bovine viral diarrhoea virus (bvdv) is an important pathogen of dairy cattle. in this study, bulk milk samples representing a total of 4105 milking cows, from 18 dairy cattle herds in the suburb of mashhad- iran, were tested for presence of bvdv by the use of a nested reverse transcription polymerase chain reaction (nested rt- pcr) assay. non of the cows in the herds had been vaccinated against...

reproductive efficiency in dairy cattle has been decreased over the last 5 decades despite significant gains in genetic selection, improved reproductive technologies and nutritional care. in high-yielding dairy cattle, the negative energy balance (neb) during the first week post-partum adversely affects ovarian activity, mainly follicle growth and steroidogenesis. circulating levels of non-este...

Invasions of gastrointestinal nematodes in dairy cows may affect animals productivity. The most frequently detected internal parasite of dairy cattle is Ostertagia ostertagi. The objective of this study was to determine O. ostertagi invasion extensiveness in selected herds of dairy cattle, with special consideration to cows being in the first lactation, and to analyze the milk yield and content...

The bacterial community composition and function in the gastrointestinal tracts (GITs) of dairy cattle is very important, since it can influence milk production and host health. However, our understanding of bacterial communities in the GITs of dairy cattle is still very limited. This study analysed bacterial communities in ten distinct GIT sites (the digesta and mucosa of the rumen, reticulum,...

A study based on bulk tank milk samples from 120 randomly selected dairy cattle herds was conducted to estimate the prevalence of Coxiella burnetii seropositive dairy herds, to describe the geographical distribution, and to identify risk factors. Using the CHEKIT Q-fever Antibody ELISA Test Kit (IDEXX), the study revealed a prevalence of 79.2% seropositive herds, 18.3% seronegative herds, and 2...

Bovine venereal campylobacteriosis, caused by Campylobacter fetus subsp. venerealis (Cfv), is regarded as one of the major threats to the cattle industry around the world. Abortion and infertility are two important reproductive problems in cows infected with C. fetus subsp. venerealis. Reports on the presence of Cfv are scarce in the cattle, in Iran. Therefore, the present study was designed to...

the purpose of this study was to analyze the instruments of risk management in the industrial dairy cattle farms in uromieh and khoy counties. the industrial dairy cattle farms in uromieh and khoy counties (n= 84) altogether constituted the statistical population of the study. by use of simple sampling method, 50 cattle farmers were selected as sample. the research design was a survey method on...

This study was an attempt to devise productive orientations of cattle herds in eastern high plains of Algeria. In this regard, 165 farms randomly identified were investigated. The selection of breeders was based to existence of cattle on the farm, and the farmer proposed to investigation must have at least two cows. The approach taken was to identify all systems adopted by farmers in a region t...

Dairy cattle are inseminated and pregnancy is established during lactation. Therefore, lactation and the reestablishment of pregnancy must overlap. Unfortunately, recent changes in the genetics, productivity, and management of dairy cows have led to a decline in reproductive efficiency. Reproductive decline in dairy cows began in the mid-1980’s and may be continuing on modern dairy farms (Lucy,...

Paratuberculosis caused by Mycobacterium avium subs. paratuberculosis a chronic, inflammatory and fatal disease of ruminants. The infection is characterized by chronic “subclinic” phase. Cattle in this phase is capable of infecting other animals in the herd. Although the presence of paratuberculosis has been known, the scientific studies on the disease and the prevalence appears to be scarced i...