147 USE OF EQUINE CHORIONIC GONADOTROPIN AFTER EMBRYO TRANSFER IN NELORE AND CROSSBRED RECIPIENT CATTLE

2011 ◽  
Vol 23 (1) ◽  
pp. 177
Author(s):  
M. C. C. Mattos ◽  
M. R. Bastos ◽  
A. C. S. Oliveira ◽  
J. R. S. Gonçalves ◽  
T. A. Oliveira ◽  
...  

Recent studies that have used eCG administration either 14 or 22 days after fixed-time AI in dairy and beef cattle have indicated a positive effect on conception rates. The aim of this study was to evaluate conception rates in embryo recipients treated with eCG 7 days after fixed-time embryo transfer (ET). A protocol for synchronization of ovulation was used in 470 Nelore and crossbred embryo recipient heifers (n = 179), dry cows (n = 152), and lactating cows (n = 139; body condition score = 3.0 to 3.5; >40 days in milk). All heifers and dry cows, but only 27.3% of lactating cows, were cycling at the beginning of the synchronization protocol. On Day 0, each female received IM injections of 2 mg of oestradiol benzoate (Gonadiol, Intervet Schering-Plough Animal Health, São Paulo, Brazil) and 0.075 mg of PGF2α (Preloban, Intervet Schering-Plough Animal Health). An intravaginal progesterone-releasing device (DIB, Intervet Schering-Plough Animal Health) was also inserted on Day 0. On Day 8, the DIB device was removed and cows or heifers received another IM treatment of 0.075 mg of PGF2α (Preloban), 300 IU of eCG (Novormon, Syntex S.A., Buenos Aires, Argentina) and 0.6 mg of oestradiol cipionate (Pfizer, Brazil). Transrectal ultrasonography was performed in all recipients on the day of ET (Day 16, 17, or 18 of the protocol) and only those with a corpus luteum greater than 15 mm in diameter were selected (n = 113 heifers, 114 dry cows, and 70 lactating cows). Transfers of fresh, frozen, and vitrified in vivo-produced embryos from Nelore donors were balanced between experimental groups. Seven days after ET, 127 animals received an IM injection of 400 IU of eCG (eCG group), and the 170 remaining cows or heifers were not treated with eCG, and were therefore considered the control group. Pregnancy diagnosis was performed 30 and 60 days after ovulation by transrectal ultrasound. Data were analysed using generalized linear models and results are presented as least squares means ± standard error. Conception rates were similar in the eCG and control groups at Day 30 (35.9 ± 5.5 and 33.5 ± 4.4, respectively; P > 0.10) and at Day 60 (27.6 ± 4.9 and 26.7 ± 3.9, respectively; P > 0.10). Contrary to other results in the literature, especially in dairy cows bred by fixed-time AI, the use of eCG 7 days after ET did not improve conception rates in Bos indicus cattle used as embryo recipients. Financial support from CNPq, FAPESP, and Intervet Schering-Plough Animal Health of Brazil and Syntex S.A. of Argentina.

2017 ◽  
Vol 29 (1) ◽  
pp. 159 ◽  
Author(s):  
A. Cedeño ◽  
A. Tribulo ◽  
S. Andrada ◽  
J. L. Barajas ◽  
J. Fonseca ◽  
...  

An experiment was designed to evaluate whether expression of oestrus in recipients synchronized with progesterone devices and oestradiol affects pregnancy rates to a fixed-time embryo transfer (FTET). A secondary objective was to determine whether administration of gonadotropin-releasing hormone (GnRH) to those recipients not showing oestrus by 48 h after device removal had an effect on pregnancy rates. Mature, non-lactating beef recipients (Bonsmara, Brangus, and Braford; n = 729), with a corpus luteum (CL) or a follicle ≥8 mm in diameter detected by ultrasonography (Mindray DP 30, Shenzhen, China) and body condition score 2 to 4 (1 to 5 scale) were synchronized in 7 replicates. On Day 0, recipients received a progesterone device (DIB 0.5 g, Zoetis, Buenos Aires, Argentina) and 2 mg of oestradiol benzoate (Gonadiol, Zoetis). On Day 8, DIB were removed and recipients received 400 IU eCG (Novormon 5000, Zoetis) plus 0.5 mg of oestradiol cypionate (Cipiosyn, Zoetis) and 500 μg of cloprostenol (Cyclase, Zoetis). In addition, all cows were tail-painted on the sacrococcygeal area (CeloTest, Biotay, Buenos Aires, Argentina) at DIB removal and were observed to determine the expression of oestrus, according to the percentage of paint loss 48 h later. The animals that showed oestrus (paint loss >30%) were recorded, and those with paint loss ≤30% (not in oestrus) were randomly allocated to receive 100 μg of gonadorelin (GnRH; Gonasyn, Zoetis) or no treatment. On Day 17, all recipients were examined by ultrasonography and those with a CL ≥18 mm (G1), ≥16 and <18 mm (G2), or ≥14 and <16 mm (G3) in diameter received in vivo-produced frozen-thawed embryos by direct transfer or fresh in vitro-produced embryos. Pregnancy was diagnosed by ultrasonography at 23 days after FTET, and data were analysed by logistic regression. There were no differences between replicates, in vivo- and in vitro-produced embryos, or operators (P > 0.2). However, the proportion of recipients transferred and pregnant (P/FTET) was higher (P < 0.05) for those that showed oestrus at 48 h after DIB removal (422/454, 93.0% and 227/471, 48.2%) than those that did not show oestrus (109/211, 51.7% and 45/120, 37.5%). Within the recipients not showing oestrus, P/FTET was significantly higher (P < 0.05) in those that received GnRH (34/74, 45.9%) than in those that did not receive GnRH (12/46, 26.1%). There was a significant interaction (P < 0.05) between CL diameter and expression of oestrus. When recipients had CL ≥18 mm in diameter (G1), P/FTET did not differ (oestrus: 164/338, 48.5% v. no oestrus 30/65, 46.2%); however, when CL diameter was <18 mm and ≥14 mm (G2 and G3), P/FTET was higher (P < 0.05) in those that showed oestrus (37/85, 43.5%) than in those that did not show oestrus (11/43, 25.6%). Finally, P/FTET was higher (P < 0.05) in recipients with a CL (268/573, 46.8%) on Day 0 than in those with follicles >8 mm in diameter (4/18, 22.2%). In conclusion, the expression of oestrus significantly affected the percentage of recipients selected for embryo transfer and P/FTET. Furthermore, treatment of recipients not showing oestrus by 48 h after DIB removal with GnRH at that time increased P/FTET.


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 ◽  
...  

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.


2016 ◽  
Vol 28 (2) ◽  
pp. 184
Author(s):  
M. Pelizzari ◽  
A. Tribulo ◽  
J. Garzon ◽  
B. Bernal ◽  
R. Tribulo ◽  
...  

A retrospective analysis of factors that affect pregnancy rates from 4214 fresh in vitro-produced (IVP) embryos that were transferred at a fixed-time (FTET) in 20 different farms. Recipients were all cycling cows or heifers that were synchronized with 1 of 3 treatments: 1) treatments with progesterone (P4) devices and 2 mg of oestradiol benzoate (EB) on Day 0 (day of insertion) and 24 h after device removal (Day 8); 2) treatments with P4 devices and EB on Day 0, but with 0.5 mg of oestradiol cypionate (ECP) at device removal (Day 8); or 3) treatments with P4 devices and GnRH on Day 0 and a second GnRH 60 h after device removal (Day 5). Cows in all treatment groups also received 500 µg of cloprostenol (prostaglandin F2α) at the time of P4 device removal and 400 IU of eCG either at device removal or 3 days before device removal. All embryos were transferred 7 or 8 days after the expected time of oestrus (24 h after EB, 48 h after ECP or at the time of the second GNRH for each synchronization treatment, respectively). On the day of embryo transfer, recipients were examined by ultrasonography and those with corpus luteum >14 mm in diameter received a fresh, IVP embryo in the uterine horn ipsilateral to the corpus luteum. Pregnancy rates were determined by ultrasonography 35 days after FTET. Data were analysed by logistic regression. Independent variables were classified into the following three categories. 1) Factors related to the recipient and the environment; there were no significant differences in pregnancy rates for corpus luteum diameter (≥14 and <16 mm, ≥16 and <18 mm, or ≥18 mm; P = 0.46), number of corpus luteum (1 or ≥2; P = 0.26), and category of recipient (cow or heifer; P = 0.21). However, there were significant effects of farm (P = 0.01) and body condition score (BCS; P = 0.01). Cows with BCS ≥4.5 (1 to 5 scale) resulted in lower pregnancy rates (4/20, 20.0%) than those with BCS 2 (74/225, 32.9%), 2.5 (502/1434, 35.0%), 3 (570/1467, 38.9%), 3.5 (193/532, 36.3%), and 4 (44/118, 37.3%). 2) Factors related to the synchronization treatment; there were no significant differences between recipients receiving eCG at device removal (84/209, 40.2%) or 3 days before device removal (874/2291, 38.1%; P = 0.35). However, recipients synchronized with P4 devices and ECP had higher (P = 0.01) pregnancy rates (232/483, 48.0%) than those treated with EB (679/1888, 36.0%) or gonadotropin-releasing hormone (47/129, 36.4%). 3) Factors related to the embryo transfer technique; day of the recipient’s oestrous cycle (P = 0.36), stage of embryo transferred (IETS stages 6 or 7; P = 0.62), and operator (P = 0.57) did not affect pregnancy rates. However transfers made in the anterior third of the uterine horn resulted in higher (649/1545, 42.0%) pregnancy rates than those in the mid-third (845/2511, 33.6%) or in the distal third (6/35, 17.1%; P = 0.01). It was concluded that factors related to the recipient and the environment (farm and BCS), the synchronization treatment (ECP), and the embryo transfer technique (site of deposition) affect pregnancy rates in recipients of embryos produced in vitro and transferred at a fixed time.


2011 ◽  
Vol 23 (1) ◽  
pp. 163 ◽  
Author(s):  
R. Núñez ◽  
T. de Castro ◽  
L. Cutaia ◽  
G. Bó ◽  
A. Menchaca

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.


2013 ◽  
Vol 25 (1) ◽  
pp. 229
Author(s):  
J. W. Thorne ◽  
C. R. Looney ◽  
J. F. Hasler ◽  
D. K. Hockley ◽  
D. W. Forrest

This study was performed to test the viability of administering Folltropin-V® (FSH, Bioniche Animal Health) diluted in hyaluronan (MAP-5 50 mg, sodium hyaluronate, Bioniche Animal Health) to beef cows enrolled in a recipient synchronization protocol to evaluate its effect on recipient fertility. All recipients were administered an estradiol 17β (2.5 mg, IM) and progesterone (50 mg, IM) combination injection on Day 0, a CIDR® (progesterone 1.34 g, Pfizer Animal Health, Groton, CT, USA) was inserted for 7 days. Lutalyse® (dinoprost tromethamine, Pfizer Animal Health, 25 mg, IM) was administered at the time of CIDR removal on Day 7, and estradiol 17β (1 mg, IM) was administered on Day 8. On Day 16, the presence of at least one corpus luteum, detected via ultrasound, resulted in the recipient receiving an embryo (both fresh and frozen–thawed embryos were used). Embryos were not transferred into cows that did not show ultrasonic evidence of a CL. Dependent variables for which data were collected included circulating progesterone levels at the time of transfer and CL diameter, area, and circumference; measured in millimeters. The total study (n = 274) consisted of both wet (n = 85) and dry (n = 189) cows and included both Bos indicus (Brahman-influenced) crossbred (n = 93) and Bos taurus (Angus-based) cows (n = 181). The experiment consisted of cows being placed in either the treated or control groups, with treated cows receiving a single 40 mg (1 mL) IM injection of Folltropin-V in hyaluronan on Day 5 and control cows receiving no additional injections. Results are shown in Table 1. Transfer rate, conception rate, and pregnancy rate were tested for significance with chi-square analysis and remaining statistics were analyzed with a t-test: two-sample assuming equal variances. There were no significant differences found between the treated and control groups for transfer rate, conception rate, or pregnancy rate. Corpus luteum diameter was shown to be larger in control cows (P < 0.05); however, CL area and circumference did not differ significantly. Folltropin-V given with hyaluronan at a 40-mg dose on Day 5 did not improve fertility, induce a larger CL, or increase circulating progesterone levels in synchronized beef recipients as hypothesized. Further work is needed with Folltropin-V in hyaluronan to determine if an alternative dose or timing of administration would be more appropriate for improving fertility in recipients. Table 1.Fertility data in beef recipients following synchronization for fixed-time embryo transfer with a protocol that included (Treated) or did not include (Control) FSH in hyaluronan


2013 ◽  
Vol 25 (1) ◽  
pp. 307
Author(s):  
S. Kmaid ◽  
J. M. Saldaña

Current superovulatory treatment combines progesterone as well as oestradiol injection at the moment of CIDR insertion to improve synchronization of follicular wave emergence [reviewed by Bo et al. 2002 Theriogenology 57, 53–172; and Mapletoft et al. 2003 J. Anim. Sci. 81 (E. Suppl.), E28–E36] The aim of the present work was to study if delaying oestradiol benzoate (EB) injection 24 or 48 h from CIDR insertion would have the same outcome on embryo production after superovulatory treatment as additional progesterone administered at CIDR insertion. One hundred and eleven superovulatory treatments conducted during the same period (5 consecutive collection days) at random stages of the oestrus cycle at the same location were retrospectively evaluated. Holstein cycling heifers of 18 months of age (body condition score 3.2 ± 0.28, 1–5 range; weighing 357 ± 28 kg) were divided according to the following treatments: control group (n = 24): Day 0: CIDR insertion (Pfizer Animal Health, New York, NY, USA), 50 mg of progesterone, and 2 mg of oestradiol benzoate (Benzadiol, Universal Laboratory, Montevideo, Uruguay); Group BE24 (n = 47): Day –1: CIDR insertion and Day 0: 2 mg of oestradiol benzoate; Group BE48 (n = 40): Day –2: CIDR insertion and Day 0: 2 mg of oestradiol benzoate. All heifers were superstimulated on Day 3.5 (Day 0 = EB injection) with 290 NIH units of FSH (Folltropin, BionicheAnimal Health, Belleville, ON, Canada) in twice-daily decreasing doses over 4.5 days. On Day 6, all cows received 2 doses (a.m. and p.m.) of a prostaglandin F2α analogue (800 µg, Delprostenate, Glandinex, Universal Laboratory), and CIDR were removed on the morning of Day 7. Cows were injected with 10 µg of GnRH (Receptal, Intervet, Boxmeer, the Netherlands) on Day 8 a.m. and were inseminated 12 and 24 h later with semen of 3 bulls of proven fertility. On Day 15, ova/embryos were collected nonsurgically and evaluated in accordance with IETS guidelines. Data were analysed with a negative binomial regression model (Table 1). Administration of EB 24 or 48 h after CIDR insertion produced similar numbers of transferable and freezable embryos as well as total ova/embryos compared with addition of progesterone and EB at the moment of CIDR insertion. According to these results, EB could be administrated without progesterone injection either 24 or 48 h after CIDR insertion without compromising embryo production. Table 1.Embryo production of heifers superstimulated after additional progesterone (P4) and different times (24 or 48 h after CIDR insertion) of oestradiol benzoate administration (results are mean ± SE)


2010 ◽  
Vol 22 (1) ◽  
pp. 162
Author(s):  
J. Almeida ◽  
O. A. Resende ◽  
D. L. Silveira

With the goal of optimizing protocols, fixed-time artificial insemination (FTAI) was performed under field conditions in a study to evaluate conception rates in Girolando (5/8) heifers (18 to 24 months of age) treated with estradiol benzoate (BE) to induce ovulation. Forty heifers were allocated to 2 groups with 20 animals each: GI-sexed semen (2 million spermatozoa/dose) and GII-nonsexed semen (20 million spermatozoa/dose), with body condition score (BCS) of 3.0 ± 0.14 (scale of 1 to 5), middleweight of 335 ± 38 kg, so that it was made for reutilization of progesterone device. On Day 0 (morning), the animals received 2.0 mg of BE (RIC-BE®,Tecnopec, São Paulo, Brazil), 0.075 mg of D-cloprostenol (Prolise®, ARSA S.R.L., Buenos Aires, Argentina), and an intravaginal device of 1 g of progesterone (Primer®, Tecnopec). On Day 8 (morning) the device was removed and 0.075 mg of D-cloprostenol was managed in the GI animals, then these animals received 1.0 mg of BE 24 h after device removal. The insemination was in the late afternoon of Day 10 with a 6-hour delay (4 to 6 pm). The GII animals received Primer previously used for 8 days (being used in the GI animals under the same protocol). After pregnancy diagnosis at 60 days, a third group was created (GIII) using the not-pregnant animals of GI and GII. In GIII, Primer from third use [disinfected in solution Kilol®-L 1:250 (Quinabra, São Paulo, Brazil) and rinsed with water, dried, and packed in plastic sacks and kept for 60 days] was used following the GI protocol with sexed semen. There were no significant differences (P > 0.05) in the conception rates of 40, 58, and 65% among groups GI (8/20), GII (11/20), and GIII (13/20). These results indicate very good conception rates for heifers, contrary to recommendations of commercial companies of sexed semen that alert for the conception rate for mated animals to be lower when using FTAI and mating protocols in mass, compared with that of AI after estrus observation.


2010 ◽  
Vol 22 (1) ◽  
pp. 247
Author(s):  
J. R. V. Pimentel ◽  
P. H. P. Miguez ◽  
A. Kehrle ◽  
E. H. Madureira ◽  
F. A. Braga ◽  
...  

Progestagen-releasing devices are commonly used for fixed-time artificial insemination and fixed-time embryo transfer (FTET). The aim of this study was to evaluate the efficacy of a new progesterone-releasing intravaginal device made of poly(3-hydroxy)butyrate-valerate copolymer (PHB-V) and poly-ϵ-caprolactone (PCL; Progestar®, Innovare, São Paulo, Brazil) to synchronize crossbredcows and heifers for FTET by determining ovulation, conception, and pregnancy rates. A total of 205 recipients ranging in age from 2 to 8 years (heifers, n = 77; non-suckled cows, n = 69; suckled cows, n = 59) were used on 3 different farms during February, March, and April 2008. The experimental design was a generalized block design (cyclicity, body condition score, postpartum interval, and animal category, i.e. heifers, suckled, or non-suckled cows), with 2 different synchronization treatments for FTET (Progestar® v. Crestar®). Cows were assigned to either Crestar® (norgestomet ear implants; Intervet Schering-Plough, Kenilworth, NJ, USA; n = 103) or Progestar® (PHB-V; n = 102) treatments. All groups were treated with 2 mg of estradiol benzoate i.m. (Innovare) and received the intravaginal or auricular device according to their group (Day 0). Together with P4 device withdrawal (Day 8), all animals received 400 IU of eCG i.m. (Novormon®, Schering-Plough) and 500 μg i.m. of PGF2α, (Sincrocio®, Ouro Fino, Brasil). On Day 9, all cows were treated with 1 mg of estradiol benzoate (Innovare) and the innovulation was performed on Day 17. Embryos were maintained at 37°C during the innovulation period. The percentage of usable recipients (AR) based on the presence of a functional CL on the day of embryo transfer, conception rate (numbers of pregnant recipients of the total number transferred; CR), and pregnancy rate (numbers of pregnant recipients of the total number synchronized; PR) were determined by ultrasonography 23 days after embryo transfer. Data were submitted to ANOVA (PROC GLM, SAS Institute Inc., Cary, NC, USA) and significant differences were considered to have a P-value of <0.05. None of the interactions were significant and there was no effect of treatment on AR (72.8% v. 83.3%), CR (47.9% v. 42.7%), and PR (34.7% v. 35.0%) for Progestar® v. Crestar® groups, respectively. This experiment showed that Progestar® was as efficacious as Crestar® to synchronize crossbred cows and heifers for FTET. FAPESP-Fundação de Amparo à Pesquisa do Estado de São Paulo and CNPq-Conselho Nacional de Desenvolvimento Científico e Tecnológico.


2020 ◽  
Vol 32 (2) ◽  
pp. 210
Author(s):  
G. Decuadro-Hansen ◽  
R. Silva ◽  
B. Lima ◽  
J. Lima ◽  
L. Durel ◽  
...  

In beef cattle production under pasture-based tropical conditions, the minerals most likely to be lacking are Ca, P, Na, Co, Cu, I, Se, and Zn, all of which are required for optimal growth and reproduction. Phosphorous deficiency, in particular, is a major problem for grazing cattle in many tropical regions. On the other hand, reproductive infectious diseases are the greatest threat to the production and profitability of beef cattle herds. To overcome reproductive failure, the present study aimed to evaluate the effects of injectable mineral supplementation and vaccination against reproductive diseases on synchronised Nelore females for fixed-time AI. A total of 1361 females were enrolled, and blood was collected from a random population (n=150) to measure serum antibodies against Leptospira sp., infectious bovine rhinotracheitis, and bovine viral diarrhea, mineral status, and creatinine. With Day 0 as the beginning of the synchronisation programme and Day 10 as the day of fixed-time AI, females were randomly assigned as follows. In the control treatment (n=365), no additional treatment was administered. In the Vaccine treatment (n=314), at Days −21 and 0 females received a 5-mL subcutaneous injection of BovigenRepro (Virbac; inactivated vaccine containing infectious bovine rhinotracheitis 1 and 5; bovine viral diarrhea 1 and 2; Campylobacter fetus ssp. fetus, venerealis, and venerealis biotype intermedius; and Leptospira pomona, wolffi, hardjo prajitno, icterohaemorrhagiae, canicola, copenhageni, bratislava, and hardjo bovis in an adjuvant of 10% Al(OH)3 with Se). In the Suppl treatment (n=314), at Day 0 females received a 15-mL intramuscular injection of Fosfosal (Virbac; 100mL containing Na glycerophosphate (14g), monosodium phosphate (20.1g), copper chloride (0.4g), potassium chloride (0.6g), magnesium chloride (2.5g), and sodium selenite (0.24g). In the SupplVacc treatment (n=363), females received a 5-mL subcutaneous injection of the vaccine at Days −21 and 0 as well as a 5-mL intramuscular injection of Fosfosal at Day 0. Pregnancy was verified by transrectal ultrasound at Days 40 and 100. Body condition score was recorded on Days −21 and 40. Data were analysed using the GLIMMIX procedure of SAS (SAS University edition, SAS Institute Inc.). When significant, Tukey and least squares means tests were used to compare means. Serum analysis showed that 89% of the animals had seroprevalence to at least two diseases. Average blood P concentration was 7.2mg dL−1. Pregnancy was affected by Ca levels (pregnant=2.55mg dL−1; non-pregnant=2.33mg dL−1; P&lt;0.05) and creatinine levels (pregnant=5.85mg dL−1; non-pregnant=5.76mg dL−1; P&lt;0.05). The average BCS was 3.2 (1=skinny; 5=fat), and there was no effect of time (Days −21 to 40). Pregnancy verified by transrectal ultrasound at Day 40 for the Vaccine, Suppl, SupplVacc, and control treatments was 54, 52, 57, and 49% (P=0.11), respectively. There was a tendency of higher pregnancy verified by transrectal ultrasound at Day 90 for the SupplVacc group (55%) compared with the control group (45%; P&lt;0.1). There was no effect of pregnancy loss among groups that were vaccinated (control=6%, vaccine=5%, Suppl=4%, and SupplVacc=3%). Considering only pluriparous cows, there was an increase in pregnancy per AI in the SupplVacc group (59%) compared with the control group (51%; P&lt;0.05). Once females presented a very good BCS, the supplement effect was only an immunostimulant. Starting a breeding season with supplementation and vaccination can increase pregnancy rate and profitability for farmers.


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 ◽  
...  

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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