145 FACTORS AFFECTING PREGNANCY RATE FOLLOWING TIMED EMBRYO TRANSFER PROGRAM IN CATTLE UNDER FIELD CONDITIONS

2009 ◽  
Vol 21 (1) ◽  
pp. 172 ◽  
Author(s):  
F. N. Scenna ◽  
C. J. Munar ◽  
I. Mujica ◽  
E. Martin ◽  
P. Lafarga ◽  
...  

Hormonal estrus synchronization followed by heat detection of recipient animals is a widely used technique in embryo transfer (ET) programs around the world. However, the successful outcomes of ET rely heavily on appropriate heat detection of recipient animals. Additionally, limited availability of personnel and time to detect heat makes ET impractical at times. Therefore, pregnancy rates (PR) following a timed embryo transfer (TET) program were evaluated taking into account different variables of recipient cows, donor embryos, and season of transfer under field conditions in Argentina. Recipient cows were synchronized utilizing a progesterone (P4) intravaginal device (DIB, Syntex, Argentina) for 7 days. On Day 0 (day of DIB insertion) 2 mg of estradiol benzoate (EB) i.m. was administered and immediately after DIB removal on Day 7, 500 μg of D(+) Cloprostenol i.m. (PG, Ciclase, Syntex), 400 IU of eCG i.m. (Novormon, Syntex) plus 1 mg of cypionate estradiol i.m. (ECP; König, Agentina) were administered to all recipient cows. Fresh (n = 1746) and frozen (n = 2047) beef bovine embryos were nonsurgically transferred into recipient cows on Day 9 after PG. The effects of body condition score (1–9, BCS I: ≤5, n = 804 and BCS II: ≥6, n = 2989), corpus luteum (CL) score (CL1: prominent papilla, n = 932, CL2: small papilla, n = 2028, and CL3: asymmetric, n = 833), location of embryo placement in uterine horn (upper, n = 3566, and lower, n = 227), and type of recipient such as heifer (n = 487), lactating (n = 1010), or dry cows (n = 2296) on PR were evaluated. Additionally, stage of embryo development (4–7), quality (1–3), and season of transfer (spring, summer, fall, and winter) were included in the analysis. Pregnancy rate was confirmed by rectal palpation 60 days after ET. Data were first screened by chi square and then analyzed by Proc Logistic of SAS (SAS Institute Inc., Cary, NC). Overall PR was 54.7%. body condition score, CL, type of recipients, stage of embryo development, and year were not significantly (P > 0.05) associated with PR. As expected, cows that received direct fresh embryos had 1.49 times greater odds of conceiving (odds ratio, OR = 1.49, 95% CI: 1.22 to 1.82) than those receiving frozen embryos. Additionally, cows receiving embryos graded as quality 1 had greater probability to conceive (OR = 1.62, 95% CI: 1.34 to 1.95, or OR = 1.64, 95% CI: 1.25 to 2.21) compared to quality 2 or 3 respectively. Moreover, embryos placed into the upper portion of uterine horn were more likely (OR = 1.48) to conceive than those placed in the lower uterine portion. Regardless of embryos and recipient cow variables analyzed, there was a greater probability for cows to conceive during winter (OR = 1.41, 95% CI: 1.13 to 1.95) as compared with summer. In conclusion, synchronized recipient animals for a TET program resulted in acceptable PR for both fresh and frozen embryos. Results suggested that the quality and location of embryos (upper portion) in uterine horn were the most important variables associated with PR in recipient cows. Therefore, TET is a viable and practical option allowing a successful outcome for many beef operations where availability of personnel is limited.

2019 ◽  
Vol 97 (Supplement_1) ◽  
pp. 50-50
Author(s):  
Clayton L McGuire ◽  
Jeremy G Powell ◽  
Reagan Cauble ◽  
Bryan Kutz ◽  
Karen Anschutz ◽  
...  

Abstract Foot soundness is essential for optimum performance in beef cattle. When evaluating foot soundness, emphasis is placed on foot angle (FA) and claw set (CS). The objective of this study was to investigate the effects of foot angle and claw set scores on cowherd performance. Data were collected on 491 crossbred Angus-based cows over a three-year period. At weaning, FA and CS were evaluated according to American Angus Association guidelines. Scores are based on a nine-point scale, where a score of one indicates straight pasterns and short, divergent toes, and nine indicates weak, sunken pasterns and long, curled toes. Cows that exhibited scores ranging from four to six were considered acceptable. If either score fell outside this range, the cow was considered undesirable. Acceptable and undesirable cows were evaluated for performance traits including pre-breeding body weight (PBW), pre-breeding body condition score (PBCS), cow body weight at weaning (CWW), cow body condition score at weaning (WBCS), pregnancy rate, 205 d adjusted weaning weight (AWW), and weaning performance (WP). Data were analyzed using the GLIMMIX procedure of SAS. Significance was declared at P ≤ 0.05. There were no differences (P ≥ 0.19) for WP, PBW, PBCS, CWW, or pregnancy rate. Cows with acceptable foot scores had a WBCS 5.49% greater (P < 0.001) than undesirable cows. Acceptable cows possessed an average WBCS of 4.9 compared to 4.6 in undesirable cows. Acceptable cows weaned calves 3.39% heavier (P = 0.024) compared to undesirable cows. Acceptable cows weaned calves with a mean AWW of 216.67 kg compared to undesirable cows with a mean of 209.56 kg. The results from this study suggest that cows with acceptable foot scores may maintain more desirable BCS and wean heavier calves. These results could be used to help predict cow performance based on FA and CS.


2013 ◽  
Vol 28 (1) ◽  
pp. 7-12
Author(s):  
Gyu-Tae Yeom ◽  
◽  
Hae-Geum Park ◽  
Nam-Tae Kim ◽  
Sung-Woo Kim ◽  
...  

2020 ◽  
Vol 21 ◽  
Author(s):  
Ricardo Zambarda Vaz ◽  
José Fernando Piva Lobato ◽  
João Restle ◽  
Pablo Tavares Costa ◽  
Lidiane Raquel Eloy ◽  
...  

Abstract The calving period influences productivity and reproductive efficiency the herds. The objective of this study was to evaluate two calving months (October and November) and their effect on the efficiency of a breeding herd for three consecutive years. A total of 298 Braford cows were evaluated at three, four, and five years of age, with their calves early-weaned at 148 days of age. The performance characteristics of the cow/calf pairs were evaluated with the calving month and calf sex as the independent variables. The animals were kept as a single group for the three years of observation. Cows calving in November were heavier and had a higher body condition score at calving. Cows calving in October were heavier and produced heavier calves at weaning. Male calves were heavier at birth and weaning than females (30.8 vs 28.6 kg and 118.9 vs 114.7 kg, respectively). The pregnancy rate was 82.35 and 69.23% for cows calving in October and November, respectively. Calving intervals were shorter in cows calving in November. Cows calving in October were more efficient compared with those calving in November, with a higher actual fertility rate. The production of kilograms of the calf/cow pair was higher for cows calving in October.


2021 ◽  
Vol 99 (Supplement_2) ◽  
pp. 5-6
Author(s):  
Uma Karki ◽  
Anand Tiwari ◽  
Kendra Norwood ◽  
Ja’Nia Johnson ◽  
Lila B Karki

Abstract Frequent inspection and provision for necessary care are of prime importance for sustainable production and improving the wellbeing of small ruminants. Most small-ruminant farmers are small-scale, with limited resources, and do not have facilities needed for routine evaluation and intensive care of animals. The identification of a predictive variable of animal health and wellbeing would be useful for small ruminant management in field conditions. The objective of this study was to assess the relation of body condition score to other health parameters in meat goats and hair sheep. Performance data (live weight, body condition score (BCS – 1–5: 1- very thin, 5 - obese), and FAMACHA (a 5-color chart used to monitor anemic condition in small ruminants caused by barber pole worm; score - 1–5: 1–2- not anemic, 5 - extremely anemic) of meat goats (Kiko) and hair sheep (Katahdin and Katahdin-St. Croix cross) were collected from different grazing studies conducted from 2015 to 2020 (15) and similar data plus hoof condition (1–3: 1-good, no trimming required; 2 – trimming required; 3 – trimming and additional care required) collected from farmers’ field (6; animals in a herd/flock ranged from 15 to 65) in 2020 were used in this study. Data from each study and for each animal species were analyzed separately for correlation among the performance variables in SAS 9.4, with alpha value set at 0.05. Except for few data sets, correlations between BCS and FAMACHA were negative and significant (P &lt; 0.05) with correlation coefficient (r) ranging from -0.18 to -0.64. BCS was positively correlated with live weight (P &lt; 0.05, r = 0.15–0.76) in most of the studies. In one study, which also included fecal egg count for the quantification of gastrointestinal parasites along with other animal performance variables, BCS was negatively correlated with the total fecal egg count (P &lt; 0.0001, r=-0.38). BCS showed negative correlation with hoof score in goats (P &lt; 0.001, r=-0.33). Results show that BCS can be used as a predictor for small-ruminant health, especially in field conditions where other evaluation methods are not available.


2022 ◽  
pp. 104823
Author(s):  
Marcelo Vedovatto ◽  
Renan Barbosa Lecciolli ◽  
Eduardo de Assis Lima ◽  
Raizza Fátima Abadia Tulux Rocha ◽  
Rafaela Nunes Coelho ◽  
...  

2005 ◽  
Vol 81 (3) ◽  
pp. 403-411 ◽  
Author(s):  
B. J. Renquist ◽  
J. W. Oltjen ◽  
R. D. Sainz ◽  
J. M. Connor ◽  
C. C. Calvert

AbstractFall-calving multiparous Angus × Hereford cows 3 to 10 years of age were stratified by age in a three by two factorial treatment arrangement to evaluate the efficacy of modifying stocking rate and supplementation strategy to manage cow body condition and production parameters over a 5-year study. Efficacy was evaluated quarterly in association with calving, breeding, weaning, and mid way between weaning and calving (i.e. in August). Three protein supplementation strategies (none, standard, strategic) were imposed across both a moderate (0·3 cows per ha) and a high (0·4 cows per ha) stocking rate. In the strategically supplemented group, protein supplement was provided to cows with a body condition score <5·5 at the quarterly evaluations. There was an effect of supplementation on pregnancy rate, which in combination with previously established culling practices resulted in different age profiles amongst supplementation strategies in years 2 to 5 (P < 0·01). Two statistical analyses were therefore conducted to dissociate the confounding effects of supplementation strategy and age. One model included the effect of stocking rate, supplementation strategy, production year, and all interactions; the second included the addition of age and its interactive effects. Stocking rate and supplementation strategy affected pregnancy rate in each of the models (P = 0·003 and P = 0·10, respectively). Standard, non-supplemented and strategically supplemented animals had estimated pregnancy rates of 0·83, 0·76, and 0·79, respectively (P = 0·10). The effects of nutrition on both calving interval and birth weight were independent of the model employed. Animals that were not supplemented had extended calving intervals (P = 0·06), but there was no effect of stocking rate (P > 0·10). Birth weight was not affected by supplementation strategy or stocking rate (P > 0·10). The lower 205-day weights of calves on a heavy compared with moderate stocking rate was independent of age (P = 0·02). However, the increased 205-day weight of calves born to strategically supplemented cows compared with those born to unsupplemented cows was only evident when data were not corrected for differences in age among groups (P = 0·03). Likewise, analyses of cow condition parameters using models without and with age resulted in different interpretations. These results suggest that strategic and standard supplementation result in similar animal performance and that the improvement in herd productivity associated with altering stocking rate and supplementation may partially be due to altered herd age dynamics.


2014 ◽  
Vol 54 (7) ◽  
pp. 862 ◽  
Author(s):  
P. Soca ◽  
M. Carriquiry ◽  
M. Claramunt ◽  
G. Ruprechter ◽  
A. Meikle

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.


2010 ◽  
Vol 45 (10) ◽  
pp. 1219-1221 ◽  
Author(s):  
Augusto Schneider ◽  
Luiz Francisco Machado Pfeifer ◽  
Eduardo Schmitt ◽  
Ivan Bianchi ◽  
Marcelo Brandi Vieira ◽  
...  

The objective of this work was to evaluate the effect of insulin alone or in association with equine chorionic gonadotropin (eCG) on the fertility of postpartum beef cows subjected to synchronization. A total of 340 cows was subjected to fixed time artificial insemination. In the trial 1, the cows were subjected to temporary weaning (TW), while in the trial 2 the same protocol was tested without TW. The addition of an insulin injection to a progesterone/eCG-based protocol without TW increased the pregnancy rate of beef cows with body condition score (BCS) equal to or lower than 2.5. Insulin had no effect on cows submitted to TW or with BCS equal to or higher than 3.0.


2016 ◽  
Vol 28 (2) ◽  
pp. 134
Author(s):  
J. B. S. Borges ◽  
H. L. D. Neri ◽  
M. R. Almeida ◽  
E. P. Silva ◽  
A. Bilha

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.


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