scholarly journals 300 Efficacy of the measurements of the vaginal electrical resistance to determine the phase of the estrous cycle in lactating dairy cattle

2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 138-138
Author(s):  
Martin G Maquivar ◽  
John Swain ◽  
Hannah Chiapetta ◽  
Tynnetta Stumvoll ◽  
Katelin Baker ◽  
...  
Keyword(s):  
Dairy Cattle ◽  
Dairy Cows ◽  
Estrous Cycle ◽  
Electrical Resistance ◽  
Luteal Phase ◽  
Economic Loss ◽  
Estrous Cycles ◽  
Follicle Diameter ◽  
Estrus Detection ◽  
Vaginal Temperature

Abstract Estrus detection in dairy cattle is an important factor that contributes to the reproductive efficiency. Lack and inaccuracy of heat detection are associated with increased days open, calving interval, economic loss and culling due to infertility. Efforts have been made to identify methods to assist in estrus detection. The objective of this study was to examine if vaginal electrical resistance (VER) measured by a commercial probe throughout the estrous cycle in lactating dairy cows aids to determine the onset of estrus. A total of 9 lactating Holstein cows were monitored for 2 – 3 estrous cycles, ultrasonography of the ovary, blood sample for progesterone and VER was assessed every other day during the luteal phase (LUT) and every day during the follicular phase (FOL). A total of 339 VER measurements were collected, 66 during the FOL phase and 273 corresponded to the LUT phase. Mean VER differed (P < 0.001) between FOL (294.5 ± 51.3) and LUT (316.4 ± 46.2), similarly the progesterone concentration was different between the LUT and FOL phases (0.38 ± 0.24 ng/mL vs. 3.41 ± 2.08 ng/mL, respectively) (P < 0.001). No differences were observed between the vaginal temperature of cows in LUT (38.2 ± 0.4 C°) or FOL phase (38.3 ± 0.3 C°). Cervix diameter differed (P < 0.01) between FOL (35.9 ± 3.8 mm) and LUT (34.5 ± 3.4mm), VER has a significant relation (P < 0.001) with the diameter of the Corpus luteum (279.8 + 1.54 x Cervix diameter). Similarly, VER had a significant relationship (P = 0.03) with diameter of the dominant follicle at estrus (355.2 + -3.9 x follicle diameter). These findings suggest that VER changes according to the phase of the estrous cycle, VER decreased during sexual receptivity and increased during the luteal phase. VER may improve the accuracy to diagnose heat in dairy cows.

Effects of Beta-carotene Administration on Fertility in Lactating Dairy Cows

2021 ◽  
Author(s):  
Ebru Karakaya Bilen ◽  
Gülnaz Yılmazbaş Mecitoglu
Keyword(s):  
Dairy Cows ◽  
Detection Rate ◽  
Beta Carotene ◽  
Prostaglandin F2 Alpha ◽  
Lactating Dairy Cows ◽  
Follicle Diameter ◽  
Ovulatory Follicle ◽  
Estrus Detection ◽  
Potential Benefits ◽  
Β Carotene

Background: Beta-(β-) carotene, is the precursor to vitamin A, in particular, has some potential benefits on reproduction. The main objective of this study was to investigate the efficacy of β-carotene administration on fertility following either prostaglandin F2 alpha (PGF) induced estrus or Ovsynch protocol in lactating dairy cows.Methods: Cows with at 47±3 postpartum days were divided into two groups: β-carotene group (βC, n=139) was treated with injectable β-carotene while untreated cows served as control (CON, n=227). In both groups, PGF was administered and heatmount detectors were applied at 54±3 days postpartum. Cows detected in estrus after PGF were inseminated. Cows that had not been detected in estrus were divided into two groups 7 days after PGF administration; βC-OVS (n=137) and CON-OVS (n=89). Ovsynch protocol was initiated 4 days after β-carotene administration.Result: The estrus detection rate was similar between the βC and CON groups (P = 0.19). Pregnancy per AI (P/AI) on d 31 was also similar between groups (P = 0.93). In the Ovsynch protocol, ovulation to the first GnRH and ovulatory follicle diameter at the time of insemination did not differ between groups. No difference was observed in P/AI at d 31 (P = 0.13). The results of this study indicated that β-carotene administration had no effect on fertility either PGF induced estrus or Ovsynch protocol in dairy cows. 

298 COMPARISON OF THREE DIFFERENT PROTOCOLS FOR SUPERSTIMULATION OF DAIRY CATTLE

2009 ◽  
Vol 21 (1) ◽  
pp. 246 ◽  
Author(s):  
R. G. Steel ◽  
J. F. Hasler
Keyword(s):  
Dairy Cattle ◽  
Dairy Cows ◽  
Estrous Cycle ◽  
Embryo Transfer ◽  
Animal Health ◽  
Bovine Embryo ◽  
Transfer Program ◽  
Frozen Semen ◽  
Pfizer Animal Health ◽  
Estradiol 17Β

Traditionally, successful superstimulation of cattle depended on initiating injections of gonadotrophin at mid-cycle, approximately at second follicular wave emergence. This approach limited the convenience of scheduling donors for superstimulation. With the use of intravaginal progesterone-releasing devices and estradiol 17β, superstimulation can be initiated successfully at any time of the estrous cycle. However, because estradiol cannot be legally injected into cattle in an increasing number of countries, the efficacy of GnRH as an estradiol substitute was investigated. A retrospective analysis was performed on data collected in a commercial bovine embryo transfer program over a period of several years. All donors were lactating dairy cows at least two years of age; approximately 75% were comprised of Holstein and the remainder of Jersey, Guernsey, or Brown Swiss breeds. The three treatments employed were (1) Controls injected twice daily for 4 days with a total of 240 to 400 mg of porcine FSH (Folltropin-V, Bioniche Animal Health, Inc.) in decreasing doses starting between day 7 and day 14 of diestrus, with PG (Lutalyse, Pfizer Animal Health) given at the time of FSH injections no. 5 (35 mg) and 6 (25 mg); (2) Estradiol females received a CIDR (Pfizer Animal Health), 5.0 mg estradiol 17β and 100 mg progesterone in oil on random days of the estrous cycle; FSH was initiated 4 days later as described for controls with CIDR removal at the time of FSH injection no. 6; (3) GnRH females received a CIDR on random days of the estrous cycle and 100 μg GnRH on day 1.5 following CIDR insertion; FSH was initiated 60 h after GnRH injection as described for controls with CIDR removal at the time of FSH injection no. 6. All donors were inseminated with one straw of frozen semen 12 and 24 h after the onset of estrus. Embryos were nonsurgically recovered 7 to 8 days after onset of estrus. Only embryos of grades 1 to 3 (IETS classification) were included in the data. Data were analyzed by ANOVA and Tukey’s hsd test was used to distinguish significance among means as shown in Table 1. Estradiol females produced approximately 2 more ova/embryos per procedure than Control and GnRH groups and an average of 0.8 more embryos per female than did the Control group, but there was no difference compared to the GnRH group. Similar to what has been shown in other commercial embryo transfer data sets, nearly 25% of the donors in each group failed to produce at least one good embryo. Clearly, all three treatments resulted in efficacious superstimulation. In light of the legality issues surrounding the use of estradiol, this study shows that GnRH can be used quite successfully to superstimulate dairy cattle at random times of the estrous cycle. Table 1.Average numbers of ova and embryos recovered from dairy cows superstimulated with three different protocols We thank G.E. Seidel, Jr. and S.C. Purcell for assistance with statistical analysis.

Effects of recombinant bovine somatotropin on hypophyseal and ovarian functions of lactating dairy cows

1991 ◽  
Vol 71 (2) ◽  
pp. 343-353 ◽  
Author(s):  
Guillermo F. Gallo ◽  
Elliot Block
Keyword(s):  
Sustained Release ◽  
Dairy Cows ◽  
Estrous Cycle ◽  
Negative Energy ◽  
Bovine Somatotropin ◽  
Release Formulation ◽  
Sustained Release Formulation ◽  
Estrous Cycles ◽  
Plasma Progesterone ◽  
Recombinant Bovine Somatotropin

Three trials were conducted to determine the effects of recombinant bovine somatotropin (rbST) on reproductive functions of lactating Holstein dairy cows. In Trial 1, 49 cows were used to investigate the effects of 0, 320 or 640 mg of rbST in a sustained-release formulation injected every 28 d on plasma progesterone (P4) concentration during estrous cycles. Total P4 area and P4 mean were increased (P < 0.05) in rbST-treated cows during the 1st and 2nd detected estrous cycle post-rbST injection. Maximum P4 value, slope of the P4 decline and length of cycles were not affected by rbST treatment. In Trial 2, 56 cows were used to investigate the effects of 0, 320, 640 and 960 mg of rbST in a sustained-release preparation injected every 28 d on plasma P4 concentration from weeks 1 to 34 of pregnancy. Mean P4 was increased (P = 0.08) in rbST-treated cows proportionally to the rbST dose received. In Trial 3, 18 cows were used to investigate the effects of 0 or 25 mg d−1 of rbST injected from days 3 to 15 postpartum (pp) on the gonadotropin-releasing hormone (GnRH) induced luteinizing hormone (LH) response curve at 14 d pp. Total area under the LH curve and LH peak value were increased (P < 0.05) in rbST-treated cows, but LH baseline and time to LH peak were not different among groups. Cows receiving rbST were in a more negative energy balance due to higher milk production. In summary, long-term administration of rbST increased the concentration of plasma progesterone during the first two estrous cycles post-treatment and during pregnancy, and enhanced the GnRH-induced LH response at 14 d pp. Key words: Bovine somatotropin, GnRH-LH induction, progesterone, estrous cycle, pregnancy

scholarly journals Cyclic changes in cortisol across the estrous cycle in parous and nulliparous Asian elephants

2014 ◽  
Vol 3 (2) ◽  
pp. 57-66 ◽  
Author(s):  
Kerry V Fanson ◽  
Tamara Keeley ◽  
Benjamin G Fanson
Keyword(s):  
Estrous Cycle ◽  
Luteal Phase ◽  
Ovarian Function ◽  
Detailed Examination ◽  
Negative Effects ◽  
Reproductive Dysfunction ◽  
Asian Elephants ◽  
Estrous Cycles ◽  
Cyclic Changes

In the context of reproduction, glucocorticoids (GCs) are generally considered to have negative effects. However, in well-studied model species, GCs fluctuate predictability across the estrous cycles, and short-term increases promote healthy ovarian function. Reproductive challenges have plagued captive elephant populations, which are not currently self-sustaining. Efforts to understand reproductive dysfunction in elephants have focused on the suppressive effects of cortisol, but the potential permissive or stimulatory effects of cortisol are unknown. In this study, we provide a detailed examination of cortisol patterns across the estrous cycle in Asian elephants (Elephas maximus). Time series analysis was used to analyze cortisol and progesterone data for a total of 73 cycles from eight females. We also compared cortisol profiles between females that successfully conceived and females that failed to conceive despite repeated mating attempts. Our results revealed that cortisol fluctuates predictably across the estrous cycle, with a peak during the second half of the follicular phase followed by low levels throughout the luteal phase. Furthermore, this pattern was significantly altered in nulliparous females; cortisol concentrations did not decline during the luteal phase to the same extent as in parous females. This study highlights the complexity of cortisol signaling and suggests future directions for understanding the role of cortisol in reproductive dysfunction.

scholarly journals Effect of GnRH or Estradiol Benzoate on Reproductive Traits during a Heatsynch Protocol in Dairy Cows

2018 ◽  
Vol 44 (1) ◽  
pp. 7
Author(s):  
Laís Mielke ◽  
Mityelle Da Costa Chaves Rodrigues ◽  
Márcio Érpen Lima ◽  
Diego Andres Velasco Acosta ◽  
Francisco Augusto Burkert Del Pino ◽  
...  
Keyword(s):  
Dairy Cattle ◽  
Dairy Cows ◽  
Reproductive Traits ◽  
Estradiol Benzoate ◽  
Pregnancy Rates ◽  
Conception Rate ◽  
Follicular Wave ◽  
Linear Probe ◽  
Estrus Detection ◽  
Conception Rates

Background: Milk production of cows is closely correlated with its reproductive efficiency. One of the several factors influencing the dairy efficiency is the decline in fertility of the cows/heifers. Use of hormonal protocol are often used to improve the fertility of the recipients. Several programs are available to inseminate dairy cows, with variation in the use of different types of hormones, time of use and range of duration period, as well as the time of AI. The objective of this study was to evaluate the efficiency of follicular wave emergence induction of estradiol benzoate in comparison to GnRH in a Heatsynch protocol and its influence on reproductive parameters.Materials, Methods & Results: In this study were used primiparous and multiparous Holstein cows (n = 325). Animals were divided randomly into two different treatments according with the hormone used to induce follicular wave emergence (D0). The GnRH group (n = 167), was given 25 mg, while in the EB group (n = 158) was used 2 mg. At same day, were inserted, a controlled internal drug-releasing containing 1.9 g of progesterone CIDR®. On day 7, CIDR was removed and cows were given 25 mg luteinizing hormone followed by an injection of 1 mg Inducer Ovulation at day 8. Cows were then observed for signs of estrus for at least two hours (twice daily at 7 am and 6 pm) for three days following CIDR® removal. Cows detected in estrus were inseminated 12 h later the estrus detection. Pregnancy status was determined by ultrasonography at 30 ± 5 d and 60 ± 5 d after AI. A single technician was responsible for the estrus detection and inseminations. A single technician was responsible for the estrus detection and inseminations. Ultrassonographic examinations with ultrasound, transrectal linear probe of 5 MHz, were performed for the diagnosis of pregnancy at 30 and 60 days after artificial insemination. Binomially distributed data, such as, estrous response, conception rate, pregnancy rate and pregnancy losses, were analyzed by Chi-square test. Pregnancy rates at 30-35 days and 60-65 days as well as pregnancy losses were considered in the model for the effect of parity (primiparous vs. multiparous) and the group of estrus behavior during the Heatsynch protocol. Conception rate was similar between GnRH (36.1%, 57/158) and EB (37.7%, 63/167) treatments. Cows showing estrus signs after CIDR removed were 71.9% in GnRH and 62% in EB group (P = 0.05). Embryonic losses were different (P = 0.03) according to groups of cows showing estrus signals or not.Discussion: Our results demonstrate that conception rates are not affected by using either EB or GnRH at the beginning of the Heatsynch protocol. Therefore, the EB can be an alternative choice to GnRH at Heatsynch beginning. Similar results were found by autor in dairy cows, once it was also observed that there is no difference in conception rate in two TAI protocols using either GnRH or EB. In Heatsynch protocols the increase in estrus detection are a key factor to increase fertility in lactating dairy cows. It can be explained once animals in regular estrous cycle have a palpable corpus luteum and circulating progesterone concentration higher than 1 ng/mL which leads than to enhance pregnancy ratios. The use of BE at the time of CIDR insertion in TAI protocols for dairy cattle proved to be an alternative to GnRH considering conception rates. Therefore, the use of BE at the time of CIDR insertion in a Heatsynch protocol in dairy cattle proved to be an alternative to GnRH which can be an important tool to increase the TAI utilization by farmers. Furthermore, in Heatsynch protocol cows showing estrus have pregnancy rates improved and lower pregnancy losses.

Alterations in vaginal temperature during the estrous cycle in dairy cows detected by a new intravaginal device—a pilot study

2020 ◽  
Vol 52 (5) ◽  
pp. 2265-2271
Author(s):  
Shuilian Wang ◽  
Hongliang Zhang ◽  
Hongzhi Tian ◽  
Xiaoli Chen ◽  
Shujing Li ◽  
...  
Keyword(s):  
Pilot Study ◽  
Dairy Cows ◽  
Estrous Cycle ◽  
Vaginal Temperature ◽  
Intravaginal Device

1076 Global gene expression in the endometrium of primiparous dairy cows during the early-luteal phase of the estrous cycle

2016 ◽  
Vol 94 (suppl_5) ◽  
pp. 515-516
Author(s):  
A. L. Astessiano Dickson ◽  
F. Peñagaricano ◽  
A. Meikle ◽  
M. Carriquiry
Keyword(s):  
Gene Expression ◽  
Dairy Cows ◽  
Estrous Cycle ◽  
Luteal Phase ◽  
Global Gene Expression

RESUMPTION OF OVARIAN ACTIVITY AND ESTRUS POSTPARTUM IN DAIRY COWS MAINTAINED INDOORS YEAR-ROUND

1985 ◽  
Vol 65 (2) ◽  
pp. 391-398 ◽  
Author(s):  
A. J. HACKETT ◽  
C. Y. LIN ◽  
A. J. McALLISTER
Keyword(s):  
Dairy Cows ◽  
Estrous Cycle ◽  
Genetic Group ◽  
Ovarian Activity ◽  
Calving Interval ◽  
Genetic Line ◽  
Estrous Cycles ◽  
Cycle Lengths ◽  
The Mean ◽  
Intensive System

Sequential milk progesterone concentrations from semi-weekly samples were plotted for 310 calvings by cows housed indoors year-round. Resumption of ovarian activity (first estrus), number of complete estrous cycles within 91 days postpartum, lengths of estrous cycles and peak progesterone levels were assessed considering diet, parity, genetic line of cow and season of calving. Patterns of ovarian activity in postpartum cows maintained indoors year-round were similar to those previously reported for cows housed in less intensive systems. On the average, the first estrus occurred 24 days postpartum. The mean number of estrous cycles was 2.6. Estrous cycle lengths averaged 20 ± 6, 22 ± 5 and 22 ± 5 days (mean ± SD) in the first three estrous cycles. Peak progesterone levels were 19 ± 10, 20 ± 10 and 22 ± 12 ng/mL (mean ± SD). Most of the dairy cows housed in the intensive system had normal estrous cycles, had ovulated within 55 days postpartum and had two periods of estrus within 91 days postpartum and should have been capable of conception at such a time to have a calving interval of 1 yr. Seasonal influences on ovarian activity were more important than diet, genetic line or parity. Of 48 interaction effects studied, only interactions of season with genetic group, parity or diet were significant, as was genetic group with parity. Key words: Ovarian activity, estrous cycle, peak progesterone

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