BACKGROUND Mycobacterium avium subsp. paratuberculosis (MAP) infections in cattle are generally challenging to detect and cost-effective test strategies are consequently difficult to identify. MAP-specific antibody ELISAs for milk and serum are relatively inexpensive, but their utility is influenced by a number of factors such as herd size, herd composition and diagnostic sensitivity. The sensi...

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...

in this study we estimated the allele and genotype frequencies of scd1 and dgat1 gene polymorphism. the analysis was conducted on 408 holstein cows from five dairy herds in isfahan province. genotypes were identified using pcr-rflp technique. two genetic variants (a and v) of the scd1 gene were observed in this experiment. the frequency of a-allele ranged from 0.49 to 0.66, while frequency of v...

Bovine-leukosis virus (BLV; also termed 'bovine-leukemia virus') is a retrovirus that primarily affects lymphoid tissue of dairy and beef cattle. Our objective was to investigate the association between BLV infection and annual value of production (AVP) on dairy herds within the United States, as part of the USDA National Animal Health Monitoring System's 1996 dairy study. 1006 herds (in 20 sta...

More than a decade of observations of dairy operations in Hawai‘i suggested that there were more black cows in the local dairy herds than white cows. Hence, the objective of the study was to investigate if hair coat color affected productive life of Holstein cows in the sub-tropics. Two large herds within 2,000 meters of each other in the Waianae Coast district were used. Lactating cows were cl...

Neospora caninum is a protozoan parasite causing bovine abortion all over the world. The aim of this study was to investigate how common N. caninum infection is among dairy herds in the Czech Republic. Bulk milk samples were collected from 495 dairy herds and analysed for the presence of specific antibodies by a commercial N. caninum iscom ELISA. Five out of 495 dairy herds (1.01%) had percenta...

Tunisia has a Mediterranean climate characterized by high ambient temperatures for a long period. Thus, one of the challenges to dairy producers is heat stress. The objectives of this work were to characterize the environmental conditions to which Holstein cows are exposed in Tunisia using the Temperature Humidity Index (THI), examine heat stress effects on lactating cows and to suggest potenti...

Cross sectional data on the prevalence of claw and (inter) digital skin diseases on 4854 Holstein Friesian cows in 50 Danish dairy herds was used in a Bayesian network to create herd specific probability distributions for the presence of three lameness causing diseases. Parity and lactation stage are identified as risk factors on cow level, for the prevalence of the three lameness causing disea...

The objective of the present study was to assess the effects of genomic inbreeding on production, reproduction, and udder health in Holstein dairy cows. First and second lactation data were collected from 1,061 Holstein dairy cows, which were born between 2006 and 2008, from 5 commercial herds across the United States. All cows were genotyped for 54,609 single nucleotide polymorphism (SNP) mark...