| toxicoses related to the petroleum industry. | during 1977, 4,976 oil and gas wells were drilled in oklahoma to an average depth of 4,892 feet. there were 2,253 successful oil wells and 1092 successful gas wells (26). the oklahoma animal disease diagnostic laboratory investigated several cases where livestock in close proximity to drilling sites became ill or die. the case histories emphasize the need for a careful and complete diagnostic work-up. the identification and quantification of petroleum hydrocarbons, toxic chemicals and heavy meta ... | 1979 | 516361 |
| rabies surveillance in the united states during 1991. | in 1991, 49 states, the district of columbia, and puerto rico reported 6,972 cases of rabies in nonhuman animals and 3 cases in human beings to the centers for disease control. ninety-one percent (6,354 cases) were wild animals, whereas 8.9% (618 cases) were domestic species. the total number of reported cases of rabies increased 42.9% over that of 1990 (4,881 cases), with most of the increase resulting from continued spread of the epizootic of rabies in raccoons in the mid-atlantic and northeas ... | 1992 | 1483899 |
| rabies surveillance in the united states during 1990. | in 1990, the united states and its territories reported 4,881 cases of rabies in animals to the centers for disease control, a 1.5% increase from 1989. of these, 553 were domestic animals, 4,327 were wild animals, and one was a human being. pennsylvania reported the highest number (611) of rabies cases in animals in 1990. for the first time since surveillance of rabies in wild animals was begun in the 1950s, the number of cases of rabies in raccoons exceeded that in skunks. particularly large in ... | 1992 | 1577642 |
| blue-green algae toxicoses in oklahoma. | | 1990 | 2124747 |
| rabies surveillance in the united states during 1989. | in 1989, 4,808 cases of rabies in animals other than human beings were reported to the centers for disease control, 1.8% more (4,724 to 4,808) than in 1988. eighty-eight percent (4,224/4,808) of those affected were wild animals and 12% (584/4,808) were domestic animals. cases were reported from 49 states, the district of columbia, and puerto rico; hawaii remained rabies-free. skunks (1,657) continued to be the most commonly reported rabid wild animal. for the second consecutive year, more cats ( ... | 1990 | 2276949 |
| potential for the spread of fasciola hepatica in cattle in oklahoma. | in 29 central and western oklahoma counties, 42 ranches were investigated for indigenous fasciola hepatica infections and their suitability for the transmission of liver fluke. a 10-year retrospective study of oklahoma cattle based on samples submitted to the oklahoma animal disease diagnostic laboratory also was done. indigenous fascioliasis was found in cattle in 12 counties (9 central and western counties identified in the combined field and retrospective studies and 3 additional eastern coun ... | 1990 | 2329078 |
| identification of genetic variation between strains of bluetongue virus serotype 11 using cdna probes. | recombinant plasmids containing inserts representing genome segments 2, 5, 6, 8, and 9 of bluetongue virus (btv) serotype 11, with tentative coding assignments for viral proteins p2, p5, ns1, ns2, and p6, respectively, have been used to study the genetic diversity within a btv serotype using northern blot hybridization. btv 11 strains were isolated in california, nevada, oklahoma, and mexico from elk, deer, and cattle. diversity was indirectly indicated in the btv 11 strains by comparisons of el ... | 1989 | 2543132 |
| preputial injuries in beef bulls: 172 cases (1980-1985). | one hundred seventy-two bulls with preputial injuries were treated from 1980 through 1985. most of the injuries developed during the breeding season (april through august), with a peak during june. the number (111) of bulls represented by 3 beef breeds (brangus, brahman, beefmaster) was greater than the number (61) of the other 9 breeds included in the survey. preputial prolapse (pp) and posthitis without obvious laceration was diagnosed in 82 of 172 bulls. preputial laceration, abscessation, st ... | 1988 | 3170324 |
| factors influencing reports of rabid animals in oklahoma. | | 1972 | 5049117 |
| blood groups in longhorn cattle. | | 1966 | 5968637 |
| a disease of cattle grazing hairy vetch pasture. | | 1966 | 6006428 |
| the trichostrongylid egg output during spring in feedlot cattle. | larval cultures prepared from faeces collected at two-week intervals from feeder cattle originating from michigan, oklahoma and kentucky, and kept in a feedlot in michigan, were examined during the winter and spring of 1979. the animals received anthelmintic treatment shortly after entering the feedlot. the larval output, consisting mainly of ostertagia larvae, was less than 20 larvae per g, but did show a seasonal increase during spring in the cattle originating from kentucky and michigan. this ... | 1984 | 6538722 |
| rabies in oklahoma: an epidemiologic view of the problem in animals. | | 1983 | 6631575 |
| nitrate poisoning in oklahoma cattle. | | 1980 | 6900438 |
| new version of lstsim for computer simulation of amblyomma americanum (acari: ixodidae) population dynamics. | a previous version of lone star tick simulation model (lstsim) for a wildlife ecosystem was revised and expanded to include a beef cattle forage area and improved handling of tick-host-habitat interactions. relationships between environmental and biological variables were also refined in the new version. general validity of the revised model was established by comparing simulated and observed host-seeking populations of amblyomma americanum (l.) at five geographic locations, three in oklahoma an ... | 1993 | 8254630 |
| managing replacement stock within the environment of the south--plant, soil, and animal interactions: a review. | the south extends from the atlantic coast and the gulf of mexico north through virginia and kentucky and west to the 100th meridian, which extends through texas and oklahoma. the soils, environment, and range of adapted forage species offer many and varied opportunities for designing forage-livestock systems for rearing replacement stock. anti-quality factors of concern when using forages for replacement stock include the presence of acremonium coenophialum (morgan-jones and gams) in tall fescue ... | 1993 | 8270541 |
| coronavirus isolation from nasal swab samples in cattle with signs of respiratory tract disease after shipping. | to monitor the prevailing viral respiratory tract infections in cattle after transportation to feedlots. | 1996 | 8635997 |
| a winter outbreak of anaplasmosis in a nonendemic area of oklahoma: a possible role for dermacentor albipictus. | | 1997 | 9211245 |
| neosporal abortion in oklahoma cattle with emphasis on the distribution of brain lesions in aborted fetuses. | | 1998 | 9683083 |
| results of a nationwide survey to determine feedstuffs fed to lactating dairy cows. | a nationwide survey to determine feedstuffs used in the diets of dairy cows was conducted. this survey was mailed to dairy nutritionists at universities in each state to describe the use of 144 feedstuffs. twenty-eight states responded and were grouped by region as follows: northeast (maine, maryland, new hampshire, new york, ohio, vermont, and west virginia), northwest (idaho, oregon, and washington), midwest (iowa, illinois, michigan, minnesota, missouri, nebraska, north dakota, south dakota, ... | 1999 | 10068966 |
| performance of light vs heavy steers grazing plains old world bluestem at three stocking rates. | live weight gains of light and heavy calves grazing plains old world bluestem at three stocking rates were evaluated during the summers of 1997 and 1998. initial weights of mixed-breed light-weight steers (lht) were 141 sd = 17 kg (n = 214) in 1997 and 160 sd = 23 kg (n = 193) in 1998. initial weights of mixed-breed heavy steers (hwt) were 265 sd = 17 kg (n = 115) in 1997 and 248 sd = 13 kg (n = 126) in 1998. initial stocking rates for both sizes of steers were as follows: light, 392 kg of live ... | 2001 | 11219460 |
| efficacy of a 1% lambdacyhalothrin cattle pour-on (saber) against sucking and biting lice infesting beef cattle. | four studies were conducted to determine the efficacy of a 1% lambdacyhalothrin pour-on (saber pour-on, schering-plough animal health) for control of sucking lice (linognathus vituli, haematopinus eurysternus, solenopotes capillatus) and biting lice (damalinia bovis) on beef cattle. seventy-four mixed-breed cattle naturally infested with one or more species of lice at locations in wisconsin, nebraska, oklahoma, and north dakota were included in the study. pretreatment lice samples were taken and ... | 2002 | 12584675 |
| seasonality of days open in us holsteins. | the objectives of this study were to establish a pattern for the seasonality of days open (do) by state and region within the united states and to present statistics on regional trends for do. data included 8,676,915 records on do for holsteins from 1997 to 2002 covering all regions of the united states. fixed effects in the model included herd, parity, milk-class, state x month of calving (moc), year of calving x moc, and parity x moc. least squares means of do were highest for calvings in marc ... | 2003 | 14672202 |
| occurrence of the gulf coast tick (acari: ixodidae) on wild and domestic mammals in north-central oklahoma. | parasitic life stages of amblyomma maculatum koch were collected from domestic cattle and several species of wild mammals during a 3.5-yr study (may 1998-october 2001) in north-central oklahoma. adult ticks were the predominant life stage collected from cattle, white-tailed deer, coyotes, and raccoons, whereas only immature ticks were collected from cotton rats and white-footed mice. the prevalence of adult a. maculatum on white-tailed deer (n = 15) examined in june, july, and august 1998 was 80 ... | 2004 | 15061275 |
| fire and grazing effects on wind erosion, soil water content, and soil temperature. | selective grazing of burned patches can be intense if animal distribution is not controlled and may compound the independent effects of fire and grazing on soil characteristics. our objectives were to quantify the effects of patch burning and grazing on wind erosion, soil water content, and soil temperature in sand sagebrush (artemisia filifolia torr.) mixed prairie. we selected 24, 4-ha plots near woodward, ok. four plots were burned during autumn (mid-november) and four during spring (mid-apri ... | 2005 | 16091608 |
| multidrug-resistant klebsiella pneumoniae isolated from farm environments and retail products in oklahoma. | multidrug-resistant enteric bacteria were isolated from turkey, cattle, and chicken farms and retail meat products in oklahoma. among the isolated species, multidrug-resistant klebsiella pneumoniae was prevalently isolated from most of the collected samples. therefore, a total of 132 isolates of k. pneumoniae were characterized to understand their potential roles in the dissemination of antibiotic-resistance genes in the food chains. multidrug-resistant k. pneumoniae was most frequently recovere ... | 2005 | 16245702 |
| rabies surveillance in the united states during 2004. | during 2004, 49 states and puerto rico reported 6,836 cases of rabies in nonhuman animals and 8 cases in human beings to the cdc, representing a 4.6% decrease from the 7,170 cases in nonhuman animals and 3 cases in human beings reported in 2003. approximately 92% of the cases were in wildlife, and 8% were in domestic animals (compared with 91% and 9%, respectively, in 2003). relative contributions by the major animal groups were as follows: 2,564 raccoons (37.5%), 1,856 skunks (27.1%), 1,361 bat ... | 2005 | 16379626 |
| environmental load of cryptosporidium parvum oocysts from cattle manure in feedlots from the central and western united states. | the first step in assessing the risk of water contamination by cryptosporidium parvum oocysts from feedlot cattle (bos taurus) production systems is to quantify the number of c. parvum oocysts present in the fecal material deposited by feedlot cattle. our primary objective for this project was to estimate the daily environmental load of c. parvum oocysts in fecal material deposited by feedlot cattle from across the central and western usa. our secondary goal was to genotype isolates of c. parvum ... | 2006 | 16391291 |
| using the near-infrared system to sort various beef middle and end muscle cuts into tenderness categories. | the objectives of this study were to determine the effectiveness of a visible-near-infrared (vis-nir) system to predict the ultimate tenderness rating of various beef muscles and conclude if a relationship exists between predicted lm shear force and tenderness of other subprimal cuts. carcasses (n = 768) were scanned with the vis-nir system in 2 commercial beef-processing facilities. carcasses were categorized based on their predicted 14-d lm slice shear force value. after carcass scanning, 100 ... | 2008 | 17965325 |
| biocontainment, biosecurity, and security practices in beef feedyards. | to determine the biocontainment, biosecurity, and security practices at beef feedyards in the central plains of the united states. | 2008 | 18275395 |
| assessment of the diversity, abundance, and ecological distribution of members of candidate division sr1 reveals a high level of phylogenetic diversity but limited morphotypic diversity. | we used a combination of 16s rrna gene clone library surveys, quantitative pcr (qpcr) analysis, and fluorescent in situ hybridization to investigate the diversity, abundance, and distribution of members of candidate division sr1 in multiple habitats. using sr1-specific 16s rrna gene primers, we identified multiple novel sr1 lineages in four different anaerobic environments: sediments from zodletone spring, a sulfide- and sulfur-rich spring in southwestern oklahoma; inner layers of microbial mats ... | 2009 | 19395567 |
| prevalence and antigenic differences observed between bovine viral diarrhea virus subgenotypes isolated from cattle in australia and feedlots in the southwestern united states. | bovine viral diarrhea virus (bvdv) is divided into 2 different species within the pestivirus genus, bvdv type 1 (bvdv-1) and bvdv type 2 (bvdv-2). further phylogenetic analysis has revealed subgenotype groupings within the 2 types. thus far, 12 bvdv-1 subgenotypes (a-l) and 2 bvdv-2 subgenotypes (a and b) have been identified. the purpose of the current study was to determine the prevalence of bvdv subgenotypes in the united states and australia and to determine if there are detectable antigenic ... | 2010 | 20224075 |
| evaluation of health status of calves and the impact on feedlot performance: assessment of a retained ownership program for postweaning calves. | the objective of this study was to evaluate animal health status at entry to a feedlot against feedlot performance and carcass value. there were 24 herds represented by 417 calves in a retained ownership program. the health status at entry was represented by the levels of serum antibody to infectious bovine rhinotracheitis virus (ibrv), bovine viral diarrhea viruses 1 and 2 (bvdv1a, bvdv2), parainfluenza 3 virus (pi3v), bovine respiratory syncytial virus (brsv), mannheimia haemolytica, and paste ... | 2002 | 12146889 |
| major surface protein 1a effects tick infection and transmission of anaplasma marginale. | anaplasma marginale, an ehrlichial pathogen of cattle and wild ruminants, is transmitted biologically by ticks. a developmental cycle of a. marginale occurs in a tick that begins in gut cells followed by infection of salivary glands, which are the site of transmission to cattle. geographic isolates of a. marginale vary in their ability to be transmitted by ticks. in these experiments we studied transmission of two recent field isolates of a. marginale, an oklahoma isolate from wetumka, ok, and a ... | 2001 | 11730800 |
| incidence of mastitis in beef cows after intramuscular administration of oxytetracycline. | there is limited information on the value of antibiotic therapy for mastitis in beef cows. effects of antibiotic treatment at weaning and the subsequent calving on calf weaning weight, milk somatic cell counts, milk components, and intramammary infection were studied in beef cows. additionally, effects of number of infected mammary quarters, number of dry mammary quarters, type of intramammary pathogen, and parity on response variables were determined. cows (n = 192) were randomly assigned to tr ... | 2001 | 11518208 |
| establishment and characterization of an oklahoma isolate of anaplasma marginale in cultured ixodes scapularis cells. | anaplasma marginale is a tick-borne hemoparasite of cattle worldwide. the virginia isolate of a. marginale was propagated previously in a cell line derived from embryos of the tick, ixodes scapularis. the cultured anaplasma (va-tc) was passaged continuously for over 4 years and retained its infectivity for cattle and antigenic stability. we report herein the continuous in vitro cultivation of a second isolate of a. marginale derived from a naturally infected cow in oklahoma (ok-tc). blood from t ... | 2000 | 10669100 |
| national beef quality audit-1995: survey of producer-related defects and carcass quality and quantity attributes. | the national beef quality audit-1995 was conducted to evaluate the progress of the beef industry since the time of the national beef quality audit-1991 in improving quality and consistency of beef. nine plants were assigned for auditing to colorado state university, oklahoma state university, and texas a&m university. personnel from each institution visited three of their nine plants twice, once in the spring/summer and once in the fall/winter. data were collected on 50% of each lot on the slaug ... | 1998 | 9464889 |
| use of a nonradioactive dna probe for detection of anaplasma marginale infection in field cattle: comparison with complement fixation serology and microscopic examination. | a sensitive anaplasma marginale-specific 409-base pair dna probe was developed in a previous study for detection of a. marginale infection in experimentally infected cattle with a test that employed slot-blot and in situ hybridization. to test the suitability of the probe to detect a. marginale in the blood of naturally infected carrier cattle, slot-blot hybridization was used to determine the infection rate of a. marginale in cattle from 3 geographic areas in oklahoma. for comparison, blood sam ... | 1997 | 9087923 |
| forage intake by and site and extent of digestion in beef cattle grazing midgrass prairie rangeland or plains bluestem pasture throughout the summer. | eight beef steers fitted with esophageal (four steers/pasture) and 12 beef calves fitted ruminal and duodenal (six calves/pasture; beginning bw = 267 +/- 6 kg) cannulas grazed either midgrass prairie rangeland (excellent range condition; midgrass) or plains bluestem (bothriochloa ischaemum var. plains) pasture (bluestem) during mid-may, late june, mid-august, and mid-october of 1990 and 1991 in order to compare nutrient intake and digestion. forage om intake (omi) by cattle grazing midgrass or b ... | 1997 | 9051473 |
| seroprevalence of bovine anaplasmosis in oklahoma from 1977 to 1991. | the prevalence of anaplasmosis in oklahoma cattle was determined on the basis of the standardized anaplasma marginale complement fixation test on 20,155 sera submitted to the oklahoma animal disease diagnostic laboratory during a 15-year period. rates of seropositivity ranged from 4.7% to 17.6% on samples submitted for anaplasmosis testing of adult cows. the geographic distribution of recorded cases of anaplasmosis was 35 oklahoma counties in 1977 and 48 oklahoma counties in 1991. | 1994 | 8068752 |
| comparative pathology of the african form of malignant catarrhal fever in captive indian gaur and domestic cattle. | the african strain of malignant catarrhal fever virus was isolated and identified in a herd of captive indian gaur (bos gaurus). gross lesions included oral ulcerations, corneal opacity, and multifocal myocarditis. microscopic lesions were characterized by lymphocytic vasculitis/perivasculitis in all tissues examined. blood was serially passed from a gaur to a domestic heifer (bos taurus), and then to a domestic calf. clinical signs and gross and microscopic lesions similar to those of the gaur ... | 1981 | 7327993 |
| extraordinary levels of production of pyrrolizidine alkaloids in senecio riddellii. | | 1984 | 6533262 |
| frequency of occurrence of viruses associated with respiratory tract disease of cattle in oklahoma: serologic survey for bovine herpesvirus dn599. | serum samples from 351 oklahoma cattle were tested for antibodies to dn599 virus by the indirect fluorescent antibody test. seven cattle (approximately 2%) were seropositive for this virus. | 1977 | 334002 |
| escherichia coli o157 in feedlot cattle feces and water in four major feeder-cattle states in the usa. | the prevalence of escherichia coli o157 was determined in 10662 fecal samples, 2130 water and 1132 water tank-sediment samples collected during the summer months in 2001 from 711 pens in 73 feedlots located in kansas, nebraska, texas, or oklahoma, usa. overall, 10.2% of fecal samples were positive for e. coli o157, with 52% of the pens and 95.9% of the feedlots having at least one positive fecal sample. there were no differences among states or months in the fecal prevalences. water or water tan ... | 2003 | 14519341 |
| vaccination of cattle with anaplasma marginale derived from tick cell culture and bovine erythrocytes followed by challenge-exposure with infected ticks. | anaplasmosis, a hemolytic disease of cattle caused by the tick-borne pathogen anaplasma marginale (rickettsiales: anaplasmataceae) has been controlled using killed vaccines made with antigen harvested from infected bovine erythrocytes. we recently developed a cell culture system for propagation of a. marginale in a continuous tick cell line. in this study, we performed a cattle trial to compare the bovine response to vaccination with a. marginale harvested from tick cell culture or bovine erythr ... | 2002 | 12243900 |
| enteric disease in postweaned beef calves associated with bovine coronavirus clade 2. | bovine coronavirus (bocv; betacoronavirus 1) infections are associated with varied clinical presentations including neonatal diarrhea, winter dysentery in dairy cattle, and respiratory disease in various ages of cattle. the current report presents information on bocv infections associated with enteric disease of postweaned beef cattle in oklahoma. in 3 separate accessions from a single herd, 1 in 2012 and 2 in 2013, calves were observed with bloody diarrhea. one calf in 2012 died and was necrops ... | 2015 | 25428188 |
| evaluation of tropically adapted straightbred and crossbred cattle: postweaning gain and feed efficiency when finished in a temperate climate. | beef cows in the subtropical usa must be adapted to the stressors of the environment, typically supplied by using brahman breeding. calves produced in the region, however, are usually grown and finished in more temperate regions, and have a perceived reputation for poor adg and feed efficiency during finishing. compromised fertility and carcass quality often associated with the brahman have increased interest in tropically adapted bos taurus breed types. the objective of this study was to evalua ... | 2012 | 22247114 |
| cooperia punctata: effect on cattle productivity? | cooperia spp. have become the most prevalent parasites in united states cow/calf operations as observed in the usda nahms (national animal health monitoring system) beef cow/calf survey in 2008. this is at least in part due to the widespread use of macrocyclic lactones that have recently been shown to have a reduced activity against these parasites. the effects of cooperia spp. on cattle productivity are largely unknown. this study was conducted to assess their effect upon cattle housed under co ... | 2011 | 21821358 |
| species of cryptosporidium detected in weaned cattle on cow-calf operations in the united states. | to determine the species and distribution of cryptosporidium in weaned beef calves in the united states, fecal specimens were collected from 819 cattle between 6 and 18 months of age from 49 operations in 20 states (alabama, california, colorado, georgia, idaho, iowa, kansas, louisiana, mississippi, missouri, nebraska, new mexico, north dakota, oklahoma, oregon, south dakota, tennessee, texas, virginia, and wyoming). fresh feces, collected either from the ground or directly from the rectum of ea ... | 2010 | 20338690 |
| effect of weaning date (normal vs. late) on performance of young and mature beef cows and their progeny in a fall calving system in the southern great plains. | data from 158 predominantly angus fall-calving beef cows were used in 4 consecutive years to determine the effects of weaning date and cow age class on cow and calf performance. treatments were arranged in a 2 x 2 factorial with 2 weaning dates and 2 age classes (young cows <or=3 yr and mature cows >or=4 yr). weaning dates were 1) normal weaning in mid-april at 210 d of age (nw) and 2) late weaning in mid-july at 300 d of age (lw). mature cows were heavier (p < 0.01) than young cows throughout t ... | 2010 | 19966151 |
| grassland bird responses to land management in the largest remaining tallgrass prairie. | extensive habitat loss and changing agricultural practices have caused widespread declines in grassland birds throughout north america. the flint hills of kansas and oklahoma--the largest remaining tallgrass prairie--is important for grassland bird conservation despite supporting a major cattle industry. in 2004 and 2005, we assessed the community, population, and demographic responses of grassland birds to the predominant management practices (grazing, burning, and haying) of the region, includ ... | 2009 | 19040653 |
| heterogeneity of thermal extremes: driven by disturbance or inherent in the landscape. | ecologists are beginning to recognize the effect of heterogeneity on structure and function in arid and semiarid ecosystems. additionally, the influences of temperature on ecosystems are widely documented, but landscape temperature patterns and relationships with vegetation are rarely reported in ecological studies. to better understand the importance of temperature patterns to the conservation and restoration of native ecosystems, we designed an experiment to investigate relationships among soi ... | 2009 | 18491182 |
| fecal shedding of foodborne pathogens by florida-born heifers and steers in u.s. beef production segments. | the objective in this study was to assess breed effects in fecal prevalence of escherichia coli o157:h7 in heifers on a development program in florida and in their steer half siblings in stocker and feedlot phases in oklahoma. a secondary objective was to characterize fecal shedding of campylobacter and salmonella in subsets of the same samples. after weaning, heifers (n = 501; purebreds and f1 crosses of angus, brahman, and romosinuano) were preconditioned and placed in a local development prog ... | 2008 | 18468037 |
| habitat edge, land management, and rates of brood parasitism in tallgrass prairie. | bird populations in north america's grasslands have declined sharply in recent decades. these declines are traceable, in large part, to habitat loss, but management of tallgrass prairie also has an impact. an indirect source of decline potentially associated with management is brood parasitism by the brown-headed cowbird (molothrus ater), which has had substantial negative impacts on many passerine hosts. using a novel application of regression trees, we analyzed an extensive five-year set of ne ... | 2006 | 16711055 |
| flow cytometric evaluation of selected antimicrobial efficacy for clearance of anaplasma marginale in short-term erythrocyte cultures. | the tick-borne rickettsia, anaplasma marginale, causes the economically important cattle disease anaplasmosis. once infected, cattle remain lifelong carriers. herein, we used flow cytometry to test the efficacy of three antimicrobials; oxytetracycline, imidocarb and enrofloxacin against virginia (vgn) or oklahoma (ok) a. marginale isolates in short-term erythrocyte cultures. parasite viability was assessed using the vital dye hydroethidine (he), which is detectable when living organisms convert ... | 2006 | 16669861 |
| calving system and weaning age effects on cow and preweaning calf performance in the northern great plains. | a 3-yr study evaluated late winter (feb), early spring (apr), and late spring (jun) calving systems in conjunction with varied weaning strategies on beef cow and calf performance from northern great plains rangelands. crossbred cows were randomly assigned to one of three calving systems (on average n= 168.calving system(-1).yr(-1)) and one of two weaning times (wean 1, 2) within each calving system. the feb and apr calves were weaned at 190 and 240 d of age, whereas jun calves were weaned at 140 ... | 2005 | 16230667 |
| anaplasma marginale msp1alpha genotypes evolved under positive selection pressure but are not markers for geographic isolates. | anaplasma marginale (order rickettsiales, family anaplasmataceae), a tick-borne pathogen of cattle, is endemic in tropical and subtropical regions of the world. many geographic isolates of a. marginale occur in the united states and have been identified by major surface protein 1a (msp1a), which varies in sequence and molecular weight due to different numbers of tandem 28- to 29-amino-acid repeats. the present study was undertaken to examine the genetic variations among isolates of a. marginale ... | 2003 | 12682152 |
| regional differences in the fescue toxicosis response of bos taurus cattle. | cattle of the same breed from different regions of the usa may have altered responses to heat stress and fescue toxicosis. angus steers from missouri (mo ang, n = 10, 513.6 ± 13.6 kg bw) and oklahoma (ok ang, n = 10, 552.8 ± 12.0 kg bw) were fed a diet containing either endophyte-infected (e+, 30 μg ergovaline/kg bw/day) or endophyte-uninfected (e-, 0 μg ergovaline/kg bw/day) tall fescue seed for 23 days. diet treatment began on day 2. animals were maintained at thermoneutrality (tn, 19-22 °c, d ... | 2015 | 24939412 |