scholarly journals Insulin effect during a Heatsynch protocol in dairy cows

2019 ◽  
Vol 49 (8) ◽  
Author(s):  
Andressa Stein Maffi ◽  
Cássio Cassal Brauner ◽  
Lais Fernanda Mielke ◽  
Marcio Erpen Lima ◽  
Eduardo Gularte Xavier ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Follicular Development ◽  
Fixed Time ◽  
Conception Rate ◽  
Control Group ◽  
Insulin Administration ◽  
Recombinant Human Insulin ◽  
Insulin Effect ◽  
Follicular Size ◽  
Intravaginal Device

ABSTRACT: The objective of this study was to evaluate the effect of exogenous insulin administration on follicular growth, estrus presentation and conception rate during a protocol of ovulation synchronization. Dairy cows were subjected to the Heatsynch protocol, with the insertion of an intravaginal device containing 1.9 g of progesterone (CIDR) and an intramuscular injection containing 2.5 mg of GnRH on day 0. On day 7, the CIDR was removed and subjects were given 12.5 mg of dinoprost. Also on day 7, Insulin Group (IG, n = 21) animals received a subcutaneous injection containing 0.25 IU / kg of recombinant human insulin and the control group (CG, n = 25) received a 0.9% NaCl injection. On day 8, an injection of 0.5 mg of estradiol cypionate was administered to all cows. Animals were inseminated 12 hours after estrus presentation or at day 10 at fixed time. Follicular development was evaluated on days 7, 9, and 10 using transrectal ultrasonography, estrus presentation was observed between days 8 and 10, and conception rate was evaluated 30 days after AI. There were no differences in growth rate, follicular diameter, estrus presentation, and conception rate. Therefore, application of a single dose of insulin does not promoted an increase in follicular size, estrus presentation and conception rate in dairy cows.

Oestrus synchronisation and fixed time artificial insemination in beef heifers

2010 ◽  
Vol 50 (7) ◽  
pp. 670
Author(s):  
Daniel Cavestany ◽  
Daniela Crespi ◽  
Alvaro Fernandez
Keyword(s):  
Artificial Insemination ◽  
Prostaglandin F2α ◽  
Fixed Time ◽  
Pregnancy Rates ◽  
Conception Rate ◽  
Control Group ◽  
Beef Heifers ◽  
Follicular Size ◽  
Follicle Size ◽  
And Control

To compare two oestrus synchronisation protocols in beef heifers presynchronised with two prostaglandin F2α (PG) treatments, 36 h after the second PG treatment one group (hCG-OB group; n = 112) received 250 IU of hCG and 0.5 mg of oestradiol benzoate (OB) followed by fixed time artificial insemination (FTAI) 30 h later. Additional oestrus detection (OD) and artificial insemination (AI) was done in this group for 3 days after FTAI; heifers rebred during this period were considered open to the FTAI. The Control group (n = 112) received only OD and AI for 6 days after the second PG treatment. Follicular size was measured at the time of AI in a subsample of heifers (59 in the hCG-OB group and 34 in the Control group). Results were evaluated separately either considering heifers pregnant at FTAI or those pregnant at FTAI + 3-day OD + AI. The FTAI conception rate was 45.5 vs 76.5% for the Control group (P < 0.0001) and pregnancy rates were 45.5 and 67.0% (P = 0.0014); FTAI + OD + AI conception rates were 63.4 and 76.2% (P = 0.0404) and pregnancy rates 63.4 and 62.8% (P = 0.5719) (hCG-OB and Control groups, respectively). There was a significant correlation (r = 0.713, P < 0.01) between follicle size at FTAI and pregnancy in the hCG-OB group, but not in the Control group (r = 0.3465, P > 0.1). In conclusion, acceptable synchronised conception rate and pregnancy rate were obtained by using this protocol, and the results were improved by complementing it with OD + AI for 3 days after FTAI.

Efficacy of Ovsynch and Ovsynch Plus Protocol for Improvement of Fertility in Postpartum Sahiwal Cows

2019 ◽  
Vol 14 (04) ◽  
Author(s):  
J. P. Lakher ◽  
M. K. Awasthi ◽  
J. R. Khan ◽  
M. R. Poyam
Keyword(s):  
Fixed Time ◽  
Conception Rate ◽  
Control Group ◽  
Group Iii ◽  
Treatment Groups ◽  
Group I ◽  
Early Postpartum ◽  
The Status ◽  
Sahiwal Cows ◽  
And Control

The present study was conducted to investigate the efficacy of Ovsynch and Ovsynch plus protocol in postpartum (day 60) Sahiwal cows (n=18). Animals were randomly divided into three equal groups, viz., Ovsynch group Ovsynch plus group and Control group. Animals of group I (n = 6) were treated with traditional Ovsynch protocol. The animals (n = 6) of group II were treated with Ovsynch plus protocol which consisted of an initial intramuscular injection of eCG (Folligon) @ 250 IU on day 60 postpartum followed 3 days later by GPG (Ovsynch) protocol. In group-III Control, no treatment was given to animals (n = 6). Treated animals were inseminated at a fixed time between 14 and 20 hrs after second GnRH injection, irrespective of estrus detection. Blood samples were collected from each animal on days 50 and 60 postpartum to determine the status of cyclicity in animals based on serum concentrations of progesterone (P4). A third blood sample was collected on the day of prostaglandin treatment to determine the response of first GnRH injection. Four animals each were cyclic, and two were acyclic in both treatment groups. Four animals each responded to first GnRH treatment in both treatment groups. Similarly, two animals each got conceived giving conception rate of 50% (2/4) in each treatment. In the control group, one out of 6 animals got conceived yielding 16.66 % conception rate (1/6) during the study period. It may be thus concluded that Ovsynch and Ovsynch plus protocol may be used during the early postpartum period to improve the reproductive efficiency in postpartum Sahiwal cows.

scholarly journals Influence of seasonality, timing of insemination and rectal temperature on conception rate of crossbred dairy cows

2016 ◽  
Vol 37 (1) ◽  
pp. 155 ◽  
Author(s):  
Fransérgio Rocha de Souza ◽  
Carla Cristian Campos ◽  
Natascha Almeida Marques da Silva ◽  
Ricarda Maria dos Santos
Keyword(s):  
Dairy Cows ◽  
Rectal Temperature ◽  
Artificial Insemination ◽  
Dairy Farm ◽  
Fixed Time ◽  
Conception Rate ◽  
Digital Thermometer ◽  
Pregnancy Diagnosis ◽  
Chi Squared

This study aimed to evaluate the effects of rectal temperature (RT) on conception rate (CR), as well as the effects of seasonality (spring-summer vs. autumn-winter) and timing of artificial insemination (AI) (morning vs. afternoon) on RT and CR in crossbred dairy cows (Holstein x Gyr). The experiment was conducted on a dairy farm in Centralina, MG, where 1,219 conventional and fixed-time inseminations were analyzed. The RT was measured immediately before AI using a digital thermometer. Pregnancy diagnosis was performed using ultrasonography between 28 and 60 days after AI. T The effects of seasonality and timing of AI on RT were analyzed with a Mann-Whitney U test and the effects of RT (above or below the average), seasonality and timing of AI on CR were analyzed with a Chi-squared test, both using the SAS program. The RT average was 39.4°C. Cows with RT ? 39.4°C had lower CR than cows with RT < 39.4°C (25.78% vs. 32.54%; P = 0.0096). During spring-summer, cows had higher RT (39.44°C ± 0.025 vs. 39.27°C ± 0.022; P < 0.0001) and lower CR (25.49% vs. 31.75%; P = 0.0146) compared with autumn-winter. Cows inseminated in the morning had lower RT (38.96°C ± 0.022 vs. 39.60°C ± 0.018; P < 0.0001) and higher CR (32.86% vs. 26.06%; P = 0.0102) than cows inseminated in the afternoon. In conclusion, crossbred dairy cows with rectal temperature equal to or greater than 39.4°C had lower conception rate. Moreover, rectal temperature and conception rate were affected by seasonality and insemination time.

116 PREGNANCY RATES AFTER ADMINISTRATION OF EQUINE CHORIONIC GONADOTROPIN (eCG) AT PROGESTERONE INTRAVAGINAL DEVICE REMOVAL AND 14 DAYS AFTER FIXED-TIME AI IN BEEF CATTLE

2011 ◽  
Vol 23 (1) ◽  
pp. 163 ◽  
Author(s):  
R. Núñez ◽  
T. de Castro ◽  
L. Cutaia ◽  
G. Bó ◽  
A. Menchaca
Keyword(s):  
Beef Cattle ◽  
Pregnancy Rate ◽  
Body Condition Score ◽  
Fetal Loss ◽  
Fixed Time ◽  
Pregnancy Rates ◽  
Control Group ◽  
Device Removal ◽  
Embryo Survival ◽  
Intravaginal Device

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.

scholarly journals REDUCTION OF THE VOLUNTARY WAITING PERIOD BY USE OF HORMONAL PROTOCOLS AND FIXED-TIME ARTIFICIAL INSEMINATION (FTAI) IN DAIRY COWS

2012 ◽  
Vol 17 (3) ◽  
Author(s):  
Miriane Suplicy ◽  
Haroldo Suplicy Filho ◽  
Luiz Ernandes Kozicki ◽  
José Carlos dos Santos Breda ◽  
Romildo Romualdo Weiss ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Pregnancy Rate ◽  
Artificial Insemination ◽  
Post Partum ◽  
Fixed Time ◽  
Estradiol Benzoate ◽  
Control Group ◽  
Waiting Period ◽  
Equine Chorionic Gonadotropin ◽  
Voluntary Waiting Period

ABSTRACT: The aim of this study was to reduce the waiting voluntary period in dairy cows by administration of two different hormonal protocols for estrus synchronization and fixed-time artificial insemination (FTAI). One hundred twenty-eight Holstein dairy cows were studied. Three groups (G) were carried out: G1 (44 treated), G2 (34 treated) and G3 (50 as control). In the treated cows the following hormonal protocols was applied between 40 and 45 days post partum: G1- Day 0 (D0) - bovine intravaginal device containing progesterone (P4) plus 1.0 mg of estradiol benzoate (EB), D8 - removal of the P4, plus 0.5 mg of cloprostenol plus 400 IU of equine chorionic gonadotropin (eCG), D9 - 1.0 mg of EB and FTAI after 36 hours. G2 - D0 - P4 intravaginal plus 50 mcg of gonadotropin-releasing hormone (GnRH), D7 - removal of the P4 plus cloprostenol plus 400 IU eCG; D9 - 50 mcg of GnRH and FTAI 16 hours after. G3 – Control group inseminated 12 hours after the visual estrus. Results: G1 and G2 were inseminated (FTAI) respectively in the D55.5 and D56.8 after calving, while the G3 in the D84.5 (p<0.01).  The pregnancy rate in the G1, G2 and G3 was respectively 47.0, 46.1 and 35.8% (p>0.05).  In Conclusion: there was significant reduction in the voluntary waiting period in treated cows and higher pregnancy rate although not significant.

13 Pre-synchronization by Induction of a Dominant Follicle Using a Progesterone Device in a GnRH-Based-Ovulation Synchronization Protocol in Lactating Dairy Cows

2018 ◽  
Vol 30 (1) ◽  
pp. 146
Author(s):  
M. P. Bottino ◽  
L. A. C. L. DaSilva ◽  
L. M. S. Simoes ◽  
G. Santos ◽  
I. Y. H. Martinez ◽  
...  
Keyword(s):  
Sustained Release ◽  
Dairy Cows ◽  
Prostaglandin F2α ◽  
Follicular Development ◽  
Experimental Period ◽  
Ovulation Rate ◽  
Dominant Follicle ◽  
Lactating Dairy Cows ◽  
Intravaginal Device ◽  
Synchronization Protocol

The objective was to compare a pre-synchronization protocol by induction of a dominant follicle using a progesterone intravaginal device before an Ovsynch protocol (Presynch) with Double-Ovsynch in lactating dairy cows. Lactating Bos indicus × Bos taurus crossbred cows (n = 440) were randomly allocated to 1 of 2 treatments (all IM injections): (1) Double-Ov (n = 228): GnRH (Day –17), prostaglandin F2α (PGF2α) 7 days later (Day –10) and gonadotropin-releasing hormone (GnRH) 3 days later (Day –7) followed by an Ovsynch protocol 7 days later (GnRH on Day 0, PGF2α on Day 7, GnRH on Day 9); (2) Presynch (n = 212): insertion of a sustained release progesterone intravaginal device (Day –10), 10 days later (Day 0), an Ovsynch protocol was initiated with progesterone device withdrawal on Day 7. All cows were artificially inseminated 15 to 20 h after the second GnRH injection of the Ovsynch protocol and were pregnancy checked by ultrasonography 30 and 60 days later. On a subsample (n = 102), ultrasonography was performed on Days 0, 7, 9, and 24 of the experimental period. On another subsample (n = 42), blood samples for progesterone analysis were taken on Days 0, 7, and 24. There were no differences between pre-synchronization methods on synchronization parameters [presence of a follicle >12 mm on D0, Double-Ov 94.2% (49/52) and Presynch 92.0% (46/50); P = 0.66], follicular diameter on the 1st GnRH (Double-Ov 17.2 ± 0.7 mm and Presynch 18.6 ± 0.9 mm; P = 0.28), ovulation rate to the 1st GnRH [Double-Ov 86.3% (44/51) and Presynch 81.2% (39/48); P = 0.50], synchronization rate [Double-Ov 84.6% (44/52) and Presynch 86.0% (43/50); P = 0.84], follicular diameter on the 2nd GnRH (Double-Ov 17.5 ± 0.6 mm and Presynch 18.0 ± 0.5 mm; P = 0.48), ovulation rate to the 2nd GnRH [Double-Ov 90.9% (40/44) and Presynch 86.0% (37/43); P = 0.48] and CL diameter on Day 24 (Double-Ov 27.9 ± 0.7 mm and Presynch 29.4 ± 0.9 mm; P = 0.19). Corpus luteum presence on Day 0 was different (P = 0.03) between treatments [Double-Ov 57.7% (30/52) and Presynch 36.0% (18/50)]. Moreover, there was no difference (P = 0.85) between pregnancy rates on Day 30 [Double-Ov 39.0% (89/228) and Presynch 40.1% (85/212)] or Day 60 after AI [Double-Ov 34.8% (79/227) and Presynch 38.7% (82/212); P = 0.41] and gestational loss between 30 and 60 days after AI [Double-Ov 7.9% (7/88) and Presynch 3.5% (3/85); P = 0.13]. Proportion of cows with P4 <1 ng mL−1 on Day 0 was similar between treatments [Double-Ov 13.6% (3/22) v. Presynch 5.0% (1/20); P = 0.37]. Likewise, the proportion of cows with P4 >1 ng mL−1 on Day 7 [Double-Ov 77.3% (17/22) v. Presynch 95.0% (19/20); P = 0.14] and P4 concentration on Day 24 (Double-Ov 4.7 ± 0.6 v. P4-Ov 5.9 ± 0.9; P = 0.84) were similar between treatments. In conclusion, pre-synchronization by induction of follicular persistence using a sustained-release progesterone device before Ovsynch yielded similar results to the Double-Ovsynch protocol on follicular development and regression patterns and on the fertility of lactating dairy cows.

72 EFFECT OF PROGESTERONE SUPPLEMENTATION ON DAY 4 AFTER TIMED ARTIFICIAL INSEMINATION ON PREGNANCY RATE OF LACTATING DAIRY COWS

2017 ◽  
Vol 29 (1) ◽  
pp. 143
Author(s):  
G. Tortorelli ◽  
A. J. Azrak ◽  
V. da Costa Andrade ◽  
R. dos Santos Ramos ◽  
A. S. Moraes ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Pregnancy Rate ◽  
Fixed Time ◽  
Lactating Dairy Cows ◽  
Embryonic Loss ◽  
Progesterone Supplementation ◽  
Group 2 ◽  
Intravaginal Device ◽  
One Way Anova ◽  
Group 1

Progesterone plays an important role in the maintenance of pregnancy. It is hypothesised that insufficient progesterone early in pregnancy may result in embryonic loss, and that supplemental progesterone would decrease pregnancy loss in dairy cows. The aim of this study was to compare the effect of progesterone supplementation after timed AI on pregnancy rate of dairy cows. The experiment was conducted in a single commercial herd, in Sao Paulo State (Brazil), during a period of 1 year (January–December 2016). The cows were assigned at a nonpregnancy diagnosis 32 ± 3 days after AI to 1 to 6 resynchronization treatments. They were submitted to the same fixed time AI protocol: Day 0, 0.1 mg of gonadorelin, 2 mg of oestradiol benzoate, and an intravaginal device of 1.9 g of progesterone; Day 7, 25 mg of dinoprost tromethamine; Day 8, 25 mg of dinoprost tromethamine, 1 mg of oestradiol cipionate, and device withdrawal; Day 10, AI. At Day 14, the cows were alternately arranged in 2 groups. Group 1 received a 900-mg progesterone supplementation IM injection, and Group 2 did not receive progesterone supplementation. Then, 32 ± 3 days after insemination, pregnancy diagnosis was performed by transrectal ultrasonography, and the data were tabulated. Full statistical analysis will be done at the end of the study, when more than 500 cows will be allocated to the 2 groups. From January until April 2016, 230 lactating dairy cows were submitted to the experiment. Both groups had similar average days in lactation (166), average number of lactations (1.95), and average number of inseminations (4.3). Group 1 had a pregnancy rate of 25% (29/116), and group 2 had a pregnancy rate of 15.8% (18/114) (P = 0.01, one-way ANOVA). Based on these preliminary data, pregnancy rates of lactating dairy cows may be improved with progesterone supplementation on Day 4 after insemination. These results need to be confirmed on larger numbers of cows.

scholarly journals The reproductive performance of dairy cows with anovulatory anoestrus that were injected with either gonadotrophin-releasing hormone or oestradiol benzoate as part of a re-treatment process after insemination

2007 ◽  
Vol 78 (1) ◽  
Author(s):  
B.V.E. Segwagwe ◽  
J. Malmo ◽  
K.L. Macmillan ◽  
P.D. Mansell
Keyword(s):  
Dairy Cows ◽  
Pregnancy Rate ◽  
Reproductive Performance ◽  
Conception Rate ◽  
Control Group ◽  
Releasing Hormone ◽  
Start Date ◽  
Oestradiol Benzoate ◽  
Conception Rates ◽  
Gonadotrophin Releasing Hormone

This experiment compared the reproductive performance of synchronised anoestrous dairy cows that were treated initially with a combination of progesterone and oestradiol benzoate and then with either gonadotrophin-releasing hormone (GnRH) or oestradiol benzoate to resynchronise returns to service. It was hypothesised that injecting anoestrous dairy cows with GnRH 12-15 days after insemination and coinciding with the time of insertion of a controlled intravaginal progesterone-releasing (CIDR) device would increase conception rates to the preceding 1st insemination compared with oestradiol benzoate treated cows; both GnRH and oestradiol benzoate would resynchronising the returns to service of those cows that did not conceive to the preceding insemination. Groups of cows in 11 herds were presented for a veterinary examination after they had not been seen in oestrus postpartum. Those cows diagnosed with anovulatory anoestrus (n = 1112) by manual rectal palpation and / or ultrasonography were enrolled in the trial. Each enrolled cow was injected with 2mg oestradiol benzoate i.m. on Day -10, (where Day 0 was the 1st day of the planned insemination) concurrently with vaginal insertion of a CIDR device. The device inserted was withdrawn on Day -2 and then each cow injected i.m. with 1 mg of oestradiol benzoate on Day -1 unless it was in oestrus. Observation for oestrus preceded each insemination. Every cow that had been inseminated on Days -1,0,1 or 2 was presented for treatment for resynchrony on Day 14 (n=891). They were divided into 2 groups; those with an even number were each injected i.m. with 250 µg of a GnRH agonist (Treatment group n = 477); each of the cows with an odd number injected i.m. with 1mg of oestradiol benzoate (control group, n = 414). Each GnRH or oestradiol benzoate injection preceded reinsertion of a CIDR device previously inserted from Days -10 to -2. It was withdrawn on Day 22, 24 hours before injecting 1mg oestradiol benzoate. Cows observed in oestrus were submitted for a 2nd insemination. Every enrolled cow still present in the herd was pregnancy tested by palpation of uterine contents per rectum about 6 weeks later and again at the end of a herd's seasonal breeding programme. The alternative use of GnRH instead of oestradiol benzoate did not affect the percentage of cows conceiving within 3 days of the mating start date (MSD) (35.6 %vs 35.3 %, P=0.90), resubmission rates for a 2nd insemination among cows not pregnant to the 1st insemination (81.6 % vs 83.5 %, P=0.41), 6-week pregnancy rate (59.3 % vs 60.6 %, P=0.65), 21-week pregnancy rate (86.6 vs 85.0, P=0.36), mean interval from MSD to conception (32.5 + 1.8 days vs 29.9 + 1.8 days, P = 0.26) or conception rate of cows reinseminated by Day 28 (43.3 % vs 38.8 %, P=0.39). When GnRH conception rate of cows reinseminated by Day 28 (43.3% vs was compared with oestradiol benzoate, it did not increase conception rates to the 1st service; it was as effective as oestradiol benzoate in synchronising returns to service in previously treated anoestrous cows that did not conceive to the 1st service. Its use affected neither conception rates to the preceding 1st inseminations nor to the following 2nd inseminations.

scholarly journals Pyruvate accumulation may contribute to acceleration-induced impairment of physical and cognitive abilities: An experimental study

2021 ◽  
Author(s):  
Fengfeng Mo ◽  
Hongwei Zhang ◽  
Yuxiao Tang ◽  
Ruirui Qi ◽  
Shuang Nie ◽  
...  
Keyword(s):  
Insulin Secretion ◽  
Physical Function ◽  
Cognitive Abilities ◽  
Rating Scale ◽  
Vehicle Group ◽  
Control Group ◽  
Insulin Administration ◽  
Insulin Effect ◽  
Negative Effect ◽  
Physical Functions

Background: Fatigue can be induced after acceleration exposure, however the mechanism of it is still unclear. The aim of the present study was to examine whether metabolites changes can decrease cognitive and physical function after acceleration. Methods: Graybiel scale and Fatigue Self-rating scale were used to assess the seasickness and fatigue degrees of eighty-seven male seafarers respectively after sailing. To test the effect of pyruvate on cognitive and physical functions, five different doses of pyruvate were administrated into rats. Insulin can reduce the accumulation of pyruvate. To observe the insulin effect on pyruvate, and cognitive, physical functions after acceleration, insulin administration or treatment of promoting insulin secretion was used. Physical and cognitive functions were assessed using Open Field test, Morris water maze and Loaded swimming test in animals. Results: Physical and cognitive abilities were decreased obviously, and Serum pyruvate level increased mostly in human and rats after acceleration. Compared to vehicle group, physical and cognitive abilities were significantly decreased after pyruvate administration. Besides, we found a significant decline in adenosine triphosphate concentration and pyruvate dehydrogenase activity in the hippocampus, prefrontal cortex, liver, and muscle of rats treated with acceleration or pyruvate injection, while insulin administration or treatment of promoting insulin secretion markedly alleviated this decline and the impairment of physical and cognitive abilities, compared to the control group. Conclusion: Our results indicates that pyruvate has a negative effect on physical and cognitive abilities after acceleration. Insulin can inhibit pyruvate accumulation and cognitive and physical function after acceleration exposure.

368 CONCEPTION RATE AT FIRST ARTIFICIAL INSEMINATION WITH SEXED SEMEN OR CONVENTIONAL SEMEN IN CROSSBRED DAIRY COWS

2010 ◽  
Vol 22 (1) ◽  
pp. 340
Author(s):  
B. T. Gerhardt ◽  
L. D. P. Sinedino ◽  
A. P. Dourado ◽  
P. A. M. Alves ◽  
L. A. G. Nogueira
Keyword(s):  
Dairy Cows ◽  
Milk Production ◽  
Genetic Selection ◽  
Conception Rate ◽  
Control Group ◽  
Chi Square ◽  
Fertility Reduction ◽  
Estrus Detection ◽  
Sexed Semen ◽  
Experimental Group

The use of sexed semen in dairy cattle almost eliminates the birth of unwanted male calves and can lead to increased milk production by means of genetic selection exerted on the females. However, AI with sexed semen still presents several obstacles to overcome. Holstein-Zebu cows are responsible for 80% of the milk produced in Brazil. These crossbred animals are used extensively throughout the country because their physiologic and morphologic characteristics are compatible with milk production in the tropics which results in an economic performance advantage. The objective of this study is to evaluate the conception rates with sexed semen, comparing it to the use of non-sorted semen in crossbred dairy cows. In addition, two insemination times had been studied to determine the best timing for AI with the sexed semen. Both studies were carried out in the Experimental Station Seropedica of Pesagro-RJ, located in the state of Rio de Janeiro, Brazil. The experiment was done in 2008/2009 (January to April). In the first Trial 56 Holstein-Zebu females, composed of 1/2 to 7/8 Holstein genetics, were inseminated 12 h after estrus detection with non-sorted semen (control group n = 29, 14 heifers and 15 cows) or with sexed semen (experimental group n = 27, 13 heifers and 14 cows). The semen utilized was from the same bull and thawing was performed intravaginally. In the second trial, 55 females were inseminated only with sexed semen from the same bull, with thawing in water at 35°C, at two different times: 12 h after estrus observation (control group n = 27, 12 heifers, 4 primiparous, and 11 multiparous) and 15 h after estrus observation (experimental group n = 28, 12 heifers, 5 primiparous, and 11 multiparous). The pregnancy diagnoses were done by rectal palpation and transrectal CAT scan at Day 45. Statistical analyses had been done using Chi-square. The conception rate in the first trial was of 17.2% (5/29) for sexed semen and 53.8% (14/26) for non-sorted semen (P < 0.05). In the second trial, the conception rate was of 37.0% (10/27) for insemination with sexed semen, 12 h after estrus observation and 50.0% (14/28) for the females inseminated 15 h after estrus observation (P > 0.05). It is possible that one of the causes of fertility reduction with sexed semen is that sexed-sperm remain viable for a shorter time after the insemination. Inseminations with sexed semen done 15 h after estrus detection, which can be more synchronized with the time of ovulation, and when accompanied by closely controlling the thawing process, show results similar to those obtained with conventional semen.

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