Resynchronization improves reproductive efficiency of suckled Bos taurus beef cows subjected to spring-summer or autumn-winter breeding season in South Brazil

2018 ◽  
Vol 122 ◽  
pp. 14-22 ◽  
Author(s):  
Gilson Antonio Pessoa ◽  
Ana Paula Martini ◽  
Manoel Francisco Sá Filho ◽  
Mara Iolanda Batistella Rubin
2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 48-48
Author(s):  
Alice Brandão ◽  
Reinaldo F Cooke ◽  
G Cliff C Lamb ◽  
José Luiz Vasconcelos ◽  
Ky G Pohler

Abstract Responses of Bos taurus (BT) and B. indicus (BI) beef cows were compared according to their body condition score (BCS) at initiation of breeding season. Cows were assigned to an estrus synchronization + AI protocol and classified as BCS < 5.0 (LBCS, BT, n = 158; BI, n = 248) or BCS ≥ 5.0 (HBCS; BT, n = 173; BI, n = 122). Pregnancy status was verified via transrectal ultrasonography at 30 and 40 d after AI for BI and BT cows, respectively. All BT cows were exposed to natural service for 50 d (beginning 18 d after AI), and all non-pregnant BI cows were immediately exposed to natural service for 60 d. Pregnancy rates to AI did not differ (P ≥ 0.16) between HBCS or LBCS cows (60.9 vs. 53.5% for BT; 37.0 vs. 31.4% for BI; respectively). Pregnancy rates to natural service were greater (P = 0.03) in HBCS BT cows compared with LBCS (82.7 vs. 67.9%; respectively) but did not differ in BI cows (78.9 vs. 71.5%; respectively). Calving rate was greater (P < 0.03) in HBCS cows, which also calved earlier (P < 0.01) compared with LBCS (93.7 vs. 85.1% in BT, 83.6 vs. 73.3% in BI; respectively). HBCS Cows weaned more (P ≤ 0.05) calves compared with LBCS, which were older (P ≤ 0.04) (215 vs. 211 d in BT, 219 vs. 209 d in BI; respectively) and heavier (P ≤ 0.09) at weaning (258 vs. 252 kg in BT, 213 vs. 203 d in BI; respectively). Lastly, kg of calf weaned/cow was greater (P ≤ 0.03) in HBCS cows compared with LBCS (221 vs. 200 d in BT, 159 vs. 129 d in BI; respectively). Therefore, HBCS cows had greater reproductive efficiency and overall productivity, and this was observed in both BT and BI.


2019 ◽  
Vol 31 (1) ◽  
pp. 131
Author(s):  
G. A. Pessoa ◽  
A. P. Martini ◽  
A. P. Baioco ◽  
E. F. Machado Filho ◽  
H. F. Pinto ◽  
...  

The objective of this study was to compare the effects of 1 and 2 prostaglandin doses in a timed AI (TAI) resynchronization protocol on the pregnancy rate. This study was performed during the 2017-2018 breeding season on 10 commercial farms located in the central and southwest region of Rio Grande do Sul, Brazil. A total of 2347Bos taurus beef cows (Angus, Hereford) with a body condition score 2.90±0.15 (1=thin, 5=obese) and 40±5.1 days postpartum were used. In the beginning of first synchronization TAI protocol, on Day −11, the animals received 2mg of oestradiol benzoate IM (Gonadiol®, Zoetis Saúde Animal, São Paulo, SP, Brazil) and a progesterone (P4) intravaginal device (CIDR®, Zoetis). On Day −4, the cows received 12.5mg of dinoprost tromethamine IM (PGF, Lutalyse®, Zoetis). On Day −2, the animals received 1.0mg of oestradiol cypionate IM (ECP®, Zoetis) associated with the treatment with 300IU of eCG IM (Novormon®, Zoetis) and the P4 device was removed. The TAI was done on Day 0 (48 h after P4 device removal). The resynchronization protocol was started on Day 23 without pregnancy or oestrus detection; all cows were randomly assigned to receive a new, once-used, or twice-used P4 device (CIDR®) and given 2mg of oestradiol benzoate. On Day 30, pregnancy diagnosis was performed with transrectal ultrasonography. Pregnant cows (n=1021) had the P4 device withdrawn and received no further treatment. Nonpregnant cows (n=1326) were randomly assigned into 2 groups. The 1PGF group (n=674) received a single dose of PGF on Day 30, and the 2PGF group (n=652) received PGF on Days 30 and 32. On Day 32, all cows received eCG and ECP, and the P4 device was removed. In both groups the TAI was performed 48h after the P4 device removal (Day 34). Pregnancy diagnosis was performed by ultrasound 30 days after TAI (Day 64 of the breeding season). Data were analysed using the GLIMMIX procedure of SAS (SAS Institute Inc., Cary, NC, USA). The pregnancy rate obtained in the first synchronization protocol was 43.5% (1021/2347). The pregnancy rate in the resynchronization protocol was similar (P=0.49) between PGF doses [1PGF=39.5% (266/674); 2PGF=40.6% (265/652). No interactions were observed between P4 device use and PGF dose (P=0.38). The pregnancy rates were similar when comparing 1PGF and 2PGF using a new P4 device [1PGF=43.2% (35/81); 2PGF=56% (93/166); P=0.67], once-used P4 device [1PGF=39% (163/418); 2PGF=40.6% (140/345); P=0.64], or twice-used P4 device [1PGF=38.9% (68/175); 2PGF=22.7% (32/141); P=0.14]. In conclusion, a second dose of prostaglandin in the resynchronization protocol was not necessary to achieve high resynchronization pregnancy rates with TAI in Bos taurus beef cows.


Author(s):  
J Ranches ◽  
R Alves ◽  
M Vedovatto ◽  
E Anne Palmer ◽  
P Moriel ◽  
...  

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 < 0.001) and day (P < 0.01) effects were observed, where Brahman cows had greater liver Cu concentration than Angus. For liver Se concentration, a day effect (P < 0.001) was observed, where liver Se concentration increased (P < 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.


2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 116-117
Author(s):  
Emily G Smith ◽  
Rachael C Bonacker ◽  
Carson M Andersen ◽  
Jordan M Thomas

Abstract Estrus detection patches were evaluated as a tool to classify postpartum cows as estrous cycling or anestrous at the start of the breeding season. EstrotectTM Breeding Indicators were applied to 257 postpartum beef cows in three locations 25 days prior to the start of estrus synchronization. Coincident with the start of estrus synchronization, patches were scored using a 1 to 4 scale (1 = 0–25%; 2 = 25–50%; 3 = 50–75%; 4 = 75–100%) with scores of 3 or 4 considered activated. Blood samples were collected from each cow 10 days prior to, and at the start of the estrus synchronization. Serum progesterone concentrations were determined via radioimmunoassay; cows were considered estrous cycling if one or both samples exceeded a concentration of 0.5 ng/ml. Based on progesterone, 54.9% of cows were estrous cycling at the start of estrus synchronization. When missing patches were considered inconclusive results, use of patches to infer estrous cyclicity resulted in 85.0% sensitivity and 79.2% specificity with a positive predictive value of 87.2%. However, 75.1% of all cows presented with missing patches at the start of synchronization. If missing patches were considered activated, sensitivity was 95.7%, but specificity (16.4%) and PPV (58.2%) were poor, as 47.6% of cows presenting with missing patches were anestrous based on progesterone. Across all cows, pregnancy rate to AI was 58.0% (149/257). Cows with activated patches that were classified as false positives based on serum progesterone concentrations achieved a 71.4% (5/7) pregnancy rate to AI, raising questions as to whether sensitivity was underestimated due to inherent Type II errors in classification of cyclicity via progesterone. In summary, estrus detection aids are a sensitive tool to identify estrous cycling postpartum cows prior to the start of the breeding season; however, poor specificity and patch retention are limitations for this application.


2010 ◽  
Vol 39 (10) ◽  
pp. 2182-2186
Author(s):  
Cristiane Reinher ◽  
Júlio Otávio Jardim Barcellos ◽  
Vanessa Peripolli ◽  
Ênio Rosa Prates ◽  
Maria Eugênia Andrighetto Canozzi

It was evaluated in this work the effect of calving sub-season on the pregnancy rate of 7,726 multiparous Hereford beef cows grazing on natural pastures in southern Brazil, from 1994 to 2007. Calving sub-season periods were divided in 20-day intervals from August 12th to 31st; from September 1st to 20th; from September 21st to October 10th; from October 11th to 31st; from November 1st to 20th. Calving in each sub-season and pregnancy rate (PR) were analyzed by the Chi-square test. Overall means of each sub-season were 92.7% (from August 12th to 31st), 90.6% (from September 1st to 20th), 82.1% (from September 21st to October 10th), 77.7% (from October 11th to 31st), and 70.6% (from November 1st to 20th). Calving sub-season significantly influenced pregnancy rate. Cows which calved in the initial sub-season showed higher pregnancy rates than cows which calved from the fourth calving sub-season. However this difference did not occur in 1999 and in 2007 since calving rates did not statistically differ among the five sub-seasons. In 1998 and 2004, calving rates were lower and the effects of calving sub-season on pregnancy rates were higher, possibly due to climate variations. In general, pregnancy rate decreases as calving occurs later in the year, particularly in years when the weather adversely affects pasture growth.


2019 ◽  
Vol 59 (2) ◽  
pp. 225 ◽  
Author(s):  
Walvonvitis Baes Rodrigues ◽  
Jean do Prado Jara ◽  
Juliana Correa Borges ◽  
Luiz Orcirio Fialho de Oliveira ◽  
Urbano Pinto Gomes de Abreu ◽  
...  

The objective of this trial was to evaluate different post-timed artificial insemination (TAI) reproductive managements in postpartum beef cows to produce crossbred calves from artificial insemination (AI). Nellore cows (n = 607), with 45 days postpartum, were inseminated at a fixed time, using a protocol that included an intravaginal progesterone-releasing device along with oestradiol benzoate, prostaglandin, equine chorionic gonadotropin, and oestradiol cypionate, followed TAI 48 h post-device removal. Four post-TAI treatments were evaluated: in CONTROL (T1, n = 161), cows were exposed to Nellore clean-up bulls until the end of the breeding season (75 days). In OBSERVATION (T2, n = 132), heat detection was performed for 15–25 days post-TAI, followed by AI. In RESYNC22 (T3, n = 157) and RESYNC30 (T4, n = 157), resynchronisation started after 22 or 30 days, following second TAI at Day 32 or 40 days after first TAI. In T2, T3 and T4, after the second AI, cows were exposed to Nellore clean-up bulls until the end of the breeding season (75 days). The pregnancy rate (PR) for the first TAI did not differ (54.6%, 53.0%, 59.2%, and 51.6% for CONTROL, OBSERVATION, RESYNC 22, and RESYNC 30, respectively; P = 0.66), and no difference was observed for the second TAI (RESYNC 22 = 45.31% and RESYNC30 = 46.05%; P = 0.137), in the PR at the end of the breeding season (86.33%, 86.36%, 78.98%, and 81.52%, P = 0.43), or embryonic losses (4.54%, 2.85%, 6.45% and 7.40%, respectively; P = 0.61), but the percentage of crossbred pregnancy was higher in groups with resynchronisation (RESYNC22 and RESYNC30) than CONTROL and OBSERVATION (98.38%, 90.62%, 63.30%, 78.95%, P < 0.001). In conclusion, resynchronisation programs of 22 or 30 days are more efficient to produce AI products, and the final pregnancy rate is similar among the treatments, differing only in the amount of calves produced by AI.


2004 ◽  
Vol 16 (2) ◽  
pp. 229 ◽  
Author(s):  
R.M. Züge ◽  
U. Rodacki ◽  
A.T. Grandi ◽  
J.M.J. Aerts ◽  
P.E.J. Bols

The most important barrier to the increase of buffalo productivity is an overall poor reproductive efficiency, characterized by late sexual maturity, seasonal anestrus and long periods of postpartum ovarian inactivity resulting in extended calving intervals and poor expression of estrus behavior (Singh J et al., 2000, Anim. Reprod. Sci. 60–61, 593–604). Buffaloes are seasonal breeders with the highest reproductive activities during winter (short day lengths) and a high frequency of anestrus during the summer months (Singh G et al. 1985, Ind. J. Anim. Res. 19, 57–60). Recent research demonstrated that a combination of progesterone, estradiol benzoate and equine chorionic gonadotropin (eCG) was effective for estrus induction and synchronization in buffalo heifers under Mediterranean conditions (Barile et al. 2001, Livestock Prod. Sci. 68, 283–287). The aim of the present study was to investigate the impact of an estrus synchronization protocol on reproductive efficiency of water buffalo during out of the normal breeding season. A total of six heifers (21 to 23 months of age) and three cows (5, 6 and 18 years of age) were enrolled in an estrus synchronization protocol lasting for 12 days. All animals were kept under tropical conditions in the coastal part of Paraná (Antonina), about 450km south of São Paulo. The experiment was performed in December, 2002, during the Brazilian summer season, when reproductive efficiency of buffaloes is greatly reduced. On the first day of the protocol (Day 0), animals were implanted with an intravaginal device containing 1g of progesterone (DIB, Syntex SA, Buenos Aires, Argentina) and injected with 10mg estradiol benzoate (Estrogin, Famavet, São Paulo, Brazil). On Day 9, the DIB implant was removed and the animals received 150μg (i.m.) of cloprostenol (Prolise, Syntex SA, Buenos Aires, Argentina) and 2500 IU of eCG (Novormon, Syntex SA, Buenos Aires, Argentina). On Day 11, all animals received 1500 IU of hCG (Vetecor, Lab. Calier, Spain). Artificial insemination (AI) was performed on Day 12 using frozen-thawed semen from a bull of proven fertility. Only one AI was performed per heifer/cow. Pregnancies were determined by ultrasound examination at 53 days following AI and confirmed by rectal palpation at 90 days post AI. The use of this estrus synchronization protocol, followed by fixed-time insemination, resulted in four pregnant heifers (66%) and three pregnant cows (100%). Our results demonstrate that buffalo reproduction can be successful during out-of-breeding season when adequate hormonal treatment is used. Additional experiments should be done to validate the protocol.


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