The use of vaginal electrical resistance to diagnose estrus and early pregnancy and its relation with size of the dominant follicle in dairy cattle

The use of vaginal electrical resistance (VER) for estrous detection and early pregnancy diagnosis were evaluated using three experiments in dairy cattle, in Ethiopia. VER was measured: 1) during the natural estrous (n = 60) cycle, 2) during estrus induced by GnRH+ PGF 2· (n = 11) and 3) during post insemination in dairy cows synchronized with GnRH+CIDR+PGF 2· (n = 25). Results from Experiment 1 indicated that VER (mean ± SD) during pro-estrus, estrus, metestrus, diestrus and anestrous was 89.6 ± 3.1, 82.2 ± 2.2 102.9 ± 3.1, 106.8 ± 1.4 and 119.7 ± 1.7 ohm, respectively. Results from Experiment 2 indicated that VER was highest (102.4 ± 2.0 ohm; P < 0.001) at the time of PGF 2· injection and significantly declined to 82.3 ± 0.7 ohm at the time of estrus and increased (94.9 ± 2.0 ohm; P < 0.001) 24 h after estrus. The mean diameter of the largest follicle (DLF) was highest (14.3 ± 0.1 mm; P < 0.001) at estrus and lowest (10.0 ± 0.1) at the time of PGF 2· injection. The VER value was inversely correlated (r = -0.50; P < 0.001) with DLF. Results from Experiment 3 showed that VER significantly (P < 0.01) declined from day 19 to day 21 post insemination in non pregnant cows compared with pregnant cows. The study proved that VER can effectively be used for estrus detection and can be used to diagnose early pregnancy (day 18-21 post insemination) in dairy cows

Estrus performance of boran and boran × holstein friesian crossbred cattle synchronized with a protocol based on estradiol benzoate or gonadotrophin-releasing hormone

The objectives of this study were to determine estrus behavior, interval to estrus, duration of estrus and time of ovulation of Boran, and Boran × Holstein Friesian (HF) breeds. A total of 113 cows and heifers from the two breeds were synchronized with two estrus synchronization protocols: 1) estradiol benzoate (EB) + controlled internal drug release (CIDR) + prostaglandin (PGF2?); and 2) gonadotrophin (GnRH) + CIDR + PGF2?. The results (mean ± SE) showed that the Boran breed had significantly longer interval to estrus (70.67 ± 5.9 versus 54.58 ± 4 h), shorter duration of estrus (8.65 ± 0.83 versus 12.1 ± 0.7 h) and lower behavioral score (mean ± SD; 883 ± 639 versus 3,399 ± 957) compared to Boran × HF crossbred cattle. Animals treated with EB + CIDR + PGF2? had a significantly shorter interval to estrus (46.75 ± 4 versus 78.5 ± 4 h), higher behavioral score (3,058 ± 1,223 versus 2,663 ± 991) and longer duration of estrus (11.31 ± 0.71 versus 9.4 ± 0.75 h) compared to animals treated with GnRH + CIDR + PGF2?. The interval from estrus to ovulation (26 ± 2.5 h) was not different between breeds and between synchronization methods. The Boran (Bos indicus) breed tended to have a longer interval to estrus, shorter duration of estrus and an estrus behavior score lower than Boran × HF crossbred cattle treated and managed under similar conditions. The protocol using EB + CIDR + PGF2? was more effective than GnRH + CIDR + PGF2? in terms of enhancing estrus behavior and creating tight synchrony

The role of indemnification agreements and legal liability in railroad disasters: A financial market perspective

Purpose – The study aims to examine the stock price performance of publicly owned railroad companies following severe railroad accidents that resulted in the loss of human lives and/or hazardous material spills. The focus is on legal liability considerations as one of the primary factors that drives a firm's abnormal performance following a given accident. Design/methodology/approach – This paper employs a sample of 97 railroad accidents that occurred between January 1967 and December 2006 and involved equipment (tracks and/or locomotives) owned by publicly traded US and Canadian railroad companies. The stock price reaction of the affected firms is examined following these disasters and a series of univariate and multivariate tests is used to investigate whether differences in abnormal returns following a given accident can be related to various factors that characterize the affected firm or the accident it was involved in. Findings – The results suggest that legal liability considerations are one of the primary factors that determine a company's stock price reaction following a railroad disaster. Specifically, it is observed that firms that are likely to be sued in connection with an accident tend to incur larger stock price losses. On the other hand, it is found that firms that are protected through indemnification agreements suffer only insignificant price declines, even if initial accident reports hold them responsible for causing the accident. Originality/value – The paper extends the prior literature on the stock market's reaction to firm-specific catastrophic events. While there are a number of studies that examine the financial consequences of aviation disasters, there is to the authors' knowledge only one prior study that performs a similar analysis for railroad accidents.Financial performance, Liability, Railway accidents, Stock prices, Stock returns