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1.
Acta Trop ; 202: 105224, 2020 Feb.
Article in English | MEDLINE | ID: mdl-31629825

ABSTRACT

Phlebotomines are important vectors of bacteria, viruses and protozoan parasites. Protozoans of the genus Leishmania which cause visceral and cutaneous leishmaniases, are among the most important etiologic agents transmitted by sand flies. Different blends of human and animal volatiles have been evaluated for use in surveillance and/or control of hematophagous insects. With regard to phlebotomine sand flies there are few records of attraction under laboratory and field conditions. This study was carried out at two collecting sites located in a Brazilian town with a high prevalence of cutaneous leishmaniasis. The aim of the present study was to evaluate the effect of adding two kinds of commercial bait which mimic human odors to light traps to attract sand flies and compare the results with those of light traps without any additional bait. The commercial baits, BG-Lure® and BG-Sweetscent®, were developed to catch anthropophilic mosquitoes. Three treatments were evaluated: 1 - HP light trap with BG-Lure® added; 2 - HP light trap with BG-Sweetscent® added and 3- HP light trap without any attractant. A total of 3,682 sand flies were collected during the study. Constrained correspondence analysis was applied to perform ordination of the captured community of sand fly species that could be explained by attractant, sampling site and sex. The most abundant species: Pintomyia nevesi, Nyssomyia whitmani and Nyssomyia antunesi were further investigated by fitting generalized linear mixed models. Only Ny. whitmani showed a slight indication of an increase in catches with BG-Lure®.


Subject(s)
Insect Control/methods , Phlebotomus , Animals , Female , Humans , Leishmaniasis, Cutaneous/transmission , Male
2.
Theriogenology ; 83(3): 385-93, 2015 Feb.
Article in English | MEDLINE | ID: mdl-25447149

ABSTRACT

The aim of the present study was to determine the optimal phase of the follicular wave to perform ovum pickup (OPU) for in vitro embryo production (IVEP) in various genetic groups. For this purpose, 27 heifers-nine Bos taurus (Holstein), nine Bos indicus (Nelore), and nine Bubalus bubalis (Mediterranean)-were maintained under the same nutritional, management, and environmental conditions. Heifers within each genetic group were submitted to six consecutive OPU trials with 14-day intersession intervals, at three different phases of the pharmacologically synchronized follicular wave (Day 1, 3, or 5 after follicular wave emergence), in a 3 × 3 crossover design. When OPU was performed at different phases of the pharmacologically synchronized follicular wave (Day 1, 3, or 5), no differences were found in the percent of oocytes recovered (70.5 ± 3.1%, 75.0 ± 3.1%, 76.0 ± 3.2%, respectively; P = 0.41) or blastocyst production rates (19.4 ± 2.9%, 16.6 ± 2.9%, 15.9 ± 2.6%, respectively; P = 0.36). Comparing genetic groups, B indicus showed a higher blastocyst rate (28.3(a) ± 2.8%; P < 0.01) than B taurus and B bubalis (14.1(b) ± 2.9% and 10.2(b) ± 2.0%, respectively). However, only B indicus heifers showed a variation in the number of visualized follicles and the total and viable oocytes along consecutive OPU sessions. In conclusion, different phases of the pharmacologically synchronized ovarian follicular wave did not affect OPU-IVEP in B indicus, B taurus, and B bubalis heifers. Additionally, B indicus heifers showed greater OPU-IVEP efficiency than did the other genetic groups, under the same management conditions.


Subject(s)
Buffaloes , Cattle , Embryo Culture Techniques/veterinary , Oocyte Retrieval/veterinary , Animals , Estrus Synchronization , Female , Fertilization in Vitro/veterinary , Oocytes/drug effects , Oocytes/metabolism , Oocytes/physiology , Ovarian Follicle/metabolism , Ovulation Induction/veterinary , Time Factors
3.
Theriogenology ; 79(5): 797-802, 2013 Mar 15.
Article in English | MEDLINE | ID: mdl-23321276

ABSTRACT

The objective was to evaluate when the LH reserve was re-established in postpartum Nellore (Bos indicus) cows by evaluating the response of the hypothalamic-pituitary axis responsiveness to exogenous GnRH or estradiol benzoate (EB). Additionally, we tested the influence of dietary supplementation (SUPL) and calf removal (CR) on the duration of postpartum anestrus. Ninety multiparous lactating Nellore cows were randomly assigned to eight groups. The EB and GnRH groups received 1.0 mg EB (N = 7), and 50 µg lecireline (N = 16), respectively. Additional cows were given the same hormones, and subjected to either nutritional supplementation (EB-SUPL, N = 9; GnRH-SUPL, N = 16), or calf removal at 72 hours after calving (EB-CR, N = 4; GnRH-CR, N = 13). The remaining two groups were the LH (12.5 mg, N = 14) and control groups (saline, N = 11). Hormones were administered weekly from 7 (±5) days postpartum to first ovulation (detection of a CL during a weekly ultrasonographic examination). Blood samples were collected just before and 2 hours (GnRH, LH, and control groups) or 18 hours (EB groups) after hormone or saline (control) administration. Ovulation occurred as early as 15 days postpartum in the GnRH group. The mean ± SEM intervals (days) from calving to first ovulation were EB, 87.7 ± 4.2; EB-CR, 20.3 ± 1.2; EB-SUPL, 60.3 ± 3.2; GnRH, 40.4 ± 2.1; GnRH-CR, 21.0 ± 1.1; GnRH-SUPL, 26.4 ± 1.1; LH, 35.6 ± 1.1; and control, 60.9 ± 2.1. We concluded that there was sufficient LH in the pituitary gland (of Nellore cows) from the second week postpartum to induce ovulation in response to exogenous GnRH. Additionally, calf removal and nutritional supplementation reduced, by 2 to 4 weeks, the interval from calving to an LH increase and ovulation induced by GnRH or EB.


Subject(s)
Cattle/physiology , Estradiol/analogs & derivatives , Gonadotropin-Releasing Hormone/pharmacology , Hypothalamo-Hypophyseal System/drug effects , Luteinizing Hormone/pharmacology , Postpartum Period/metabolism , Animal Feed , Animals , Body Weight , Cattle/anatomy & histology , Estradiol/pharmacology , Female , Ovulation/metabolism
4.
Vet Parasitol ; 192(1-3): 183-91, 2013 Feb 18.
Article in English | MEDLINE | ID: mdl-23177359

ABSTRACT

Gastrointestinal nematode (GIN) infection is a major cause of production losses in cattle. This study was carried out to evaluate the natural resistance against nematode infection in Crioulo Lageano and crossbred Angus male calves. Crioulo Lageano is a local cattle breed in the state of Santa Catarina, in southern Brazil. Ten weaned calves of each breed were grazed together on pasture and naturally infected with nematodes between July 2009 and December 2010. Once every 28 days, we collected fecal and blood samples for parasitological and immunological tests, as well as recording body weights. After 19 samplings, all animals were slaughtered for quantification and identification of GINs. We found that the animals had been infected with the following nematode species, in decreasing order by the mean number of specimens: Trichostrongylus axei, Cooperia punctata, Ostertagia ostertagi, Haemonchus placei, Oesophagostomum radiatum, and Trichuris spp. There were no significant differences between the Crioulo Lageano and crossbred Angus groups in terms of worm burden or nematode fecal egg count, nor in terms of the mean levels of immunoglobulin (G and A) against C. punctata and H. placei antigens, except in IgA mean level in abomasal mucus against H. placei adult worms that was significantly higher in crossbred Angus cattle (p<0.05). At the end of the study, the crossbred Angus cattle were heavier than were the Crioulo Lageano cattle (mean live weight, 507.35 and 390.3 kg, respectively). Comparative parasitological and immunological evaluation revealed no difference between two breeds in terms of their natural resistance against GINs.


Subject(s)
Cattle Diseases/immunology , Disease Resistance , Gastrointestinal Diseases/veterinary , Nematoda/immunology , Nematode Infections/veterinary , Animals , Brazil , Cattle , Cattle Diseases/parasitology , Feces/parasitology , Gastrointestinal Diseases/immunology , Gastrointestinal Diseases/parasitology , Gastrointestinal Tract/parasitology , Immunoglobulin A/blood , Immunoglobulin G/blood , Larva , Male , Nematode Infections/immunology , Nematode Infections/parasitology , Parasite Egg Count/veterinary , Weight Gain
5.
Theriogenology ; 77(1): 139-47, 2012 Jan 01.
Article in English | MEDLINE | ID: mdl-21924480

ABSTRACT

The objective was to determine the relationship among the diameter of ovarian follicles, ovulation rate, and gene expression of the LH receptor (LHR) in Nelore cattle. In Experiment 1, ovulation was synchronized in 53 Nelore cows. Three days after ovulation, ovaries were assessed with ultrasonography, all cows were given 6.25 mg LH im, and they were allocated into three groups, according to diameter of their largest ovarian follicle: G1 (7.0-8.0 mm); G2 (8.1-9.0 mm); and G3 (9.1-10.0 mm). For these three groups, ovulation rates were 9, 36, and 90%, respectively, (P<0.03; each rate differed significantly from the other two). In Experiment 2, granulosa and theca cells were subjected to total RNA extraction, and gene expression of the LHR was determined by RT-PCR. Follicles were allocated in three groups based on their diameter (similar to the Experiment 1), which were denoted Groups A, B, and C. Expression of the LHR gene in granulosa cells was lower in Group A than Group C (P<0.05). However, there were no significant differences among groups in expression of the LHR gene in theca cells. We concluded that ovulatory capacity in Nelore cattle was related to increased follicular diameter and expression of the LHR gene in granulosa cells.


Subject(s)
Cattle/physiology , Gene Expression , Ovarian Follicle/anatomy & histology , Ovulation/physiology , Receptors, LH/genetics , Animals , Estrus Synchronization , Female , Ovarian Follicle/diagnostic imaging , Receptors, LH/physiology , Ultrasonography
6.
Anim Reprod Sci ; 114(1-3): 54-61, 2009 Aug.
Article in English | MEDLINE | ID: mdl-18980815

ABSTRACT

In vitro studies have shown that Bos taurus indicus (B. t. indicus) embryos submitted to heat shock at early stages of development are better able to survive as compared to Bos taurus taurus embryos. Embryo genotype influences resistance to heat shock thus leading to the question as to whether embryos sired by thermo-tolerant breeds exhibit the same resistance to heat shock. In the present study the influence of both oocyte and semen, on the resistance to heat shock (HS) at early stages of in vitro development, was assessed in B. t. indicus [Nelore (N) breed], B. t. taurus [Holstein (H) and Angus (A) breeds] and crossbreds. In Experiment 1, Nelore and crossbred oocytes were collected from slaughterhouse ovaries and fertilized with spermatozoa from Nelore and Angus bulls. Presumptive embryos were collected and randomly assigned to control (39 degrees C) or HS at 12, 48 or 96 h post insemination (hpi; 41 degrees C for 12h) treatments. The cleavage rates and proportion of embryos developing to the blastocyst and hatched blastocyst stages were recorded on Days 2, 8 and 10, respectively. Heat shock treatment decreased development of both Nelore and crossbred embryos. There was a significant interaction between time (12, 48 or 96 hpi) and temperature for blastocyst rates, i.e., the embryos became more thermotolerant as development proceeded. In Experiment 2, oocytes from Nelore and Holstein cows were fertilized with semen from bulls of either Nelore or Angus breeds, and subjected to 12 h HS at 96 hpi. Heat shock at 96 hpi, decreased embryo development. Additionally, cowxtreatment and bullxtreatment interactions were significant for blastocyst rates, i.e., both breed of cow and breed of bull affected the decline in blastocyst rate caused by heat shock treatment. In conclusion, the present results indicate that Nelore embryos (indicus) are more resistant to heat shock than Holstein (taurus) at early stages of in vitro development, and that embryos become more thermo-tolerant as development proceeds. Additionally, the resistance to heat shock was a result of the genetic contribution from both oocyte and spermatozoa.


Subject(s)
Cattle/embryology , Cattle/genetics , Fertilization in Vitro/veterinary , Hot Temperature , Animals , Blastocyst/physiology , Female , Male , Oocytes/physiology , Spermatozoa/physiology
7.
Alcohol Alcohol ; 43(4): 470-6, 2008.
Article in English | MEDLINE | ID: mdl-18364361

ABSTRACT

AIM: The aim of this paper was to compare the quantity and frequency of alcohol use and its associated negative consequences between two groups of college students who were identified as being "risky drinkers." Subjects were randomly allocated in a clinical trial to intervention or control groups. METHODS: Risky drinking use was defined as Alcohol Use Disorders Identification Test (AUDIT) >or=8 and/or Rutgers Alcohol Problem Index (RAPI) >or=5 problems in the previous year. Students who had undergone the Brief Alcohol Screening and Intervention for College Students (BASICS) (N = 145 at baseline; 142 at 12 months, and 103 at 24 months, loss of 29.7%) were compared with a control group (N = 121 at baseline; 121 at 12 months and 113 at 24 months, loss of 9.3%), the nonintervention group. Variables included drinking frequency, quantity and peak consumption, dependence assessment, and family and friends' abuse assessment. RESULTS: Treated students at a 24-month follow-up decreased quantity of alcohol use per occasion and lowered AUDIT and RAPI scores. CONCLUSIONS: This is the first brief intervention work on risky drinking with college students in Brazil and the results are encouraging. However, it is difficult to conduct individual prevention strategies in a country where culture fosters heavy drinking through poor public policy on alcohol and lack of law enforcement.


Subject(s)
Alcohol Drinking/epidemiology , Alcohol Drinking/prevention & control , Alcohol-Related Disorders/epidemiology , Alcohol-Related Disorders/prevention & control , Risk-Taking , Students/statistics & numerical data , Universities/statistics & numerical data , Adolescent , Adult , Brazil/epidemiology , Culture , Female , Humans , Law Enforcement , Male , Mass Screening/methods , Public Policy , Surveys and Questionnaires
8.
Theriogenology ; 67(4): 692-7, 2007 Mar 01.
Article in English | MEDLINE | ID: mdl-17118436

ABSTRACT

Heat stress has negative effects on pregnancy rates of lactating dairy cattle. There are genetic differences in tolerance to heat stress; Bos taurus indicus (B. t. indicus) cattle and embryos are more thermotolerant than Bos taurus taurus (B. t. taurus). In the present study, the effects of sire and sire breed on conception and embryonic/fetal loss rates of lactating Holstein cows during the Brazilian summer were determined. In Experiment 1, cows (n=302) were AI after estrus detection or at a fixed-time with semen from one Gyr (B. t. indicus) or one Holstein sire (B. t. taurus). Pregnancy was diagnosed 80 days after AI. In Experiment 2, cows (n=811) were AI with semen from three Gyr and two Holstein sires. Pregnancy was diagnosed at 30-40 and at 60-80 days after AI. Cows diagnosed pregnant at the first examination but non-pregnant at the second were considered as having lost their embryo or fetus. Data were analyzed by logistic regression. The model considered the effect of sire within breed, sire breed, days postpartum, period of lactation, and AI type (AI after estrus versus fixed-time). There was no effect of the AI type, days postpartum or milk production on conception or embryonic loss rates. The use of Gyr bulls increased pregnancy rate when compared to Holstein bulls [9.1% (60/657) versus 5.0% (23/456), respectively, P=0.008; data from Experiments 1 and 2 combined]. Additionally, in Experiment 2, cows inseminated using semen from sire #4 (Gyr) had lower embryonic loss (10%) when compared with other B. t. indicus (35.3% and 40%) or B. t. taurus sires (18.2% and 38.5%, P=0.03). In conclusion, the use of B. t. indicus sires may result in higher conception rates in lactating Holstein cows during summer heat stress. Moreover, sire can affect embryonic loss and selection of bulls according to this criterion may result in higher parturition rates in lactating Holstein cows.


Subject(s)
Abortion, Veterinary , Breeding , Cattle Diseases/pathology , Heat Stress Disorders/veterinary , Lactation/physiology , Reproduction/physiology , Animals , Body Constitution/physiology , Cattle/physiology , Cattle Diseases/metabolism , Female , Male , Pregnancy , Pregnancy Rate , Seasons , Species Specificity , Time Factors
9.
Theriogenology ; 67(3): 655-60, 2007 Feb.
Article in English | MEDLINE | ID: mdl-17109947

ABSTRACT

The objective was to analyze and report field data focusing on the effect of type of progesterone-releasing vaginal insert and dose of pLH on embryo production, following a superstimulatory protocol involving fixed-time artificial insemination (FTAI) in Nelore cattle (Bos taurus indicus). Donor heifers and cows (n = 68; 136 superstimulations over 2 years) received an intravaginal, progesterone-releasing insert (CIDR or DIB, with 1.9 or 1.0 g progesterone, respectively) and 3-4 mg of estradiol benzoate (EB) i.m. at random stages of the estrous cycle. Five days later (designated Day 0), cattle were superstimulated with a total of 120-200 mg of pFSH (Folltropin-V), given twice daily in decreasing doses from Days 0 to 3. All cattle received two luteolytic doses of PGF2alpha at 08:00 and 20:00 h on Day 2 and progesterone inserts were removed at 20:00 h on Day 3 (36 h after the first PGF2alpha injection). Ovulation was induced with pLH (Lutropin-V, 12.5 or 25 mg, i.m.) at 08:00 h on Day 4 with FTAI 12, 24 and in several cases, 36 h later. Embryos were recovered on Days 11 or 12, graded and transferred to synchronous recipients. Overall, the mean (+/-S.E.M.) number of total ova/embryos (13.3 +/- 0.8) and viable embryos (9.4 +/- 0.6) and pregnancy rate (43.5%; 528/1213) did not differ among groups, but embryo viability rate (overall, 70.8%) was higher in donors with a DIB (72.3%) than a CIDR (68.3%, P = 0.007). In conclusion, the administration of pLH 12 h after progesterone removal in a progestin-based superstimulatory protocol facilitated fixed-time AI in Nelore donors, with embryo production, embryo viability and pregnancy rates after embryo transfer, comparable to published results where estrus detection and AI was done. Results suggested a possible alternative, which would eliminate the need for estrus detection in donors.


Subject(s)
Cattle/physiology , Insemination, Artificial/veterinary , Luteinizing Hormone/pharmacology , Ovulation Induction/veterinary , Progestins/administration & dosage , Reproduction/drug effects , Administration, Intravaginal , Animals , Embryo, Mammalian/physiology , Female , Hormones/administration & dosage , Hormones/pharmacology , Luteinizing Hormone/administration & dosage , Ovulation Induction/methods , Pregnancy , Pregnancy Rate
10.
Menopause ; 13(2): 202-11, 2006.
Article in English | MEDLINE | ID: mdl-16645534

ABSTRACT

OBJECTIVE: This study evaluated the augmentation of venlafaxine with hormone therapy in the treatment of postmenopausal depression. The hormones evaluated were estrogen (0.625 mg) in combination with medroxyprogesterone acetate (2.5 mg) and methyltestosterone (2.5 mg). DESIGN: Seventy-two menopausal women (mean age: 53.6 +/- 4.27 years) diagnosed with depression (Montgomery-Asberg Depression Rating Scale [MADRS] scores > or = 20) were treated with venlafaxine and one of the following hormone therapy combinations, in a double-blind regimen: estrogen + medroxyprogesterone + methyltestosterone (group 1, n = 20); estrogen + medroxyprogesterone acetate (group 2, n = 20); methyltestosterone only (group 3, n = 16); and no hormone therapy (group 4, n = 16). Study duration was 24 weeks. Primary efficacy outcome was remission according to the MADRS, whereas secondary efficacy measures included the Clinical Global Impression (CGI), Blatt-Kupperman Index, and Women's Health Questionnaire (WHQ). RESULTS: Forty-eight patients completed the study. All groups showed significant improvement from baseline. Group 3 demonstrated significant improvement on the MADRS compared with placebo (group 4) at weeks 20 (P = 0.048) and 24 (P = 0.030); effect size 8.04 (0.83; 15.26) (P = 0.029), but also had the highest dropout rate. Groups 1 and 3 had significant CGI improvement rates compared with placebo: 42.23% (P = 0.012) and 44.45% (P = 0.08), respectively. There were no differences in the WHQ or BKI scores among the groups. CONCLUSIONS: Methyltestosterone 2.5 mg had the highest effect size compared with placebo, but the high dropout rate prevented its efficacy from being determined. Estrogen plus medroxyprogesterone, combined with methyltestosterone or otherwise, demonstrated a trend toward increased efficacy of venlafaxine. Further larger-scale clinical trials are needed to elucidate the findings of this pilot study.


Subject(s)
Antidepressive Agents, Second-Generation/therapeutic use , Cyclohexanols/therapeutic use , Depression/drug therapy , Estrogen Replacement Therapy/methods , Methyltestosterone/administration & dosage , Postmenopause/psychology , Selective Serotonin Reuptake Inhibitors/therapeutic use , Antidepressive Agents, Second-Generation/administration & dosage , Brazil , Cyclohexanols/administration & dosage , Depression/blood , Depression/etiology , Double-Blind Method , Drug Therapy, Combination , Estrogen Replacement Therapy/adverse effects , Estrogens/administration & dosage , Female , Gonadal Steroid Hormones/blood , Humans , Medroxyprogesterone Acetate/administration & dosage , Middle Aged , Multivariate Analysis , Pilot Projects , Postmenopause/blood , Quality of Life , Research Design , Selective Serotonin Reuptake Inhibitors/administration & dosage , Surveys and Questionnaires , Treatment Outcome , Venlafaxine Hydrochloride
11.
Braz. j. vet. res. anim. sci ; 41(4): 268-273, jul.-ago. 2004. ilus, tab
Article in Portuguese | LILACS | ID: lil-404990

ABSTRACT

O objetivo do trabalho foi avaliar a taxa de maturação nuclear in vitro de oócitos provenientes de gatas doméstica púbere e pré-púbere. Foram utilizadas 15 fêmeas felinas, 10 púberes e 5 pré-púberes; sendo os oócitos obtidos por aspiração quantificados e classificados. Os oócitos classificados como excelentes e regulares foram reunidos em grupos de 10, em meio de cultura, recobertos em óleo mineral em Placas de Petri siliconizadas e descartáveis. Após permanência em estufa, a 38ºC e 5 por cento de CO2 por 48 horas, os oócitos foram submetidos a duas lavagens com solução de hialuronidase a 0,4 por cento, fixados em metanol/acido acético e corados com orceína acética. A avaliação da configuração cromossômica de oócitos maturados in vitro resultou em 44,68 por cento das células em metáfase II no grupo das fêmeas púberes e 25,32 por cento no grupo das doadoras pré-púberes, indicando que a puberdade influencia a capacidade dos oócitos se desenvolverem in vitro.


Subject(s)
Animals , Female , Cats , Oocytes/cytology , Ovulation/metabolism
12.
Theriogenology ; 61(7-8): 1283-90, 2004 May.
Article in English | MEDLINE | ID: mdl-15036962

ABSTRACT

The objective of this study was to evaluate the effects of equine chorionic gonadotropin (eCG) treatment on the number of induced accessory corpora lutea (CL), plasma progesterone concentrations and pregnancy rate in cross-bred heifers after transfer of frozen-thawed (1.5M ethylene glycol) embryos. All recipients received 500 microg PGF2alpha (dl-cloprostenol, i.m.) at random stages of the estrous cycle (Day 0) and were observed for estrus for 7 days. On Day 14, heifers detected in estrus between 2 and 7 days after PGF2alpha treatment were randomly allocated to four groups ( n=83 per group) and given 0 (control), 200, 400, or 600 IU of eCG. Two days later (Day 16), these recipients were given PGF2alpha and observed for estrus. Six to eight days after detection of estrus, plasma samples were collected to determine progesterone concentration and ultrasonography was performed to observe ovarian structures. Heifers with multiple CL or a single CL >15 mm in diameter received an embryo by direct transfer. Embryos of excellent and good quality were thawed and transferred to the recipients by the same veterinarian. Pregnancy was diagnosed by ultrasonography and confirmed by transrectal palpation 21 and 83 days after embryo transfer (ET), respectively. Plasma progesterone concentrations on the day of transfer (Day 7 of the estrous cycle) were 3.9+/-0.7, 4.2+/-0.4,6.0+/-0.4 and 7.8+/-0.6 ng/ml for groups Control, 200, 400, and 600, respectively (Control versus treated groups P=0.009; 200 versus 400 and 600 groups P=0.0001; and 400 versus 600 P=0.012 ). Conception rates 83 days after ET were 41.9, 50.0, 25.0, and 20.9% for groups Control, 200, 400, and 600, respectively (200 versus 400 and 600 groups P=0.0036 ). In conclusion, an increase in progesterone concentration, induced by eCG treatment, did not improve pregnancy rates in ET recipients. Conversely, there was a decline in conception rates in the animals with the highest plasma progesterone concentrations.


Subject(s)
Cattle/physiology , Dinoprost/administration & dosage , Embryo Transfer/veterinary , Estrus Synchronization , Gonadotropins, Equine/administration & dosage , Progesterone/blood , Animals , Corpus Luteum/anatomy & histology , Female , Pregnancy
13.
Theriogenology ; 57(6): 1625-34, 2002 Apr 01.
Article in English | MEDLINE | ID: mdl-12035974

ABSTRACT

The aim of this study was to evaluate the effect of delaying ovulation subsequent to superstimulation of follicular growth in beef cows (Bos indicus) on embryo recovery rates and the capacity of embryos to establish pregnancies. Ovulation was delayed by three treatments using either progesterone (CIDR-B) or a GnRH agonist (deslorelin). Multiparous Nelore cows (n = 24) received three of four superstimulation treatments in an incomplete block design (n = 18 per group). Cows in Groups CTRL, P48 and P60 were treated with a CIDR-B device plus estradiol benzoate (EB, 4 mg, i.m.) on Day-5, while cows in Group D60 were implanted with deslorelin on Day-7. Cows were superstimulated with FSH (Folltropin-V, 200 mg), from Day 0 to 3, using twice daily injections in decreasing amounts. All cows were treated with a luteolytic dose of prostaglandin on Day 2 (08:00 h). CIDR-B devices were removed as follows: Group CTRL, Day 2 (20:00 h); Group P48, Day 4 (08:00 h); Group P60, Day 4 (20:00 h). Cows in Group CTRL were inseminated at 10, 20 and 30 h after first detected estrus. Ovulation was induced for cows in Group P48 (Day 4, 08:00 h) and Groups P60 and D60 (Day 4, 20:00 h) by injection of LH (Lutropin, 25 mg, i.m.), and these cows were inseminated 10 and 20 h after treatment with LH. Embryos were recovered on Days 11 or 12, graded and transferred to synchronized recipients. Pregnancies were determined by ultrasonography around Day 100. Data were analyzed by mixed procedure, Kruskal-Wallis and Chi-square tests. The number of ova/embryos, transferable embryos (mean +/- SEM) and pregnancy rates (%) were as follows, respectively: Group CTRL (10.8+/-1.8, 6.1+/-1.3, 51.5), P48 (12.6+/-1.9, 7.1+/-1.0, 52.3), P60 (10.5+/-1.6, 5.7+/-1.3, 40.0) and D60 (10.3+/-1.7, 5.0+/-1.2, 50.0). There were no significant differences among the groups (P > 0.05). It was concluded that fixed time AI in association with induced ovulation did not influence embryo recovery. Furthermore, pregnancy rates in embryos recovered from cows with delayed ovulation were similar to those in embryos obtained from cows treated with a conventional superstimulation protocol.


Subject(s)
Cattle/physiology , Embryo, Mammalian , Follicle Stimulating Hormone/administration & dosage , Gonadotropin-Releasing Hormone/analogs & derivatives , Ovarian Follicle/physiology , Ovulation/drug effects , Animals , Embryo Transfer/veterinary , Estradiol/administration & dosage , Female , Gonadotropin-Releasing Hormone/administration & dosage , Insemination, Artificial/veterinary , Luteinizing Hormone/administration & dosage , Ovarian Follicle/drug effects , Ovary/diagnostic imaging , Ovulation Induction/veterinary , Pregnancy , Pregnancy Tests , Progesterone/administration & dosage , Superovulation , Tissue and Organ Harvesting/veterinary , Triptorelin Pamoate/analogs & derivatives , Ultrasonography
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