445 RELATIONSHIPS OF LUTEAL PHASE VARIABLES (PRIOR TO AI) WITH FOLLICULAR WAVES IN WATER BUFFALOES

2010 ◽  
Vol 22 (1) ◽  
pp. 379
Author(s):  
H. Kohram ◽  
G. Mohammadi ◽  
E. Dirandeh
Keyword(s):  
Luteal Phase ◽  
Ultrasound Examination ◽  
Limit Of Detection ◽  
Area Under The Curve ◽  
Prostaglandin F2α ◽  
Control Treatment ◽  
Estrous Cycles ◽  
Plasma Progesterone ◽  
Blood Samples ◽  
Follicular Waves

This study was done to consider relationships of luteal phase variables (prior to AI) with follicular waves. The estrous cycles of 15 buffaloes were synchronized with 2 i.m. injections of prostaglandin F2α given 11 days apart. The buffaloes were randomly assigned to 1 of 3 treatments. Buffaloes in the control treatment received no treatment, whereas G6 buffalos received a GnRH injection between Day 5 and 7 and G16 buffalos received a GnRH injection between Day 15 and 17 of the estrous cycle (estrus = Day 0). Daily, from estrus Day 0 to the next estrus Day 23, buffaloes had their ovaries scanned by ultrasound. Blood samples were collected by tail following each ultrasound examination from estrus until next estrus (estrus = 0). Concentrations of plasma progesterone were determined by radioimmunoassay kit. The limit of detection of the assay was 0.1 45 ng mL-1 and the intra- and interassay coeffients of variation were 7.4% and 9.2%, respectively. Data were analyzed by using PROC GLM of SAS (SAS Institute, Cary, NC, USA). For comparisons between groups, the 2-sample t-test was used for continuous traits, such as size of CL or hormone concentrations. Prospective comparisons of indices of progesterone indicated that the length of luteal lifespan was longer in 3-wave than in 2-wave buffaloes (P < 0.01). Plasma progesterone concentrations were similar at peak and measured as area under the curve on Day 5 through 17 preceding insemination in 2-wave (5.30 ± 0.40 ng mL-1) and 3-wave buffaloes (5.10 ± 0.20 ng mL-1). Length of the luteal phase (defined as from the day of estrus until the last day on which plasma progesterone remained >2 ng mL-1) was <2 days shorter in 2-wave buffaloes than in 3-wave buffaloes (15.20 ± 0.40 v. 17.10 ± 0.50 d; P < 0.05). In addition, the day of peak progesterone occurred earlier in 2-wave buffaloes (13.50 ± 0.30 v. 15.30 ± 0.70 d; P < 0.05).

517. RELATIONSHIPS OF LUTEAL PHASE VARIABLES (PRIOR TO AI) WITH FOLLICULAR WAVES IN DAIRY COWS

2009 ◽  
Vol 21 (9) ◽  
pp. 116
Author(s):  
E. Dirandeh ◽  
H. Kohram ◽  
M. Aryanezhad
Keyword(s):  
Luteal Phase ◽  
Limit Of Detection ◽  
Area Under The Curve ◽  
Prostaglandin F2α ◽  
Control Treatment ◽  
Estrous Cycles ◽  
Plasma Progesterone ◽  
Follicular Waves ◽  
Coefficients Of Variation ◽  
D 23

This study was done to consider relationships of luteal phase variables (prior to AI) with follicular waves. The estrous cycles of 10 cows were synchronized with 2 im injections of prostaglandin F2α given 11 d apart. The cows were randomly assigned to 1 of 2 treatments. Cows in the control treatment received no treatment, whereas GnRH6 cows received a GnRH injection on d 6 of the estrous cycle (estrus = d 0). Daily, from estrus d 0 to the next estrus d 23, cows had their ovaries scanned by ultrasound. Blood samples were collected by tail following each ultrasound examination from estrus until next estrus (estrus = d 0). Concentrations of plasma progesterone were determined by radioimmunoassay kit. The limit of detection of the assay was 0.125 ng/mL and the intra- and interassay coefficients of variation were 8.4% and 10.2%, respectively. Data that were analyzed by using PROC GLM of SAS. For comparisons between groups, the 2-sample t-test was used for continuous traits, such as size of cl or hormone concentrations. Prospective comparisons of indices of progesterone indicated that the length of luteal lifespan was longer in three-wave than in two-wave cows (P<0.01). Plasma progesterone concentrations were similar at peak and measured as area under the curve on day 5 through 17 preceding insemination in two-wave (6.70±0.30 ng/ml) and three-wave cows (7.30±0.50 ng/ml). Length of the luteal phase (defined as from the day of estrus until the last day on which plasma progesterone remained greater than 2 ng/ml) was <2 days shorter in two-wave cows than in three-wave cows (16.7±0.30 vs. 18.40±0.50 d; P<0.05). In addition, the day of peak progesterone occurred earlier in two-wave cows (13.50±0.40 vs. 16.30±0.70 d; P<0.05).

171 ADMINISTRATION OF GnRH ON DAY 6 ALTERS THE NUMBER OF FOLLICULAR WAVES FROM 2 TO 3 DURING THE ESTROUS CYCLE OF HOLSTEIN COWS

2009 ◽  
Vol 21 (1) ◽  
pp. 184
Author(s):  
E. Dirandeh ◽  
H. Kohram ◽  
A. Zare Shahneh
Keyword(s):  
Estrous Cycle ◽  
Prostaglandin F2α ◽  
Control Treatment ◽  
Control Group ◽  
Third Wave ◽  
Estrous Cycles ◽  
Follicular Waves ◽  
Follicular Wave ◽  
Lactating Cows ◽  
Ovulatory Follicle

It is suggested that pregnancy rate is greater in lactating cows inseminated following ovulation of a third-wave follicle compared with a second-wave follicle. The number of follicular waves is not apparent during the estrous cycle. However, GnRH injection on Day 6 is supposed to initiate a new follicular wave earlier; as a result, the number of cows with 3 follicular waves will be increased. This study was done to change the 2-follicular-wave cycles to 3 follicular waves during the estrous cycle. The estrous cycles of 10 cows were synchronized with 2 i.m. injections of prostaglandin F2α given 11 days apart. The cows were randomly assigned to 1 of 2 treatments. Cows in the control treatment received no treatment, whereas GnRH6 cows received a GnRH injection on Day 6 of the estrous cycle (estrus = Day 0). Ovaries of all cows were scanned daily, from estrus (Day 0) to the subsequent estrus (Day 23). Profiles of the mean number of follicles (i.e. 4- to 6-mm and ≥7 mm), the diameter of the largest follicle (F1), and comparison of 2- and 3-wave cows were compared by least squares analysis of variance using the general linear model (GLM) procedure of SAS. The number of 4 to 6 mm follicles had a tendency to decline until Day 6 (3.0 ± 2.1 v. 0.8 ± 1.6). In response to an injection of GnRH, the number of small follicles in group GnRH6 on Day 6 (1.5 ± 1.6 follicles) increased (P < 0.05) on Day 8 (5.0 ± 1.7 follicles) and the number of medium and large follicles (≥7 mm) on Day 6 (1.8 ± 0.5 follicles) decreased (P < 0.05) on Day 9 (0.8 ± 0.6 follicles). Over the 4-day period before GnRH treatment, the diameter of F1 was increasing (from 4.7 ± 0.9 mm to 10.0 ± 0.6 mm) in cows treated with GnRH on Day 6 of the estrous cycle; thereafter, the diameter of the F1 decreased (P < 0.05) within 2 days of GnRH treatment. In the control group the diameter of the F1 increased over the 4-day period before GnRH treatment (from 5.0 ± 0.9 mm to 11.2 ± 0.6 mm), whereas it remained constant (11.2 ± 1.2 mm to 11.2 ± 1.2 mm) between Days 6 and 9 of the estrous cycle (P < 0.003). Results showed that 4 out of 5 cows in control group had 2 follicular waves, whereas all of the cows (n = 5) in GnRH6 group had 3 follicular waves. The first follicular wave begins at Day 1.1 ± 0.50 and 0.70 ± 0.50 in the control and GnRH groups, respectively. The second follicular waves appeared at Day 11.00 ± 0.80 and 8.30 ± 1.50 (P ≤ 0.05) for the 2- and 3-wave animals, respectively. The third follicular waves (n = 6) initiated at Day 16.30 ± 1.50. Cows with 2 follicular waves had shorter estrous cycles (P ≤ 0.05) than 3-wave cows (20.50 ± 0.60 v. 22.40 ± 0.90). The ovulatory follicle in 2-wave cows grew larger (14.00 ± 1.80 v. 12.50 ± 0.90 mm; P ≤ 0.05), and maintained for a longer period of time (9.50 ± 1.80 v. 6.1 ± 0.90; P ≤ 0.05) than in 3-wave cows. In conclusion, an injection of GnRH on Day 6 of the estrous cycle could promote the emergence of a new follicular wave earlier in cows and alter the estrous cycles with 2 waves into 3 follicular waves.

Influence of PMSG antiserum on serum progesterone and estrous cycles of PMSG-treated gilts

1992 ◽  
Vol 72 (1) ◽  
pp. 173-176 ◽  
Author(s):  
R. N. Kirkwood ◽  
P. A. Thacker
Keyword(s):  
Key Words ◽  
Luteal Phase ◽  
Ovarian Activity ◽  
Serum Estradiol ◽  
Serum Progesterone ◽  
Estrous Cycles ◽  
Blood Samples ◽  
Effect Of Treatment

Forty-seven prepubertal gilts (88.4 ± 0.9 kg) received an injection of 750 IU PMSG to stimulate ovarian activity. After 96 h, 23 gilts received an injection of an anti-PMSG serum. Blood samples were obtained at the time of PMSG injection (day 0) and at 2, 4, 6, 11, 18, 25 and 32 d. There was no effect of treatment on serum estradiol concentrations or on the occurrence of normal estrous cycles. However, luteal phase serum progesterone concentrations were higher (P < 0.01) in gilts receiving the anti-PMSG. Key words: PMSG, antiserum, gilts, ovulation

RECEPTORS FOR GONADOTROPHIN AND PROSTAGLANDIN F2α IN BOVINE CORPORA LUTEA OF EARLY, MID AND LATE LUTEAL PHASE

1979 ◽  
Vol 91 (3) ◽  
pp. 529-537 ◽  
Author(s):  
Ch. V. Rao ◽  
V. L. Estergreen ◽  
F. R. Carman ◽  
G. E. Moss
Keyword(s):  
Luteal Phase ◽  
Specific Binding ◽  
Prostaglandin F2α ◽  
Progressive Increase ◽  
Corpora Lutea ◽  
Apparent Dissociation Constant ◽  
Plasma Progesterone ◽  
Peripheral Plasma ◽  
Late Luteal Phase ◽  
Dissociation Constant Kd

ABSTRACT A total of 15 corpora lutea representing early (day 3), mid (day 13) and late luteal phase (days 20 and 21–24) were obtained by ovariectomy on cycling cows. The luteal weights and peripheral plasma progesterone levels just prior to ovariectomy, were consistent with the above luteal phases. The specific binding of [125I]human chorionic gonadotrophin to membranes prepared from corpora lutea was significantly higher (P < 0.01) for days 13 and 20 than for days 3 and 21–24. The binding in day 21–24 corpora lutea was higher (P < 0.01) than day 3. Although there was no difference either in number or affinity (apparent dissociation constant (Kd) = 0.04 nm) of gonadotrophin receptors in days 13 and 20 corpora lutea, only in the former did the binding correlate well with plasma progesterone levels. The specific binding of [3H]prostaglandin (PG)F2α to the membranes of these same corpora lutea showed a progressive increase (P < 0.01) from day 3, reached the highest value at a time when corpora lutea were actively regressing (day 20) and then declined (P < 0.01) by day 21–24. Although a considerable number of PGF2α receptors existed at day 13, the affinity of these same receptors was 203 times lower (Kd = 3458 nm) than the affinity of receptors in day 20 corpora lutea (Kd = 17 nm). In summary, the above results show that gonadotrophin receptors correlate with luteotrophic, whereas PGF2α receptors correlate with luteolytic phases in bovine corpora lutea.

PERIPHERAL PLASMA PROGESTERONE CONCENTRATIONS IN SHEEP DURING THE OESTROUS CYCLE

1973 ◽  
Vol 58 (2) ◽  
pp. 219-225 ◽  
Author(s):  
K. P. McNATTY ◽  
K. J. A. REVFEIM ◽  
A. YOUNG
Keyword(s):  
Luteal Phase ◽  
Oestrous Cycle ◽  
Diurnal Changes ◽  
Progesterone Concentration ◽  
Once Daily ◽  
Plasma Progesterone ◽  
Blood Samples ◽  
Peripheral Plasma ◽  
The Hours

SUMMARY Progesterone concentrations in peripheral plasma were measured once daily during one oestrous cycle in each of eight sheep. In addition, on days 4–5, 8–9, 12–13 and 15–16 of the oestrous cycle, blood samples were collected at 30-min intervals throughout each 24-h period. A total of three ewes was sampled in each 24-h period and the same three animals were not bled again for at least 1 week. Plasma progesterone concentrations in all the ewes fluctuated considerably throughout each 24-h period. The within-sheep within-day variations observed in peripheral progesterone concentrations were compared with the between-sheep within-day variations and the within-sheep between-day variations previously reported. It is concluded that these previously reported variations in peripheral plasma progesterone concentration could be attributed to within-day variations in each animal. On days 8–9 and 12–13 of the oestrous cycle there were significantly higher concentrations of progesterone in plasma during the hours of daylight than during the hours of darkness. In contrast, progesterone concentrations on days 4–5 and 15–16 were not found to be significantly different between the hours of daylight and darkness. These results suggest that diurnal changes in peripheral plasma progesterone concentration occur during the luteal phase of the ovine oestrous cycle.

7 PLASMA PROGESTERONE CONCENTRATIONS IN OVARIECTOMIZED COWS WITH INTRAVAGINAL DEVICES CONTAINING DIFFERENT LEVELS OF PROGESTERONE

2006 ◽  
Vol 18 (2) ◽  
pp. 112
Author(s):  
M. Aviles ◽  
L. Cutaia ◽  
I. Videla Dorna ◽  
M. Aba ◽  
G. A. Bo
Keyword(s):  
Los Angeles ◽  
Repeated Measures ◽  
Solid Phase ◽  
Body Condition Score ◽  
Animal Health ◽  
Area Under The Curve ◽  
Beef Cows ◽  
Sudden Increase ◽  
Plasma Progesterone ◽  
Blood Samples

An experiment was designed to determine plasma progesterone (P4) concentrations in ovariectomized cows treated with either CIDR-B devices (Pfizer Animal Health, Hamilton, New Zealand) impregnated with 1.9 g of P4 or DIB devices (Syntex, Argentina) impregnated with 0.5 or 1.0 g of P4. Fifteen ovariectomized beef cows, weighing 350 to 450 kg and with a body condition score (BCS) 2.5 to 3.0 out of 5 were used. All cows were ovariectomized 30 days before the beginning of the trial and had plasma P4 concentrations <1 ng/mL (measured by radioimmunoassay (RIA)) 10 days before the trial. On Day 0, cows were stratified by weight and randomly assigned to one of three treatment groups to receive intravaginal devices containing 0.5 g of P4 (DIB 0.5), 1 g of P4 (DIB 1.0), or 1.9 g of P4 (CIDR-B). Blood samples were taken 12 and 24 h after intravaginal device insertion and then every 24 h until device removal on Day 7. Jugular blood samples were drawn into heparinized tubes and centrifuged within 20 min of collection; the plasma was harvested, frozen, and stored at −10°C. Progesterone was measured in plasma samples using a commercial solid-phase RIA (Coat-a-count; Diagnostic Products Corp., Los Angeles, CA, USA). All of the samples were analyzed at one time and the intra-assay coefficient of variation was 13%. Plasma P4 concentrations were compared among treatments by calculating the area under the curve over time and testing for differences by ANOVA. Plasma P4 profiles were also analyzed by ANOVA for repeated measures. Analysis of plasma P4 profiles revealed a day effect (P < 0.001) but not a treatment effect (P > 0.13) or a day by treatment interaction (P > 0.16; Table 1). The area under the curve did not differ (P = 0.95) among groups (DIB 0.5: 2236.4 ng, DIB 1.0: 2164.6 ng, and CIDR-B: 2266.8 ng). In all treatments, plasma P4 profiles were characterized by a sudden increase in P4 concentrations within 12 h of device insertion and a gradual decrease during the following several days. It was concluded that the use of CIDR-B devices impregnated with 1.9 g of P4 or DIB devices impregnated with 1.0 or 0.5 g of P4 did not result in different plasma P4 concentrations in ovariectomized cows. Further studies are needed to confirm these results in lactating and dry intact (not ovariectomized) cattle. Table 1. Mean plasma P4 concentrations (ng/mL ± SEM) in ovariectomized cows treated with intravaginal devices containing 0.5 g (DIB 0.5), 1.0 g (DIB 1.0), or 1.9 g (CIDR-B) of P4*

323 EFFICIENCY OF CLOPROSTENOL-INDUCED LUTEOLYSIS IN SUPEROVULATED COWS

2011 ◽  
Vol 23 (1) ◽  
pp. 258
Author(s):  
J. H. M. Viana ◽  
M. S. B. Vargas ◽  
L. G. B. Siqueira ◽  
B. R. C. Alves ◽  
A. P. Oliveira ◽  
...  
Keyword(s):  
Prostaglandin F2α ◽  
Control Group ◽  
Corpora Lutea ◽  
Considerable Decrease ◽  
Plasma Progesterone ◽  
Blood Samples ◽  
Standard Procedures ◽  
Luteal Tissue ◽  
To Receive

The induction of multiple ovulations is a key procedure for in vivo embryo production. Many corpora lutea (CL) are developed, resulting in abnormally high progesterone concentrations. Luteolysis induction by prostaglandin F2α and its analogues is well described in cows bearing one or few, but not multiple, CL, as occurs after superovulation. The objective of the first experiment was to compare the efficacy of a single prostaglandin F2α treatment on inducing luteolysis in embryo donors immediately after flushing (D7, N = 24) or 4 days later (D11, N = 22). Holstein cows were superovulated with 400 IU of FSH following standard procedures. Embryo flushing was performed 7 days after AI, and cows were randomly allocated into 2 groups to receive either a 0.5 mg of sodium cloprostenol IM treatment immediately after flushing (D7 group) or the same treatment 4 days later (D11 group). Occurrence of luteolysis was monitored by plasma progesterone concentrations (P4), measured by radioimmunoassay in blood samples taken at 4-h intervals. There was no difference in P4 before treatment between D7 and D11 groups (28.6 ± 5.2 v. 36.4 ± 7.4 ng mL–1, respectively; P > 0.05). Although cloprostenol caused a remarkable decline in P4 48 h after treatment in both groups (1.8 ± 0.3 and 1.6 ± 0.4 ng mL–1 for D7 and D11 groups, respectively; P < 0.05), P4 continued decreasing in D11 cows thereafter, remaining smaller than 1 ng mL–1 up to 196 h after treatment, whereas in D7 cows, there was no further reduction in P4. Luteolysis (P4 <1 ng mL–1) was observed in all D11 cows, but failed in 11 of 20 (55%) D7 cows, in which P4 increased after the initial cloprostenol-induced decrease. The second experiment compared luteolysis in superovulated v. nonsuperovulated cows. Non-superovulated (control group, CG, N = 8) and superovulated cows (SOV, N = 6) received a single dose of sodium cloprostenol IM (0.5 mg) on day 11 after oestrus. Morphological and functional luteolysis were monitored daily by ovarian ultrasonography and P4 analysis; also, plasma LH was measured in blood samples taken every 20 min for 1 h, during 5 days. Individual CL size was smaller (1.8 ± 0.1 v. 3.5 ± 0.4 cm2) but total luteal tissue was greater (29.8 ± 7.0 v. 3.5 ± 0.4 cm2; P < 0.05) in SOV than in CG. A considerable decrease in P4 occurred in both groups 24 h after treatment (from 51.1 ± 12.9 to 5.1 ± 0.9 ng mL–1 in SOV and from 5.9 ± 0.6 to 1.1 ± 0.1 ng mL–1 in CG); however, SOV cows did not reach P4 values similar to CG until 96 h after treatment (0.9 ± 0.3 v. 0.4 ± 0.2 ng mL–1, respectively; P > 0.05). There was no difference in initial LH values between SOV and CG (1.5 ± 0.1 and 1.5 ± 0.1 ng mL–1; P > 0.05), but the slower decrease in P4 in the SOV group prevented LH from increasing up to 96 h after luteolysis induction, whereas mean LH values increased (P < 0.05) in CG after 24 h. In conclusion, luteolysis failure may occur when cloprostenol is given at the day of flushing (7 days after AI) in superovulated cows. In addition, luteolysis induction on day 11 after SOV is efficient, but the initial high progesterone concentration results in a slower rate of P4 decrease to basal levels. The authors acknowledge CNPq and FAPEMIG Project CVZ AQP 01654/09.

Oestrus in relation to peak oestradiol levels in ovariectomized Galloway cows

2001 ◽  
Vol 72 (2) ◽  
pp. 401-405
Author(s):  
A. O. Darwash ◽  
G. E. Lamming ◽  
L. M. Hicking
Keyword(s):  
Luteal Phase ◽  
Intramuscular Injection ◽  
High Plasma ◽  
Plasma Progesterone ◽  
Blood Samples ◽  
Measured Dose ◽  
Oestradiol Benzoate ◽  
The Mean ◽  
Plasma Oestradiol ◽  
Follicular Activity

AbstractThe objective of the present study was to characterize the variation in oestrous behaviour among ovariectomized cows in response to a measured dose of oestradiol benzoate (OB) . In study 1, nine ovariectomized Galloway cows, approximately 10 years old, were challenged with an intramuscular injection of either 0·25, 0·5 or 1·0 mg of OB. Following this, 0·5 mg OB was chosen as the appropriate dose required to induce oestrous behaviour in ovariectomized Galloway cows. In study 2, nine cows injected with 0·5 mg OB were monitored for oestrous behaviour using KAMAR® heat mount detectors. Blood samples for plasma oestradiol-17β (E2) assay were taken every 4 h between 0 to 72 h and once at 96 h, following OB administration. The plasma E2 concentrations between 0 to 96 h following OB administration differed significantly ( P < 0·001) among cows. The interval to peak E2 concentrations averaged 17·42 (s.e. 2·21) h and the mean peak E2 concentration was 5·86 (s.e. 0·57) ng/l. The mean interval from OB administration until onset of mounting activity was 24·57 (s.e.2·38) h and the duration of oestrus averaged 10·5 (s.e. 1·99) h . In all cows, mounting activity occurred following peak E2 concentrations after an average interval of 7·73 (s.e. 1·84) h. There was no significant association between peak E2 concentrations and the interval to onset of mounting activity or its duration. Since the variation among Galloway cows in the manifestation of behavioural oestrus was independent of systemic E2 concentrations, it implies that there are inherent differences between individuals in the sensitivity of the hypothalamus to physiological E2 thresholds. This may help to explain the incidence of silent ovulation in some animals and the occurrence of overt oestrus associated with follicular activity during the luteal phase of the cycle or during the various stages of pregnancy, in the presence of high plasma progesterone concentrations.

Luteolytic effect of prostaglandin F2α in Boran and Boran × Friesian cross-bred heifers

1993 ◽  
Vol 120 (1) ◽  
pp. 103-106 ◽  
Author(s):  
E. R. Mutiga ◽  
E. Mukasa-Mugerwa ◽  
T. Azage
Keyword(s):  
Luteal Phase ◽  
Prostaglandin F2α ◽  
Oestrous Cycle ◽  
Corpora Lutea ◽  
Plasma Progesterone ◽  
Significant Difference ◽  
Prostaglandin F ◽  
Elisa Technique ◽  
The Cross

SUMMARYThe luteolytic effect of prostaglandin F2α (PGF2α) during the confirmed luteal phase of the oestrous cycle was evaluated in ten Boran and ten Boran × Friesian cross-bred heifers. Following injection with 25 mg Lutalyse, animals were bled every 6 h for 96 h and plasma progesterone (P4) determined by the ELISA technique. Borans had significantly (P < 0·05) smaller corpora lutea (12·01±0·72 ν. 17·03±2·10 mm) and responded faster to PGF2α injection (65·57±1·40 ν. 78·27±2·18 h) than the cross-bred heifers. However, there was no significant difference in either the initial P4 values (6.24±0·98 ν. 8·00±1·71 ng/ml) or the rate of its decline following PGF2α injection between the two breeds. Values declined sharply to basal levels (11% of the initial pretreatment values) within 48 h in both breeds. All ten cross-breds and eight Borans showed standing oestrus within a week of treatment. However, oestrus was better synchronized (P < 0·05) in Borans than cross-breds. It was concluded that PGF2α is effective for oestrus synchronization in both breeds, but oestrus occurred earlier and was more precise in Borans than in cross-breds.

scholarly journals Experimental Infection of Pregnant Cattle with Bluetongue Virus Serotype 11 between Postbreeding Days 21 and 48

1993 ◽  
Vol 5 (3) ◽  
pp. 329-335 ◽  
Author(s):  
Andrés de la Concha-Bermejillo ◽  
Anselmo Odeon ◽  
Robert H. BonDurant ◽  
Bennie I. Osburn
Keyword(s):  
Bluetongue Virus ◽  
Reproductive Tract ◽  
Virus Isolation ◽  
Ultrasound Examination ◽  
Virulent Strain ◽  
Clinical Signs ◽  
Lymphocytic Infiltration ◽  
Plasma Progesterone ◽  
Blood Samples ◽  
Virus Serotype

Four bluetongue virus (BTV)-seronegative heifers and 2 BTV-seropositive heifers were inoculated with the virulent strain UC-8 of BTV-11 between postbreeding days (PBD) 21 and 30. The heifers were observed for 10–18 days after inoculation for clinical signs, and pregnancy was monitored by ultrasound examination of the uterus and by plasma progesterone levels. Blood samples were collected daily after inoculation and processed for virus isolation and titration. Heifers were euthanized between PBD31 and PBD48, and tissues were collected for virologic and pathologic examination. All but 1 heifer inoculated on PBD21 remained pregnant after BTV inoculation, A cystic corpus luteum was found in the ovary of the nonpregnant heifer, but BTV was not isolated from the reproductive tract of this heifer. Three of the inoculated heifers that remained pregnant showed mild multifocal areas of perivascular lymphocytic infiltration in the ovary. BTV was reisolated from spleen and prescapular and peribronchial lymph nodes 10 days after inoculation from 3 of the 4 BTV-seronegative heifers. BTV was also reisolated from the uterus of 1 of the heifers that remained pregnant, but microscopic lesions were not found in this organ.

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