scholarly journals Reproductive and cost assessment of a seasonal breeding program with Bos indicus in tropical Mexico

2021 ◽  
Vol 26 (2) ◽  
pp. e2130
Author(s):  
José Francisco Martínez-Albarrán ◽  
Carlos Salvador Galina-Hidalgo ◽  
Ivette Rubio-Gutiérrez ◽  
Wendy Leticia Balam-Villarreal ◽  
Manuel D. Corro-Morales

Objective. To compare the reproductive performance of postpartum and open Bos indicus cows and to study the cost effectiveness of retaining non-pregnant animals after a short breeding season in tropical region of Mexico. Material and Methods. A total of 128 Bos indicus were included, 87 postpartum cows (PP) with ≤90 days after calving and 41 open cows (OC) with >90 days open. The study was divided into three phases: 1) Estrus synchronization followed by FTAI (day 0-10), 2) Estrus detection and AI (day 11-45) and 3) Natural mating (day 46-90). For the first phase, all animals were synchronized and AI at fixed time (day 10). Cows displaying overt signs of estrus (day 11-45) were AI. Open cows during the previous two phases were exposed to the bull. Results. Pregnancy in phase 1 was different (p<0.01) for PP and OC groups, 58.6% and 34.1%, respectively. Overall pregnancy percentage over the second service was 42.5% (p>0.05). No differences (p>0.05) were observed at phase 3, average 44.2%. By the end of the breeding season, the cost of OC, was 3 times more than PP cows. Conclusions. Pregnancy rate at first phase was higher in PP cows than OC cows. At the end of breeding season, a pregnancy rate of 80% was found. Incorporation of open cows from previous breeding season was more expensive than PP cows in all phases of the breeding program. Retaining an open cow for rebreeding one year or more could not be economically feasible.

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 &lt; 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.


Author(s):  
Jorge Alonso Peralta-Torres ◽  
Jesús Ricardo Aké-López ◽  
Carlos Luna-Palomera ◽  
José Candelario Segura-Correa ◽  
Oswaldo Margarito Torres-Chablé ◽  
...  

Evaluation of the reproductive tract development (RTD) is a criterion rarely used when heifers are included in estrous synchronization programs. The objective of the present study was to determine the effect of RTD (mature and immature) and hormonal treatment (EC and EB) on estrous expression rate and pregnancy rate in Bos indicus heifers under tropical conditions. RTD was evaluated with an ultrasound and classified as mature (n=99) or immature (n=101). Heifers received an intravaginal device (DIB®; day 0), 2 mg of estradiol benzoate (EB) and 250 µg of cloprostenol (PGF2α). The DIB was removed on day 7 post insertion, and 250 µg of PGF2α was applied and heifers were divided into two groups: One group of heifers received 0.5 mg of estradiol cypionate (EC group), and on day 8, a second group of heifers received 1 mg of estradiol benzoate (EB group). Estrus was detected by visual observation, and all heifers were inseminated at a fixed-time (FTAI). Fifteen days after insemination, bulls were introduced to the treatment groups. Data were analyzed using general modeling and binary logistic regression procedures. The percentage of estrus was similar for both mature and immature heifers (P>0.05), however, the heifers treated with EB had 17% animals in estrus, than the heifers that received EC (P <0.05). The pregnancy rate after FTAI (74.8%) and total pregnancy (FTAI + natural mating = 91.9%) was greater for the group of heifers with a mature reproductive tract (P<0.05). The hormone treatment had not effect (P>0.05) on the pregnancy rate. In conclusion, the heifers with mature reproductive tracts had the highest pregnancy rate after artificial insemination and total pregnancy. Hormonal treatment did not influence the pregnancy rate.


2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 30-31
Author(s):  
Vitor R G Mercadante ◽  
Robin R White ◽  
Heather L Bradford ◽  
Nicholas W Dias ◽  
Claire Timlin ◽  
...  

Abstract The objective of this study was to assess how well estrus detection patch readings correlated to successful AI breedings and to characterize the within-cow repeatability of estrus detection patch readings across breeding seasons. Data from the Virginia Department of Corrections beef cattle herds were collated for 7 locations over 7 years, with 2 calving seasons per year. Data from Spring of 2011 were missing. The full dataset contained 19,253 individual animal observations, of which 2,389 observations were omitted for failure to report estrus detection patch data. The relationship between estrus patch reading and pregnancy rate to fixed-time AI and subsequent natural service pregnancy rate was assessed by calculating the sensitivity and specificity of patch readings within each location during each breeding season. A true positive was defined as a patch activating and a cow being confirmed pregnant. A true negative was a patch remaining in the non activated state and a cow being confirmed open. A false positive was defined as a patch activating and a cow being confirmed open. A false negative was a patch failing to activate and a cow being confirmed pregnant. Pregnancy rate to AI sensitivity ranged from 0.2 to 1 with a mean of 0.583. Specificity ranged from 0 to 1 with a mean of 0.525. Subsequent natural service pregnancy rate), ranges in sensitivity (0.197 to 1.00, mean 0.563) and specificity (0 to 1, mean 0.545) were similar. Of the 6,249 animals with usable patch data, 934 never presented with an activated patch and 2,064 presented with an activated patch every breeding season. The remaining 3,251 animals averaged presenting with an activated patch 47% of the time and a non-activated patch 46% of the time. Odds of getting pregnant by AI for cows that always flag with the heat patch were 0.415.


2014 ◽  
Vol 43 (7) ◽  
pp. 358-362 ◽  
Author(s):  
Ériklis Nogueira ◽  
Dayanna Schiavi do Nascimento Batista ◽  
Luiz Carlos Cesar da Costa Filho ◽  
Alexandre Menezes Dias ◽  
Juliana Corrêa Borges Silva ◽  
...  

2016 ◽  
Vol 37 (6) ◽  
pp. 4149
Author(s):  
Jefferson Tadeu Campos ◽  
Fábio Morotti ◽  
Camila Bortoliero Costa ◽  
Larissa Zamparone Bergamo ◽  
Marcelo Marcondes Seneda

This study evaluated the pregnancy rate in Nelore cows (Bos indicus) that were subjected to fixed-time artificial insemination (FTAI) using different protocols consisting of injectable progesterone (P4) or an intravaginal device (impregnated with P4). Multiparous cows 72-84 months in age, 30-45 days postpartum, were selected on the basis of the absence of a corpus luteum (CL) and follicles < 8 mm after transrectal palpation and ultrasound examinations. On a random day of the estrus cycle (D0), the selected animals (n = 135) were randomly assigned to one of three experimental groups (n = 45 each). Group I (injectable P4/FTAI 36 hours) received 250 mg of injectable P4 and 2 mg EB on D0; on D7, they received 500 µg of cloprostenol; on D8, 300 IU of eCG and 1 mg of EB were administered; and finally, FTAI was performed 36 hours after the application of EB. Group II (injectable P4/FTAI 48 hours) received the same protocol as Group I, except that the FTAI was performed 48 hours after ovulation induction. The animals of Group III (Control/CIDR) received a conventional protocol for FTAI using an intravaginal device (D0: P4 and 2 mg EB; D8: device removal, 500 µg cloprostenol, 300 IU eCG, 1 mg EB; and FTAI performed 48 hours after removal of the device). The results showed that cows synchronized with the conventional protocol for FTAI (Control/CIDR) had a higher pregnancy rate (60 %, 27/45) than those synchronized with an injectable P4/FTAI 36 hours (33.33 %; 15/45, P = 0.010). However, the group receiving injectable P4 group/FTAI 48 hours had a similar pregnancy rate (48.9 %; 22/45; P = 0.290) when compared to both the group receiving the conventional protocol and that receiving injectable P4/FTAI 36 hours (P = 0.134). Although the injectable P4 may affect pregnancy rate with the FTAI performed in 36 hours, we found similar pregnancy rates from cows inseminated 48 hours after induction ovulation, considering injectable or intravaginal P4. Therefore, we suggest that injectable P4 represents an alternative source of progesterone for synchronization of cattle for FTAI.


2020 ◽  
Vol 48 ◽  
Author(s):  
Caio Cezar Da Silva ◽  
Hélton Aparecido Garcia Gregianini ◽  
Jennifer Teodoro Ferreira Gregianini ◽  
José Antônio Dell’Aqua Junior ◽  
Jefferson Viana Alves Diniz ◽  
...  

Background: In vitro embryo production (IVEP) allows the spread of superior animal genetics, but pregnancy rates show a high variability with this biotechnique. In the initial stage of pregnancy, progesterone plays a fundamental role in uterine preparation, acting on embryonic growth, implantation, and development. However, on the day of the IVEP transfer to the recipients, progesterone levels may be lower than that expected, influencing the uterine environment and, consequently, the pregnancy rate. Therefore, the objective of this study was to evaluate the pregnancy rate in heifers after the administration of injectable progesterone (P4) in the fixed-time embryo transfer (FTET) protocol.Materials, Methods & Results: The experiment was conducted inside a rural property near the city of Rio Branco, Acre, Brazil. The experimental group consisted of 232 animals, including 78 zebuine (Bos indicus) and 154 mixed (½ blood B. indicus and ½ blood B. taurus) animals, aged between 16 and 24 months, with a mean weight of 300 and 330 kg for zebuine and mixed animals, respectively. The selected animals were previously synchronized using the progesterone-estrogen-prostaglandin-estrogen protocol. Embryo transfer was performed on day 18 of the protocol, which was 9 days after the removal of intravaginal progesterone implant. On day 15 of the protocol, that is, 144 h (6 days) after the device removal, the animals were randomly distributed into two experimental groups: Control Group (CG; 0.5 mL of 0.9% saline solution, intramuscular) and Treated Group (P4G; 0.5 mL of injectable P4, 150 mg, intramuscular). Chi-square test was used for the statistical analysis of the pregnancy rate at a 5% probability. After 23 days of embryo transfer, pregnancy was diagnosed by ultrasonography. The general pregnancy rate, considering all groups (CG and P4G) and breeds included, was 55.17% (128/232). The pregnancy rates of the P4G and CG groups, regardless of breeds, were 55.08% (65/118) and 55.26% (63/114), respectively, with no statistical difference (P = 0.8344). Angus animals presented a similar pregnancy rate in the P4G and CG groups of 54.93% (39/71) and 57.83% (48/83), respectively. Furthermore, similar results were found for the Nellore breed, with no difference in pregnancy rate between the CG (55.81%, 24/43) and P4G (48.57%, 17/35) groups.Discussion: The strategy of using P4 to increase the pregnancy rate is very widespread in fixed-time artificial insemination (FTAI) protocols, although differences still exist. The literature presents zero or negative effects, as in this study, when exogenous P4 was used to increase endogenous P4 concentrations and, consequently, the pregnancy rate. However, some studies demonstrated the beneficial effects of increasing blood P4 concentrations, and that the increased fertility depends on the method and time of P4 supplementation and the animal’s physiological state. In this context, the fact that the injectable progesterone supplementation did not increase the pregnancy rate in this study is justified mainly by factors such as the animal category used (heifers), time of P4 supplementation (day 4 after ovulation), biotechnology used (FTET), and the heterogeneous characteristics related to phases of the estrous cycle of heifers. Supplementation with 150 mg of injectable long-acting progesterone intramuscularly did not interfere in the pregnancy rate of Angus and Nellore heifers receiving bovine embryos.


2013 ◽  
Vol 25 (1) ◽  
pp. 159
Author(s):  
J. P. Detomini ◽  
R. R. Tirloni ◽  
C. V. Araujo ◽  
L. R. Martins

The aim of this study was to establish a comparison between heterospermic and monospermic semen on the pregnancy rate of fixed-time AI Bos indicus cows. The experiment was conducted in the state of Mato Grosso, Brazil, during December 2010 and February 2011. Multiparous (n = 173) and primiparous (n = 204) Nelore cows, 45 ± 15 days postpartum, were evaluated on body condition score (BCS; score 1 to 9), and those that presented BCS between 5 and 8 were selected. Two protocols of estrous cycle synchronization were performed (PeCG and Pshang). Synchronization of the estrous cycle was achieved with the aid of the following protocol: on Day 0, all animals were treated with a progesterone vaginal implant with 1.9 g of progesterone combined with an IM injection of 2 mg of estradiol benzoate. On Day 7, an IM injection of 12.5 mg of dinoprost was administered. On Day 9, implants were withdrawn and the animals received an IM injection of 0.5 mg of estradiol cypionate. On Day 9, part of the animals (n = 222) received an IM injection of 300 IU mg of eCG (PeCG) and the other part (n = 155) had their calves removed for 48 hours (Pshang). All animals were inseminated 46 to 52 h after the end of the protocol. Cows were allocated randomly in 4 groups according to the donor male sample in the semen straw and groups were designated as MA (monospermic straw from bull A; n = 110), MB (monospermic straw from bull B; n = 102), MC (monospermic straw from bull C; n = 108), and HT (heterospermic sample from bulls A, B, and C; n = 57). Commercially available semen straws from Aberdeen Angus donors were used (ABS Pecplan, Brazil). Pregnancy diagnosis was performed 35 days after AI using real-time ultrasonography. Results are summarized in Table 1. There was no statistical difference between MA, MB, MC, and HT in any group according to the chi-square test (P > 0.05). However, there was a remarkable difference in pregnancy rates among the 3 bulls tested considering both protocols, probably due to the variation in the ovulation moment. Table 1.Pregnancy rates of Nelore cows submitted to FTAI protocol inseminated with monospermic (bull A, B, or C) or heterospermic (HT) semen


2011 ◽  
Vol 35 (2) ◽  
pp. 95-104
Author(s):  
HA . AL-Mutar

Present experimental was carried out on 22 does 2-4 years old. The aim was to induction of estrous in non-breeding season using impregnated sponge with 20 mg of medroxy progesterone acetate (MPA) for 13 days and with an i/m injection of 500 IU Pregnant Mare Serum Gonadotropin (PMSG) hormone 24 hrs before sponge withdrawal and to compare the pregnancy rate using three different methods of insemination; natural , cervical and laparoscopic artificial insemination at fixed time 24-48 hrs after estrous onset. All does were showed signs of estrous (100%), the estrous time was 46.9±4.90hrs (24-60hrs) after sponge withdrawal. While estrous length was 37.09±1.91 (24–72hrs). All experimental animals followed up by abdominal palpation, ultrasonography at 30, 60 and 90 days post-insemination, while the laparoscopic examination was performed at day 30 post-insemination, to improve the efficiently of the different methods of inseminations in pregnancy rate ultrasonographical diagnosed by rectal and abdominal methods of 14 does post-inseminations appeared that two were pregnant, seven suspected and five non pregnant. At day 60th , post-insemination the pregnancy diagnosis of (22) does appeared that (14) were pregnant, six suspected and two non pregnant. While at day 90, the examination of all does appeared that (16) animals were pregnant and six were not. The laparoscopic examination, at 30 days post-insemination showed that eight does were pregnant, two suspected and two were not pregnant. In conclusion that the pregnancy rate of laparoscopic insemination is (75%), comparisons to natural (66.7%) and cervical AI method (75%) but there is no significant different between them, while the kidding percentage was appear in natural insemination (75%), cervical (100%) and laparoscopic insemination (150%). The results of this study indicate that estrus can be efficiently induced in female goats during non-breeding season using 20mg MPA impregnated spongewith 500IU PMSG.


2010 ◽  
Vol 22 (1) ◽  
pp. 170 ◽  
Author(s):  
L. A. Lima ◽  
V. G. Pinheiro ◽  
J. R. Cury ◽  
C. M. Barros

There are reports in the literature indicating that use of eCG improves pregnancy rates in Bos indicus anestrous cows treated with a progesterone-based fixed-time AI (FTAI) protocol. More recently, replacement of eCG by FSH in FTAI protocols was reported to have beneficial effects (Bos indicus) or no effect (Bos taurus) on pregnancy rates. In the present experiment the effects of eCG and FSH on pregnancy rates were compared in an FTAI protocol. Primiparous lactating Nellore cows (40 to 80 days postpartum, n = 421) with a body condition score of 2.5 to 3.0 (on a 1 to 5 scale) were randomly allocated in 3 groups: Control (CTR), eCG, and FSH. In the control group, all animals received a progesterone (P4)-releasing intravaginal device (1.55 g, PRID®, Ceva Sante Animale S.A., Libourne, France) and 2.5 mg of estradiol benzoate (EB, i.m. Estrogin®, Farmavet, São Paulo, Brazil), on Day 0 (D0). Eight days later (D8), at the time of the intravaginal device withdrawal, PGF2α (150 μg, D-cloprostenol, i.m. Prolise®, ARSA S.L.R., Buenos Aires, Argentina) was administered. Twenty-four hours after PRID removal, cows were treated with EB (1.0 mg, i.m.), and FTAI was done 30 to 36 h later. In the eCG and FSH groups, the cows were treated with 20 mg of FSH (Folltropin-V®, i.m. Bioniche, Belleville, Canada) or400IU of eCG (Novormon®, i.m. Syntex, Buenos Aires, Argentina), respectively, at the time of PGF2α administration. Ovarian ultrasonography (Aloka SSD 500, 7.5-MHz probe, Aloka, Tokyo, Japan) was performed 10 days prior to and at the beginning of FTAI protocol to select the animals in postpartum anestrous (absence of CL in both examinations). The pregnancy diagnosis was performed by ultrasonography 30 days after FTAI. Data were analyzed by logistic regression (SAS Institute, Cary, NC, USA). Cows treated with eCG had a higher pregnancy rate (41.5%, 95/229; P < 0.05) than those treated with FSH (22.7%, 22/97) or in the control group (26.3%, 25/95). Pregnancy rates of animals treated with FSH did not differ (P > 0.05) from those in the control group. These results indicated that, in lactating primiparous anestrous Nellore cows, the use of eCG in a FTAI protocol improves the pregnancy rate, whereas FSH has no beneficial effect. V. G. Pinheiro received a fellowship from FAPESP (São Paulo, Brazil). The authors are grateful to Ceva Animal Health for providing the intravaginal devices (PRID®) used in this experiment.


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