Dairy cattle breeding programs have been based in the selection for traits related to milk production. In this research a data set of 63 herds of East Azerbaijan province Holstein cattle, collected during 2002-2013 by the Iranian Animal Breeding Center was used to estimate the repeatability and heritability of three traits of economic importance. Genetic parameters for first three lactations of...

Herd optimization models that determine economically optimal insemination and replacement decisions are valuable research tools to study various aspects of farming systems. The aim of this study was to develop a herd optimization and simulation model for dairy cattle. The model determines economically optimal insemination and replacement decisions for individual cows and simulates whole-herd re...

this study was carried out in the winter of the year 2007 in a dairy herd at the vicinity of tehran (eslamshahr). measurements were performed on 18 holstein cows during first-lactation. five holstein dairy cattle were randomly selected and clinically studied, too. length of the claw’s dorsal flexure was measured with a ruler and also the hooves trimmed in the toe vertically for measuring of the...

The most recent issue of the Journal of Dairy Science has several papers regarding decreased fertility in dairy cattle, and the efforts to develop hormonal treatment regimens to improve fertility. Much of the recent work focuses on trying to reduce loss of fetuses during early pregnancy. This prompted me to search the literature about this extensive and important subject area. I suspect that Ut...

Infections with Chlamydophila abortus and C. pecorum are highly prevalent in cattle and have been associated with bovine mastitis. A prospective cohort study was conducted with a herd of 140 Holstein dairy cows to investigate the influence of Chlamydophila infection on subclinical inflammation of the bovine mammary gland as characterized by somatic cell numbers in milk. PCR detection of C. abor...

Lumpy skin disease (LSD) is a severe viral disease of cattle. Circumstantial evidence suggests that the virus is transmitted mechanically by blood-feeding arthropods. We compared the importance of transmission via direct and indirect contact in field conditions by using mathematical tools. We analyzed a dataset collected during the LSD outbreak in 2006 in a large dairy herd, which included ten ...

The paper describes how the comprehensive surveillance of bovine spongiform encephalopathy (BSE) and studies carried out on these data has enhanced our knowledge of the epidemiology of BSE. Around 7, 000 BSE cases were detected through the screening of about 50 million cattle with rapid tests in Europe. It confirmed that the clinical surveillance had a poor capacity to detect cases, and also sh...

Stenlund S. 2000. Neospora caninum in cattle in Sweden. Isolation of the parasite and studies of its transmission. Doctoral thesis. ISSN 1401-6257. ISBN 91-576-5940-0 Neospora caninum is a coccidian parasite with a two-host life cycle including a canine definitive host. In cattle the parasite is an important cause worldwide of abortion, stillbirth and calves born weak. This thesis, which deals ...

Cattle are animals that stay in the herd for a large period of day open air pasture. This daily routine leaves them exposed and susceptible to infectious diseases. One is Bovine Parasitic Sadness which considered one greatest cattle health problems due its high rate mortality morbidity. In this work preliminary results presented from calf inoculated with anaplasmosis. Blood samples were collect...

A high rate of on-farm cow mortality (i.e. unassisted death and euthanasia) is both a financial concern and an important animal welfare issue. The overall aim of this thesis was to evaluate the development of mortality in Swedish dairy herds and to identify characteristics associated with on-farm mortality at cow and herd levels. In paper I, two analyses were performed using data from the cattl...