bovine Oocytes

The objective of this research was to study the effect of ECS on cumulus expansion and rate of nucleus maturation of bovine oocytes. Media maturation were used： （1） TCM 199 ＋ FCS 10%; （2） TCM 199 ＋ FCS 10% ＋ ECS 5%; （3） TCM 199 ＋ FCS 10% ＋ ECS 7, 5%; （4） TCM 199 ＋ FCS 10% ＋ ECS 10%; （5） TCM 199 ＋ ECS 10%. Supplementation of ECS had significantly difference （P 〈 0.05） on expansion of cumulus cells and rate of nucleus maturation. Supplementation of ECS 5% was the best result in expanded cumulus cells and metaphase II rate： 82% and 72% respectively. It was concluded that medium of TCM 199 ＋ FCS 10%o ＋ ECS 5% was the best maturation medium

Comparative Study of Two Methods of Induction of Estrus and Fertility Following Artificial Insemination in Azawak Zebu in Niger

A comparative of two induction methods of estrus induction and fertility has been carried out on 28 females Azawak zebu in Niger. This study mains chiefly and identifying the most effective method for better inseminations. The females have been divided into two sets following two intra-vaginal devices used. Two sub-sets of 7 females have been formed according to the PMSG dose associated with the treatment. Two inseminations have been carried out. The results are as follows： response to the induction： PRIDe, 57.14%; CIDR-B, 61.53%. Fertility rate： PRIDe, 28.57%; CIDR-B, 38.46%. There has been no significant difference to the estrus induction and fertility, between the PRIDe and the CIDR-B synchronization. Since the two methods virtually lead to the same response rate, the stock breeder can choose one of the methods depending on the cost and by paying attention to the feeding and less stressful factors.

Management Practice and Comparison of Reproductive and Productive Performance of Dairy Cattle between Beneficiary and None Beneficiary of Estrus Synchronization and Mass Insemination in North Shewa Zone,Amhara Region,Ethiopia

The aim of this study was to assess the overall management practice and comparison of reproductive and productive performance between beneficiaries and none beneficiaries of oestrus synchronization and mass insemination(OSMI)of dairy cattle in north shewa zone of dairy cattle.Data were obtained by interviewing 270 estrus synchronization and mass insemination beneficiaries and 135 none beneficiaries’dairy farmers.Data were analyzed using Statistical Packaging for social science(SPSS)version 20.Natural pasture and crop residue were the most common feed resources in the study areas.River water was the major source of water for their cattle and well water was used when river water is not available.In their order of importance;FMD,mastitis,and abortion were the major diseases of cattle in the study area.The reproductive performance of dairy cows in OSMI beneficiaries were age at first service(30.81±7.6),calving interval(6.9±5.2),lactation length(8.95±2.46),day open(5.3±3.18)and number of service per conception(1.5±0.38)whereas in none beneficiary age at first service(32.88±6.64),calving interval(18.18±5.8),lactation length(9.6±0.54),day open(5.17±3.43)and number of service per conception(1.22±0.54)months.There was a significant(p<0.05)difference in milk yield between beneficiaries and none beneficiaries in HFC,HHFC and JERC dairy cows per day per cow.The major factors affecting reproductive performance of dairy cows are management,nutritional status,genotype,and disease.Therefor the productive and reproductive performance of the dairy cows reared by the participants were better than those of the nonparticipants.

Pharmacological Control of Estrus in Tropical Cattle,an Economical Assessment of Different Synchronization Protocols

To compare the fertility results and to assess the cost-effectiveness of several synchronization protocols applied under the conditions of beef cattle enterprises in Colombia, 1658 multiparous zebu crossbred cows mostly Brahman and Nelore ranging between 2 - 6 parities were used. Five protocols of pharmacological treatments varying in hormones used, dosage and the time of application were tested. All cows were inseminated at 52 h by appointment. Pregnancy diagnosis was undertaken over 45 d after insemination by rectal palpation. The total cost per cow and the total cost per gestation, for each protocol, were calculated. Taking a herd of one-hundred cows as baseline for calculations, it was estimated the cost of the total amount of pregnancies possibly obtained in each protocol;then, the excess between the costs of a pregnant cow and the cost of a treated cow was estimated. Additionally, the costs due to cows empty after four services were calculated. A total of 874 pregnancies were registered (52.7%), with pregnancies per protocol varying between 46.9% and 66.2% (p < 005). The cost per treated cow, varied between $64.08 and $97.47 and the cost per gestation from $126.01 to $177.26, without association between the cost of the treatment and the pregnancy rate. Protocol A was the best cost-effective with the lowest additional costs, the lowest amount of open days (2107.7 to 2231.7 d) and IA straws (average = 134), with an additional costs of $6940.00. Synchronization of estrus using pharmacological products seems to have a place in the management of cattle;however, caution should be called upon a careful assessment both from the part of the farm and the professional in charge of the enterprise to avoid using the technique indiscriminatively thus propitiating the use of a method that might not be cost efficient.

Automatic detection of sow estrus using a lightweight real-time detector and thermal images

Determination of ovulation time is one of the most important tasks in sow reproduction management.Temperature variation in the vulva of the sows can be used as a predictor of ovulation time.However,the skin temperatures of sows in existing studies are obtained manually from infrared thermal images,posing an obstacle to the automatic prediction of ovulation time.In this study,an improved YOLO-V5s detector based on feature fusion and dilated convolution(FDYOLOV5s)was proposed for the automatic extraction of the vulva temperature of sows based on infrared thermal images.For the purpose of reducing the model complexity,the depthwise separable convolution and the modified lightweight ShuffleNet-V2 module were introduced in the backbone.Meanwhile,the feature fusion network structure of the model was simplified for efficiency,and a mixed dilated convolutional module was designed to obtain global features.The experimental results show that FD-YOLOV5s outperformed the other nine methods,with a mean average precision(mAP)of 99.1%,an average frame rate of 156.25 fps,and a model size of only 3.86 MB,indicating that the method effectively simplifies the model while ensuring detection accuracy.Using a linear regression between manual extraction and the results extracted using this method in randomly selected thermal images,the coefficients of determination for maximum and average vulvar temperatures reached 99.5%and 99.3%,respectively.The continuous vulva temperature of sows was obtained by the target detection algorithm,and the sow estrus detection was performed by the temperature trend and compared with the manually detected estrus results.The results showed that the sensitivity,specificity,and error rate of the estrus detection algorithm were 89.3%,94.5%,and 5.8%,respectively.The method achieves real-time and accurate extraction of sow vulva temperature and can be used for the automatic detection of sow estrus,which could be helpful for the automatic prediction of ovulation time.

Application of Artificial Insemination in Selective Breeding of Native Beef Cattle in Wenzhou

[Objective]The paper was to improve the quality and growth rate of native yellow cattle in Wenzhou.[Method]Three groups of cattle were subjected to artificial insemination using frozen semen from Wagyu bull.The groups consisted of 20 native yellow cattle,20 Angus catle,and 20 Luxi yellow cattle.The heifers were subsequently evaluated for body size and body weight,and underwent treatment with estrus synchronization,artificial insemination,and early pregnancy diagnosis.[Result]The mean body size and body weight of native yellow cattle were found to be significantly lower than those of Angus cattle and Luxi yellow cattle(P<0.05).The estrus synchronization rate and mating rate of native yellow cattle were both 100%,while the corresponding rates for Angus cattle and Luxi yellow cattle were 90%and 95%,respectively.The ultrasound examination conducted on the 32m day following the mating revealed a distinct image of gestation sac,which,when considered alongside the findings of the rectal examination,may be indicative of pregnancy.The conception rates were 75%,72%,and 74%for native yllow cattle,Angus cattle,and Luxi yellow cattle,respectively.[Conclusion]The reproductive performance of native beef cattle is relatively superior.

Potential of an activity index combining acceleration and location for automated estrus detection in dairy cows

The objective of this study was to assess the effectiveness and practicability of an activityindex combining acceleration and location data for automated estrus detection in dairycows. By using a wearable neck tag, measurements of acceleration and location were gathered from 22 multiparous cows monitored incessantly for 6 days to derive activity recordsof each cow. The maximum-minimum distance clustering (MMDC) method was used todivide hourly activity data into low, medium, high, and intensity level groups. The weightedsum of the proportions of the low, medium, high, and intensity activities in an hour constituted the activity level. The activity index was defined as the ratio of the variation inhourly activity level compared to the same time period during the previous three days. Furthermore, whether the cow was in estrus was judged above a set threshold. The studyshowed that the power consumption and communication effects of the neck tags wereacceptable for indoor-housing conditions. For the two consecutive time periods, theactivity-index-based detection algorithm achieved 90.91% for accuracy, 100% for precision,100% for specificity, 83.33% for recall, 90.91% for F1 score, and 0.82 for Kappa coefficient. Onthe basis of these results, it can be concluded that the combination of acceleration andlocation in the activity index can promote estrus detection in dairy cows.

Relationship between estrus cycles and behavioral durations of captive female alpine musk deer

Owing to poor breeding success in captive alpine musk deer, an understanding of the behavioral patterns of muskdeer in captivity is important. This study was conducted from June 2004 to January 2005 at the Xinglongshan MuskDeer Farm, which is located within Xinglongshan National Nature Reserve, Gansu Province, China. Focal samplingand continuous recording were used to observe the behaviors of 51 female alpine musk deer (Moschus sifanicus),42 of which had completed a single estrus cycle and nine of which had completed two or more estrus cycles. Allanimals were adults that had been born and raised in captivity. The durations of 12 behaviors, including environmentalsniffing, moving and feeding, were recorded during the non-breeding seasons and behavioral patterns werecompared. The behavioral patterns of females that had completed a single estrus cycle and females that hadcompleted multiple estrus cycles were compared to assess potential behavioral differences. The results showed thatfemales who had only one complete estrus cycle demonstrated more resting behavior, but less feeding and locomotorbehavior than females who had completed multiple estrus cycles. Furthermore, single estrus cycle femalesdemonstrated tail-rubbing during the breeding season. The results may yield useful information that can be used indeveloping better musk deer farming practices.

Resumption of ovary activity and normal estrus cycles in postpartum cows after inclusion of placenta-containing additives in the diet

Food additives made of placenta tissues of healthy cattle,included in the diet of cows 23-38 days before calving and/or in different intervals of the postpartum period,stimulated the resumption of ovary activity and the manifestation of normal estrus cycles(with ovulation)in cows.The cow fertilization rates during 80 days after calving was 50-80%.These values increased more than twofold in comparison with the fertility level of cows fed a normal diet.The level of fertilization after inclusion of placenta-containing additives in the diet of cows 5 days before ovulation,in estrus cycles that took place during 6 months after calving,increased 38%on average,in comparison with that of cows fed a normal diet.

Fecal progesterone and estradiol changes during the breeding season in captive female wolf

Understanding basic reproductive physiology is crucial for the management of both captive and free-ranging wolf. In the present study, we determined hormonal changes during pregnancy and the estrous cycle in captive female wolf by measuring fecal steroids collected during the breeding season with high performance liquid chromatography （HPLC）. These biochemical analyses were validated using chemical devivatization and mass spectrometry, and interpreted along with the behavioral data. All four females undergoing estrus cycles were copulated with their partners and delivered pups successfully. We found that estradiol concen-trations were significantly higher during the estrus cycle than other stages （p0.01） and progesterone was also significantly increased throughout the pregnancy （p0.01）. These hormonal fluctuations demonstrated pregnancy-specific changes in the fecal progesterone and estradiol con-centrations. Patterns of fecal estradiol and progesterone concentrations during estrous cycles were similar to those reported for other canids.