12 PROGESTERONE SUPPLEMENTATION DAY 3 TO 5 POST-OVULATION IN AI-BRED MARES

2013 ◽  
Vol 25 (1) ◽  
pp. 153 ◽  
Author(s):  
H. Richard ◽  
P. Appleton ◽  
D. J. Kesler ◽  
C. E. Ferguson
Keyword(s):  
Treatment Group ◽  
Ovulation Induction ◽  
Low Dose ◽  
Pregnancy Rates ◽  
Blood Samples ◽  
Treatment Groups ◽  
The Mean ◽  
Open Control ◽  
Progesterone Supplementation ◽  
In Pregnancy

The purpose of this study was to determine the effectiveness of increasing progesterone (P4) concentrations during early pregnancy, by supplementing a low dose of Regu-Mate® (Intervet, Millsboro, DE, USA) on Days 3, 4, and 5, post-ovulation to AI mares. Sixty-three AI-bred mares were randomly allocated to 1 of 2 treatment groups. All mares underwent ovulation induction using 1.5 mg mL–1 of deslorelin acetate (IM) following observation of ≥30-mm follicles and were inseminated with either fresh (n = 57) or cooled (n = 6) semen from fertile stallions approximately 24 h later. Ovulation was verified via ultrasonography in all mares. Mares allocated to the treatment group (n = 29) received altrenogest (Regu-Mate®) orally at a rate of 15 mg per day on Days 3, 4, and 5 following ovulation (d = 0), whereas control mares (n = 34) received no treatment. Blood samples were collected from all mares from Day 0 (ovulation) through Day 6 post-ovulation via jugular venipuncture. Pregnancies were determined via ultrasonography at 18 days post-ovulation. The pregnancy rate for untreated mares (18/34, 53%) was not different (P > 0.05) from altrenogest-treated mares (13/29, 45%). There was no difference (P > 0.50) in pregnancy rates when mares were AI bred 1 (19/39, 49%) or 2 (10/20, 50%) days from ovulation. The mean plasma P4 concentration on Day 5 was higher (P < 0.06) for pregnant control mares (4.75 ± 0.59 ng mL–1) compared with open control mares (3.50 ± 0.25 ng mL–1). There was a greater increase (P < 0.02) in plasma P4 concentrations (Day 5 – Day 1 concentration) in untreated pregnant mares (3.87 ± 0.56 ng mL–1) compared with untreated open mares (2.38 ± 0.22 ng mL–1). In conclusion, it was determined that altrenogest supplementation from Day 3 to 5 post-ovulation was ineffective in improving pregnancy rates. However, it is unknown if this was the result of the dose used or the length of supplementation. Additionally, the timing of altrenogest coincided with a significant increase in P4 in pregnant mares compared with open mares, indicating that the timing may be correct or there was action of an unknown embryonic luteotropin(s), which would describe the differences between P4 concentrations in pregnant versus open mares.

Weaning at birth: the effect on the reproduction of the sow

1985 ◽  
Vol 41 (3) ◽  
pp. 375-382 ◽  
Author(s):  
M. A. Varley ◽  
T. Atkinson
Keyword(s):  
Treatment Group ◽  
Reproductive Performance ◽  
Post Partum ◽  
Large White ◽  
Blood Samples ◽  
Treatment Groups ◽  
The Mean

AbstractThirty-six Landrace × Large White sows were allocated at random to one of three treatment groups. Sows on treatment A (no. = 6) did not lactate at all and the piglets from these sows were removed at birth. Sows on treatment B (no. = 15) lactated for 1 day after parturition and sows on treatment C (no. = 15) acted as controls and lactated for 42 days. The reproductive performance of each treatment group was recorded and all sows were bled every 2nd day from parturition to 30 days post partum. All blood samples were assessed for oestradiol-17β and progesterone concentrations. In treatments A and B, a high proportion of anoestrous sows was seen (0·28). None of the sows in treatment C became anoestrous. The mean interval from weaning to the onset of oestrus for treatments A and B (19·0 (s.e. 6·5) days and 19·7 (s.e. 3·8) days respectively) were not significantly different, while that for treatment C (5·6 (s.e. 0·4) days) was significantly shorter (P < 0·01). The number of piglets born alive at the subsequent farrowing for treatments A, B and C respectively was 7·3 (s.e. 0·8), 9·1 (s.e. 0·8) and 10·5 (s.e. 0·67) (P < 0·05). The calculated annual sow productivity (piglets born alive per sow per year), excluding the first litter born, for treatments A, B and C respectively was 18·4, 22·8 and 22·9. Weaning at, or close to, parturition did not, therefore, influence sow productivity compared with weaning after 6 weeks of lactation.

scholarly journals Effects of imidacloprid and thiamethoxam on the development and reproduction of the soybean aphid Aphis glycines

PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0250311
Author(s):  
Aonan Zhang ◽  
Lin Zhu ◽  
Zhenghao Shi ◽  
Tianying Liu ◽  
Lanlan Han ◽  
...  
Keyword(s):  
Treatment Group ◽  
Reproductive Rate ◽  
Soybean Aphid ◽  
Aphis Glycines ◽  
Intrinsic Rate Of Increase ◽  
Control Group ◽  
Net Reproductive Rate ◽  
Treatment Groups ◽  
Rate Of Increase ◽  
The Mean

The soybean aphid Aphis glycines Matsumura (Hemiptera: Aphididae) is a primary pest of soybeans and poses a serious threat to soybean production. Our studies were conducted to understand the effects of different concentrations of insecticides (imidacloprid and thiamethoxam) on A. glycines and provided critical information for its effective management. Here, we found that the mean generation time and adult and total pre-nymphiposition periods of the LC50 imidacloprid- and thiamethoxam-treatment groups were significantly longer than those of the control group, although the adult pre-nymphiposition period in LC30 imidacloprid and thiamethoxam treatment groups was significantly shorter than that of the control group. Additionally, the mean fecundity per female adult, net reproductive rate, intrinsic rate of increase, and finite rate of increase of the LC30 imidacloprid-treatment group were significantly lower than those of the control group and higher than those of the LC50 imidacloprid-treatment group (P < 0.05). Moreover, both insecticides exerted stress effects on A. glycines, and specimens treated with the two insecticides at the LC50 showed a significant decrease in their growth rates relative to those treated with the insecticides at LC30. These results provide a reference for exploring the effects of imidacloprid and thiamethoxam on A. glycines population dynamics in the field and offer insight to agricultural producers on the potential of low-lethal concentrations of insecticides to stimulate insect reproduction during insecticide application.

scholarly journals Topiramate Versus Propranolol in the Prophylaxis of Migraine in Bangladeshi Population

2020 ◽  
Vol 18 (2) ◽  
pp. 12-17
Author(s):  
Muhammad Tayeb ◽  
Md Hasanuzzaman ◽  
Abul Mansur Md Rezaul Karim ◽  
Mohammad Sanaullah ◽  
Md Ashraful Islam
Keyword(s):  
Migraine Attack ◽  
Divided Dose ◽  
Low Dose ◽  
Primary Headache ◽  
Headache Disorder ◽  
Treatment Groups ◽  
Primary Headache Disorder ◽  
Significant Difference ◽  
The Mean ◽  
Bangladeshi Population

Background : Migraine is primary headache disorder characterized by recurring attacks of pain and associated symptoms. The management modality is still unsatisfactory due to poor understanding of its cause and pathogenesis. To assess the efficacy and safety of low dose Topiramate vs Propranolol in migraine prophylaxis. Materials and methods : A randomized clinical trial including 130 patients with frequent migraine headache >5 attacks per month was performed in the out patients Department of Medicine and Neurology, CMCH for a period of 12 weeks. The patients were randomly divided into two treatment groups – treated by Topiramate 50mg/day and Propranolol 80mg/day respectively. Topiramate started with 25mg/day for 7 days then increased up to 50mg/day in two divided dose. Propranolol started with 40mg/day for 7 days then increased up to 80mg/day in two divided dose. The patients were assessed at 0, 8 and 12 weeks of the study. Results: The Topiramate group showed a reduction in the mean (±SD) of frequency of migraine attack from 6.95(±2.88) to 1.75(±1.08) episode per month, headache days per month from 7.62(±4.14) to 1.83(±1.10), intensity of headache per attack from 8.98(±1.05) to 6.10(±2.50) based on VAS scale, duration of headache per episode from 11.56(±9.16) to 5.40(±2.97) per hour and MIDAS score from 16.19(±3.91) to 8.14(±3.93). In patient treated with Propranolol, the mean (±SD) of monthly frequency of migraine attack declined from 7.09(±2.87) to 1.92(±0.98) episode per month, headache days per month from 8.17(±4.52) to 1.86(±o.83), intensity of headache per attack from 8.47(±1.10) to 6.03(±2.05) based on VAS scale, duration of headache per episode from 11.16(±8.08) to 5.97(±3.45), MIDAS score from 15.48(±3.55) to7.77(±3.49). Pre- and post-treatment values were significantly different for individual groups but no significant difference observed between groups. Conclusion: This study demonstrated that both low dose Topiramate and propranolol could significantly reduce migraine frequency, intensity and duration. Chatt Maa Shi Hosp Med Coll J; Vol.18 (2); July 2019; Page 12-17

Exogenous progesterone and embryo survival in Booroola-cross ewes

1991 ◽  
Vol 3 (1) ◽  
pp. 71 ◽  
Author(s):  
DO Kleemann ◽  
SK Walker ◽  
RJ Grimson ◽  
DH Smith ◽  
TI Grosser ◽  
...  
Keyword(s):  
Drug Release ◽  
Pregnancy Rates ◽  
Embryo Survival ◽  
Treatment Groups ◽  
F Gene ◽  
Exogenous Progesterone ◽  
In Pregnancy ◽  
Australian Merino

To investigate if exogenous progesterone improves embryo survival, 209 multiparous Booroola Merino x South Australian Merino ewes, heterozygous for the F gene (F+) were allocated to seven treatment groups and inseminated at a synchronized oestrus. Six groups received progesterone from controlled internal drug release G dispensers on the following days after ovulation: 4-7, 4-11, 4-14, 7-11, 7-14 and 11-14. Concentration of peripheral progesterone increased (P less than 0.05) in most supplemented groups, but there were no significant differences in pregnancy rates between treatments. However, the number of fetuses per pregnancy was increased for progesterone treatments starting on Day 4 (Days 4-7, 4-11 and 4-14 combined v. control; P less than 0.05) and for all supplemented treatments compared with the control (P less than 0.05).

46 Effect of Bioxcell® and Triladyl® Extenders on Washed Semen of South African Indigenous Bucks

2018 ◽  
Vol 30 (1) ◽  
pp. 162
Author(s):  
L. P. Nethenzheni ◽  
M. L. Mphaphathi ◽  
N. C. Negota ◽  
T. L. Nedambale
Keyword(s):  
Treatment Group ◽  
South African ◽  
Liquid Nitrogen ◽  
Seminal Plasma ◽  
Semen Parameters ◽  
Mean Values ◽  
Treatment Groups ◽  
Frozen Semen ◽  
The Mean

Semen extenders and seminal plasma are vital for cryopreservation of buck semen. The objectives of the study were to evaluate the effect of 2 extenders: Triladyl® (Minitube, Tiefenbach, Bavaria) and Bioxcell® (IMV, L’Aigle, France) and the removal of seminal plasma on buck semen. Six indigenous bucks were used in this study and 6 ejaculates were collected from individual bucks. The semen was pooled and then randomly allocated into 6 groups: (1) raw-washed, (2) raw-non-washed, (3) Triladyl®-washed, 4) Triladyl®-non-washed, (5) Bioxcell®-washed, and (6) Bioxcell®-non-washed. Spermatozoa viability was assessed using Eosin-Nigrosin and morphology using Spermac® (Vitrolife, Göteborg, Sweden) stains. The washed semen samples were all diluted into (1:4 v/v) with PBS and centrifuged at 1500 × g for 10 min. Semen samples were then extended with Triladyl® or Bioxcell® per treatment groups and equilibrated for 2 h at 5°C. The semen samples were loaded into straws per treatment groups and placed 5 cm above a liquid nitrogen vapour for 10 min and then stored at –196°C until use. After 1 month of storage, frozen semen straws per treatment group were thawed at 37°C for 30 s, and spermatozoa parameters were analysed post-thaw. Significant differences among the mean values of semen parameters were determined by Tukey’s test using ANOVA, GLM procedure of SAS version 12.1 of 2010 (SAS Institute Inc., Cary, NC, USA). There was a higher (P < 0.05) live and normal spermatozoa percentage in non-washed semen extended with Bioxcell® (45.7 ± 21.2) than the semen extended with Triladyl® (24.5 ± 22.2%). Live and normal spermatozoa percentages were drastically reduced in the Bioxcell® (5.2 ± 4.9) and Triladyl® (6.9 ± 8.6%) washed semen groups. There was a higher (P < 0.05) percentage of spermatozoa with head abnormalities in non-washed semen extended with Triladyl® (20.4 ± 10.2), compared with the semen extended with Bioxcell® (18.3 ± 12.4%) following freeze-thawing. There was a higher (P < 0.05) percentage of spermatozoa with head abnormalities in washed semen samples extended with Triladyl® (34.0 ± 16.0) compared with the semen extended with Bioxcell® (10.1 ± 7.0%). There were higher (P < 0.05) percentages of spermatozoa with coiled tail abnormalities in washed semen extended with Bioxcell® (65.4 ± 25.0) compared with Triladyl® (35.9 ± 21.6%). In conclusion, the liveability of spermatozoa was negatively affected by washing of semen extended with Bioxcell® and Triladyl® extender. Bioxcell® significantly increased tail abnormalities and Triladyl® gave less protection against head abnormalities following cryopreservation of South African unimproved indigenous bucks’ semen.

Results of a Randomized, Open-Label, Phase IIIb Study of 2 Schedules of Decitabine in Higher-Risk Myelodysplastic Syndrome Patients

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 3846-3846
Author(s):  
Depei Wu ◽  
Xin Du ◽  
Jie Jin ◽  
Zhijian Xiao ◽  
Zhixiang Shen ◽  
...  
Keyword(s):  
Plasma Concentration ◽  
Treatment Group ◽  
Complete Remission ◽  
Myelodysplastic Syndrome ◽  
De Novo ◽  
Day Treatment ◽  
Treatment Schedule ◽  
Open Label ◽  
Treatment Groups ◽  
The Mean

Abstract Abstract 3846 Aim: To evaluate the efficacy and safety of 3-day and 5-day treatment schedules of decitabine (nucleoside analogue) in Chinese patients with Myelodysplastic Syndrome (MDS). Methods: In this open-label, multi-center, phase 3b study, consenting men and women (n=132) above 18 years of age with de novo or secondary MDS fitting any of the recognized French-American-British classifications, with score on International Prognostic Scoring System (IPSS) ≥ 0.5 within 30 days before randomization, and having Eastern Cooperative Oncology Group performance (ECOG) status of 0–2, were enrolled. Patients were randomized (1:1) to either 3-day treatment schedule (15 mg/m2/day decitabine administered by continuous intravenous infusion within a 3-hour period, repeated every 8 hours for 3 consecutive days/cycle; cycles repeated every 6 weeks) or to 5-day treatment schedule (20 mg/m2 decitabine administered by a 1-hour infusion once-daily, on days 1 through 5/cycle; cycles repeated every 4 weeks), until minimum of 30 patients were included in the 3-day treatment group. All remaining patients were enrolled for the 5-day treatment. Patients were treated for ≥4 treatment cycles and for a maximum of 2 years, as long as the patient continued to benefit (absence of overt progression of disease or unacceptable toxicity). The primary efficacy endpoint was overall response rate (ORR) that included complete remission, bone marrow complete remission and partial remission, according to the International Working Group (IWG) 2006 response criteria. The secondary endpoints included hematological improvement, time to acute myeloid leukemia (AML) progression or death, and overall survival (OS). Safety and pharmacokinetics of decitabine were evaluated. Assuming a 10% dropout rate, with 132 enrolled patients, the study had 90% power at a 5% significance level to detect a &gt;10% ORR. Results: Thirty-four patients were included in the 3-day treatment group and 98 patients were included in the 5-day treatment group. Overall, 78 (59.5%) patients prematurely discontinued the study (16 [12.2%] patients discontinued due to disease progression). The demographic and baseline characteristics were comparable between the 2 treatment groups. In the overall population, the median age was 53.9 years (range: 18.5 – 84.0), 59% were men, all had de novo MDS, the mean (SD) time since diagnosis of MDS was 4.2 (9.38) months, 41.4% patients were IPSS Intermediate-1 (0.5–1.0), 43% were IPSS Intermediate −2 (1.5–2.0) and 15.6% were IPSS high risk (≥2.5) and the majority (68.9% of patients) had ECOG score of 1. Median number of treatment cycles was 3 for each of the treatment groups. Based on the single sample proportion comparison with given value (10%), the significant ORR was achieved in the overall population (22.9%; 95% CI: 16.0, 31.1; p&lt;0.001) as well as in the 3-day treatment group (26.5%; 95% CI: 12.9, 44.4) and 5-day treatment group (21.6%; 95% CI: 13.9, 31.2). The hematological improvement (CR+PR+HI) rate (% [95% CI]) for overall population, 3-day treatment group and 5-day treatment group was 39.7 (31.3, 48.6), 44.1 (27.2, 62.1) and 38.1 (28.5, 48.6) respectively. AML transformations or deaths occurred in 21 (16.0%) patients overall, and in 5 (14.7%) and 16 (16.5%) patients in the 3-day and 5-day treatment group respectively. For the overall population, the maximum estimated time to AML transformations or death was 27.8 months (3-day treatment: 17.9 months, 5-day treatment: 27.8 months). For the overall population, the 12-month OS was 80.6 % and 24-month OS was 60.7%. At steady state, the mean (SD) maximum plasma concentration and mean (SD) area under plasma concentration-time curve (AUC0-∞) was 54.44 (20.07) ng/mL and 118.93 (50.55) ng.hr/mL, respectively for the 3-day treatment group (n=7) and 222.35 (53.74) ng/mL and 180.43 (43.78) ng.hr/mL, respectively for the 5-day treatment group (n=17). Overall, at least one treatment-emergent adverse event (TEAE) occurred in 97 (74%) patients (32 [94.1%] patients in the 3-day treatment group and in 65 [67%] patients in the 5-day treatment group); TEAEs were related to study drug in 31 (91.2%) patients in the 3-day treatment group and 60 (61.9%) patients in the 5-day treatment group. Conclusion: Decitabine was found to be efficacious and safe for treatment of MDS. Results of this study were consistent with similar decitabine studies conducted previously. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Efficacy of flumethrin pour on against Haematobia exigua infesting cattle under field conditions

2021 ◽  
Author(s):  
Periyasamy Anbarasi ◽  
Gurusamy Ponnudurai ◽  
Kandasamy Senthilvel ◽  
Kuppannan Sukumar ◽  
Palani Sriniva
Keyword(s):  
Body Weight ◽  
Treatment Group ◽  
Tamil Nadu ◽  
Treatment Intensity ◽  
Treatment Groups ◽  
Significant Difference ◽  
The Mean ◽  
Pre Treatment ◽  
And Control ◽  
Cattle Farms

Abstract The efficacy of flumethrin 1% pour-on (1% w/v, Flumitas) was evaluated against Haematobia exigua on cattle farms in Namakkal district, Tamil Nadu from November 2019 to February 2020. In this study, five farms, which had fly menace, selected randomly were divided as treatment (F1, F2, F3 and F4) and control (Fc) groups. Flies collected from the farms were identified as Haematobia exigua and a mean pre-treatment intensity was 195.56 ± 14.07. In the treatment groups (F1,F2,F3 and F4) flumethrin 1% pour on was applied to the back of cattle at the rate of 1 ml/10 kg body weight and fly intensity was recorded for a period of 2 months. The fly intensity reduced to zero within 30 minutes of application and the same trend continued till 28 DPT in F2 and F3, while it was effective 35 DPT in F1 and F4. A highly significant difference in the mean H. exigua fly counts between control and treatment group (P < 0.0001) was observed.

214 EFFECT OF TIMING OF PGF, eCG, AND ESTRADIOL BENZOATE IN RECIPIENTS SYNCHRONIZED WITH A PROGESTIN-BASED PROTOCOL FOR FIXED-TIME EMBRYO TRANSFER

2007 ◽  
Vol 19 (1) ◽  
pp. 224
Author(s):  
L. C. Peres ◽  
D. Pincinato ◽  
L. Cutaia ◽  
R. Tribulo ◽  
G. A. Bo
Keyword(s):  
Embryo Transfer ◽  
Body Condition Score ◽  
Fixed Time ◽  
Estradiol Benzoate ◽  
Pregnancy Rates ◽  
Control Treatment ◽  
Treatment Groups ◽  
Condition Score ◽  
The Mean ◽  
Time Of Administration

An experiment was designed to evaluate alternative treatment protocols for fixed-time embryo transfer (FTET) in recipients in order to reduce cattle handling. Non-lactating, cycling Bos taurus � Bos indicus beef cows (n = 918), with a body condition score (BCS) of 2.5 to 3.5 out of 5, received a progesterone-releasing device (DIB; Syntex, Buenos Aires, Argentina) and 2 mg estradiol benzoate (EB; Syntex) IM on random days of the cycle (Day 0); DIB were removed on Day 8. Cows were placed randomly into 6 treatment groups in a 3 � 2 factorial design. The factors evaluated were time of administration of PGF and eCG [control treatment: PGF Day 5 and eCG Day 5 (Bo et al. 2002 Theriogenology 57, 53–72); PGF Days 0 and 8 and eCG Day 5; PGF Days 0 and 8 and eCG Day 8] and the time of administration of the second injection of EB (at DIB removal or 24 h later). Therefore, cows in the control treatment received 150 �g of d-Cloprostenol (PGF, Ciclase; Syntex) and 400 IU eCG (Novormon; Syntex) on Day 5, whereas cows in the other 2 treatments received 75 �g of PGF on Days 0 and 8 and 400 IU eCG on either Day 5 or Day 8. Each treatment group was further subdivided to receive 1 mg EB IM on either Day 8 (EB Day 8) or Day 9 (EB Day 9). All recipients, whether observed in estrus or not and with more than one CL with luteal area (total CL area minus cavity area) &gt;76 mm2 on the day before embryo transfer, received frozen-thawed embryos (IETS Grade 1) on Day 16 (EB Day 8) or Day 17 (EB Day 9) by direct transfer. Pregnancy was determined by ultrasonography 30 days after FTET. Continuous data were analyzed by ANOVA and pregnancy rates were analyzed by logistic regression. No effects of body condition score or technician were detected (P &gt; 0.1). Although there were no differences in conception rates between recipients treated with EB on Day 8 or Day 9 (168/321, 52.3% vs. 203/350, 58.0%, respectively; P &gt; 0.1), treatment with EB on Day 8 resulted in fewer recipients selected/treated (321/460, 69.7% vs. 350/458, 76.4%; P &lt; 0.05) and pregnant/treated (168/460, 36.5% vs. 203/458, 44.3%; P &lt; 0.05) than 24 h later (EB Day 9), respectively. The mean interval from DIB removal to estrus was shorter (P &lt; 0.05) for recipients in the EB Day 8 (28.1 � 7.2 h) than in the EB Day 9 (43.5 � 9.4 h) group, and the mean (� SEM) CL area was also less in the EB Day 8 group than in the EB Day 9 group (261.7 � 96.7 vs. 293.1 � 114. mm2; P &lt; 0.05). The number of recipients selected/treated was higher in the group receiving PGF on Days 0 and 8 and eCG on Day 8 (243/305, 79.6%) than in the group receiving PGF on Days 0 and 8 and eCG on Day 5 (208/301, 69.1%) or the control group (220/312, 70.5%). Although the luteal area was greater (P &lt; 0.05) in the PGF on Days 0 and 8 and eCG on Day 5 group (304.4 � 127.1 mm2) than in the groups receiving PGF and eCG on Day 5 (274.6 � 98.6 mm2) or PGF on Days 0 and 8 and eCG Day 8 (258.4 � 90.2 mm2), pregnancy rates did not differ between PGF and eCG treatment groups (P &gt; 0.05). It was concluded that it may be possible to reduce animal handling by treating recipients with a half dose of PGF at the time of DIB insertion and removal, when eCG is also administered, without compromising pregnancy rates.

11 COMPARISON OF CONTROLLED INTERNAL DRUG-RELEASE INSERT–BASED AND PROGESTERONE-FREE METHODS FOR OVULATION SYNCHRONIZATION AND TIMED ARTIFICIAL INSEMINATION OF GOATS

2016 ◽  
Vol 28 (2) ◽  
pp. 135 ◽  
Author(s):  
A. Llanes ◽  
W. B. Knox ◽  
C. E. Farin
Keyword(s):  
Gonadotropin Releasing Hormone ◽  
Pregnancy Rates ◽  
Serum Progesterone ◽  
Releasing Hormone ◽  
Treatment Groups ◽  
The North ◽  
Frozen Semen ◽  
Time Of Breeding ◽  
Agricultural Experiment ◽  
The Mean

A CIDR synchronization program is an important tool for facilitating ovulation synchronization and timed AI (OvSynch-TAI). The objective of this study was to test the efficacy of reusing CIDR for OvSynch-TAI compared with that for a progesterone-free OvSynch-TAI protocol (NCS) or a breed by oestrus detection (ED) control. A total of 87 does were randomised into 1 of 5 treatments: (1) ED (control, n = 18), (2) NCS (n = 18), (3) CIDR6-New (n = 17), (4) CIDR6–1X (n = 17), and (5) CIDR6–2X (n = 17). Does in the ED group received two 15-mg doses of PGF2α at a 10-d interval and were bred 12 h after the onset of oestrus following the second PGF2α injection. The NCS group received 15 mg of PGF2α on Day 0, 50 μg of gonadotropin-releasing hormone on Day 8, 15 mg of PGF2α on Day 15, and 50 μg of gonadotropin-releasing hormone on Day 18, concurrently with TAI. The CIDR groups (new, 1X-used, or 2X-used) received a P4 device for a 6-d period, and 15 mg of PGF2α was administered at CIDR removal. Does were bred 48 h after CIDR removal and were given 50 μg of gonadotropin-releasing hormone at TAI. The CIDR in the CIDR6–1X group were previously in place for 10 days before use, whereas CIDR in the CIDR6–2X group were previously in place for 16 days before use. Reused CIDR were rinsed in a diluted Nolvasan solution, followed by a clean water rinse, allowed to air dry, and stored in a refrigerator until time of use. The experiment was conducted in 2 replicates. Within each replicate, all treatments were scheduled so that does were bred during the same 2-day period, and all does were inseminated with a single dose of frozen semen using a nonsurgical (transcervical) technique. Blood samples were taken daily in all treatment groups to monitor concentrations of serum progesterone until the time of breeding. Pregnancy was determined by ultrasonography at 54 and 85 days of gestation. Data were analysed using GLM procedures of SAS (SAS Institute Inc., Cary, NC, USA). Data for pregnancy rates were analysed with a model that included effects of treatment, replicate, and their interactions. Data for serum progesterone concentrations were analysed with a model that included the effects of treatment, replicate, day, and their interactions. Means were separated by Duncan’s test. Mean progesterone differed (P < 0.001) with treatment (5.3 ± 0.8bc, 3.5 ± 0.8c, 7.0 ± 0.8ab, 7.9 ± 0.8a, 6.2 ± 0.8ab ng mL–1 for ED, NCS, CIDR6-New, CIDR6–1X, and CIDR6–2X, respectively; least squares mean ± standard error of the mean). Pregnancy rates for the ED, NCS, CIDR6-New, CIDR6–1X, and CIDR6–2X treatment groups were 39 ± 11%bc, 22 ± 11%c, 64 ± 12%ab, 77 ± 12%a, and 57 ± 12%ab, respectively. In conclusion, reused CIDR were as effective as new CIDR for attaining satisfactory pregnancy rates. Timed AI using a once-used CIDR was more effective for establishing pregnancy than ED and NCS treatments. The lower pregnancy rates in the ED and NCS groups were associated with lower mean progesterone levels during the Ovsynch treatment period before breeding. This research was supported by the North Carolina Agricultural Experiment Station.

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