A dynamic stochastic simulation model for discrete events, SIMMAST, was developed to simulate the effect of mastitis on the composition of the bulk tank milk of dairy herds. Intramammary infections caused by Streptococcus agalactiae, Streptococcus spp. other than Strep. agalactiae, Staphylococcus aureus, and coagulase-negative staphylococci were modeled as were the milk, fat, and protein test d...

Bulk milk samples from 220 dairy herds were collected at 9 public milk collection centres in the northeastern and northern Thailand, and a subset of 11 herds was selected for individual testing. The samples were tested for presence of antibodies to BVDV and BHV-1 using an indirect ELISA. The results from the bulk milk testing demonstrated a moderate level of exposure to BVDV and BHV-1 (73% and ...

To estimate the prevalence of Escherichia coli O157 on Dutch dairy herds, faecal samples were collected once from 678 randomly selected dairy farms in the period October 1996-December 2000. Samples were cultured for E. coli O157. Thirty-eight isolates were tested for virulence genes (eae, VT1 and VT2). A questionnaire about farm characteristics was taken from the farm manager, resulting in vari...

Our objective was to determine the seroprevalence of Hypoderma spp. and to develop a spatial model describing the risk surface of warble-fly infection in Belgian cattle herds (adjusting for herd size, herd type, local temperature, rainfall, relative air humidity and land-cover). This survey was carried out in 390 selected herds of all types (dairy, mixed and beef) from December 1997 to March 19...

Infectious bovine rhinotracheitis (IBR) is a highly infectious disease of cattle caused by bovine herpesvirus 1 (BHV-1) that causes considerable economic losses to the dairy and beef industry. This report describes the results of two surveys in which prevalence of serum antibodies against BHV-1 in Galicia (NW Spain) was determined. The first was performed on the entire cattle population of the ...

The objective of this study was to identify associations of bedding type and selected management practices with bulk milk quality and productivity of larger Wisconsin dairy farms. Dairy herds (n=325) producing ≥11,340 kg of milk daily were surveyed during a single farm visit. Monthly bulk milk SCC and total bacteria counts were obtained from milk buyers for 255 farms for a 2-yr period. Of farms...

J. Anim. Sci. Vol. 87, E-Suppl. 2/J. Dairy Sci. Vol. 92, E-Suppl. 1 NDMI. The correlation between DMI and NDMI was 0.52 (P<0.001) and were most strongly associated during the first 10 weeks of lactation, after which point DMI was less than NDMI. The correlation between FCM and DMI across all herds was 0.23 (P<0.001). However, there was considerable variation among herds, with correlations betwe...

Staphylococcus aureus is one of the most important causes of mastitis in dairy cattle. Based on previous research, Staph. aureus genotypes with different pathogenic and contagious properties can cause intramammary infection (IMI) and coexist in the same herd. Our study aimed to compare Staph. aureus strains from herds that differed in IMI prevalence using different molecular approaches such as ...

BACKGROUND The main aim of the study was to assess the prevalence of claw and limb disorders in Norwegian beef-cow herds. METHODS Twenty-six herds with >or=15 cow-years were selected by computerized systematic assignment from the three most beef cattle-dense regions of Norway. The study population consisted of 12 herds with 28 heifers and 334 cows. The animals were trimmed and examined once b...

faecal samples from 291 dairy calves from 10 dairy herds in kerman were examined to investigate theprevalence of cryptosporidium infection. cryptosporidium spp. oocysts were identified by using themodified ziehl-neelsen staining technique in 63 (21.65%) calves. calves were grouped according to theirage as follows: