Seasonal changes in reproductive and pelage status during the initial ‘quiescent’ and first ‘active’ breeding seasons of the peripubertal pony colt

2001 ◽  
Vol 72 (1) ◽  
pp. 55-64 ◽  
Author(s):  
C. McG. Argo ◽  
M.G. R. Collingsworth ◽  
J. E. Cox
Keyword(s):  
Breeding Season ◽  
Seasonal Changes ◽  
Day Length ◽  
Low Concentrations ◽  
Lh Release ◽  
Group 2 ◽  
Plasma Prl ◽  
Breeding Seasons ◽  
Biphasic Profile ◽  
Group 1

AbstractPony colts (~12 m) are generally infertile during the breeding season of mature stallions. The mechanism which ‘delays’ puberty beyond the first potential breeding opportunity has not been described. Four pre- and four post-pubertal colts were monitored from November for 13 (group 1, 6 to 19 months of age) and 9 months (group 2, 18 to 27 months of age). Fortnightly, 15 blood samples were collected at hourly intervals from each colt to determine concentrations of prolactin (PRL), LH, FSH and testosterone (T). Testicular biopsies were collected monthly to evaluate spermatogenic activity. Puberty occurred between 17 and 19 months, and at the onset of the 2-year-old breeding season, all colts were fertile. Seasonal changes in the concentrations of all four hormones were observed in both groups. Prolactin concentrations were correlated with changes in day length (r = 0·88) in both groups, but a biphasic profile was noted in group 1. Moulting of the winter coat was coincident with seasonally increased PRL concentrations (P < 0·001). Seasonal changes in FSH, LH and T concentrations were similarly timed between groups and levels were maximal in mid April, mid March and mid May, respectively. However, overall mean concentrations of LH and T in group 1 animals were only 0·33 and 0·22 of group 2 values (P < 0·001). Suppression of gonadal activity during the colts’ first ‘quiescent’ breeding season was associated with low concentrations of circulating LH. Appropriately timed changes in plasma PRL, FSH and T concentrations and pelage indicated that the photoperiodic mechanism was functional in the pre-pubertal colt but pituitary LH release may be blocked by immaturity or active suppression.

scholarly journals Measurement of drug concentration and bacterial contamination after diluting morphine for intrathecal administration: an experimental study

2020 ◽  
Author(s):  
Aart Jan W. Teunissen ◽  
Mark V Koning ◽  
Elisabeth J Ruijgrok ◽  
Willem J Liefers ◽  
Bart J Bruijn ◽  
...  
Keyword(s):  
Bacterial Contamination ◽  
Intrathecal Injection ◽  
Intrathecal Administration ◽  
Contamination Rate ◽  
Target Concentration ◽  
Low Concentrations ◽  
The Difference ◽  
Group 2 ◽  
Process Trial ◽  
Group 1

Abstract Background: We did this study to analyse the risks posed by manual diluted morphine solutions intended for intrathecal use. Dilution of morphine is needed to achieve low concentrations for intrathecal injection. Dilution poses the risk of dilution errors and bacterial contamination. The primary goal was to compare the concentrations of morphine and bupivacaine between four groups of syringes. The secondary goal was to investigate the difference in contamination rate between these groups. Methods: 25 experienced anaesthesia providers were asked to prepare a mixture of bupivacaine 2.0 mg/ml and morphine 60 µg/ml using 3 different methods as clean and precise as possible. The fourth method used was the aspiration of ampoules prepared by the pharmacy. The concentrations of morphine and bupivacaine were measured by High-Pressure Liquid Chromatography (HPLC). The medication was cultured for bacterial contamination. Results: Group 1 (60 µg/ml; 95% CI: 59-110 µg/ml) yielded 3 outliers above 180 µg/ml morphine concentration. Group 2 (76 µg/ml; 95% CI: 72-80 µg/ml) and 3 (69 µg/ml; 95% CI: 66-71 µg/ml) were consistently higher than the target concentration of 60 µg. The group “pharmacy” was precise and accurate (59 µg/ml; 95% CI: 59-59 µg/ml). Two groups had one contaminated sample with a spore-forming aerobic gram-positive rod. Conclusion: Manually diluted morphine is at risk for deviating concentrations, which could lead to increased side-effects. Medication produced by the hospital pharmacy was highly accurate. Furthermore, even when precautions are undertaken, contamination of the medication is a serious risk and appeared to be unrelated to the dilution process. Trial registration: Not applicable

scholarly journals Seasonal expressions of VEGF and its receptors VEGFR1 and VEGFR2 in the prostate of the wild ground squirrels (Spermophilus dauricus)

2021 ◽  
Vol 65 (2) ◽  
Author(s):  
Yuchen Yao ◽  
Wenqian Xie ◽  
Di Chen ◽  
Yingying Han ◽  
Zhengrong Yuan ◽  
...  
Keyword(s):  
Mrna Expression ◽  
Breeding Season ◽  
Stromal Cells ◽  
Seasonal Changes ◽  
Ground Squirrels ◽  
Vascular Endothelial ◽  
Expression Levels ◽  
Breeding Seasons ◽  
Endothelial Growth Factor ◽  
Endothelial Growth Factors

As a vital male accessory reproductive gonad, the prostate requires vascular endothelial growth factors for promoting its growth and development. In this study, we investigated the localizations and expressions of vascular endothelial growth factor (VEGF) and its receptors including VEGF-receptor1 (VEFGR1) and VEGF-receptor2 (VEGFR2) in the prostate of the wild ground squirrels during the breeding and the non-breeding seasons. The values of total prostate weight and volume in the breeding season were higher than those in the non-breeding season. Histological observations showed that the exocrine lumens of the prostate expanded in the breeding season and contracted in the non-breeding season. The mRNA expression levels of VEGF and VEGFR2 in the prostate were higher in the breeding season than those in the non-breeding season, but the mRNA expression level of VEGFR1 had no significant change between the breeding and non-breeding seasons. Immunohistochemical results revealed that VEGF, VEGFR1 and VEGFR2 were presented in epithelial and stromal cells during the breeding and non-breeding seasons. In addition, the microvessels of the prostate were widely distributed and the number of microvessels increased obviously in the breeding season, while decreased sharply in the non-breeding season. These results suggested that expression levels of VEGF and VEGFR2 might be correlated with seasonal changes in morphology and functions of the prostate, and VEGF might serve as pivotal regulators to affect seasonal changes in the prostate functions of the wild male ground squirrels via an autocrine/paracrine pathway.

519. INFLUENCE OF THE DURATION OF CIDR INSERTION ON OVARIAN RESPONSES IN AN eCG PROGRAM DURING NON-BREEDING SEASON IN EWES

2009 ◽  
Vol 21 (9) ◽  
pp. 118
Author(s):  
R. Salehi ◽  
H. Kohram
Keyword(s):  
Breeding Season ◽  
Weight Maintenance ◽  
Live Weight ◽  
Standing Position ◽  
Beneficial Effects ◽  
The Mean ◽  
Group 2 ◽  
Maintenance Ration ◽  
Group 1 ◽  
Follicular Activity

The aim of this study was to investigate the effect of 14 versus 7 days CIDR insertion before eCG treatment on superovulatory responses during non-breeding season in ewes. 10 Iranian Shall ewes, between 2 and 3 years old were kept inside during the experiment period and were fed a live weight maintenance ration. Ewes were randomly assigned to 1 of 2 groups. CIDR was inserted to the ewes of group 1 for 14 days and for 7 days to group 2. Each ewe received 1500 IU eCG on the day of CIDR removal. Ovarian follicular activity was monitored by transrectal ultrasonography on the days of eCG treatment, estrus, and 7 days after estrus to monitor the number of corpus lutium. During examination the animals were held in a standing position. Scanning of both ovaries was recorded using a MP4 player. The number of medium and large follicles (≥3 mm in diameter) were recognized, measured and mapped to their location using printed images of both ovaries. Data were analyzed using GLM procedure of the SAS. The results presented in Table 1 shows that the ovarian responses in terms of the number of ≥3 mm follicles at estrus is greater (P<0.05) in group 1 than group 2 ewes. The mean number of CL after eCG injection in group 1 and 2 were also significantly different (3.6±0.24 vs 2.4±0.51; P<0.05). The results showed that the 14 days synchronization before eCG treatment during non-breading seasons in ewes had the beneficial effects on ovarian responses.

scholarly journals Testosterone-related and seasonal changes in sebaceous glands in the back skin of adult male brown bears (Ursusarctos)

2018 ◽  
Vol 96 (3) ◽  
pp. 205-211 ◽  
Author(s):  
Jumpei Tomiyasu ◽  
Yojiro Yanagawa ◽  
Yoshikazu Sato ◽  
Michito Shimozuru ◽  
Masashi Nagano ◽  
...  
Keyword(s):  
Breeding Season ◽  
Adult Male ◽  
Seasonal Changes ◽  
Ursus Arctos ◽  
Scent Marking ◽  
Plasma Testosterone ◽  
Sebaceous Glands ◽  
Brown Bears ◽  
Tissue Samples ◽  
Breeding Seasons

Adult male brown bears (Ursus arctos Linnaeus, 1758) display tree-marking behavior to chemically signal their dominance throughout the nondenning period, and this behavior peaks during the breeding season. Within the scent-marking sequence, back rub is a core marking posture. The present study investigated (i) seasonal changes in sebaceous glands in the back skin of brown bears and (ii) the relationship between those changes and testosterone levels. Back skin tissue samples and blood were collected from captive adult intact and castrated males during prebreeding, transitional, breeding, and postbreeding seasons, which were concurrent with back skin observations. In intact males, during the transitional and breeding seasons, an oily secretion from the back skin was observed along with enlarged sebaceous glands. The plasma testosterone concentrations during the transitional and breeding seasons were increased compared with the pre- and post-breeding seasons. Secretions and enlarged sebaceous glands were not found in castrated males, and the plasma testosterone concentrations remained at baseline levels. Oily secretions of the back skin glands that appear more abundant during the breeding season are rubbed against trees. Changes in size and volume of sebaceous glands, and thus their secreting capacity, are likely testosterone-regulated.

Itchgrass (Rottboellia cochinchinensis) Biotypes in World Populations

Weed Science ◽  
1993 ◽  
Vol 41 (3) ◽  
pp. 379-387 ◽  
Author(s):  
Rex W. Millhollon ◽  
David M. Burner
Keyword(s):  
Papua New Guinea ◽  
New Guinea ◽  
Day Length ◽  
Short Day ◽  
Group 4 ◽  
Natural Photoperiod ◽  
Group 5 ◽  
Group 2 ◽  
Reliable Marker ◽  
Group 1

Itchgrass biotypes from 34 countries or territories were evaluated under controlled and natural day length at Houma, LA. They could be placed in five broad groups based primarily on the effect of day length on flowering but also on general morphology and pattern of growth. The Group 1 biotypes (Argentina, Bolivia, Costa Rica, Cuba-1, Ecuador-1, Florida, Guadeloupe, Honduras-1, Louisiana-1, North Carolina, Papua New Guinea-1, Panama, Peru, Philippines-1, and Venezuela) were not affected by day lengths of 12 and 14 h (day length neutral) and flowered 35 to 57 d after germination. The Group 2 biotypes (Australia, Kenya-1, Reunion, South Africa, and Zimbabwe) also were not greatly affected by photoperiod and flowered 54 to 67 d after germination, and were taller with fewer and larger diameter culms than the Group 1 biotypes. The Group 3 biotypes (Brazil, Colombia, Jamaica, and Philippines-2) were moderately sensitive to photoperiod. They took longer to flower at 14 h than at 12 h and flowered in 63 to 95 d. The Group 4 biotypes (Cuba-2, Dominican Republic, Ecuador-2, Honduras-2, India, Louisiana-2, Malaysia, Papua New Guinea-2, Puerto Rico, Taiwan, and Thailand) were short-day plants that did not flower in the screenhouse until August or September (130 to 163 d), after the natural photoperiod had decreased to 13 h. The Group 5 biotypes (Indonesia, Kenya-2, Nigeria, Sudan, Tanzania, and Trinidad) were strict short-day plants that flowered only in September to November (167 to 226 d), after the day length had decreased to about 12 h. Most biotypes were diploids with 2n = 20 chromosomes, but some were polyploids (2n = 40 or 2n = 60). The shape of the glume tip on the pedicellate spikelet was found to be acuminate, acute, or obtuse for the biotypes with 2n = 20, 40, and 60 chromosomes, respectively, and was a reliable marker to distinguish diploids from polyploids.

scholarly journals Reduced LH sensitivity in vivo and in vitro of corpora lutea induced during anoestrus by GnRH, and during the late breeding season, in Scottish Blackface ewes

2004 ◽  
Vol 183 (3) ◽  
pp. 517-526 ◽  
Author(s):  
T A Bramley ◽  
D Stirling ◽  
G S Menzies ◽  
D T Baird
Keyword(s):  
Breeding Season ◽  
High Plasma ◽  
Corpora Lutea ◽  
Plasma Progesterone ◽  
Group 4 ◽  
Group 3 ◽  
Group 2 ◽  
Group 1

Scottish Blackface ewes were synchronised in mid-breeding (November; group 1; n=12 ewes) or late-breeding season (March; group 2; n=16). Anoestrous ewes (May) were treated with progestagen sponges for 7 days and then given 250 ng GnRH 3-hourly for 24 h, 2-hourly for 24 h and hourly for a further 24 h (group 3; n=12). A second group of anoestrous ewes (group 4, n=19) received three bolus injections (30 μg) of GnRH at 90-min intervals without progestagen pretreatment. After ovulation, ewes were bled twice daily until slaughter (day 4 or day 12: oestrus=day 0). Mid-breeding season (group 1) and anoestrous ewes in group 3 formed ‘adequate’ corpora lutea (CL) with high plasma progesterone levels (3–4 ng/ml) maintained for at least 12 days, and responded in vivo to ovine LH (oLH) (10 μg) with a rise in plasma progesterone on day 11 (group 3, but not group 1, ewes also responded on day 3). CL minces from these ewes responded to human chorionic gonadotrophin (hCG) in vitro with a dose-dependent increase in progesterone secretion. Ewes in group 4 had a foreshortened luteal phase (8–10 days) and low plasma progesterone levels (~1 ng/ml), consistent with formation of inadequate CL. LH injection failed to induce a significant plasma progesterone increase. Furthermore, although progesterone secretion in vitro in response to maximally stimulating doses of hCG or dibutyryl cAMP (dbcAMP) was similar to that in adequate CL, the sensitivity of these CL to hCG (EC (effective concentration)50, 1 IU hCG/ml) was reduced 10-fold compared with adequate CL (EC50, 0.1 IU hCG/ml; P<0.01). Ewes that ovulated in the late breeding season (group 2) had high plasma progesterone, although levels began to decrease after day 10. Injection of oLH in vivo increased plasma progesterone. However, sensitivity to hCG in vitro (EC50, 0.5 IU hCG/ml) was intermediate between that of adequate luteal tissue (groups 1 and 3; EC50, 0.1 IU/ml) and that of group 4 ewes (EC50, 1 IU hCG/ml). Our data demonstrate a markedly reduced luteal sensitivity to LH in vivo and hCG in vitro in Scottish Blackface ewes with inadequate CL, and suggest that a similar loss of sensitivity to LH may occur in the late breeding season.

scholarly journals Impact of Photoperiod Length and Treatment with Exogenous Melatonin during Pregnancy on Chemical Composition of Sheep’s Milk

Animals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1721
Author(s):  
Edyta Molik ◽  
Michał Błasiak ◽  
Henryk Pustkowiak
Keyword(s):  
Fatty Acids ◽  
Chemical Composition ◽  
Milk Yield ◽  
Saturated Fatty Acids ◽  
Monounsaturated Fatty Acids ◽  
Day Length ◽  
Exogenous Melatonin ◽  
Group 3 ◽  
Group 2 ◽  
Group 1

The aim of the study was to determine the effect of photoperiod and exogenous melatonin on milk yield and chemical composition of sheep’s milk. Sheep (n = 60) were randomly divided into three groups: lambing in February (Group 1—n = 20), lambing in June (Group 2—n = 20), and lambing in June and treated with subcutaneous melatonin implants (Group 3—n = 20). Milk yield was higher for Group 1 and Group 2 than for Group 3 (p < 0.01). The milk of ewes of Groups 2 and 3 had a significantly (p < 0.01) higher content of dry matter, protein, and fat. Group 3 sheep’s milk contained significantly more (p < 0.01) of SFA (Saturated Fatty Acids). The highest content of MUFA (Monounsaturated Fatty Acids) and PUFA (Polyunsaturated Fatty Acids) was found in the samples collected from Group 1, the lowest was in the milk of Group 3 animals. The highest (p < 0.01) CLA, content was identified in the milk of Group 1, while the lowest was recorded for the milk obtained from sheep treated with exogenous melatonin (Group 3). The experiment carried out has shown that day length and treatment with exogenous melatonin modulate the chemical composition of milk.

154 EVALUATION OF EMBRYO RECOVERY RATE AND EMBRYO TRANSFER IN ANGORA GOATS

2015 ◽  
Vol 27 (1) ◽  
pp. 168
Author(s):  
K. Karakas ◽  
H. Alkan ◽  
G. Onur ◽  
D. Ozen ◽  
M. Kaymaz ◽  
...  
Keyword(s):  
Pregnancy Rate ◽  
Breeding Season ◽  
Recovery Rate ◽  
Pregnancy Rates ◽  
Corpora Lutea ◽  
Embryo Survival ◽  
Embryo Recovery ◽  
Angora Goats ◽  
Group 2 ◽  
Group 1

The aims of this study were to compare the embryo recovery rate in Angora goats based on application timing; at the beginning (September – October; Group 1) and end (December; Group 2) of the breeding season and to evaluate the viability and survivability of fresh or vitrified-thawed embryos when transferred. For this purpose, nine Angora goats were used as donors and thirthy Angora goats were used as recipients. Donor goats were synchronized and superovulated with traditional protocol and were mated with fertile bucks. At the 156th hour of the mating, embryos were collected surgically and evaluated under a stereo microscope. In group 1, 103 embryos and in group 2, 63 embryos were collected from nine goats. Fresh or vitrified-thawed embryos were transferred surgically to synchronized recipients. In Group 1 fresh/thawed embryos were transferred to 15/15 goats and in group 2, fresh/thawed embryos were transferred to 8/8 goats, respectively. Each recipient received 1 or 2 embryos ipsilateral to the ovary containing one or more corpora lutea. On day 30 of the transfer, goats were examined by transrectal ultrasonography, pregnancy rates of fresh/thawed embryos were 66.6%/26.6% for group 1 and 62.5%/62.5% for group 2. On day 100 of the transfer, goats were examined again by ultrasonography, and pregnancy rates were 46.6%/0% for group 1 and 37.5%/0% for group 2, respectively. After about 50 days, goats were kidded. In group 1, 3 twins and 4 single kids were born; in group 2, 2 twins were born. The total number of collected embryos and pregnancy rates among the groups were analysed using SPSS® (version 14.01, Chicago, IL, USA) and for all comparisons, differences were considered with a minimum of 5% significance level. After statistical analyses, the numbers of collected embryos at the beginning and at the end of the breeding season were compared. There was no difference in freezable/transferable embryo quality. As a result, embryos could be collected after superovulation protocols in Angora goats both at beginning and end of the breeding season, however there might be a decrease in numbers of collected embryos and the reasons for this might not be only the seasonal factors but also the environment, care, nutrition and previous superovulation protocols. The pregnancy rate following transfer of fresh embryos was satisfactory but not all does confirmed pregnant kidded; hence, reducing the number of recipients kidding. The pregnancy rate following transfer of vitrified-thawed embryos was generally low and unsatisfactory. Further research is warrented in improving the cryopreservation techniques and thus the embryo survival rate of Angora goat embryos. This study was financed with the University of Ankara Grant.

scholarly journals Measurement of drug concentration and bacterial contamination after diluting morphine for intrathecal administration: an experimental study

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Aart Jan W. Teunissen ◽  
Mark V. Koning ◽  
Elisabeth J. Ruijgrok ◽  
Willem J. Liefers ◽  
Bart de Bruijn ◽  
...  
Keyword(s):  
Hospital Pharmacy ◽  
Bacterial Contamination ◽  
Intrathecal Administration ◽  
Contamination Rate ◽  
Target Concentration ◽  
Anesthesia Providers ◽  
Low Concentrations ◽  
The Difference ◽  
Group 2 ◽  
Group 1

Abstract Background Low concentrations of morphine are required for safe dosing for intrathecal injections. Sometimes, manual dilution of morphine is performed to achieve these low concentrations, but risks dilution errors and bacterial contamination. The primary goal was to compare the concentrations of morphine and bupivacaine between four groups of syringes. The secondary goal was to investigate the difference in contamination rate between these groups. Methods Twenty-five experienced anesthesia providers were asked to prepare a mixture of bupivacaine 2.0 mg/ml and morphine 60 μg/ml using 3 different methods as clean and precise as possible. The fourth method used was the aspiration of ampoules prepared by the pharmacy. The concentrations of morphine and bupivacaine were measured by High-Pressure Liquid Chromatography (HPLC). The medication was cultured for bacterial contamination. Results Group 1 (median 60 μg/ml; 95% CI: 59–110 μg/ml) yielded 3 outliers above 180 μg/ml morphine concentration. Group 2 (76 μg/ml; 95% CI: 72–80 μg/ml) and 3 (69 μg/ml; 95% CI: 66–71 μg/ml) were consistently higher than the target concentration of 60 μg. The group “pharmacy” was precise and accurate (59 μg/ml; 95% CI: 59–59 μg/ml). Group 2 and “pharmacy” had one contaminated sample with a spore-forming aerobic gram-positive rod. Conclusion Manually diluted morphine is at risk for deviating concentrations, which could lead to increased side-effects. Medication produced by the hospital pharmacy was highly accurate. Furthermore, even when precautions are undertaken, contamination of the medication is a serious risk and appeared to be unrelated to the dilution process.

Ultrasonography and hormone profiles of persistent ovarian follicles (cysts) induced with low doses of progesterone in cattle

Reproduction ◽  
2000 ◽  
pp. 361-366 ◽  
Author(s):  
KM Noble ◽  
JE Tebble ◽  
D Harvey ◽  
H Dobson
Keyword(s):  
Ovarian Follicles ◽  
Oestrous Cycle ◽  
Blood Collection ◽  
Progesterone Concentration ◽  
Plasma Progesterone ◽  
Follicular Wave ◽  
Low Concentrations ◽  
Group 2 ◽  
Intravaginal Device ◽  
Group 1

The aims of this study were to expose dominant ovarian follicles at the end of the oestrous cycle to low progesterone concentrations similar to those that occur during stress, and to examine the effect of a subsequent small increase in progesterone 10 days later. Half a progesterone releasing intravaginal device (0.5 PRID) was administered to 13 heifers from day 15 of the oestrous cycle. In group 1 (n = 7), one 0.5 PRID remained in place until day 40 or until each heifer ovulated. In group 2 (n = 6), the first 0.5 PRID was removed on day 28, and replaced immediately with a second 0.5 PRID. Ultra-sonography and blood collection (10 ml) were conducted each day for 26 days from day 14 and then on alternate days. The largest follicle that emerged during the first 5 days after insertion of the initial 0.5 PRID remained > 10 mm in diameter for 15.3 +/- 1.7 and 11.6 +/- 0.4 days in groups 1 and 2, respectively. This period of dominance, during which no other follicles emerged, was closely correlated with the duration of plasma oestradiol concentrations exceeding 10 pg ml(-1). In four heifers from group 1, the persistent follicle ovulated between days 30 and 37 (sub-group 1a; 0.5 PRID expelled). In three heifers from sub-group 1b (0.5 PRID retained), the dominant follicle secreted oestradiol for 17 +/- 5 days but remained detectable by ultrasonography for a total of 33 +/- 8 days (range 26-52 days). Monitoring continued beyond day 40 in these animals. In group 2, the new 0.5 PRID inserted on day 28 resulted in an increase in plasma progesterone concentration of 0.9 +/- 0.3 ng ml(-1). Simultaneously, oestradiol decreased by 10.1 +/- 3.3 pg ml(-1), and a new follicular wave emerged 5-7 days later. In conclusion, exposure to very low concentrations of progesterone produced persistent follicles that secreted oestradiol for 17 days. This oestradiol production could be disrupted by a second increase of 0.9 ng ml(-1) in peripheral progesterone concentration. In the absence of the second progesterone treatment, some of the persistent follicles remained detectable by ultrasonography for up to 52 days, despite cessation of oestradiol secretion.

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