Mean Plasma Progesterone Concentrations Research Articles

Effect of early administration of progesterone on the function of the corpus luteum of llamas

The aim of the present study was to evaluate if early administration of progesterone immediately after ovulation affects corpus luteum lifespan in llamas. Female llamas (n = 16) were induced to ovulate by Buserelin injection in the presence of an ovulatory follicle (Day 0). On Day 2, ovulation was confirmed and animals were randomly divided into two groups: treated animals (n = 8) received an intravaginal device containing 0.3 g of progesterone from Day 2 to Day 6 post-induction of ovulation and control group (n = 8) received a device with 0 g of progesterone. Blood samples were collected daily to determine plasma progesterone concentration and transrectal ultrasonographies were performed from Day 7 to Day 12 post-induction of ovulation. Mean maximum diameter of the corpus luteum was significantly lower and was reached before in the treated group than in the control group. The mean highest plasma progesterone concentration and the day that concentration was achieved were similar between groups. However, mean plasma progesterone concentration was significantly higher in the treated group than in the control group on Days 3 and 4 and lower on Days 8 and 9 post-induction of ovulation. The day that plasma progesterone concentration returns to 1 ng/ml differed between groups, occurring earlier in the treated group. In conclusion, the early increase of plasma progesterone concentration during the luteal phase, promoted the premature activation of the luteolytic process affecting corpus luteum function in llamas as it was previously reported in other species.

Ovarian Dynamics, Plasma Endocrine Profile and Fertility Response Following Synchronization Protocols in Crossbred Cows with Cystic Ovaries

Background: Cystic ovarian degeneration (COD) with prevalence of 10-13% is a common and economically important condition in dairy cattle affecting fertility. Predisposing factors and aetiology of ovarian cysts are multifaceted. The most widely accepted cause is either absent, insufficient or wrong time occurrence of pre-ovulatory LH-surge. The accuracy of differential diagnosis of cyst per rectum can be increased by simultaneous use of USG and/or plasma progesterone assay and therapeutic success depends on type and duration of cystic condition. The literature on these aspects in crossbred cows is meagre, hence was planned to differentially diagnose the ovarian follicular and luteal cysts based on clinical, sonographic and endocrine findings and to study the estrus response and conception rates following different treatment modalities of COD in crossbred cattle. Methods: This study was conducted on greater than 90 days postpartum HF crossbred cows with cystic ovaries (n=58) confirmed by per rectal palpation and ultrasonography. The animals with follicular cysts were randomly treated with either conventional Ovsynch or Ovsynch + CIDR protocol (n=10 each) and those with luteal cysts with either Double PG injections 11 days apart or modified Ovsynch protocol (n=16 each) with fixed time AI. A group of six cystic cows was kept as untreated control. Blood samples were collected in heparinized vacutainers, together with trans-rectal ultrasonography, on day 0 (just before initiation of treatment), on day of last PGF2á injection, on day of induced estrus/FTAI and on day 12 post-AI for determination of plasma progesterone and estradiol-17â by RIA technique. Results: The mean diameters and wall thickness of ovarian cysts regressed significantly (p less than 0.01) among responded cows of all four protocols. The estrus induction response within 48-96 hrs of last PG injection with Ovsynch, Ovsynch + CIDR, Modified Ovsynch and Double PG protocols was 90.00, 100.00, 87.50 and 81.25 %, respectively. The conception rates at induced estrus with FTAI for these protocols were 50.00, 40.00, 50.00 and 43.75 %, respectively and the corresponding overall conception rates for 3 cycles’ post-treatment were 60.00, 70.00, 68.75 and 56.25 %, respectively, compared to zero result of control group. The mean plasma progesterone concentration varied highly significantly (p less than 0.01) between periods of treatment in all protocols, the values were lower (p less than 0.01) on day 0 and on day of FTAI than on the day of last PG injection and on day 12 post-AI. The values on day 12 post-AI were significantly higher in conceived than non-conceived cows. The trend of estradiol-17â profile on day of last PG injection was reversed than on day 0. The higher levels of estradiol-17â on day of FTAI were associated with regression of cystic structures and development of new dominant follicles with estrogenic activity concomitant to induced estrus and ovulatory LH surge in most of the animals as evident from USG monitoring, behavioural signs and conception rates.

Intrafollicular Injection of Prostaglandins in the Preovulatory Follicle of the Mare

The aim of this study was to evaluate the effectiveness of a protocol based on GnRH and PGF2α to synchronize the emergence of a new wave of ovarian follicular development in llamas and, therefore, when a new dominant follicle develops. Llamas (n = 18) were assigned to growing, mature or regressing follicle groups according to the phase of the follicular wave at the beginning of treatment. The protocol was initiated with a GnRH analogue (GnRHa) injection on Day 0 followed 7 days later with a d-cloprostenol injection and a second GnRHa injection on Day 10. Ovulation rate after the first GnRHa treatment, day of new follicle emergence, mean plasma progesterone concentration and percentage of animals with a newly developed dominant follicle ≥ 7 mm on Day 10 were evaluated. Ovulation rate after the first GnRHa was less in the regressing than mature and growing follicle groups and new follicular wave emergence occurred earlier in the regressing follicle group than in the other two groups. Mean plasma progesterone concentration in females that had ovulations after the first GnRHa injection was similar. The percentage of animals that had a new follicle ≥ 7 mm on Day 10 was not different among groups and the overall percentage was 66.6%. The total synchronization rate for development of a new wave of follicular development on Day 10 was greater in females having ovulations after the first GnRHa injection than in those that did not have ovulations. In conclusion, the protocol used in the present study was useful for synchronizing ovarian follicular development in 66% of the llamas regardless of the phase of the follicular wave development at the beginning of treatment.

Effect of Doublesynch and Estradoublesynch protocols on estrus induction, conception rate, plasma progesterone, protein, and cholesterol profile in anestrus Gir heifers.

AimThis study aimed to evaluate the efficacy of Doublesynch and Estradoublesynch protocols on estrus induction, conception rates, plasma progesterone, protein, and cholesterol profile in anestrus Gir heifers.Materials and MethodsIn this study, 50 pubertal anestrus Gir heifers were selected from the field and farm conditions. The heifers were dewormed (injection ivermectin, 100 mg, s/c) and supplemented with minerals and vitamins (injection organic phosphorus 800 mg and injection Vitamin AD3E and Biotin 10 ml i/m) and multi-mineral bolus at 1 bolus daily for 7 days. The heifers were randomly divided into three groups: Doublesynch (n=20), Estradoublesynch (n=20), and control (n=10). The animals were monitored for estrus response, estrus interval, behavioral signs, and conception rates after induced/first, second, and third cycle post-treatment. Blood samples were obtained on day 0, day 9, day 12, and on day 12 post-artificial insemination (AI) for determination of plasma progesterone, protein, and cholesterol profile.ResultsThe estrus response rate between Doublesynch and Estradoublesynch protocols was similar between treated heifers (85% and 95%). The interval from the second prostaglandin F2α (PGF2α) injection to estrus induction did not differ between the groups (63.87±4.19 vs. 58.27±3.83 h). The conception rates following induced estrus (20% vs. 30%), at the second cycle (23.07% vs. 16.66%), at the third cycle (22.22% vs. 30.00%), and the overall conception rate (45% and 55%) within 27.89±5.75 and 26.45±5.48 days were the same across the treatment groups. The mean plasma progesterone concentrations were significantly (p<0.01) higher on day 9 (second PGF2α injection) and day 12 post-AI compared to day 0 (first PGF2α injection) and the day of fixed-timed artificial insemination. The concentrations were also significantly (p<0.05) higher in conceived than non-conceived heifers on day 9 of treatment and day 12 post-AI in both the protocols. The mean plasma cholesterol concentrations were significantly higher during peak follicular and luteal phases compared to the initial anestrus phase in both the protocols. The values were also higher in non-conceived than conceived animals in both the protocols. The plasma protein profile was not influenced by the sampling days or conceived and non-conceived status.ConclusionThe results showed that both Doublesynch and Estradoublesynch protocols resulted in similar estrus induction and conception rates with modulation of plasma progesterone and cholesterol profile in anestrus Gir heifers.

Synchronization of time of ovarian follicular development in llamas (Lama glama) using a protocol based on GnRH and PGF2α

The aim of this study was to evaluate the effectiveness of a protocol based on GnRH and PGF2α to synchronize the emergence of a new wave of ovarian follicular development in llamas and, therefore, when a new dominant follicle develops. Llamas (n = 18) were assigned to growing, mature or regressing follicle groups according to the phase of the follicular wave at the beginning of treatment. The protocol was initiated with a GnRH analogue (GnRHa) injection on Day 0 followed 7 days later with a d-cloprostenol injection and a second GnRHa injection on Day 10. Ovulation rate after the first GnRHa treatment, day of new follicle emergence, mean plasma progesterone concentration and percentage of animals with a newly developed dominant follicle ≥ 7 mm on Day 10 were evaluated. Ovulation rate after the first GnRHa was less in the regressing than mature and growing follicle groups and new follicular wave emergence occurred earlier in the regressing follicle group than in the other two groups. Mean plasma progesterone concentration in females that had ovulations after the first GnRHa injection was similar. The percentage of animals that had a new follicle ≥ 7 mm on Day 10 was not different among groups and the overall percentage was 66.6%. The total synchronization rate for development of a new wave of follicular development on Day 10 was greater in females having ovulations after the first GnRHa injection than in those that did not have ovulations. In conclusion, the protocol used in the present study was useful for synchronizing ovarian follicular development in 66% of the llamas regardless of the phase of the follicular wave development at the beginning of treatment.

Estrus Induction Response Vis-a-Vis Serum Progesterone and estradiol 17-β Profile in Postpartum Subestrus Surti Buffaloes Primed with Heatsynch Alone and Heatsynch plus PRID Protocol

This study was conducted on 18 subestrus Surti buffaloes at University farm to estimate steroid hormone values before, during and after use of Heatsynch (T1) and Heatsynch+PRID (T2) protocols. In the Heatsynch protocol (n=6), buffaloes were administered intramuscularly with inj. Busereline - GnRH analogue on day 0, inj. Cloprostenol sodium-PGF2α analogue on day 7 and inj. Estradiol Benzoate (EB-) on day 8. In the Heatsynch+PRID protocol (n=6), PRID was inserted intra-vaginally and kept in situ for 7 days with inj. Buserelineon day 0. The PRID was removed on day 7 together with inj. of Cloprostenol and inj. EB was administered on day 8. FTAI was done twice on day 10 in both the groups. No treatment was given to control (n=6) group (T3). The estrus response was 100% in all three groups, but the conception rate at first cycle/service was 50.00, 66.66 and 33.33%, respectively, in three groups. The mean plasma progesterone concentrations were significantly lower on day of estrus (0.26±0.05, 0.63±0.07and 0.58±0.08 ng/ml in T1, T2 and T3 respectively) as compared to the corresponding values on day 0, 4, 8 of treatment and 18 post-AI in all the three groups.The mean values of estradiol-17β markedly increased (p less than 0.01) on the day of estrus in treatment groups T1 and T2 (43.45±1.42 pg/ml and 42.86±1.53 pg/ml) than control group T3 (35.74±0.63 pg/ml) and thereafter markedly decreased at 18th day post-AI in all the groups (17.93±4.49; 16.34±2.14; 25.52±3.10 pg/ml) with non-significant difference.

Comparative Efficacy of Different Medicaments for Induction of Estrus in True Anestrus Jafarabadi Buffalo Heifers

The relative efficacy of different treatment modalities was evaluated for induction of estrus in 32 post-pubertal true anestrus Jafarabadi buffalo heifers randomly divided into four equal groups. Animals of Group I received intravaginal CIDR and i/m injection of 1.0 mg estradiol valerate on day 0, i/m injection of 500 μg PGF2α on day 7 while removing CIDR, and 0.75 mg estradiol valerate on day 8. Fix timed insemination (FTAI) was performed at 48 and 72 h following PGF2α injection. Animals of Group II received standard Ovsynch protocol with FTAI. In Group III, Prajana HS 3 caps/ day for 3 days along with i/m injection of Vitamin AD3E (5 ml) and Tonophosphan (15 ml) on first day were administered. Group IV animals received no treatment and served as control. Among all inseminated heifers, in non-return cases pregnancy was confirmed per rectum 60 days postbreeding. The estrus induction response in Group I and II animals was 100 %, whereas in Group III and IV it was 37.5 % and 12.5%, respectively. In Group I, one animal conceived at induced estrus and another four at second service while in Group II, five animals conceived at second service giving overall conception rate (CR) of 62.5% in each group within 77 days of treatment. In Group III, three animals conceived by 70 days and in Group IV, only one animal (12.5%) showed estrus and conceived by 50 days of treatment with overall CR of 37.5% and 12.5%, respectively. Mean plasma progesterone concentration was significantly (p less than 0.05) higher on day 7 as compared to day 0, at estrus and on day 20 post-AI in all the animals. It was concluded that both CIDR and Ovsynch protocols are better than herbal heat inducer + supplements in inducing fertile estrus in anestrus buffalo heifers.

Effect of peripartum nutritional management on plasma profile of steroid hormones, metabolites, and postpartum fertility in buffaloes.

Aim:The aim of this study was to evaluate the influence of peripartum protein and minerals supplementation on plasma profile of steroid hormones, metabolites, and fertility in rural buffaloes.Material and Methods:A total of 85 advanced pregnant (~8 months) pluriparous buffaloes selected at farmers’ doorstep in three tribal villages of Middle Gujarat were randomly divided into two groups, viz., control (n=45) and nutrients treatment (40). The buffaloes of treatment group (n=40), in addition to farmers feeding schedule/control, received daily 1.5 kg compound concentrate mixture (22% CP) and 50 g of chelated ASMM for 2 months each pre- and post-partum. Further, 15 buffaloes, each of control and treatment group, were injected parentrally (deep i/m) with 5 ml of micro-minerals (each ml containing Se, Zn, Cu and Mn at 5, 40, 15 and 10 mg, respectively), twice 2 months before and on the day of calving, keeping rest of the animals (control, n=30 and treatment, n=25) as controls. Blood sampling was done on days −60, −30, −15, 0, 15, 30, 45, and 60 peripartum for estimation of plasma progesterone and estradiol by standard RIA techniques and other metabolites using assay kits on biochemistry analyzer. The puerperal events and postpartum fertility were monitored through history and by fortnightly palpation per rectum till day 45 and then again at 120 days postpartum for both the groups and subgroups.Results:The mean plasma progesterone concentrations in all groups declined significantly (p<0.05) from day 60 to day 15 prepartum, reached to the basal levels (<0.5 ng/ml) on the day of parturition, and subsequently, reduced nonsignificantly till day 15 postpartum and then showed a rising trend from day 30 to 60 postpartum with significantly higher values at day 45 and/or 60. The mean plasma estradiol values increased with approaching parturition and were at its peak on the day of calving (p<0.01). Thereafter, there was a rapid fall in the levels by day 15 and it remained low till day 45-60 postpartum. The blood glucose values showed an increasing trend with advancing gestation, reaching the highest on the day of calving, dropped significantly (p<0.01) within 15 days postpartum, and thereafter showed consistent values. The buffaloes supplemented with peripartum nutrients maintained significantly (p<0.05) higher blood glucose concentrations than the control during the peak lactation. The plasma protein levels varied significantly (p<0.05) between days within the group with the lowest values on the day of calving, as well as between groups with higher (p<0.05) values on day 30 and 60 postpartum in treated group. Micro-minerals injected did not reveal significant influence on steroid hormones, blood glucose, or plasma protein. The mean plasma total cholesterol was significantly lower (p<0.05) in treatment than the control group. The mean values in micro-minerals injected subgroup were higher than the non-injected control subgroup during postpartum phase. The mean plasma triglyceride values in the pregnant buffaloes under both the groups and subgroups gradually decreased as parturition approached with significantly lowest values on the day of calving. The values increased nonsignificantly by day 15 and then remained steady throughout postpartum period without influence of nutrient supplementation or micro-minerals injection. The incidence of retained fetal membranes (RFMs) was 5.00 and 13.33% in treatment and control groups, respectively, with placental expulsion time of 3.27±0.37 and 4.44±0.53 h (p>0.05). The micro-minerals injection appreciably reduced the incidence of RFMs and significantly (p<0.05) reduced the placental expulsion time over non-injected controls. In treatment group, the period for involution of uterus was significantly shorter (29.39±0.50 vs. 32.12±0.82 days, p<0.05), with early onset of first postpartum estrus (67.65±1.67 vs. 79.43±3.06 days, p<0.01), shorter service period (90.89±4.41 vs. 105.09±4.76 days, p<0.05) and higher conception rate (55.00 vs. 40.00%) than in control group. The micro-minerals injection apparently and/or significantly improved all these traits in both the groups. Thus, the postpartum reproductive performance was significantly improved in treated than control groups and subgroups.Conclusion:The results showed that nutrient supplementation in terms of high protein concentrate, ASMM and injection of sustained release micro-minerals (Se, Zn, Cu, and Mn) during transition period minutely altered the plasma steroid hormones and blood metabolites though it significantly improved the postpartum reproductive performance in buffaloes under field conditions.

Dietary conjugated linoleic acid supplementation alters the expression of genes involved in the endocannabinoid system in the bovine endometrium and increases plasma progesterone concentrations

Endocannabinoids are derived from phospholipids and reduce fertility by interfering with implantation. Identification of changes in the expression of genes of the endocannabinoid system as a result of dietary inclusion of conjugated linoleic acid (CLA) is critical to the advancement of our understanding of the nutritional regulation of uterine function. An experiment was conducted on transition cows to evaluate the expression of key endocannabinoid genes in bovine endometrium in response to dietary supplementation with CLA. A total of 16 cows were randomly assigned to two treatments: (1) control (75 g/day palm oil) and (2) CLA (75 g/day CLA) from 21 days prepartum to Day 42 postpartum. Cows underwent uterine biopsy on days 21 and 42 postpartum. The abundance of mRNA encoding endocannabinoid receptor (CNR2), N-acyl phosphatidylethanolamine phospholipase D (NAPEPLD), fatty acid amide hydrolase (FAAH), N-acylethanolamine acid amidase (NAAA), and monoglyceride lipase (MGLL) was measured by real-time PCR. Results reported that relative levels of mRNA encoding CNR2 and NAPEPLD were decreased (P < 0.05) compared with control cows between Days 21 and 42 postpartum. Relative levels of mRNA coding for NAAA and MGLL were not different (P > 0.05) in the same situation. Mean plasma progesterone concentrations were higher in CLA-fed cows compared with control cows at Day 42 postpartum (3.51 and 1.42 ng/mL, respectively, P < 0.05). In conclusion, we suggest that the beneficial effects of a diet enriched with CLA are the result of a decrease in relative gene expression of the endocannabinoid receptor (CNR2) and enzymes that synthesize fatty acid amides (NAPEPLD) and of an increase in the expression of PTGS2 that in turn can oxidate endocannabinoids and consequently resulted in increased plasma progesterone concentrations during early lactation.

Comparative efficacy of different estrus synchronization protocols on estrus induction response, fertility and plasma progesterone and biochemical profile in crossbred anestrus cows.

Aim:To evaluate estrus induction response and fertility including plasma progesterone and biochemical profile following use of three standard hormonal protocols in anestrus crossbred cows.Materials and Methods:The study was carried out on 40 true anestrus and 10 normal cyclic cows. 10 anestrus cows each were treated with standard intravaginal controlled internal drug release (CIDR) device, Ovsynch (GPG) protocol, and Norgestomet ear implant with fixed-time artificial insemination (FTAI). 10 anestrus cows were kept as untreated control while 10 cows exhibiting the first estrus within 90 days postpartum without any treatment served as normal cyclic control. Blood samples were obtained from treated cows on day 0, 7, 9 (AI) of treatment and day 21 post-AI, and from control groups on the day of AI and day 21 post-AI for estimation of plasma progesterone, protein, cholesterol, calcium, and inorganic phosphorus profile.Results:The use of CIDR, Ovsynch, and Norgestomet ear implant protocols resulted in 100% estrus induction with conception rates at induced estrus of 60%, 50%, and 50%, and the overall of three cycles as 80%, 80%, and 70%. In untreated anestrus control (n=10), only three cows exhibited spontaneous estrus within 90 days of follow-up and conceived giving the first service and overall conception rates of 66.66% and 30.00%, respectively. In normal cyclic control (n=10), the conception rates at first and overall of three cycles were 50% and 80%. The overall mean plasma progesterone (P4) concentrations in anestrus cows studied on day 0 (initiation), 7 (prostaglandin injection and/or removal of implant), 9 (FTAI) of treatment and on day 21 post-AI revealed that the values on day 7 and 21 were significantly (p<0.01) higher than other two periods in all three groups. The concentrations were significantly (p<0.05) higher in conceived than non-conceived group on day 21 post-AI in CIDR (4.36±0.12 vs. 1.65±0.82 ng/ml) and Ovsynch (4.85±0.62 vs. 1.59±0.34 ng/ml), but not in Norgestomet ear implant (4.50±0.53 vs. 3.02±1.15 ng/ml) or normal cyclic group (5.39±0.67 vs. 3.13±0.37 ng/ml). The cholesterol and protein levels were significantly higher, but not the calcium and phosphorus, in normal cyclic control than in anestrus groups. The influence of treatment days and pregnancy status was not significant for any of the biochemical constituents in any of the groups.Conclusion:Ovsynch and/or CIDR synchronization protocol can be effectively used to improve fertility up to 80% in anestrus cows, as compared to 30% in anestrus control, combined with plasma progesterone to delineate the reproductive status before and after treatment.

Influence of controlled breeding techniques on fertility and plasma progesterone, protein and cholesterol profile in true anestrus and repeat breeding buffaloes

Aim: The aim was to evaluate the estrus response, conception rate and plasma profile of progesterone, protein and cholesterol following use of different hormonal protocols in anestrus and repeat breeding buffaloes. Materials and Methods: This study was carried out on 20 true anestrus, 20 repeat breeders, and 10 normal cyclic buffaloes. Ten anestrus buffaloes each were treated with standard controlled internal drug releasing (CIDR) i/vg device and Ovsynch (GPG) protocols with fix timed artificial insemination (FTAI), and blood samples were obtained on day 0, 7, 9/10 (AI) of treatment and day 21 post-AI. Ten repeat breeding buffaloes with mature mid-cycle palpable corpus luteum (CL) were treated with i/m injection of 25 mg prostaglandin F2α (PGF 2 α) with FTAI twice at 72 and 96 h later, whereas other ten repeat breeding buffaloes in standing estrus were inseminated with simultaneous i/m injection of buserelin acetate-gonadotropinreleasing hormone (GnRH) 20 μg. 10 buffaloes exhibiting first estrus within 90 days postpartum and inseminated without any treatment served as normal cyclic control. Blood samples were obtained on day of PG injection, day of AI and day 21 post-AI for estimation of plasma progesterone, protein, and cholesterol. Results: CIDR and Ovsynch protocols resulted in 100 and 80% induction of estrus with conception rates of 40 and 30% at induced estrus, respectively, in anestrus buffaloes. Mid-cycle PGF 2 α treatment resulted in 90% estrus induction and 40% conception rate at induced estrus, while Buserelin acetate-GnRH 20 μg injection at AI resulted in 30% conception rate in repeat breeders. In normal cyclic control group also, the first service conception rate was 30%. The mean plasma progesterone concentrations on day 0, 7, 9/10 (AI) of treatment and on day 21 post-AI were found to be significantly (p<0.05) different in both CIDR and Ovsynch protocols, being higher on day 7 (day of PG injection) and on day 21 post-AI than on day 0 and 9/10 (FTAI), which were near basal levels. The mean plasma progesterone level was significantly (p<0.01) higher on the day of initiation of mid-cycle PGF 2 α treatment (3.81±0.67 ng/ml) in a repeat breeding buffaloes suggesting luteal phase. The mean plasma P 4 levels on day 21 post-AI were significantly (p<0.01) higher than on the day of estrus in both repeat breeders and in normal cyclic controls. The plasma P 4 value on day 21 post-AI was significantly (p<0.01) higher in conceived than non-conceived buffaloes in all five groups. The mean plasma total cholesterol and total protein concentrations in anestrus and repeat breeding buffaloes under different treatments did not vary significantly between sampling days. However the cholesterol content was significantly (p<0.05) lower (79.96±2.17 vs. 92.27±6.04 mg/dl) and protein higher (8.14±0.73 vs. 7.69±0.59 g/dl) in conceived than non-conceived animals. In both anestrus and repeat breeding buffaloes, the values of cholesterol and protein were significantly lower than in normal cyclic control group (138.04±11.98 mg/dl and 7.82±0.11 g/dl, respectively). Conclusion: The results showed that CIDR was better than Ovsynch protocol in inducing fertile estrus in anestrus buffaloes, while mid-cycle PG treatment was superior over AI + GnRH in repeat breeders, and all four treatment protocols significantly influenced plasma P4 profile, but not the protein or cholesterol.

Effects of varying doses of β-nerve growth factor on the timing of ovulation, plasma progesterone concentration and corpus luteum size in female alpacas (Vicugna pacos).

Ovulation in camelids is induced by the seminal plasma protein ovulation-inducing factor (OIF), recently identified as β-nerve growth factor (β-NGF). The present study measured the total protein concentration in alpaca seminal plasma using a bicinchoninic acid (BCA) protein quantification assay and found it to be 22.2±2.0mgmL(-1). To measure the effects of varying doses of β-NGF on the incidence and timing of ovulation, corpus luteum (CL) size and plasma progesterone concentration, 24 female alpacas were synchronised and treated with either: (1) 1mL 0.9% saline (n=5); (2) 4µg buserelin (n=5); (3) 1mg β-NGF protein (n=5); (4) 0.1mg β-NGF (n=5); or (5) 0.01mg β-NGF (n=4). Females were examined by transrectal ultrasonography at 1-2-h intervals between 20 and 45h after treatment or until ovulation occurred, as well as on Day 8 to observe the size of the CL, at which time blood was collected to measure plasma progesterone concentrations. Ovulation was detected in 0/5, 5/5, 5/5, 3/5 and 0/4 female alpacas treated with saline, buserelin, 1, 0.1 and 0.01mg β-NGF, respectively. Mean ovulation interval (P=0.76), CL diameter (P=0.96) and plasma progesterone concentration (P=0.96) did not differ between treatments. Mean ovulation interval overall was 26.2±1.0h. In conclusion, buserelin and 1mg β-NGF are equally effective at inducing ovulation in female alpacas, but at doses ≤0.1mg, β-NGF is not a reliable method for the induction of ovulation.

Plasma concentrations of PGFM and uterine and ovarian responses in early lactation dairy cows fed omega-3 and omega-6 fatty acids

A total of 120 dairy cows were assigned randomly to three diets to determine the effects of omega-6 or omega-3 fatty acid (FA) supplementation on uterine diseases, ovarian responses, and blood concentrations of estradiol, progesterone, and PGFM in lactating Holstein dairy cows. Diets contained either protected palm oil (C), extruded linseed (L), or roasted whole soybeans (S), and they were fed from calving to Day 70 postpartum. Estrous cycles were synchronized and ovarian follicular development was monitored daily for an entire cycle. There were no differences among diets in the incidence of lameness, mastitis, or metritis, but the incidence of clinical endometritis was lower (P < 0.05) in cows fed S (0%) compared with cows fed C (28.2%) and L (20.5%). Uterine involution in cows fed S occurred 3.77 and 2.78 days earlier, respectively, than in those fed C and L. The PGFM response 60 minutes after an oxytocin challenge was highest for cows fed S and lowest for cows fed L. Mean plasma progesterone concentration on Day 15 of the synchronized cycle was higher in cows fed S (14.5 ng/mL) and L (15.0 ng/mL) than in those fed C (12.0 ng/mL). The ovulatory follicle on Day 21 of the estrous cycle (estrous = Day 0) was larger in cows fed S (16.1 ± 0.9 mm) and L (15.7 ± 0.7 mm) compared with cows fed C (13.2 ± 0.87 mm; P = 0.02) but there were no significant differences between cows fed diets S and L. The mean number of small and medium follicles and diameter of subordinate follicle were similar among diets. In conclusion, feeding a source of omega-6 FA can be a strategy to improve uterine health after calving, although a source of omega-3 FA such as L should be fed after uterine involution to decrease PGF2α secretion.

Factors affecting live foal rates ofThoroughbred mares that undergo manual twin elimination

Mares diagnosed with twin vesicles at 13-17 days after ovulation commonly have one of 2 vesicles manually reduced. It is not known whether vesicle location (adjacent vs. nonadjacent), mare age, mare reproductive status, parity, month of breeding or mare plasma progesterone concentration affects live foal rates. To determine factors associated with a positive outcome (live foal) in mares undergoing manual twin reduction between 13 and 17 days post ovulation when performed by a single operator. Retrospective case-control study. Breeding records and the Jockey Club records of registered Thoroughbreds were used to evaluate factors affecting the outcome of pregnancies in mares undergoing twin elimination and mares with singleton pregnancies. Thoroughbred mares with twin pregnancies (n = 129) were matched by age, parity, farm location and month bred with mares diagnosed with a singleton pregnancy (n = 127). The effects of location of embryonic vesicles, mare age, reproductive status, parity, month of breeding, vesicle size and plasma progesterone concentration at pregnancy diagnosis on live foal rate were examined. Position of embryonic vesicles at time of manual elimination, parity and month bred had no effect on live foal rate. Live foal rates in mares >9 years of age were lower (71.8%) than in all mares ≤9 years (87.1%; P<0.05). Mares >9 years of age that had a twin reduced lost more pregnancies (34.8%) than age-matched control mares (20.0%; P<0.005). Mean plasma progesterone concentration of twin-reduced mares was greater than in control mares when compared on the same day post ovulation. Plasma progesterone concentrations did not differ between mares that lost their pregnancy and those that delivered a live foal. Mare age of >9 years is associated with decreased pregnancy rate after twin reduction. Furthering the understanding of factors that affect live foal outcome following manual twin elimination in mares.

Electroejaculation increased vocalization and plasma concentrations of cortisol and progesterone, but not substance P, in beef bulls

Electroejaculation is a reliable method of obtaining a semen sample for a bull breeding soundness examination, but is sometimes regarded as painful. Substance P is a neuropeptide involved in the integration of pain, stress, and anxiety. We hypothesized that substance P is a measure of pain in bulls following electroejaculation. The specific objective was to compare vocalization and plasma concentrations of cortisol, progesterone, and substance P immunoreactivity in bulls following electroejaculation. Nine Angus bulls (501.9 ± 14.3 kg) were used. Blood samples were collected at −60, −30, 0, 2, 10, 20, 30, 45, 60, 75, 90, 120 min relative to treatment. At Time 0, bulls were subject to electroejaculation, rectal probe insertion without electroejaculation, or no manipulation. Treatments were administered contemporaneously to three bulls. Treatments were repeated weekly until each bull had received each treatment in a 3 × 3 Latin square design. More bulls (P = 0.0147) in the electroejaculation group vocalized (5 of 9 bulls; 55.6%) when compared to controls (0 of 9 bulls; 0%). Mean plasma cortisol and progesterone concentration following electroejaculation in bulls were higher (P < 0.05) than concentrations in probed and control bulls through the 45 min sample. However, mean plasma substance P concentration following electroejaculation in bulls (77.2 ± 17.2 pg/mL) was not different (P = 0.6264) from probed (79.1 ± 17.2 pg/mL) or control bulls (93.4 ± 17.2 pg/mL). A significant increase in vocalization and plasma cortisol and progesterone concentrations in bulls following electroejaculation was likely owing to acute stress. However, the lack of a difference in plasma concentrations of substance P after electroejaculation was interpreted as a lack of pain associated with nociception.

Effect of estrus synchronization protocols on plasma progesterone profile and fertility in postpartum anestrous Kankrej cows

The study was aimed at induction/synchronization of estrus in postpartum anestrous Kankrej cows of zebu cattle maintained at an organized farm. The study included use of different hormone protocols, viz., Ovsynch, CIDR (controlled internal drug release), Ovsynch plus CIDR, and Heatsynch with estimation of plasma progesterone on days 0, 7, 9/11 (artificial insemination--AI) and on day 20 post-AI following fixed time insemination. Thirty selected anestrous animals were divided into five equal groups (four treatment and one control), and the findings were compared with the normal cyclic control group of six cows. All the protocols were initiated in cows with postpartum anestrous period of more than 4 months, considering the day of first GnRH injection or CIDR insertion as day 0. The animals were bred by fixed time artificial insemination. Pregnancy was confirmed per rectum on day 60 post-AI in non-return cases. The conception rates at induced/first heat in Ovsynch, CIDR, Ovsynch + CIDR, and Heatsynch protocols were 33.33, 66.66, 50.00 and 16.67%, respectively. The corresponding overall conception rates of three cycles post-treatment were 50.00% (3/6), 100.00% (6/6), 66.66% (4/6), and 50.00% (3/6). In normal cyclic and anestrous control groups, the pooled pregnancy rates were 83.33% (5/6) and 16.67% (1/6), respectively. The pooled mean plasma progesterone (nanograms per milliliter) concentrations were significantly (P < 0.05) higher on day 7 in Ovsynch (5.727 ± 1.26), CIDR (4.37 ± 0.66), Ovsynch plus CIDR (3.55 ± 0.34), and Heatsynch (5.92 ± 1.11) protocols as compared with their corresponding values obtained on days 0, 9/11 (AI), and on day 20 post-AI. In anestrous control group, the mean progesterone concentration at the beginning of experiment was 0.67 ± 0.33 ng/ml, which was at par with values of all other groups. The overall plasma progesterone levels on the day of initiating treatment were low in all groups, with smooth small inactive ovaries palpated per rectum twice at 10 days interval, suggesting that most of the animals used in the study were in anestrous phase. Mean (± SE) values of plasma progesterone (nanograms per milliliter) on day 20 post-AI were higher in conceived cows than the non-conceived cows of all the groups, but differed significantly (P < 0.05) only in normal cyclic group. These results suggest that use of different hormone protocols particularly Ovsynch, CIDR, and Ovsynch + CIDR may serve as an excellent tool for induction and synchronization of estrus and improvement of conception rate in postpartum anestrous Kankrej cows.

Köpeklerde İstenmeyen Çiftleşmeleri Takiben Gebeliğin Engellenmesinde Standarttan Düşük Dozlarda Aglepristonun Etkinliğinin Araştırılması

Summary The objective of this study was to evaluate the clinical efficacy of three different doses of aglepristone administered in early diestrus for prevention of pregnancy in mismated dogs. A total of 48 mismated, copulation confirmed bitches were used as material. Bitches were randomly allocated into one of four groups and treatment groups received 5 mg/kg (group I, n=12), 7.5 mg/kg (group II, n=12) or 10 mg/kg (group III, n=12) of aglepristone by two injections, 24 h apart within 10 days of diestrus. Twelve bitches (group IV) served as controls. Pregnancy was assessed by ultrasonography on day 30 of diestrus. Blood samples were collected for determination of plasma progesterone concentrations by radioimmunoassay on days 0, 3 and 7 of first aglepristone administration and on the day of ultrasonographic examination. None of aglepristone treated bitches except for one bitch in group I became pregnant. Pregnancy rate in the control group was 83.3%. There was no significant difference between mean plasma progesterone concentrations in study groups on day 0 and 3 (P>0.05). On day 30 of diestrus, plasma concentrations of progesterone were significantly lower in aglepristone treated bitches (group I: 92.60±5.74 nmol/L; group II: 85.66±3.69 nmol/L; group III: 78.87±4.86 nmol/L) compared to controls (110.62±6.24 nmol/L, P 0.05). Twenty aglepristone treated bitches were bred in the subsequent estrus and overall pregnancy rate obtained was 90%. In conclusion, aglepristone at lower-than-standard doses administered in early diestrus effectively prevents pregnancy in mismated bitches and potentially offers a cost-effective treatment option.

Effects of GnRH or Progesterone Treatment on Day 5 Post‐AI on Plasma Progesterone, Luteal Blood Flow and Leucocyte Counts During the Luteal Phase in Dairy Cows

This study was designed to test the effects of progesterone or GnRH treatment on day 5 post-AI on fertility and luteal function in dairy cows and heifers. Five days after AI, 32 animals were randomly assigned to a control, intravaginal progesterone for 14 days progesterone releasing intravaginal device (PRID) or GnRH treatment group. On days 5, 7, 12, 14, 17 and 19 post-AI, each animal underwent colour Doppler ultrasonography of the corpus luteum and blood samples were collected for cell counts and plasma progesterone determination. Through general linear model repeated measures analysis of variance, significant effects were observed of treatment, parity, inseminating bull, reduced vascularization of the CL and pregnancy on plasma progesterone concentrations, whereas mean plasma progesterone and time luteal phase day, and treatment and plasma progesterone concentration on day 5 post-AI were found to, respectively, affect neutrophil and lymphocyte counts throughout the luteal phase. Moreover, two binary logistic regression analyses were performed. Based on the odds ratio, the likelihood of pregnancy by days 26-32 post-AI was 23.4 times higher in animals with high mean progesterone levels throughout the study period, compared with animals with low mean progesterone. The likelihood of reduced CL vascularization was 14 times higher in animals treated with PRID, compared with control and GnRH-treated animals. In conclusion, our results indicate that treatment on day 5 post-AI with PRID reduced subsequent CL vascularization, whereas GnRH treatment increased plasma progesterone concentrations on day 12 post-AI, although an effect was identified of the inseminating bull on plasma progesterone levels. Pregnant animals showed higher mean plasma progesterone concentrations than in nonpregnant ones and heifers higher than in lactating cows, whereas blood cell counts differed depending on the treatment and on the mean plasma progesterone concentration on day 5 post-AI.

Assessment of luteal function in goats by ultrasonographic image attribute analysis

The aim of this study was to evaluate the potential of luteal echotexture (mean pixel value and heterogeneity), as a tool for assessing luteal function during different phases of the estrous cycle in Toggenburg goats. Sonographic evaluations of the ovaries were performed daily in nulliparous goats ( n = 21), using a 5 MHz linear rectal probe, commencing at estrus (day 0). Blood samples were collected daily for plasma progesterone RIA and images recorded on VHS tape and then digitized in TIFF format at a resolution of 1500 × 1125 pixels. A representative elementary area (REA) of 5625 pixels (0.31 cm 2) of these images was analyzed using custom-developed software, for mean pixel value and heterogeneity. Mean plasma progesterone, luteal area and pixels all reached maximum values at approximately days 13 and 14, during luteogenesis. Luteolysis was characterized by an abrupt decrease in blood progesterone concentration following ovulation, and a gradual decline in luteal area and pixel values. The luteal tissue area was positively correlated with plasma progesterone concentration during both luteogenesis ( r = 0.63; P < 0.05) and luteolysis ( r = 0.50; P < 0.05). Weak correlations were recorded between the mean pixel value and luteal tissue area during luteogenesis ( r = 0.34; P < 0.05) and luteolysis ( r = 0.26; P < 0.05). Similarly, weak correlations between the mean pixel value and plasma progesterone concentration were recorded during luteogenesis ( r = 0.24; P < 0.05) and luteolysis ( r = 0.37; P < 0.05). The pixel heterogeneity was not correlated with luteal tissue area or the plasma progesterone concentration at any stage of the estrous cycle. The results show the association between the corpus luteum echotexture and steriodogenic function to be weak and the present ultrasound technology, to have limited potential in evaluating luteal function in goats.

Embryo transfer technique: Factors affecting the viability of the corpus luteum in llamas

The aim of the present study was to evaluate the effect of the embryo transfer (ET) maneuvers on plasma progesterone concentrations in recipient Lama glama females and the relationship between the site the embryo was transferred to and corpus luteum (CL) localization. Experiment I (effect of transcervical threading): adult non-pregnant, non-lactating llama females were randomly assigned into two groups: control group (without cervical threading, n = 10) and group A (with cervical threading, n = 10). In both groups, CL activity was evaluated through measurement of progesterone plasma concentrations. In group A, on Day 6 after inducing ovulation with buserelin, the cervix was threaded to evaluate the effect of the maneuver on CL viability. No significant differences were observed in mean progesterone concentrations between groups ( P > 0.05). Experiment II (effect of depositing PBS): females ( n = 66) were randomly assigned into six groups ( n = 10 per group and control group: n = 6) to evaluate the effect of depositing PBS in different sites in the uterus in relation to the localization of the CL: group ‘Left-Ipsilateral’: transcervical placing of PBS in the left uterine horn (CL in left ovary); group ‘Left-Contralateral’: transcervical placing of PBS in the left uterine horn (CL in right ovary); group ‘Right-Ipsilateral’: transcervical placing of PBS in the right uterine horn (CL in right ovary); group ‘Body-Left’: transcervical placing of PBS in the uterine body (CL in left ovary); group ‘Body-Right’: transcervical placing of PBS in the uterine body (CL in right ovary) and control group. Corpus luteum activity was evaluated in all groups by measuring plasma progesterone concentrations. On Day 6 post-buserelin, the corresponding maneuver was carried out according to the group. No significant differences were found for the mean plasma progesterone concentrations between groups ( P > 0.05). Experiment III (effect of ET on CL viability): females ( n = 22) were used as embryo donors and 50 females as recipients, in order to evaluate if placing the embryo in different areas of the uterus influences CL viability. Recipients were randomly divided into five groups, according to the place in the uterus where the ET was conducted with respect to the ovary where ovulation occurred: group ‘Left-Ipsilateral’: ET in the left uterine horn (CL in left ovary); group ‘Left-Contralateral’: ET in the left uterine horn (CL in right ovary); group ‘Right-Ipsilateral’: ET in the right uterine horn (CL in right ovary); group ‘Body-Left’: ET in the uterine body (CL in left ovary) and group ‘Body-Right’: ET in the uterine body (CL in right ovary). Corpus luteum activity was evaluated in all groups by measuring plasma progesterone concentrations. Embryos were recovered by flushing the uterus on Day 8 after the first mating of the donor and transcervical ET was carried out in recipients 6 days after buserelin administration. Pregnancy rates were: group ‘Left-Ipsilateral’: 50%; group ‘Left-Contralateral’: 20%; group ‘Right-Ipsilateral’: 30%; group ‘Body-Left’ and ‘Body-Right’: 10%. No significant differences ( P = 0.4728) were detected between the pregnancy rates in the five groups. Threading the cervix and transcervical placing of PBS either in the uterine horns or the body did not affect plasma progesterone concentrations in the llama, indicating that the different embryo transfer maneuvers do not interfere with CL viability. To improve pregnancy rates it could be suggested that ET in the left uterine horn with an ipsilateral CL, is the most desirable option.