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J S Cullor

Publications and source records attributed to J S Cullor.

At least 37 records · Page 2Linked to original sources
PubMed1998

Research notes: Prevalence of selected microbial pathogens in processed poultry waste used as dairy cattle feed.

Processed poultry litter intended for dairy cattle feed was collected on 13 dairy ranches in the San Joaquin Valley of California and analyzed for the presence of significant bacterial pathogens associated with clinical disease in cattle or foodborne disease in humans. Litter samples were collected from the surface and interior of the litter piles upon arrival on the dairies and 2 to 4 wk later. Litter samples were cultured for Salmonella, Escherichia coli, Campylobacter, and other bacteria. The temperature of the litter piles was obtained on the surface and interior at each sampling. Dry matter was determined for each sample. No Salmonella, E. coli O157, or Campylobacter was identified (n = 104). Other E. coli strains were found in 8 out of 52 samples on arrival and 4 out of 52 samples at 2 to 4 wk after arrival. Although the surface and interior temperatures of the litter pile were different (23 C vs 50 C, respectively), the mean temperatures did not significantly change with time on the ranches. Average dry matter content did not differ between samples. In conclusion, the pathogens under investigation were not detected in processed poultry litter on these California dairy ranches upon arrival at the dairy or 2 to 4 wk later.

Animal Feed↗
PubMed1998

PCR detection of North American and Central African isolates of epizootic hemorrhagic disease virus (EHDV) based on genome segment 10 of EHDV serotype 1.

PCR amplification technology for the detection of epizootic hemorrhagic disease virus (EHDV) ribonucleic acid in cell culture and clinical specimens was developed. With oligoribonucleotide primers selected from genome segment 10 of EHDV serotype 1 (EHDV-1), which codes for two nonstructural proteins (NS3 and NS3a), the PCR-based assay resulted in a 535-bp PCR product. RNAs from North American EHDV-1 prototype, EHDV-2 prototype, and a number of EHDV field isolates, including the Central African isolates of EHDV-5 and EHDV-318 propagated in cell cultures, were detected by this PCR-based assay. The specific 535-bp PCR products were visualized onto agarose gels, and the identity of the PCR products was confirmed by chemiluminescent hybridization with a 352-bp internal probe. The sensitivity of the EHDV PCR assay was increased by chemiluminescent hybridization; by this EHDV-NS3 PCR, 10 fg of EHDV RNA was detected (equivalent to 600 viral particles). Amplification product was not detected when the PCR-based assay was applied to RNAs from North American bluetongue virus prototype serotypes 2, 10, 11, 13, and 17; total nucleic acid extracts from uninfected BHK-21 cells; or unfractionated blood from calves and deer that were EHDV seronegative and virus isolation negative. The described EHDV PCR-based assay with primers derived from segment 10 of EHDV-1 resulted in detection of EHDV RNA from blood and tissues collected from calves and deer with natural and experimental EHDV infections and provides a valuable tool to study the epidemiology of EHDV infection in susceptible ruminants.

Africa, Central↗
PubMed1998

Antimicrobial properties of human lysozyme transgenic mouse milk.

The antimicrobial properties of standard human lysozyme and the milk of transgenic mice expressing human lysozyme were investigated using bacterial strains important to the dairy industry. Standard human lysozyme was found to be effective at significantly slowing the growth of the milk cold-spoilage organism Pseudomonas fragi (P < 0.001), of a clinical isolate of the mastitis-causing organism Staphylococcus aureus (P < 0.005), and a nonpathogenic strain of E. coli (P < 0.05). Milk from transgenic mice secreting human lysozyme in their milk at an average concentration of 0.3 mg/ml was found to be bacteriostatic against the cold-spoilage organisms Pseudomonas fragi and Lactobacillus viscous and a mastitis-causing strain of Staphylococcus aureus, but not against a pathogenic strain of E. coli. These results demonstrate that transgenic animals producing human lysozyme in their milk can affect the microbial nature of milk.

Animals↗
PubMed1997

T cell populations and cytokine expression in milk derived from normal and bacteria-infected bovine mammary glands.

This study investigated the effect of naturally acquired bacterial infection of the bovine mammary gland on subpopulations of T lymphocytes and cytokine expression in milk. Twenty-nine lactating cows with mastitis were compared to 12 normal animals. CD4+ lymphocytes represented a significantly greater percentage of the milk-derived lymphocytes in infected mammary glands compared to normal controls. Cytokine mRNA expression by cells derived from milk was investigated using reverse transcriptase-polymerase chain reaction (RT-PCR). No IL-2 or IL-4 mRNA was detected in any samples, while IFN-gamma mRNA was detected in all milk samples. IL-10 mRNA was detected in cells from the milk of 2 mastitic cows and 1 normal cow, and IL-12 mRNA was detected in 2 cows with mastitis. While TNF-alpha mRNA was not detected in this study, IL-6 mRNA was identified in cells from the milk of all animals, with levels being greater in mastitic animals.

Animals↗
PubMed1997

Number of viable bacteria and presumptive antibiotic residues in milk fed to calves on commercial dairies.

OBJECTIVE: To assess the number of bacteria and presumptive antibiotic residues in milk fed to calves and to identify those bacteria and the antibiotic susceptibility of selected bacterial strains. DESIGN: Cross-sectional prospective study. SAMPLE POPULATION: 189 samples obtained from 12 local dairies. PROCEDURE: Samples of waste milk and milk-based fluids (eg, milk replacer, colostrum, bulk-tank milk) were obtained. Cumulative number of viable bacteria was determined. Bacteria were cultured aerobically, and antibiotic susceptibility testing of selected strains was performed. Presumptive antibiotic residues were detected by use of test kits. RESULTS: Geometric mean of the cumulative number of bacteria for waste milk samples was significantly higher than for other types of milk or milk-based products. Streptococcus sp (84/165 samples) and Enterobacteriaceae (83/165 samples) were the predominant bacteria identified, followed by Staphylococcus sp (68/165 samples). Escherichia coli was the gram-negative species most commonly isolated (52/165 samples; 32%); however, none were strain O157. Salmonella sp or Mycoplasma sp were not isolated. Of 189 samples, 119 (63%) were positive when tested for beta-lactams or tetracycline by use of 2 commercially available assays. In vitro, some bacteria were resistant to commonly used antibiotics. CLINICAL IMPLICATIONS: Waste milk that has not been effectively treated (eg, pasteurization) to reduce microbial load prior to use as calf feed should be used with caution, because it may contain a high number of bacteria that may be pathogenic to cattle and human beings. Antibiotic residues that would constitute violative amounts and existence of multiple antibiotic resistant bacterial strains are concerns in calf health management and dairy food safety.

Animal Feed↗
PubMed1997

Risks and prevention of contamination of dairy products.

Consumers and regulatory officials are becoming increasingly aware of the human health risk of the presence of micro-organisms or chemicals in the agricultural environment. Providing 'on-farm food safety' programmes which address the daily management of the production unit with regard to animal health and well-being, public health and environmental health must be a top priority for agriculturalists and veterinarians. Developing critical control point management (CCPM) procedures for animal and human health concerns is a viable approach to aid in alleviating public concerns about dairy products and the food supply in general. Such CCPM programmes may be created for individual production units based upon risk analysis, total quality management and hazard analysis and critical control point principles. Implementation of these programmes will be essential both in addressing food safety concerns for the resident population of a nation and in developing or maintaining international markets for the export of animal products.

Animals↗
PubMed1997

HACCP (Hazard Analysis Critical Control Points): is it coming to the dairy?

The risks and consequences of foodborne and waterborne pathogens are coming to the forefront of public health concerns, and strong pressure is being applied on agriculture for immediate implementation of on-farm controls. The FDA is considering HACCP (Hazard Analysis Critical Control Points) as the new foundation for revision of the US Food Safety Assurance Program because HACCP is considered to be a science-based, systematic approach to the prevention of food safety problems. In addition, the implementation of HACCP principles permits more government oversight through requirements for standard operating procedures and additional systems for keeping records, places primary responsibility for ensuring food safety on the food manufacturer or distributor, and may assist US food companies in competing more effectively in the world market. With the HACCP-based program in place, a government investigator should be able to determine and evaluate both current and past conditions that are critical to ensuring the safety of the food produced by the facility. When this policy is brought to the production unit, the impact for producers and veterinarians will be substantial.

Animals↗
PubMed1996

Evaluation of udder health and mastitis in llamas.

OBJECTIVE: To investigate intramammary infections in llamas, identify the pathogens responsible, and determine whether effects of intramammary infection could be detected by use of mastitis indicator tests commonly used for cows. DESIGN: Observational study. ANIMALS: 100 llamas on 10 farms. PROCEDURE: Milk samples were evaluated by bacterial culturing and by determination of somatic cell count (SCC), using direct microscopic and automated counting methods, California Mastitis Test score, pH, and N-acetyl-beta-d-glucosaminidase activity. Correlation coefficients were determined among the various mastitis indicator tests, and test results were determined for milk from infected and uninfected glands. RESULTS: Evidence of intramammary infection was evident in 76 of 369 (21%) milk samples, with 54 of 94 (57%) llamas having at least 1 infected gland. Staphylococcus sp other than Staphylococcus aureus were the predominant pathogens. None of the llamas had clinical signs of mastitis, and significant differences were not detected in SCC, California Mastitis Test score, pH, or N-acetyl-beta-d-glucosaminidase activity between infected and uninfected samples. California Mastitis Test scores were negative or trace for 307 of 313 (98%) samples, and SCC were low. In contrast, pH and N-acetyl-beta-d-glucosaminidase activity of milk from uninfected glands were higher than values reported for milk from uninfected cows, and neither variable was significantly correlated with the number of somatic cells in samples of llama milk. CLINICAL IMPLICATIONS: Although intramammary infections develop in llamas, inflammation (mastitis) appears to be rare. Values for mastitis indicator tests used for cows cannot be directly extrapolated to llamas. Subclinical mastitis is apparently not an important problem in llamas in the United States.

Acetylglucosaminidase↗
PubMed1996

Alterations in blood lymphocyte subpopulations and hematologic values in neonatal calves after administration of a combination of multiple-antigen vaccines.

OBJECTIVE: To evaluate alterations in lymphocyte subpopulations, CBC results, and clinical signs in neonatal calves inoculated with 3 commercially available proprietary multiple-antigen vaccines containing known quantities of endotoxin. DESIGN: Prospective, randomized controlled field trial. ANIMALS: 36 healthy Holstein heifer calves between 3 and 31 days old. PROCEDURE: Vaccines were administered to 18 calves according to label instructions, except for the recommended age of administration. The 18 other calves served as unvaccinated controls. Two weeks after entry into the study, calves were given secondary doses of the same vaccines. Calves in both groups were examined and blood samples were collected for determination of lymphocyte subpopulations and hematological parameters once daily for 5 days beginning on the day that both the primary and the secondary vaccinations were given. Lymphocyte subpopulations, including BoCD2+, BoCD4+, BoCD8+, B cells, and gamma/delta T cells, were determined by use of flow cytometry, using monoclonal antibodies as markers. RESULTS: Vaccinated calves did not develop clinical signs of illness. There were no significant differences in absolute numbers of lymphocyte subpopulations between vaccinated and unvaccinated calves. Vaccinated calves had significantly higher rectal temperatures, total WBC counts, and absolute neutrophil counts than did control calves. These differences persisted for 3 to 4 days after vaccination. CLINICAL IMPLICATIONS: Findings confirm empirical observations that vaccination with multiple products at the same time may induce evidence of an inflammatory response in most calves. Additional research is indicated to further evaluate the safety of using multiple vaccines simultaneously.

Animals↗
PubMed1996

Monensin concentrations measured in feeder cattle using enzyme immunoassay.

Thirty heifers were fed a ration containing 30 g monensin/ton. Fecal, urinary and seral samples were collected at varying intervals prior to and after initiating administration of the monensin-containing feed, and monensin concentrations were determined using a modified indirect enzyme immunoassay. Fecal samples contained measurable (micrograms/g; ppm) concentrations of monensin in most samples. The majority of sera and urine samples contained monensin at ng/ml (ppb) concentrations, which were above background levels prior to monensin feeding. Twelve head were fed monensin at 60 g/ton and 90 g/ton for 5 d with collection of similar samples. Higher concentrations of monensin were detected with increasing ration amounts in all 3 sample types. Enzyme immunoassay for monensin in these biological samples identified presence of the feed additive.

Animal Feed↗
PubMed1995

Associations among prostaglandin F2alpha, plasma zinc, copper and iron concentrations and fetal loss in cows and mares.

The objective of this study was to test the hypothesis that PGF2alpha is associated with abortion and changes in plasma Zn, Cu, and Fe concentrations in cows and mares in their first trimester of pregnancy. Eleven pregnant cows were infused with endotoxin (n = 5) or endotoxin plus an inhibitor of cycloxygenase, flunixin meglumine (n = 6). Blood was collected over a 5-d period. Additionally, 4 mares were treated every 24 h with cloprostenol sodium and blood was collected hourly until abortion. Plasma Zn, Cu, and Fe were determined. Three of five cows treated with endotoxin aborted, but none of the six cows treated with endotoxin and flunixin meglumine aborted. Aborting cows had lower plasma Zn (P = 0.048) over the 5-d study period compared with the nonaborting cows. The changes in Zn corresponded to release of PGF2alpha. All 4 mares aborted and plasma Zn concentrations were lower (P = 0.008) and Cu/Zn was higher (P = 0.02) 12 h after cloprostenol treatment. Plasma Zn may be a useful biomarker for risk of spontaneous abortion, and the decline in plasma Zn may be caused by PGF2alpha.

Journal Article↗
PubMed1995

Passive immunotherapy in neonatal calves--I. Safety and potency of a J5 Escherichia coli hyperimmune plasma in neonatal calves.

A pair of studies designed to assess the clinical safety and potency of hyperimmune plasma administration was undertaken in neonatal calves. Bovine plasma from Holstein heifers hyperimmunized with a mutant Escherichia coli O111:B4 (J5) vaccine which had a geometric mean (GM) immunoglobulin G (IgG) ELISA titer of 3.5 x 10(4), was administered subcutaneously to < or = 2-day-old calves. In the first (study A) of two prospective trials, hyperimmune plasma was administered in two doses to colostrum-deprived (CD) (n = 7) and colostrum-fed (CF) (n = 16) neonatal dairy calves. Data were collected immediately before (0 h) and 6, 24, 48, 72, 96, 120 and 288 h after the first plasma administration. Total serum protein and serum IgG concentration elevated in both groups with a significant (p < 0.01) rise of E. coli J5-specific IgG from the corresponding baseline by 6 h post-plasma administration. In the second (study B) trial, calves (N = 75) allocated into three protocol groups received two doses of either the hyperimmune (TT) J5 plasma (n = 30) or the control (CT) plasma (n = 30), and the third group (NT) received no plasma (n = 15). Data were collected up to 96 h post-plasma administration. Serum IgG and J5 specific ELISA antibody titer increased significantly (p < 0.01) in TT calves compared to the other group calves. The endotoxin contents of the administered plasma were < or = 1 EU ml-1 by limulus amebocyte lysate (LAL) method and the collected physiological and hematological data values were similar in all groups in both trials. In addition, no immediate adverse reaction or death was observed in any phase of the plasma administration. The E. coli J5 hyperimmune bovine plasma, as prepared and administered to neonatal calves in the current trials, proved to be a safe and potent biomedical fluid.

Animals↗
PubMed1995

Passive immunotherapy in neonatal calves--II. The efficacy of a J5 Escherichia coli hyperimmune plasma as immunotherapy in neonatal calves.

Hyperimmunized bovine plasma containing antibodies to a mutant Escherichia coli O111:B4 (J5) was used to conduct a prospective double-blind clinical trial to evaluate its efficacy as an immunotherapy to bovine neonates in field conditions. Two- to three-day-old calves (N = 150) were randomized into three groups (n = 50) to receive (1) no plasma (NP) or (2) control (traces or no J5 antibody) bovine plasma (CP), or (3) hyperimmune bovine anti J5 plasma (HP) in two subcutaneous total doses of 10 ml kg-1 body weight at a 24 h interval. Various physiological, pathological and clinical parameters of the study subjects were observed up to three weeks while other data such as morbidity, mortality and the effect on heart girth increase were collected up to the end of the eighth week. Weekly serum total protein and immunoglobulin G (IgG) concentrations were preferentially increased from the baseline values in HP calves but not statistically significant (p > 0.05) in group comparison. Mean (geometric) serum J5 ELISA titers in the HP group were significantly (p < 0.001) higher than the other two groups that increased about 1-log by the first week of plasma intervention, followed by a gradual decline by the third week. Out of three total deaths due to septicemia and colitis, one was from the NP group while the other two were from the HP group. Morbidity as measured daily on a 13-point scoring scale were not statistically (p > 0.05) different among the groups. Variation in the mean heart-girth increase was non-significant (p > 0.05) among groups by the eighth week. Higher increase in heart girth was generally associated with higher initial serum IgG (p < 0.01) concentration. Our results suggest that this lot of hyperimmune J5 plasma at this dose was not superior to control plasma or to no intervention in terms of calf morbidity and mortality.

Animals↗
PubMed1995

The effect of Escherichia coli J5 and modified live Salmonella dublin vaccines in artificially reared neonatal calves.

One thousand neonatal calves, allocated in a factorial design into four groups, were vaccinated subcutaneously with two doses each of either killed Escherichia coli (0111:B4) J5 bacterin or a UC Davis modified live, genetically altered (aro-) Salmonella dublin vaccine, or both, or with a placebo. In this prospective double-blind study to determine the immunogenicity and protective effects of both vaccines on bovine neonates in field conditions, calves were observed daily until 2 months of age, and serum samples from selected study calves were obtained at five different time points. No clinical adverse vaccine reactions were observed. Overall mortality was 7.5% (75 of 1000), E. coli and S. dublin infection being the most commonly associated aetiological agents of deaths. Both J5 (p < 0.01) and Salmonella (p = 0.05) vaccines were significantly effective in reducing the mortality rate but without an additive effect. The role of passive transfer was important in calf survival. The E. coli J5 and (aro-) S. dublin vaccination schedule employed significantly (p < 0.001) elevated J5 and Salmonella-specific serum ELISA antibody titres, respectively, by the sixth week of age.

Animals↗
PubMed1995

Financial analysis of alternative treatments for clinical mastitis associated with environmental pathogens.

For two large California dairy herds with twice daily milking, 171 infected quarters of lactating cows with mild clinical mastitis were randomly assigned to one of three treatment groups. Group A (50 cows) was treated with 62.5 mg of intramammary amoxicillin every 12 h for three milkings. Group C (50 cows) was treated with 200 mg of intramammary cephapirin every 12 h for two milkings. Group O (71 cows) was treated with 100 U of intramuscular oxytocin every 12 h for three milkings. Clinical cure rates did not differ among treatment groups. The cost per episode of clinical mastitis was higher ($54.47) for group C than for groups A ($38.53) or O ($34.88). Group O had a higher incidence of relapse (41%), and a greater percentage of group O cows (65%) experienced an additional mastitic event in the enrolled lactation than did cows in groups A and C. Treatment had no effect on the mean number of nonsalable milkings (24.7) associated with mastitis in the lactation interval subsequent to enrollment on the trial. Twenty-two percent of the cows accrued more than 30 nonsalable milkings and produced 55% of the total nonsalable milkings associated with mastitis. There was no treatment effect on total milk production, fat production, or time to removal of the enrolled cows from the herd.

Amoxicillin↗