Publications

contamination of fresh and ensiled maize by multiple penicillium mycotoxins.	toxins produced by penicillium species are reported in maize silage and have been associated with health problems in cattle. our objectives were to evaluate the prevalence and dynamics of patulin (pat), mycophenolic acid (mpa), cyclopiazonic acid (cpa), and roquefortine c (roc) in fresh and ensiled maize. to achieve these objectives we developed a high-performance liquid chromatography method coupled with mass spectrometry to detect all four toxins simultaneously in silage. in addition we collec ...	2008	18944084
a survey of bacteriological quality and the occurrence of salmonella in raw bovine colostrum.	in recent years, bovine colostrum has gained popularity as a human food because it is an excellent source of bioactive proteins, which have been claimed to inhibit viral and bacterial pathogens, improve gastrointestinal health, and enhance body condition. a study was conducted to determine bacteriological quality and occurrence of salmonella in colostrum collected from dairy herds (n = 55) in pennsylvania. colostrum samples were analyzed for standard plate count, preliminary incubation count, la ...	2008	18991543
mortality, culling by sixty days in milk, and production profiles in high- and low-survival pennsylvania herds.	the objectives were to describe culling patterns and reasons for culling across lactation, estimate mortality and the proportion of cows leaving from 21 d before an expected calving date through 60 d in milk (dim; cull60) for pennsylvania (pa) dairy herds, and to describe production measures for herds with high and low mortality and cull60. weekly culling frequencies and reasons for culling from 3 wk before a reported expected calving date through >or= 100 wk of lactation were calculated for all ...	2008	19038939
a whole genome association analysis identifies loci associated with mycobacterium avium subsp. paratuberculosis infection status in us holstein cattle.	the purpose of this study was to identify loci associated with mycobacterium avium subspecies paratuberculosis (map) infection status in us holsteins using the illumina bovinesnp50 beadchip whole genome single nucleotide polymorphism (snp) assay. two hundred forty-five cows from dairies in new york, pennsylvania and vermont enrolled in longitudinal herd studies between january 1999 and november 2007 were assessed for the presence of map in both faecal and tissue samples. an animal was considered ...	2009	19422364
assessing the potential impact of salmonella vaccines in an endemically infected dairy herd.	salmonella spp. in cattle contribute to bacterial foodborne disease for humans. reduction of salmonella prevalence in herds is important to prevent human salmonella infections. typical control measures are culling of infectious animals, vaccination, and improved hygiene management. vaccines have been developed for controlling salmonella transmission in dairy herds; however, these vaccines are imperfect and a variety of vaccine effects on susceptibility, infectiousness, salmonella shedding level, ...	2009	19446567
genotypic diversity of escherichia coli in a dairy farm.	dairy cattle are known reservoirs of pathogenic escherichia coli, but little is known about the dynamics of e. coli in dairy cows or within the dairy farm environment. this study was conducted to evaluate the diversity and distribution of e. coli strains in a dairy farm using pulsed-field gel electrophoresis and to determine the relationships between e. coli isolated from feces and throughout the farm environment. water from watering troughs, feces from cows, manure composites, milk, and milk fi ...	2009	19459756
extended-spectrum and cmy-type beta-lactamase-producing escherichia coli in clinical samples and retail meat from pittsburgh, usa and seville, spain.	infections due to escherichia coli producing extended-spectrum beta-lactamase (esbl) or cmy-type beta-lactamase (cmy) are increasingly observed in non-hospitalized patients. the origin of these organisms is uncertain, but retail meat contaminated with e. coli may be a source. in the present study, clinical information and strains collected from patients infected or colonized with esbl-producing and cmy-producing e. coli at hospitals in pittsburgh, usa and seville, spain were investigated. retail ...	2010	19681957
the genetic relationship of body weight and early-lactation health disorders in two experimental herds.	the objectives of this study were to estimate genetic parameters for body weight (bw) and bw change (bwc) and genetic correlations of bw and bwc with diseases and genomic predicted transmitting abilities (pta) of productive and conformation traits of holsteins during the first 120 dim. daily bw data were from the afiweigh cow body weighing system (sae afikim, kibbutz afikim, israel), which records bw as a cow exits the milking parlor. disease categories included metabolic diseases, ketosis, infe ...	2010	20172239
trends in the northeast dairy industry: large-scale modern confinement feeding and management-intensive grazing.	this paper provides a summary of results from a recent survey of 987 dairy farmers in 4 northeastern us states. the survey results provide descriptive characteristics of the current state of dairy farming in the region, as well as farmer satisfaction levels, concerns, and plans for the future of their farming operations. the paper analyses characteristics of two increasingly important dairy production systems used in the northeast. averages from across the survey states (maryland, pennsylvania, ...	2010	20338456
correlation between herrold egg yolk medium culture and real-time quantitative polymerase chain reaction results for mycobacterium avium subspecies paratuberculosis in pooled fecal and environmental samples.	real-time quantitative polymerase chain reaction (qpcr) testing for mycobacterium avium subspecies paratuberculosis (map) in fecal samples is a rapid alternative to culture on herrold egg yolk medium (heym), the traditional antemortem reference test for map. although the sensitivity and specificity of these 2 tests have been estimated based on dichotomized test results, the correlation between real-time qpcr threshold cycle (ct) values and colony-forming units (cfu) on heym for fresh and thawed ...	2010	20807920
evaluation of calf milk pasteurization systems on 6 pennsylvania dairy farms.	waste milk has been fed to calves for many years, but concerns with bacterial contamination as well as possible transmission of diseases have discouraged widespread use of this feed. pasteurization of waste milk is one option to reduce management risk while utilizing a valuable, low-cost, liquid feed source for calves. however, many farms currently pasteurizing waste milk lack a system to adequately monitor the efficiency of the process. a study was carried out to evaluate 6 on-farm pasteurizati ...	2010	20965367
molecular epidemiological analysis of mycoplasma bovis isolates from the pennsylvania animal diagnostic laboratory showing genetic diversity.	we have examined the genetic variability of mycoplasma bovis strains submitted to the pennsylvania animal diagnostics laboratory, university park (pa-adl), between december 2007 and december 2008. of 4,868 total samples submitted for mycoplasma testing, 302 were determined to be culture positive. mycoplasma bovis (63.6%), mycoplasma californicum (7.3%), mycoplasma bovirhinis (2.7%), mycoplasma bovigenitalium (0.7%), mycoplasma alkalescens (4.9%), mycoplasma putrefaciens (0.3%), and mycoplasma di ...	2011	21426978
heritability of gross feed efficiency and associations with yield, intake, residual intake, body weight, and body condition score in 11 commercial pennsylvania tie stalls.	the objectives of this study were to calculate the heritability of feed efficiency and residual feed intake, and examine the relationships between feed efficiency and other traits of productive and economic importance. intake and body measurement data were collected monthly on 970 cows in 11 tie-stall herds for 6 consecutive mo. measures of efficiency for this study were: dry matter intake efficiency (dmie), defined as 305-d fat-corrected milk (fcm)/305-d dmi, net energy for lactation efficiency ...	2011	21427002
environmental and economic comparisons of manure application methods in farming systems.	alternative methods for applying livestock manure to no-till soils involve environmental and economic trade-offs. a process-level farm simulation model (integrated farm system model) was used to evaluate methods for applying liquid dairy (bos taurus l.) and swine (sus scrofa l.) manure, including no application, broadcast spreading with and without incorporation by tillage, band application with soil aeration, and shallow disk injection. the model predicted ammonia emissions, nitrate leaching, a ...	2011	21520751
environmental contamination with mycobacterium avium subsp. paratuberculosis in endemically infected dairy herds.	environmental contamination with mycobacterium avium subsp. paratuberculosis (map) is thought to be one of the primary sources of infection for dairy cattle. the exact link between fecal shedding of map by individual cows and environmental contamination levels at the herd level was explored with a cross-sectional analysis of longitudinally collected samples on 3 dairy farms. composite samples from multiple environmental sites in 3 commercial dairy herds in the northeast us were cultured quarterl ...	2011	21775002
The effect of sire selection on cow mortality and early lactation culling in adverse and favorable cow survival environments.	The objective of this study was to determine the extent that genetic selection can help reduce dairy cow mortality and early lactation culling in adverse cow survival environments. Two datasets were constructed. The first contained 100,911 mortality records and 171,178 sixty-day culling records from 1467 herds. Cows that left the herd (culled or died) from 21 days prior to a due date through 60 days in milk were considered a 60-day cull. Cows were classified as belonging to herds with adverse co ...	2012	21993276
notes from the field: yersinia enterocolitica infections associated with pasteurized milk --- southwestern pennsylvania, march-august, 2011.	on july 22, 2011, a pediatric infectious disease physician reported a culture-confirmed case of yersinia enterocolitica infection to the allegheny county health department (achd), pennsylvania. two additional cases in allegheny county with onset around the same time were identified by pennsylvania's version of the national electronic disease surveillance system aberration detection algorithm, which routinely evaluates disease reports, searching for unusual events. during march-august for the 3-y ...	2011	22012118
herd-level risk factors for lameness in freestall farms in the northeastern united states and california.	the objective was to investigate the association between herd-level management and facility design factors and the prevalence of lameness in high-producing dairy cows in freestall herds in the northeastern united states (ne; vermont, new york, pennsylvania) and california (ca). housing and management measures such as pen space, stall design, bedding type, and milking routine were collected for the high-producing pen in 40 farms in ne and 39 farms in ca. all cows in the pen were gait scored using ...	2013	23141819
competitiveness of management-intensive grazing dairies in the mid-atlantic region from 1995 to 2009.	this paper used farm income tax returns (schedule f) data from 62 dairy farmers who milked 200 cows or fewer in western and central maryland and southwestern pennsylvania (hereafter, the mid-atlantic region) to assess the relative financial performance of management-intensive grazing (mig) and confinement dairy operations over the 15-yr period from 1995 through 2009. data were not available from all farmers in all years; on average, the sample analyzed contained 11 mig farms and 26 confinement f ...	2013	23313000
regional distribution of two dairy-associated salmonella enterica serotypes.	salmonella enterica is a zoonotic pathogen that is often associated with dairy farms. the organism can cause disease in cows but is also frequently shed in large numbers by dairy cows that are asymptomatic. long-term asymptomatic infections with serotypes cerro and kentucky were previously identified in cows on a 100-head dairy farm in pennsylvania, united states (focal dairy). milk filters were collected from farms within 30 miles of the focal dairy to determine whether the infections by cerro ...	2013	23536986
herd-level risk factors for hock injuries in freestall-housed dairy cows in the northeastern united states and california.	the aim of this study was to investigate the associations between management and facility design factors and the prevalence of hock injuries in high-producing dairy cows in 76 freestall herds in the northeastern united states (ne-us; vermont, new york, pennsylvania) and california (ca). one group of high-production multiparous cows was monitored on each farm, and data on management, facility and stall design, and the conditions of the hocks were collected. focal cows [n=38 ± 3 (mean ± standard d ...	2013	23548284
evaluation of performance of bacterial culture of feces and serum elisa across stages of johne's disease in cattle using a bayesian latent class model.	the objective of this study was to evaluate the performance of bacterial culture of feces and serum elisa to correctly identify cows with mycobacterium avium ssp. paratuberculosis (map) at heavy, light, and non-fecal-shedding levels. a total of 29,785 parallel test results from bacterial culture of feces and serum elisa were collected from 17 dairy herds in minnesota, pennsylvania, and colorado. samples were obtained from adult cows from dairy herds enrolled for up to 10 yr in the national johne ...	2015	26364104
short communication: analytical method and amount of preservative added to milk samples may alter milk urea nitrogen measurements.	milk urea n (mun) is used by dairy nutritionists and producers to monitor dietary protein intake and is indicative of n utilization in lactating dairy cows. two experiments were conducted to explore discrepancies in mun results provided by 3 milk processing laboratories using different methods. an additional experiment was conducted to evaluate the effect of 2-bromo-2-nitropropane-1, 3-diol (bronopol) on mun analysis. in experiment 1, 10 replicates of bulk tank milk samples, collected from the p ...	2017	27988113
histopathology case definition of naturally acquired salmonella enterica serovar dublin infection in young holstein cattle in the northeastern united states.	salmonella enterica subsp. enterica serovar dublin ( salmonella dublin) is a host-adapted bacterium that causes high morbidity and mortality in dairy cattle worldwide. a retrospective search of archives at the new york animal health diagnostic center revealed 57 culture-confirmed salmonella dublin cases from new york and pennsylvania in which detailed histology of multiple tissues was available. tissues routinely submitted by referring veterinarians for histologic evaluation included sections of ...	2017	28599615
blood plasma traits associated with genetic merit for feed utilization in holstein cows.	the objective of this study was to evaluate the potential of selection for feed utilization on associated blood plasma metabolite and hormone traits. dry matter intake (dmi) was recorded in 970 holsteins from 11 commercial farms in pennsylvania and used to derive dry matter efficiency (dme; fat-corrected milk yield/dmi), crude protein efficiency (cpe; protein yield/crude protein intake), and residual feed intake (rfi, defined as actual feed intake minus expected feed intake for maintenance and m ...	2017	28755931