10 EFFECT OF ESTRADIOL BENZOATE OR hCG ON DAY 22 AFTER TIMED ARTIFICIAL INSEMINATION ON THE CORPUS LUTEUM SIZE, PROGESTERONE CONCENTRATION, AND PREGNANCY RATE IN RESYNCHRONIZED BEEF HEIFERS

2016 ◽  
Vol 28 (2) ◽  
pp. 134
Author(s):  
J. B. S. Borges ◽  
H. L. D. Neri ◽  
M. R. Almeida ◽  
E. P. Silva ◽  
A. Bilha
Keyword(s):  
Corpus Luteum ◽  
Pregnancy Rate ◽  
Body Condition ◽  
Body Condition Score ◽  
Pregnancy Rates ◽  
Control Group ◽  
Beef Heifers ◽  
Pregnancy Diagnosis ◽  
Condition Score ◽  
And Control

This study aimed to compare the effects of 2 inducers of new follicular wave [oestradiol benzoate (EB) or hCG] administrated at onset of resynchronization protocols initiated 22 days after the first timed AI (TAI) of beef heifers. We evaluated the effect of treatments on corpus luteum (CL) development, serum progesterone (P4) concentrations, and pregnancy rates. A total of 467 grazing Brangus heifers, with 24- to 26-months, 320 ± 10 kg of body weight, and 3.2 ± 0.5 body condition score, were utilised. The resynchronization protocol began 22 days after the first TAI (Day 22). Heifers were randomly allocated into 1 of 3 groups: EB (n = 199), hCG (n = 101), or control untreated (n = 167). The EB- and hCG-treated heifers received an intravaginal P4 device (Procliclar, 0.75 g of P4; Hertape, Brazil) and an IM treatment with 1 mg of EB (Benzoato HC, Hertape) or 1000 IU of hCG (Vetecor 5000, Hertape), respectively. On Day 30, P4 device was removed, and the pregnancy diagnosis was performed. At this time heifers had the CL area (cm2) determined by ultrasound and seric P4 concentration evaluated by chemiluminescence assay. The assay sensitivity was 0.1 ng mL–1, and the intra- and interassay coefficients of variation were 7.9 and 10.6%, respectively. Nonpregnant heifers after the first TAI (EB = 97, hCG = 36) received intramuscularly 150 μg of sodium cloprostenol (Veteglan Luteolítico, Hertape) and 1 mg of oestradiol cypionate (Cipionato HC, Hertape). The second TAI was performed 48 to 52 h after the P4 device removal. On Day 62, heifers were submitted to a second pregnancy diagnosis. No effect of the body condition score (P = 0.28) was observed on the first and second pregnancy per AI. Pregnancy rates after the first TAI were higher (P = 0.03) on hCG-treated heifers (64.4%) than EB (51.3%) or the control group (58.7%). The EB group determined greater (P = 0.04) pregnancy rate after the second TAI (49.5%) than the hCG group (22.2%). The cumulative pregnancy rates were similar (P = 0.46) between groups [EB (72.4%) and hCG (68.3%)]; however, both were greater (P < 0.05) than the control group (58.6%). Heifers treated with hCG (3.42 ± 0.76) presented greater CL area at Day 30 (P < 0.05) than the EB (2.44 ± 0.57) and control (2.61 ± 0.61) groups. The treatment with hCG 22 days after TAI determined greater (12.43 ± 3.48; P < 0.05) serum P4 concentrations on Day 30 than the EB (6.92 ± 3.04) and control (7.29 ± 2.45) groups. Therefore, the use of hCG at the beginning of resynchronization protocol 22 days after the TAI increased pregnancy rate following the first TAI. However, the use of 1 mg of EB determined greater pregnancy rate after the second TAI, and no detrimental effects on CL development, P4 concentration, and on first TAI pre-established pregnancy.

Metabolic and endocrine profiles of primiparous beef cows grazing native grassland. 2. Effects of body condition score at calving, type of suckling restriction and flushing on plasmatic and productive parameters

2014 ◽  
Vol 54 (7) ◽  
pp. 862 ◽  
Author(s):  
P. Soca ◽  
M. Carriquiry ◽  
M. Claramunt ◽  
G. Ruprechter ◽  
A. Meikle
Keyword(s):  
Pregnancy Rate ◽  
Body Condition ◽  
Body Condition Score ◽  
Beef Cows ◽  
Cholesterol Concentration ◽  
Control Group ◽  
Native Grassland ◽  
Endocrine Profiles ◽  
Igf I ◽  
Condition Score

The objective of the present experiment was to analyse the effect of body condition score (BCS) at calving, type of suckling restriction and flushing on metabolic and endocrine profiles, and productive and reproductive responses of primiparous beef cows grazing native grassland. Primiparous beef (n = 56) cows in anestrus classified by BCS at calving (low ≤3.5 and moderate ≥4; 1–8 visual scale) were assigned randomly to four treatments in a two by two factorial arrangement of type of suckling restriction and flushing. Type of suckling restriction started at 55 ± 10 days postpartum (DPP ± s.e.m.; Day 0 = initiation of the treatment) and consisted of applying nose plates to calves for 12 days (i.e. TS treatment) or 5 days of isolation of the cow–calf pair, followed by applying nose plates to calves for 7 days as calves were reunited with their mothers (i.e. IS treatment). Immediately after the suckling restriction treatments were finished, the breeding season started, and each cow received (flushing group) or not (control group) 2 kg/day (fresh basis) of whole-rice middling for 22 days. The BCS was superior in moderate-BCS cows through the experiment. The type of suckling restriction did not affect any plasma parameter, but insulin-like growth factor I (IGF-I) concentrations increased in all cows during suckling restriction. Cholesterol concentration was affected by flushing × day interaction (P < 0.05), while insulin and IGF-I concentrations were affected by the interaction among BCS at calving, flushing and days (P < 0.03). Flushing increased cholesterol concentration in both BCS groups at calving, while insulin and IGF-I concentrations increased during flushing only in moderate-BCS cows. Suckling restriction, flushing, and BCS at calving did not affect calf weight or milk production. Moderate BCS cows had a shorter postpartum anestrous interval (PPI) (98 vs 123 DPP; P < 0.01). Isolated type of suckling reduced postpartum anestrous interval when compared with TS treatment (97 vs 115 DPP, P < 0.05). Early pregnancy rate was greater in flushed than in control cows (0.8 vs 0.55, P < 0.01) and in moderate-BCS cows than in low-BCS cows (0.84 vs 0.46, P < 0.01). Total pregnancy rate was also greater in flushed and moderate cows and tended to be affected by the interaction between flushing and BCS at calving (P = 0.06; flushed cows: moderate = 1 vs low = 0.5, P < 0.08; and control cows: moderate = 0.8 vs low = 0.4, P < 0.09). These results confirmed the great value of suckling restriction and flushing during post-calving and relevance of BCS at calving as a link between energetic nutrition and metabolic and reproductive processes in primiparous beef cows grazing native grassland.

scholarly journals Impact of prepartum body condition score loss on metabolic status during the transition period and subsequent fertility in Brown Swiss dairy cows

2019 ◽  
Vol 63 (3) ◽  
pp. 375-382
Author(s):  
Hatice Esra Çolakoğlu ◽  
Murat Onur Yazlık ◽  
Mert Pekcan ◽  
Ufuk Kaya ◽  
Cihan Kaçar ◽  
...  
Keyword(s):  
Body Condition ◽  
Transition Period ◽  
Body Condition Score ◽  
Pregnancy Rates ◽  
Metabolic Status ◽  
Control Group ◽  
Reproductive Outcomes ◽  
Brown Swiss ◽  
Subsequent Fertility ◽  
Condition Score

Abstract Introduction The objectives of this study were to determine the role of a fall in pre-calving body condition score (BCS) in postpartum metabolic status and reproductive outcomes, and gauge the indicativeness of blood metabolites during the transition period. Material and Methods Cows were grouped based on BCS loss between days −14 ±3 and 0 relative to calving. Cows that lost no BCS were the BCS control group (BCS-C), cows that lost 0.25 BCS points the low BCS loss group (BCS-L), and those that lost 0.5 points or more the high BCS loss (BCS-H) group. Blood was taken on days −14 ±3, 3, 14, and 30 ±4 for determination of comprehensive metabolic panel biomarker levels. Beta-hydroxybutyric acid (BHBA) levels were quantified on postpartum examination days. Vaginal discharge scores, ovarian activity on day 30 ±4, and subsequent fertility parameters were evaluated. Results The BCS-H cows had lower mean Ca concentrations before calving and on day 3, when the group’s BHBA and CK were higher (P < 0.05); on day 14 they had higher AST concentrations (P < 0.05). The BCS-L cows had greater bilirubin levels (P < 0.05). The BCS-H cows had lower cyclicity and higher endometritis rates. First service pregnancy rates were 50%, 50%, and 61.9%, open days 96.8, 95.75, and 89.2, and overall pregnancy rates 56.25%, 65%, and 80.95 % in the BCS-H, BCS-L, and BCS-C groups, respectively. Conclusion Prepartum BCS loss of ≥ 0.5 points could be associated with Brown Swiss cow low Ca and BHBA concentrations early postpartum, and with subsequent uterine health and overall pregnancy rate. Prepartum Ca concentration might be a prognostic biomarker for postpartum metabolic status and reproductive outcomes.

7 Pregnancy rates in suckled beef cows synchronized with a shortened progesterone/oestradiol-based protocol (J-synch) and inseminated with conventional or sexed-sorted semen

2019 ◽  
Vol 31 (1) ◽  
pp. 129 ◽  
Author(s):  
G. A. Bo ◽  
E. E. Huguenine ◽  
J. J. de la Mata ◽  
R. L. R. de Carneiro ◽  
A. Menchaca
Keyword(s):  
Corpus Luteum ◽  
Linear Model ◽  
Body Condition ◽  
Binary Data ◽  
Body Condition Score ◽  
General Linear Model ◽  
Beef Cows ◽  
Pregnancy Rates ◽  
Oestradiol Benzoate ◽  
Condition Score

An experiment was designed to evaluate pregnancy rates (P/AI) in suckled beef cows synchronized with a progesterone (P4)/oestradiol-based protocol (J-Synch) and inseminated (AI) with sexed or nonsexed (conventional) semen. Angus or Angus crossbred cows (n=877), 60 to 90 days postpartum, with a body condition score of 2.5 to 3.5 (scale of 1 to 5) and a corpus luteum or a follicle &gt;8mm in diameter detected by ultrasonography, were randomly allocated to be AI with sexed-sorted or nonsexed (conventional) semen. The experiment was performed in 4 farms, and the sexed-sorted (SexedUltra™ 4M, with 4 million sperm; ST Genetics, Navasota, TX, USA) and conventional (25 million sperm) semen were from split ejaculates from 5 Angus bulls. All cows received a P4 device (DIB 0.5, Zoetis, Villa Adelina, Argentina) and 2mg of oestradiol benzoate (Gonadiol, Zoetis) on Day 0. On Day 6, cows received 400IU of eCG (Novormon 5000, Zoetis) and 500µg of cloprostenol (Ciclase DL, Zoetis) and DIB was removed. All cows were also tail painted and observed for signs of oestrus (i.e. &gt;30% of the tail paint rubbed off) at 60, 72, and 84h after DIB removal. Cows with the tail paint rubbed off by 60 or 72h after DIB removal were artificially inseminated at 72h with either sexed or conventional semen. Those not showing oestrus by 72h received 100µg of gonadorelin acetate (Gonasyn GDR, Zoetis) at that time and were artificially inseminated with either sexed-sorted or conventional semen 12h later (i.e. 84h). Pregnancy was diagnosed by ultrasonography 30 days after AI. Data were analysed by general linear model for binary data with a logit link. Overall, 76.4% (678/877) of cows showed oestrus 60 to 84h after DIB removal, and there were differences in P/AI between sexed-sorted and conventional semen (P&lt;0.01; Table 1); however, there was no farm effect (range: 52-59%) and no interactions. Fertility differed (P&lt;0.05) among bulls and ranged from 25.8 to 55.3% for sexed-sorted semen and from 53.1 to 73.9% for conventional semen. In cows artificially inseminated with sexed-sorted semen, P/AI was the highest in cows showing oestrus and AI at 84 h; however, no differences were detected among cows artificially inseminated with conventional semen (Table 1). Although P/AI was lower for sexed-sorted than conventional semen, tail painting for oestrus detection can be successfully applied to AI beef cows with sexed-sorted semen synchronized with a shortened P4/oestradiol-based protocol. Table 1.Effect of semen type (sexed-sorted or conventional) and time of oestrus and AI on P/AI in suckled beef cows synchronized with a shortened P4/oestradiol-based protocol Research was supported by Fondo Nacional de Ciencia y Tecnología (FONCYT PICT 2017-4550) and UNVM.

scholarly journals Luteogenesis and Embryo Implantation Are Enhanced by Exogenous hCG in Goats Subjected to an Out-of-Season Fixed-Time Artificial Insemination Protocol

Biology ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 429
Author(s):  
Jorge A. Bustamante-Andrade ◽  
César A. Meza-Herrera ◽  
Rafael Rodríguez-Martínez ◽  
Zurisaday Santos-Jimenez ◽  
Oscar Ángel-García ◽  
...  
Keyword(s):  
Corpus Luteum ◽  
Artificial Insemination ◽  
Body Condition Score ◽  
Embryo Implantation ◽  
Implantation Rate ◽  
Fixed Time ◽  
Efficiency Index ◽  
Control Group ◽  
Condition Score ◽  
Interesting Approach

The aim of this study was to evaluate the possible effect of two doses of hCG (100 and 300 IU) applied at two different times (7 and 14 d) after a fixed-time artificial insemination protocol (FTAI) upon some variables involved in the embryonic implantation rate in goats during the natural deep anestrous season (April, 25° north). The experimental units considered crossbred, multiparous, anovulatory goats (n = 69, Alpine, Saanen, Nubian x Criollo), with average body weight (43.6 ± 5.7 kg) and body condition score (1.86 ± 0.28 units) located in northern–semiarid Mexico (25° N, 103° W). Once the goat’s anestrus status was confirmed, goats were subjected to an estrus induction protocol. Upon estrus induction confirmation, goats (n = 61) were subjected to a FTAI procedure. Immediately after the FTAI, the goats were randomly distributed to five experimental groups: (1). G100-7 (n = 13) 100 IU, hCG 7 d post-FTAI, (2). G100-14 (n = 12) 100 IU hCG, 14 d post-FTAI, (3). G300-7 (n = 12) 300 IU, hCG, 7 d post-FTAI, (4). G300-14 (n = 12) 300 IU hCG 14 d post-FTAI, and (5). Control group, CONT (n = 12) 0.5 mL saline, 7 and 14 d post-FTAI. The response variables conception rate (39.36 ± 0.23), fertility rate (27.96%), prolificacy rate (1.1 ± 0.29 kids), ovulation rate (0.74 ± 0.20 corpus luteum) corpus luteum diameter (10.15 ± 0.59 mm), embryo number (1.58 ± 0.20), and embryo implantation rate (48.96%), did not differ between treatments. However, while the variables fecundity rate (67%), embryo efficiency index-1 (33.99 ± 0.20%), and embryo efficiency index-2 (27.94 ± 0.30%) were favored by the G300-14 treatment, the corpus luteum area was favored (p < 0.05) by both G300-7 (113.30 ± 0.19 mm2) and G300-14 (103.04 ± 0.17 mm2). Such reproductive strategy emerges as an interesting approach, not only to enhance the out-of-season reproductive outcomes, but also to boost one of the main rulers defining the global reproductive efficiency of a heard, namely, the embryo implantation efficiency.

scholarly journals Tylosin injectable for the treatment of porcine proliferative enteropathy in experimentally inoculated pigs

2019 ◽  
Vol 39 (3) ◽  
pp. 168-174
Author(s):  
Luisa V.A. Otoni ◽  
Michelle P. Gabardo ◽  
Núbia R. Macêdo ◽  
Mariane M. Wagatsuma ◽  
Marina M. Pereira ◽  
...  
Keyword(s):  
Body Condition Score ◽  
Initial Period ◽  
Etiologic Agent ◽  
Economic Losses ◽  
Control Group ◽  
Lawsonia Intracellularis ◽  
Medication Group ◽  
Proliferative Enteropathy ◽  
Condition Score ◽  
And Control

ABSTRACT: Porcine proliferative enteropathy (PPE) is one of the most common enteric diseases in growing and finishing pigs. PPE is characterized by reduced growth performance, accompanied or not by diarrhea. PPE is highly prevalent in several countries of the Americas, Europe and Asia, causing high economic losses in swine herds. The most common form of PPE control in pigs is antibiotic therapy. The objective of this study was to evaluate a new product based on tylosin injectable (Eurofarma Laboratórios S.A.) to control PPE in experimentally inoculated animals. Sixty 5-week-old pigs with mean weight of 9.5kg were divided into two experimental groups of 30 animals: medication and control. All pigs were challenged with Lawsonia intracellularis, the etiologic agent of PPE, on day zero. Fecal score, body condition score, and behavior were daily evaluated. Pigs were weighted on days -2, 13 and 21 of the experiment. Pigs in the Medication Group received tylosin injectable 13 days after inoculation, in three doses with a 12-hour interval between them. Pigs in the Control Group received injectable saline solution following the same protocol. In the Control Group, 23pigs presented with diarrhea before day 13. After day 13, the number of diarrheic animals in this group was reduced to 17. In the Medication Group, 26 pigs presented with diarrhea in the initial period, and in the period after medication, only 11 animals had diarrhea. The score of gross intestinal PPE lesions in the Medication Group was lower than that in the Control Group (p=0.031). The Medication Group also showed lower score for Lawsonia intracellularis antigen-labeling by immunohistochemistry compared with that of the Control Group (p=0.032), showing lower level of infection. These results demonstrate that tylosin injectable (Eurofarma Laboratórios S.A.), administrated in three doses (1mL/20kg) every 12 hours, was effective for the control of PPE in experimentally inoculated pigs.

10 INFLUENCE OF ADMINISTRATION OF HUMAN CHORIONIC GONADOTROPIN ON DAY 4 AFTER FIXED-TIME AI ON CORPUS LUTEUM SIZE, FUNCTION, AND PREGNANCY RATE IN BEEF COWS

2014 ◽  
Vol 26 (1) ◽  
pp. 119
Author(s):  
J. B. S. Borges ◽  
D. X. Thedy
Keyword(s):  
Corpus Luteum ◽  
Pregnancy Rate ◽  
Fixed Time ◽  
Beef Cows ◽  
Pregnancy Rates ◽  
Control Group ◽  
Chi Square ◽  
Prostaglandin F2a ◽  
Successful Establishment ◽  
Early Rise

Successful establishment of pregnancy in the cow depends on early rise of progesterone (P4) to improve embryo development. The present study was carried out to determine the corpus luteum (CL) function and pregnancy rate following the administration of 1.500 IU of hCG in suckled beef cows on Day 4 after fixed-time AI (FTAI). Crossbred Angus cows (n = 429), 40 to 70 days postpartum, were synchronized using 2 mg of oestradiol benzoate (EB) i.m. and an intravaginal progesterone-releasing device containing 1 g of P4 for 7 days. At device removal, prostaglandin F2a (150 mg of D-cloprostenol) was injected i.m.; 24 h later, 1 mg of EB was given and the FTAI were done 30 to 36 h after EB using semen of just 1 bull. Cows were assigned alternatively to receive 1.500 IU of hCG i.m. (n = 200) or 1 mL of saline i.m. (n = 229) on Day 4 after FTAI. Ovaries were examined by transrectal ultrasonography (n = 71) on Days 4 and 7 to detect the presence and to measure the area of CL. Blood samples were collected on Days 4, 7, 10, 14, and 30 post-oestrus to determine P4 concentration by RIA. Pregnancy diagnoses were done 30 days after FTAI. The effects of treatments on CL area and serum P4 levels were analysed by ANOVA (Proc GLM, SAS Institute Inc., Cary, NC, USA) and pregnancy rates compared by chi-square (Proc CATMOT, SAS). The induction of accessory CL determined on Day 7 was 44% in cows treated with hCG and not observed in the control group. The area of the CL on Day 7 was significantly higher (P < 0.01; 3.37 ± 2.56 v. 2.56 ± 0.22 cm2) in the hCG group. Despite the increase in CL size, the mean levels of P4 on Days 4, 7, 10, 14, and 30 post-AI indicated no difference (P > 0.05) in CL function between control and hCG-treated cows. On Day 30, pregnancy rates were not different (P = 0.08), at 46.7 and 55% for control and hCG-treated cows, respectively. In conclusion, administration of 1.500 IU of hCG on Day 4 post-FTAI did not improve pregnancy rate in suckled beef cows.

116 PREGNANCY RATES AFTER ADMINISTRATION OF EQUINE CHORIONIC GONADOTROPIN (eCG) AT PROGESTERONE INTRAVAGINAL DEVICE REMOVAL AND 14 DAYS AFTER FIXED-TIME AI IN BEEF CATTLE

2011 ◽  
Vol 23 (1) ◽  
pp. 163 ◽  
Author(s):  
R. Núñez ◽  
T. de Castro ◽  
L. Cutaia ◽  
G. Bó ◽  
A. Menchaca
Keyword(s):  
Beef Cattle ◽  
Pregnancy Rate ◽  
Body Condition Score ◽  
Fetal Loss ◽  
Fixed Time ◽  
Pregnancy Rates ◽  
Control Group ◽  
Device Removal ◽  
Embryo Survival ◽  
Intravaginal Device

An important proportion of embryonic deaths in cattle occur during the critical period of embryo development and maternal recognition of pregnancy. High serum progesterone concentrations during this period are associated to higher embryo survival, and the use of eCG could enhance luteal activity. Two experiments were carried out to evaluate the effect of administering eCG at the time of removal of a progesterone-releasing device and 14 days after fixed-time artificial insemination (FTAI) in beef cattle. Multiparous suckled cows between 60 and 90 days postpartum (n = 297; Exp. 1), and two-year old prepuberal heifers (n = 689; Exp. 2) with a body condition score (BCS) between 3.5 and 5 (1 to 8 scale) were used. At the beginning of the experiments, none of females used had a corpus luteum detected by ultrasonography. Females received an intravaginal device containing 0.5 g progesterone (DIB 0.5, Syntex, Buenos Aires, Argentina) and 2 mg oestradiol benzoate i.m. (Benzoato de Oestradiol, Syntex). Eight days later, 500 μg of cloprostenol (Ciclase DL, Syntex) and 0.5 mg oestradiol cypionate (Cipiosyn, Syntex) were given i.m. and devices were removed; FTAI was performed 52 to 56 h after DIB removal. At the time of device removal, the animals were randomly allocated to 4 groups, to receive 400 IU of eCG i.m. (Novormon, Syntex) or placebo at device removal and/or 14 days after FTAI, in a 2 × 2 factorial design. Control group did not receive eCG. In Exp. 1, nose plates were placed on calves on the day of DIB insertion and left for 10 days in order to prevent suckling. Pregnancy diagnosis was performed by ultrasonography at 30 and 60 days after FTAI. Data were analysed by logistic regression. Pregnancy rate at 30 days after FTAI was affected by treatment (P < 0.05; Table 1). Late embryonic/fetal loss rates (non-pregnant females at 60 days after FTAI over those pregnant at 30 days) were 1.6% (3/182) for cows in Exp. 1 and 4.8% (14/292) for heifers in Exp. 2; no differences were detected among groups. In conclusion, administration of 400 IU of eCG at device removal increases pregnancy rate, both in anestrus cows and heifers. However, the administration of a second dose of eCG 14 days after FTAI suggests a possible effect on embryo survival within the first 30 days of pregnancy in cows but not in heifers. Further studies are required to confirm these results. Table 1.Pregnancy rates after administration of eCG at time of progesterone device removal and/or 14 days after insemination in beef cattle Supported by Syntex.

20 ADMINISTRATION OF FOLLICLE-STIMULATING HORMONE AT CIDR REMOVAL DOES NOT AFFECT THE PREGNANCY RATE IN A CIDR-BASED, COSYNCH PROTOCOL IN LACTATING BEEF COWS

2008 ◽  
Vol 20 (1) ◽  
pp. 90 ◽  
Author(s):  
J. Small ◽  
F. Dias ◽  
L. Pfeifer ◽  
K. Lightfoot ◽  
M. Colazo ◽  
...  
Keyword(s):  
Logistic Regression ◽  
Pregnancy Rate ◽  
Bos Taurus ◽  
Body Condition Score ◽  
Animal Health ◽  
Beef Cows ◽  
Pregnancy Rates ◽  
Condition Score ◽  
Secondary Objective ◽  
Pfizer Animal Health

In previous studies, giving eCG at CIDR removal significantly increased the pregnancy rate after timed-AI in beef cows. However, eCG is not universally available. Therefore, we tested the hypothesis that giving pFSH at CIDR removal might improve the pregnancy rate in a CIDR-based, Cosynch protocol in postpartum, suckled Bos taurus beef cows; a secondary objective was to compare pregnancy rates when GnRH v. pLH was used to synchronize wave emergence and ovulation. This work was conducted as two experiments (separate locations). All cows were given a CIDR (containing 1.9 g progesterone; Pfizer Animal Health, Montreal, QC, Canada) on Day 0 (without regard to stage of estrous cycle or cyclicity). On Day 7, CIDRs were removed, all cows were concurrently given 25 mg PGF (Lutalyse; Pfizer Animal Health, Groton, CT, USA), half were given 20 mg pFSH (Folltropin-V; Bioniche Animal Health, Belleville, ON, Canada), and all cows were timed-AI 54 h later (Day 9). In Experiment 1, 240 cows [94 � 10.8 days postpartum; body condition score (BCS: 1 = emaciated, 9 = obese; mean � SD): 5.8 � 0.4] were used; at CIDR insertion and AI, cows were allocated to receive either 100 µg GnRH (n = 160; Cystorelin, Merial Canada Inc., Victoriaville, QC, Canada) or 12.5 mg pLH (n = 80; Lutropin-V, Bioniche Animal Health). In Experiment 2, 109 cows (59.2 � 19.5 days postpartum; BCS: 5.6 � 1.1) were used; all received 100 µg GnRH (Cystorelin) at CIDR insertion and AI. In Experiment 1, three cows that lost their CIDR were excluded; pregnancy rates after timed-AI (logistic regression, backward selection: parity, pFSH, synchronizing treatment, and their interactions) were not different between cows given pFSH v. control cows (64.7 v. 65.2%; P > 0.80), nor between cows given GnRH v. pLH (62.7 v. 69.6%; P = 0.91). However, there was an interaction (P < 0.04) between parity and the synchronizing treatment; in primiparous cows, pregnancy rates were significantly lower in those given GnRH v. pLH (59.3 v. 83.3%). In Experiment 2, pregnancy rates after timed-AI (logistic regression, backward selection: parity, pFSH, and their interaction) were not different between cows given pFSH v. control cows (38.2 v. 42.6%; P > 0.6). In conclusion, our hypothesis was not supported; giving pFSH at CIDR removal did not significantly improve the pregnancy rate in a CIDR-based, Cosynch protocol in postpartum, suckled Bos taurus beef cows.

39 EFFECT OF TIME OF FIXED-TIME AI ON PREGNANCY RATES IN ZEBU CROSS-BRED BEEF HEIFERS TREATED WITH PROGESTERONE RELEASING DEVICES AND ESTRADIOL CYPIONATE

2010 ◽  
Vol 22 (1) ◽  
pp. 177 ◽  
Author(s):  
M. Ramos ◽  
L. Cutaia ◽  
P. Chesta ◽  
G. A. Bó
Keyword(s):  
Bos Taurus ◽  
Body Condition Score ◽  
Bos Indicus ◽  
Fixed Time ◽  
Estradiol Benzoate ◽  
Pregnancy Rates ◽  
Beef Heifers ◽  
Treatment Groups ◽  
Condition Score ◽  
To Receive

Two experiments were designed to evaluate the effect of the timing of fixed-time AI (FTAI) in relation to the removal of an intravaginal progesterone-releasing device (1 g of progesterone, DIB, Syntex SA, Buenos Aires, Argentina) on pregnancy rates in Bos indicus × Bos taurus cross-bred heifers. In experiment 1, 285 Bonsmara × zebu cross-bred heifers, between 18 and 24 months of age and with a body condition score (BCS) between 3.0 and 3.5 (1-5 scale) were used. On the day of initiation of treatment (Day 0), the heifers’ ovaries were palpated (92% of them had a CL) and they received a new DIB plus 2 mg of estradiol benzoate (EB; Syntex SA) and 250 μg of cloprostenol (Ciclase DL, Syntex SA). On Day 8, DIB devices were removed and all heifers received 250 μg of Ciclase plus 0.5 mg of estradiol cypionate (ECP; Cipiosyn, Syntex SA). At that time the heifers were randomly divided to receive FTAI between 48 to 49 h, 53 to 54 h, or 58 to 59 h after DIB removal. The heifers underwent FTAI with semen from 4 bulls by 2 inseminators. In experiment 2, 260 heifers from the same group as those used in experiment 1 (87% with a CL) were treated exactly as those in experiment 1, except that previously used DIB was inserted on Day 0. Pregnancy diagnosis was performed 30 days post-fixed-time AI by ultrasonography. The data were analyzed by logistic regression, taking into account the effect of time of FTAI, semen, and inseminator on pregnancy rates. In experiment 1, pregnancy rates were lower (P = 0.04) in the heifers undergoing FTAI between 48 and 49 h after DIB removal (46/95, 48.4%) than those undergoing FTAI 53 to 54 h (61/99, 61.6%) or 58 to 60 h (57/91, 62.6%) after DIB removal. However, no differences in pregnancy rates were found (P = 0.72) in experiment 2 between the 3 treatment groups, with 39/91 (42.9%) for the 48 to 49 h group, 45/89 (50.6%) for the 53 to 54 h group, and 35/89 (43.8%) for the 58 to 59 h group. There was no effect of the semen or inseminator (P > 0.2) in either experiment. We conclude that when Bos indicus × Bos taurus beef heifers are synchronized with new DIB devices and ECP, higher pregnancy rates are obtained in heifers undergoing FTAI late (between 53 to 60 h after DIB removal) than in those undergoing FTAI early (48 to 49 h after DIB removal). However, time of insemination does not apparently affect pregnancy rates when Bos indicus × Bos taurus beef heifers are synchronized with previously used DIB devices and ECP.

8 Evaluation of puberty induction protocol in peripubertal beef heifers prior to fixed-time AI programs

2019 ◽  
Vol 31 (1) ◽  
pp. 129
Author(s):  
J. B. S. Borges ◽  
D. S. V. Luiz ◽  
P. R. L. Aguiar ◽  
C. G. B. Berlitz ◽  
G. S. Velho ◽  
...  
Keyword(s):  
Breeding Season ◽  
Body Condition ◽  
Body Condition Score ◽  
Animal Health ◽  
Hormonal Treatment ◽  
Fixed Time ◽  
P Value ◽  
Ovarian Activity ◽  
Beef Heifers ◽  
Condition Score

Beef heifers that conceive early during their first breeding season calve earlier, wean heavier calves, and tend to continue doing so throughout the rest of their reproductive lives. Otherwise, under extensively managed systems in Southern Brazil, only a variable proportion of 2-year-old beef heifers reach puberty before the start of the breeding season. The aim of this study was to evaluate a protocol to induce puberty in peripubertal beef heifers using injectable progesterone (P4) and oestradiol cypionate (EC) to improve pregnancy per AI (P/AI) in fixed-time AI (FTAI) programs. A total of 311 Angus heifers, 24±3 months of age, 3.1±0.3 body condition score (1=emaciated; 5=obese), and 328±41kg of body weight (BW), were examined before FTAI protocol (Day −24) by transrectal ultrasonography to determine reproductive tract score (RTS; 1=prepubertal; 5=pubertal). Prepubertal heifers (RTS 1; 12.8%, 40/311) were excluded from the study. Heifers with RTS=2 (n=271) were assigned to 2 groups: P4 (RTS 2 or 3, n=100) and cyclic (RTS 4 and 5, n=171). Peripubertal heifers were treated on Day −24 with 150mg of injectable P4 IM (Sincrogest® injectable, Ourofino Animal Health, Cravinhos, Brazil) and on Day −12 received 1mg of EC IM (Sincro CP®, Ourofino Animal Health). Cyclic heifers received no hormonal treatment before FTAI protocol. On Day 0, heifers in the P4 group were evaluated again to determine RTS, body condition score, and BW. Induction of puberty was defined by the presence of a follicle &gt;8.5mm (RTS=4) or a corpus luteum (RTS=5). All heifers received an FTAI protocol consisting of 2mg of oestradiol benzoate IM (Sincrodiol®, Ourofino Animal Health) and an intravaginal progesterone implant (1 g; Sincrogest®, Ourofino Animal Health). On Day 8, heifers had implants removed and were injected with 1mg of EC and 500µg of sodium cloprostenol IM (Sincrocio®, Ourofino Animal Health). After 48h, all heifers received an FTAI. Thirty days after AI, the diagnosis of gestation was performed by ultrasonography. Statistics included chi-square and linear regression with coefficients analysed as independent variables, considering a significant P-value of 0.05. On Day 0, percentages of RTS 5, 4, and 3 in the P4 heifers were 37, 27, and 36%, respectively, resulting in 64% of puberty induction. The P/AI was similar (P=0.14) in P4-treated and cyclic heifers (59v. 50.3%, respectively). The regression analysis presented a linear and positive effect of BW on P/AI (P&lt;0.001) in cyclic heifers and a positive influence of BW on RTS (P=0.05) and RTS on P/AI (P=0.008) in P4-treated heifers. The application of RTS system associated with P4 treatment of peripubertal heifers before FTAI protocol improved ovarian activity and might have contributed to higher P/AI, comparable with that achieved in cyclic heifers.

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