Ovarian follicular and luteal characteristics in Bos indicus-influenced beef cows using prostaglandin F2α with or without GnRH at the onset of the 5-day CO-Synch + controlled internal drug release (CIDR) protocol

2019 ◽  
Vol 204 ◽  
pp. 1-9 ◽  
Author(s):  
J.O. Scarpa ◽  
M.M. O’Neil ◽  
R.C. Cardoso ◽  
R.L Stanko ◽  
G.L. Williams
Keyword(s):  
Drug Release ◽  
Bos Indicus ◽  
Prostaglandin F2α ◽  
Beef Cows

9 TIMED ARTIFICIAL INSEMINATION IN BLOCKS: A NEW ALTERNATIVE TO IMPROVE FERTILITY IN BEEF COWS

2015 ◽  
Vol 27 (1) ◽  
pp. 97
Author(s):  
L. F. M. Pfeifer ◽  
N. A. Castro ◽  
L. G. B. Siqueira ◽  
K. R. Lagos ◽  
A. Bagon ◽  
...  
Keyword(s):  
Artificial Insemination ◽  
Meta Analysis ◽  
Bos Indicus ◽  
Prostaglandin F2α ◽  
Beef Cows ◽  
Ovulation Rate ◽  
Control Group ◽  
Block Group ◽  
Preovulatory Follicle ◽  
Timed Artificial Insemination

The objective of this study was to evaluate whether timed artificial insemination (TAI) according to the diameter of the dominant preovulatory follicle (POF) would improve pregnancy rates in beef cows. In Experiment 1, a retrospective meta-analysis of 5 oestradiol- or gonadotropin-releasing hormone-based TAI experiments from 2011 to 2014 was performed to evaluate the interval from luteolysis to ovulation. In these experiments, crossbred cows (Gyr × Holstein; n = 60) were examined by ultrasonography at 12-h intervals from progesterone-releasing device (CIDR) removal to ovulation. A linear regression model was used to predict the effect of POF diameter on the time of ovulation. Cows with a larger POF at the time of AI ovulated earlier than cows with smaller POF (y = –8.25x + 115.22; R2 = 0.93; P < 0.0001). In Experiment 2, lactating Nelore cows (Bos indicus; n = 59) on random days of the oestrous cycle were given 2 mg of oestradiol benzoate IM and a CIDR device (Day 0) to synchronize follicular waves. The CIDR were removed, and cows were given 500 μg of d-Cloprostenol (prostaglandin F2α) IM, 1 mg of oestradiol cypionate IM, and 300 IU of eCG IM on Day 8. On the morning of Day 10 (07:00 a.m.), the diameter of the POF was assessed by ultrasonography, and cows were randomised into Control (n = 29) and Block (n = 30) groups. 1) Control-group cows were TAI 48 h after CIDR removal (08:00 a.m. on Day 10), and Block-group cows were inseminated at 4 time points according to the diameter of the POF: B0 (POF ≥15 mm, TAI at 08:00 a.m. on Day 10, n = 6), B1 (POF 13 to 14 mm, TAI at 02:00 p.m. on Day 10, n = 8), B2 (POF 11 to 12 mm, TAI at 08:00 a.m. on Day 11, n = 11), and B3 (POF ≤ 10 mm, TAI at 02:00 p.m. on Day 11, n = 5). Pregnancy status was assessed 30 days post-AI by ultrasonography. No differences were detected in the diameter of the POF 48 h after CIDR removal (P = 0.77) or ovulation rate (P = 0.65; combined ovulation rate 52/59, 88%) between Control and Block groups. Block group had a higher pregnancy rate than Control (22/30, 73% v. 13/29, 45%, respectively; P = 0.02). In conclusion, our results document that interval from luteolysis to ovulation depends on the size of preovulatory follicle, timing of AI in relation to ovulation time is critical, and AI time according to the diameter of the POF can be an effective tool to improve fertility of cows in TAI protocols.

166 Comparison of the 7 and 7 Synch protocol and the 7-day CO-Synch + controlled internal drug release protocol among recipient beef cows in an embryo transfer programme

2020 ◽  
Vol 32 (2) ◽  
pp. 210
Author(s):  
R. C. Bonacker ◽  
K. R. Gray ◽  
C. A. Breiner ◽  
J. M. Anderson ◽  
D. J. Patterson ◽  
...  
Keyword(s):  
Drug Release ◽  
Embryo Transfer ◽  
Body Condition Score ◽  
Prostaglandin F2α ◽  
Beef Cows ◽  
Corpora Lutea ◽  
Frozen Embryos ◽  
Condition Score ◽  
Recommended Guidelines ◽  
Mixed Groups

An experiment was designed to evaluate the effectiveness of the recently developed 7 and 7 Synch protocol to synchronise oestrus and ovulation among recipients before embryo transfer (ET). Postpartum beef cows (n=1358) across 13 locations were assigned to either the 7-day CO-Synch + controlled internal drug release (CIDR) protocol or the 7 and 7 Synch protocol before oestrus detection and subsequent ET. Cows were pre-assigned to balanced treatments within location based on age and days postpartum, and body condition score was recorded at ET. Cows assigned to the 7-day CO-Synch + CIDR protocol were administered gonadotrophin-releasing hormone (GnRH; 100µg of gonadorelin acetate) on Day 0, an intravaginal CIDR insert (1.38g of progesterone) from Day 0 to 7, and prostaglandin F2α (PG; 25mg of dinoprost tromethamine) coincident with CIDR removal on Day 7. Cows assigned to the 7 and 7 Synch protocol were administered PG (25mg of dinoprost tromethamine) coincident with CIDR insertion on Day −7, GnRH (100µg of gonadorelin acetate) on Day 0, and PG (25mg of dinoprost tromethamine) coincident with CIDR removal on Day 7. The 7 and 7 Synch protocol was hypothesised to enhance response to GnRH administration on Day 0 among mixed groups of oestrous cycling and anestrous cows, ultimately resulting in improved oestrous response and synchrony of oestrus before ET. Cows were observed for visible signs of oestrus following oestrus synchronisation, with GnRH (100µg of gonadorelin acetate) administered to cows failing to express oestrus during the detection period. Length of the detection period varied among locations but was consistent across treatments within location. Embryo transfer was performed approximately 7 days after oestrus or GnRH administration. Presence of corpora lutea (CL) was determined via transrectal palpation by a single veterinarian blinded to treatment, and embryos were transferred only to cows with palpable CL. Embryo transfer was performed using fresh or frozen embryos staged and graded according to IETS recommended guidelines, with embryo information recorded for each recipient. Data were analysed using the PROC GLIMMIX procedure of SAS (SAS Institute Inc.). Proportion of cows expressing oestrus was improved (P&lt;0.0001) among cows assigned to the 7 and 7 Synch protocol (86% (529/615) vs. 76% (488/640)). The proportion of recipient females with palpable CL tended to be greater (P=0.07) among cows assigned to the 7 and 7 Synch protocol (82% (478/586) vs. 80% (451/565)). Among cows that expressed oestrus, a greater proportion (P&lt;0.01) had palpable CL following the 7 and 7 Synch protocol (88% (466/529) vs. 86% (418/488)). Consequently, irrespective of embryo type received, the proportion of recipients pregnant to ET was greater (P&lt;0.01) following the 7 and 7 Synch protocol (39%; 263/668) compared with the 7-day CO-Synch + CIDR protocol (33%; 228/690). In summary, the 7 and 7 Synch protocol improved the likelihood of oestrus expression in recipient cows, increased the proportion eligible to receive an embryo, and resulted in greater pregnancy rate to ET.

Administering an additional prostaglandin F2α injection to Bos indicus beef cows during a treatment regimen for fixed-time artificial insemination

2020 ◽  
Vol 219 ◽  
pp. 106535
Author(s):  
Isabella M. Noronha ◽  
Reinaldo F. Cooke ◽  
Cícero F.G. Martins ◽  
Ramiro V. Oliveira Filho ◽  
Ky G. Pohler ◽  
...  
Keyword(s):  
Treatment Regimen ◽  
Artificial Insemination ◽  
Bos Indicus ◽  
Prostaglandin F2α ◽  
Fixed Time ◽  
Beef Cows

scholarly journals 71 Effects of timing of supplementation during late gestation in Bos indicus-influenced beef cows on post-weaning growth, immunity, and carcass characteristics of steer progeny

2020 ◽  
Vol 98 (Supplement_2) ◽  
pp. 59-59
Author(s):  
Elizabeth Palmer ◽  
Marcelo Vedovatto ◽  
Juliana Ranches ◽  
Vinicius Gouvea ◽  
Rhaiza Oliveira ◽  
...  
Keyword(s):  
Bos Indicus ◽  
Carcass Characteristics ◽  
Beef Cows ◽  
Late Gestation ◽  
Experimental Unit ◽  
Carcass Quality ◽  
Diarrhea Virus ◽  
Randomized Design ◽  
Distillers Grain ◽  
Dried Distillers Grain

Abstract This study evaluated the growth, immunity, and carcass characteristics of beef steers born to cows offered dried distillers grains (DDG) at different timing during late gestation. Approximately 84 d before calving (d 0), 84 mature Brangus cows were stratified by BW and BCS (422 ± 42 kg; 5.0 ± 0.14) and allocated into 1 of 6 bahiagrass pastures (14 cows/pasture). Treatments were randomly assigned to pastures: 1) no prepartum supplementation (CON); 2) 1 kg/d DDG from d 0 to 84 (LATE84); or 3) 2 kg/d from d 0 to 42 (LATE42). Calves were weaned at 261 ± 23 d of age. At weaning, 38 steers were vaccinated against bovine viral diarrhea virus (BVDV-1) and parainfluenza-3 (PI-3) and transported to a feedlot facility. Steers were penned according to cow prepartum pasture distribution and fed a similar diet until slaughter (d 587). Data were analyzed as complete randomized design using MIXED procedure of SAS, pasture as the experimental unit, treatment as fixed effect, and pasture(treatment) and steer(pasture) as random effects. Steer feedlot BW, ADG, DMI, and G:F did not differ (P ≥ 0.12) among treatments. Plasma haptoglobin concentrations were greater (P ≤ 0.03) for LATE42 and LATE84 vs. CON steers 2 d after feedlot entry. Plasma cortisol and seroconversion for BVDV-1 and PI-3 did not differ (P ≥ 0.15) among treatments. The percentage of carcasses grading Choice did not differ (P = 0.13), but carcasses grading low Choice were greater (P = 0.03) for CON vs. LATE42, with LATE84 being intermediate (91, 40, and 58%, respectively). Thus, prepartum dried distillers grain supplementation to B. indicus-influenced cows did not enhance feedlot growth but had subtle positive impacts on carcass quality and innate immunity in steer progeny. In addition, timing of dried distillers grain supplementation (last 84 d vs. first 42 d of late gestation) did not impact steer post-weaning feedlot performance and carcass quality.

scholarly journals Differences in copper and selenium metabolism between Angus (Bos taurus) and Brahman (Bos indicus) cattle

2021 ◽  
Author(s):  
J Ranches ◽  
R Alves ◽  
M Vedovatto ◽  
E Anne Palmer ◽  
P Moriel ◽  
...  
Keyword(s):  
Bos Taurus ◽  
Bos Indicus ◽  
First Trimester ◽  
Beef Cows ◽  
Experimental Unit ◽  
University Of Florida ◽  
Brahman Cattle ◽  
Research And Education ◽  
The University ◽  
Se Status

Abstract A two-year study was conducted at the University of Florida – IFAS, Range Cattle Research and Education Center (Ona, FL) to evaluate differences in the metabolism of Cu and Se of Angus (Bos taurus) and Brahman (Bos indicus) cattle. Thirty-two pregnant beef cows (n = 8 Brahman and 8 Angus/year) were enrolled in the study in the first trimester of gestation. The study consisted of 3 phases: (1) restriction (d 0 to d 90); (2) supplementation (d 91 to 150), and (3) calving. During all 3 phases, cows were individually fed and housed in partially covered drylot pens. During the restriction and supplementation phases cows were provided a 1.5 kg/d of a grain-based concentrate supplement, which was fortified with flowers of S (50 g of supplemental S/cow daily; restriction phase) or Cu and Se (100 and 3 mg/d of Cu and Se, respectively; supplementation phase). Blood and liver samples were collected from all cows on 30 d intervals and from both cows and calves within 24 h of calving. Colostrum and milk samples were collected at calving and 7 d after birth. All data were analyzed using the MIXED procedure of SAS, where cow and calf were the experimental unit. During the restriction phase, a breed × day effect (P = 0.03) was observed where Brahman had greater liver Cu concentration than Angus cows in all sampling days. For liver Se concentration, a tendency (P = 0.07) for a breed effect was observed where Angus cows tended to have greater liver Se concentration than Brahman. During the supplementation phase, breed (P &lt; 0.001) and day (P &lt; 0.01) effects were observed, where Brahman cows had greater liver Cu concentration than Angus. For liver Se concentration, a day effect (P &lt; 0.001) was observed, where liver Se concentration increased (P &lt; 0.001) from d 90 to 120 and remained unchanged (P = 0.86) until d 150. At calving no effects of breed (P = 0.34) were observed for liver Cu concentration of cows, however, Brahman calves tended (P = 0.09) to have greater liver Cu concentration than Angus calves. For Se liver concentration at calving, Angus cows tended (P = 0.07) to have greater liver Se concentration than Brahman cows, however no breed differences (P = 0.70) were observed for liver Se concentration of calves at birth. In summary substantial differences in multiple indicators of Cu and Se status were observed between Angus and Brahman cattle, implying that Angus and Brahman cattle possibly have different mechanisms to maintain adequate Cu and Se status.

scholarly journals 35 Vaginal pH changes due to the use of a controlled internal drug release (CIDR) and its effects on fertility of beef cows

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 25-26
Author(s):  
Nicholas W Dias ◽  
Claire L Timlin ◽  
Stefania Pancini ◽  
Nicholas W Dias ◽  
Zackary Seekford ◽  
...  
Keyword(s):  
Drug Release ◽  
Scoring System ◽  
Beef Cows ◽  
Ph Changes ◽  
Ph Values ◽  
Vaginal Ph ◽  
Pregnancy Status ◽  
System 1

Abstract The objective of this study was to evaluate changes in vaginal pH of beef cows enrolled in a 7-d CO-Synch+controlled internal drug release (CIDR) protocol and its effects on pregnancy. A total of 46 multiparous beef cows with no signs of vaginitis were enrolled. Individual vaginal flushes were collected from cows on D0, D7 and D10. Individual flushes were immediately analyzed for pH with a portable pH meter. As evidence of vaginitis, a CIDR score was determined at CIDR removal (D7), following a 1 to 4 scoring system: 1 = clean, no secretion; 2 = clean, clear secretion; 3 = purulent secretion; 4 = purulent secretion and blood. Pregnancy status was determined by rectal ultrasonography approximately 40 days after TAI. No cows had CIDR scores of 1 or 4, 19.6% of cows had a score of 2 and 80.4% a score of 3. Vaginal pH increased from D0 (6.88±0.007) to D7 (7.32±0.047), regardless of CIDR score (P &lt; 0.001). Cows with a CIDR score 2 had greater pH on D7 (7.35±0.084) than on D0 (6.90± 0.14; P = 0.001), and pH on D10 was intermediate (7.14±0.14; P = 0.14). Cows with CIDR score 3 had reduced pH on D10 (7.09±0.07) when compared to D7 (7.29±0.04; P = 0.003), but greater pH on D10 than on D0 (6.87±0.07; P = 0.007). There was a pregnancy by day interaction for pH values (P = 0.046). Pregnant cows had greater vaginal pH in comparison with non-pregnant cows on D0 (6.99±0.081 and 6.68±0.09, respectively; P = 0.01) and D10 (7.26±0.08 and 6.89±0.09, respectively; P = 0.006), but not on D7 (7.34±0.05 and 7.27±0.06, respectively; P = 0.38). Non-pregnant cows had reduced vaginal pH on D10 in comparison to D7 (6.89±0.09 and 7.27±0.06, respectively; P &lt; 0.001), whereas pregnant cows had similar vaginal pH on D10 and D7 (7.26±0.08 and 7.34±0.05, respectively; P = 0.35). We conclude that CIDR increases vaginal pH overtime and greater pH at TAI is beneficial to fertility.

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