bovine immunodeficiency virus is a lentivirus which can cause varieties of infectious complications and induce remarkable losses to dairy industry. considering to the probability of worldwide distribution of the biv infection, this study was conducted for the first time in iran to determine of the status of biv infection in the holstein cattle and evaluate the associated findings. according to ...

Background: Tumor necrosis factor- a (TNF-α) is a cytokine that was identified as a factor with a wide range of proinflammatory activities. The expression of bovine TNF-α in mammary tissue during pregnancy seems to have a role in development of the corresponding glands.Objective: Single nucleotide polymorphisms (SNPs) were defined in 3′-flanking region of...

Improving reproductive performance of dairy cattle has become one of the major challenges of the dairy industry worldwide. Most studies have investigated cow fertility while bull fertility has received much less attention. However, there is growing evidence that the service sire represents an important source of variation for conception rate in dairy cattle. As such, the main objective of this ...

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...

A survey was conducted to quantify incidence of Beef Quality Assurance (BQA)-related defects in market beef and dairy cows and bulls selling at auction during 2 seasons in 2008. Twenty-three BQA-related traits were evaluated by 9 trained personnel during sales at 10 livestock auction markets in Idaho (n = 5; beef and dairy), California, (n = 4; dairy only), and Utah (n = 1; beef and dairy). Ove...

Background: Metabolic profiles have been used in efforts to predict pre parturient problems and fertility, to diagnose metabolic diseases, and to assess nutritional status in dairy cows. These profiles may help to confirm the diagnosis of sub clinical diseases, to be aware of possible causes of infertility in the herds, or to monitor improvement in herd animals. OBJECTIVES: This study investiga...

the objective of this study was to investigate the effect of birth weight (bw) on future milk production and reproductive performance in iranian holstein cattle. records of holstein cows between 1967 and 2010 were obtained from the animal breeding center of iran. birth weights within each herd were grouped into five categories based on the standard normal distribution curves (z ≤-0.8416, -0.841...

Bovine Viral Diarrhea Virus (BVDV) is a Pestivirus of the Flaviviviridaefamily that infects cattle, and its widespread distribution can cause substantial economic losses worldwide. The aims of this study were: (1) to estimate the prevalence of animals persistently infected (PI) with BVDV in industrial dairy cattle herds in suburb of Mashhad- Iran; and (2) to compare the occurrence of persistent...

Body weight and fat mass vary distinctly between German Holstein (dairy cattle) and Charolais (beef cattle). The aim of this study was to determine whether the expression of the obese (Ob) gene and lipoprotein lipase (LPL) gene in fat tissues and expression of the long isoform leptin receptor (Ob-Rb) gene in the hypothalamus were different between these two cattle breeds. Body weight and the ar...

Dairy products are a key source of valuable proteins and fats for many millions of people worldwide. Dairy cattle are highly susceptible to heat-stress induced decline in milk production, and as the frequency and duration of heat-stress events increases, the long term security of nutrition from dairy products is threatened. Identification of dairy cattle more tolerant of heat stress conditions ...