mohammadjavad behzadi shahrbabak

The aim of present study was to evaluate the length of post-partum anestrus in Sistani cows of Zahak research station and also to investigate the causes of prolongation of post-partum anestrus in this breed. The data included the date of 1188 calvings and the first post-calving estrus were extracted from the farm archive. The average calving-first estrus interval was calculated in Excel and considered as the length of post-partum anestrus. Comparison of average length of post-partum anestrus in different decades was done using One-way ANOVA test in SPSS software. To determine the causes of prolongation of post-partum anestrus, all cows that did not show estrus more than 2 months after calving at the period of the study (N: 33) were evaluated in two stages of rectal ultrasound, 12 days apart. The average length of post-partum anestrus for 1188 calvings was 126.5 ± 90.1 days. Among the anestrus cows examined ultrasonographically, 75% did not have corpora lutea in both examinations and had inactive ovaries, and 25% had corpora lutea in one or both stages, and silent estrus was considered the cause of anestrus. None of the anestrous Sistani cows had ovarian cyst or pyometra. According to the results of the present study, the period of post-partum anestrus in Sistani cows of Zahak research farm is long and the main cause for this prolongation is the delay of the ovary in returning to cyclic activity, In addition, silent estrus is the cause of some cases of anestrus.

Subclinical mastitis is one of the common problems of dairy farms, which leads to a decrease in production and economic damage to the farmers. Identification of the pathogens causing subclinical mastitis in each region is necessary to prevent and control this problem. The aim of this study was to investigate the molecular prevalence of Staphylococcus aureus bacteria in subclinical mastitis cows in dairy farms of Neyshabur city. A total of 500 milking cows from 13 dairy farms located in different parts of Neyshabur city were included in the study. Milk samples were taken from all quarters and checked for subclinical mastitis using the California mastitis test. Milk samples were taken from the quarters that were positive in the California mastitis test, and evaluated for contamination with Staphylococcus aureus using polymerase chain reaction. Out of 500 dairy cows studied (2000 quarters), 94 (18.8%) had subclinical mastitis, and Staphylococcus aureus infection was detected in 8 cows (8 quarter). Based on the results of this study, the occurrence rate of subclinical mastitis as well as the prevalence of Staphylococcus aureus among subclinical mastitis cows in dairy farms of Neyshabur city is low.

pregnancy wastage is a serious economic problem in the reproductive management of dairy and beef farms. Various agents including genetic disorders, nutritional deficiencies, poisonings, physical injuries and infections cause pregnancy loss in cows. Infectious agents including bacteria, viruses, protozoa and fungi have a significant effect on pregnancy loss of cows. Diagnosis of infectious abortive agents in each region is necessary to control and prevent abortions on farms. The purpose of this study is to review all studies that have investigated viral agents of cattle pregnancy loss in Iran. Therefore, all Persian and English articles on the subject of cattle abortion with viral origin or any of the viruses causing abortion were searched in databases including Scince Direct, Pub Med, Scopus, Google Scholar, Magiran and Iran Doc. All the studies found were placed in the tables for easier analysis. The data of present study indicate that although many studies show a high prevalence of viral infections causing pregnancy loss of cattle including BVD and IBR viruses, but studies investigate their role in pregnancy loss of cattle in Iran are few. These few studies indicate that BVD and IBR viruses have a significant role in causing abortion in cattle in Iran. Only one study has examined the role of Blue tongue virus in bovine abortion in Iran, which no trace of this virus has been found.

Abortion is one of the problems of sheep and goats breeders in Iran and imposes significant economic losses on farmers. Infectious agents are the most common reason for abortion in sheep and goats. Some of these agents, such as Brucella and Toxoplasma, Leading to zoonotic diseases. Regarding the important role of sheep and goat breeding in livelihood of the people, it is very important in terms of economics and public health, to accurately know the abortive infectious agents in sheep and goat flocks.The purpose of this study was to investigate all the literature which attempts to diagnose Bacterial, viral and protozoan agents of sheep and goat abortion in Iran. Therefore, all articles related to abortion of sheep and goats, individual infectious agents and their prevalence in the geographical area of Iran or neighboring countries, were included in databases including Science Direct, Pub Med, Scopus, Google scholar , Magiran and Iran doc were searched. Of the English and Persian studies found, 36 studies were conducted on abortion of sheep and goats that their results inserted in a table for better evaluation. Based on studies that examined the causes of abortion of sheep and goats in different provinces of Iran, Brucella, Toxoplasma, Chlamydophila, Campylobacter and Salmonella are the most common causes of abortion in the country. No study has tracked the viral agents in abortion of sheep and goats in Iran.

Given to the proven role of endogenous PGF2α on ovulation, the aim of the present study was to evaluate the effect of exogenous PGF2α (D-cloprostenol) administration on conception rate in a large dairy herd. Total number of 362 lactating dairy cows in Zagrous Company of Shahrekord were selected for this study in summer (From 20 August to 6 September, 2014). The estrus of all cows was synchronized by the Heatsynch protochol and following heat detection the cows were artificially inseminated according to am-pm rule. The animals were submitted to two groups; the treatment group that received 150µg D-cloprostenol intravenously at the time of AI and the control group that didn’t receive any more treatment at the time of AI. To measure the concentration of serum progesterone, blood samples were obtained from 13 cows of each group at the time of insemination and 4 and 15 days later. Pregnancy was diagnosed by rectal ultrasound examination on 35-40 days after insemination. There was no significant difference between both groups in terms of conception rate and the serum progesterone levels (P>0.05). In conclusion, this study showed no beneficial effects of intravenous administration of D-cloprostenol on conception rate of dairy cows.