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Biomedical subjects

J Fetrow

Publications and source records attributed to J Fetrow.

At least 19 recordsLinked to original sources
PubMed2006

Invited review: Culling: nomenclature, definitions, and recommendations.

Replacing cows on a dairy is a major cost of operation. There is a need for the industry to adopt a more standardized approach to reporting the rate at which cows exit from the dairy, and to reporting the reasons why cows are replaced and their destination as they exit the dairy. Herd turnover rate is recommended as the preferred term for characterizing the cows exiting a dairy, in preference to herd replacement rate, culling rate, or percent exiting, all of which have served as synonyms. Herd turnover rate should be calculated as the number of cows that exit in a defined period divided by the animal time at risk for the population being characterized. The terms voluntary and involuntary culling suffer from problems of definition and their use should be discouraged. Destination should be recorded for all cows that exit the dairy and opportunities to record one or more reasons for exiting should be provided by management systems. Comparing reported reasons between dairies requires considerable caution because of differences in case definitions and recording methods. Relying upon culling records to monitor disease has been and will always be an ineffective management strategy. Dairies are encouraged to record and monitor disease events and reproductive performance and use this information as the basis for management efforts aimed at reducing the need to replace cows.

Abattoirs↗
PubMed2006

Heat treatment of bovine colostrum. I: effects of temperature on viscosity and immunoglobulin G level.

The objective of this study was to identify the critical temperature, at or below which heat-treatment of bovine colostrum would produce no significant changes in viscosity, IgG concentration, or Ig activity. Results of preliminary work, using a Rapid Visco Analyzer (RVA) to heat 50-mL aliquots from 6 unique batches of bovine colostrum at 59, 60, 61, 62, and 63 degrees C, suggested that colostrum could be heated to 60 degrees C for up to 120 min without changing viscosity or IgG concentration. This finding was confirmed by heating 50-mL aliquots from 30 unique batches of colostrum in an RVA for 120 min at 60 and 63 degrees C. Heating colostrum to 63 degrees C resulted in an estimated 34% decrease in IgG concentration and 33% increase in viscosity. However, there was no difference in IgG concentration between preheat-treated (73.4 +/- 26.5 mg/mL) and post-heat-treated (74.5 +/- 24.3 mg/mL) samples after heating colostrum to 60 degrees C in an RVA for 120 min. Similarly, viscosity was unaffected after heating colostrum to 60 degrees C in an RVA for 120 min. High quality colostrum (> or =73.0 mg/mL) suffered greater losses of IgG and greater viscosity changes when heated to 63 degrees C than did moderate quality colostrum (<73.0 mg/mL). However, the effects of colostrum quality were minor if high quality colostrum was only heated to 60 degrees C. The results of a bovine viral diarrhea serum neutralization assay suggested that antibody activity was unchanged after heating colostrum to either 60 or 63 degrees C. However, these results were interpreted as being inconclusive due to a high proportion of missing results because of the congealing of many samples after heat treatment. The results of this study indicate that 50-mL volumes of bovine colostrum can be heat treated at 60 degrees C for up to 120 min in an RVA without affecting IgG concentration or viscosity.

Animals↗
PubMed2006

Heat-treatment of bovine colostrum. II: effects of heating duration on pathogen viability and immunoglobulin G.

Batches (30-L) of first-milking bovine colostrum, inoculated with Mycoplasma bovis (10(8) cfu/mL), Listeria monocytogenes (10(6) cfu/mL), Escherichia coli O157:H7 (10(6) cfu/mL), Salmonella enteritidis (10(6) cfu/mL), and Mycobacterium avium subsp. paratuberculosis (Map; 10(3) cfu/mL), were heat-treated at 60 degrees C for 120 min in a commercial on-farm batch pasteurizer system. Duplicate 50-mL subsamples of colostrum were collected at 15-min intervals throughout the heat-treatment process for the purpose of bacterial culture and for measurement of IgG concentration (mg/mL) and antibody activity [log2(bovine viral diarrhea virus type 1 serum neutralization titer)]. Four replicate batches of colostrum were run for each of the 5 pathogens studied. There was no effect of heating moderate- to high-quality colostrum at 60 degrees C for at least 120 min on mean IgG concentration (pre = 60.5 mg/mL; post = 59.1 mg/mL). Similarly, there was no effect of heat-treatment on the mean log2 bovine viral diarrhea virus type 1 serum neutralization titer (pre = 12.3; post = 12.0). Viable M. bovis, L. monocytogenes, E. coli O157:H7, and S. enteritidis added to colostrum could not be detected after the colostrum was heat-treated at 60 degrees C for 30 min. Average bacteria counts showed that Map was not detected when batches were heated at 60 degrees C for 60 min. Although the authors believe that heat-treating colostrum at 60 degrees C for 60 min should be sufficient to eliminate Map from colostrum in most situations, further research is needed to determine whether these findings may be replicated, given that variability was observed in Map culture results.

Animals↗
PubMed2005

Preventing bacterial contamination and proliferation during the harvest, storage, and feeding of fresh bovine colostrum.

The objectives of this study were to identify control points for bacterial contamination of bovine colostrum during the harvesting and feeding processes, and to describe the effects of refrigeration and use of potassium sorbate preservative on bacteria counts in stored fresh colostrum. For objective 1, first-milking colostrum samples were collected aseptically directly from the mammary glands of 39 cows, from the milking bucket, and from the esophageal feeder tube. For objective 2, 15-mL aliquots of colostrum were collected from the milking bucket and allocated to 1 of 4 treatment groups: 1) refrigeration, 2) ambient temperature, 3) refrigeration with potassium sorbate preservative, and 4) ambient temperature with potassium sorbate preservative. Subsamples from each treatment group were collected after 24, 48, and 96 h of storage. All samples underwent bacteriological culture for total plate count and coliform count. Bacteria counts were generally low or zero in colostrum collected directly from the gland [mean (SD) log10 cfu/mL(udder) = 1.44 (1.45)]. However, significant bacterial contamination occurred during the harvest process [mean (SD) log10 cfu/mL(bucket) = 4.99 (1.95)]. No additional bacterial contamination occurred between the bucket and the esophageal feeder tube. Storing colostrum at warm ambient temperatures resulted in the most rapid increase in bacteria counts, followed by intermediate rates of growth in nonpreserved refrigerated samples or preserved samples stored at ambient temperature. The most effective treatment studied was the use of potassium sorbate preservative in refrigerated samples, for which total plate count and total coliform counts dropped significantly and then remained constant during the 96-h storage period.

Animals↗
PubMed2004

Evaluation and use of three cowside tests for detection of subclinical ketosis in early postpartum cows.

The objective was to evaluate the performance of 3 cowside diagnostic tests for detection of subclinical ketosis, defined as a serum beta-hydroxybutyrate (BHBA) concentration >or=1400 micromol/L. On 16 d over a 5-mo period, samples of serum, milk, and urine were collected on a large dairy facility from cows of all parities between 2 and 15 DIM. The sample proportion of subclinical ketosis was 7.6% (n = 859 samples from 545 cows). The KetoCheck powder (Great States Animal Health, St. Joseph, MO) detecting acetoacetate in milk samples was very specific (99%) but poorly sensitive (41%). Respective sensitivities and specificities of the Ketostix strip detecting acetoacetate in urine samples (Bayer Corporation, Elkhart, IN) were 78 and 96% with a cut-off point of "small", or 49 and 99% with a cut-off of "moderate." The KetoTest strip (Sanwa Kagaku Kenkyusho Co. Ltd., Nagoya, Japan) using milk samples had a sensitivity and specificity of 73 and 96% with a cut-off of 100 micromol of BHBA/L or 27 and 99% with a cut-off of 200 micromol of BHBA/L. On average, use of the Ketostix at the "small" cut-off point or the KetoTest at 100 micromol/L would result in no more than 3 or 4 false positives per 100 cows screened, with prevalence levels ranging from 5 to 30%, whereas the number of false negatives would range from one false negative at 5% prevalence to 7 or 8 false negatives at 30% prevalence. Either the Ketostix or KetoTest strips would provide acceptable results for screening individual cows on commercial dairies to detect subclinical ketosis. Over this prevalence range, the KetoCheck powder test would have limited application as a screening test. Despite only one false positive per 100 animals screened, false negatives resulting from screening with the KetoCheck test would be too frequent, ranging from 3 false negatives at 5% prevalence to 18 at 30% prevalence in a population of 100 tested cows. Finally, given their relative imprecision, use of any of these individual cowside tests to estimate herd prevalence must be done cautiously, especially when only a small number of animals are sampled.

3-Hydroxybutyric Acid↗
PubMed2003

Effectiveness of an internal teat seal in the prevention of new intramammary infections during the dry and early-lactation periods in dairy cows when used with a dry cow intramammary antibiotic.

The objectives of this study were to determine the effect of infusion with an internal teat seal at dry off, when used as an adjunct to long-acting antibiotic infusion at dry off, on the risk for acquiring a new intramammary infection (IMI) during the dry period, prevalence of IMI and linear score (LS) after calving, and risk for experiencing a clinical mastitis event between dry off and 60 DIM. A total of 437 cows from 2 dairy herds, with no clinical mastitis and 4 functional quarters, were enrolled at dry off. Prior to the final milking, all quarters were sampled for bacteriological culture and SCC analysis. After milking, all 4 quarters were infused with a commercially available long-acting dry cow antibiotic. Two contralateral quarters were then infused with an internal teat seal (Orbeseal, Pfizer Animal Health, New York). Following calving the teat seal was stripped out at first milking. Duplicate milk samples were collected between 1 to 3 DIM and again between 6 to 8 DIM for culture and SCC analysis. Quarters treated with Orbeseal had significantly lower prevalence of IMI at 1 to 3 DIM (tx = 22.8%, control = 29.1%), had significantly fewer quarters that acquired a new IMI between dry off and 1 to 3 DIM (tx = 20.2%, control = 25.4%), and had significantly fewer quarters affected by a clinical mastitis event between dry off and 60 DIM (tx = 5.9%, control = 8.0%). Multivariable analysis showed a significant effect of treatment, with treated quarters being 30% less likely to develop a new IMI between dry off and 1 to 3 DIM, 31% less likely to have an IMI present at 1 to 3 DIM, 33% less likely to experience a clinical mastitis event between dry off and 60 DIM, and having significantly lower linear score measures at 1 to 3 DIM and 6 to 8 DIM, compared with control quarters.

Animals↗
PubMed2002

Hatchery and transportation factors associated with early poult mortality in commercial turkey flocks.

A prospective ecologic study, using routinely collected data from commercial turkey companies, was done of 312 turkey flocks placed over a 1-yr period. The objective was to identify hatchery- and transportation-associated risk factors for poult mortality in the first 14 d after placement using statistical models. Logistic regression was used to determine the effects of hatchery-and transportation-related factors on odds of mortality for hen and tom flocks separately. Hatchery and transportation-related risk factors for hen flock mortality included truck, truck temperature, and number of poults dead on arrival at the farm. Hatchery and transportation-related risk factors for tom flock mortality included desnooding, truck, truck temperature, shipping time, and weather conditions at placement.

Animals↗
PubMed1993

Economics of mastitis and mastitis control.

Mastitis is the most costly disease of dairy cows. The major economic loss of all forms of mastitis results from reduced milk production. Because of the difficulty in controlling environmental mastitis organisms, mastitis will maintain this role in the foreseeable future.

Animals↗
PubMed1991

Partial budget analysis of vaccinating dairy cattle against coliform mastitis with an Escherichia coli J5 vaccine.

Partial budget analysis of clinical coliform mastitis prevention supported vaccination of dairy cows with an Escherichia coli J5 vaccine. Increased profits of $57/cow lactation were predicted using a computer spreadsheet derived partial budget with generalized herd input data. Herd vaccination programs were predicted to be profitable when greater than 1% of cow lactations resulted in clinical coliform mastitis. Herd vaccination programs were predicted to be profitable at all herd milk production levels.

Animals↗
PubMed1991

Production losses from mastitis: carry-over from the previous lactation.

The study examined whether elevation in SCC in the second lactation was associated with reduced milk production in the third lactation. Lactation records from 10,705 Holstein cows from 770 herds were taken from the Dairy Records Processing Center at Raleigh. Cows in the data set were selected so that no SCC test in the first lactation was elevated above a linear score of 4.5 (no mastitis in the first lactation). Using actual and mature equivalent milk production in the first lactation as a baseline, effects of elevated SCC on production in the second and third lactations were examined using linear regression. The effect of high SCC during a cow's current lactation was found to be essentially the same as previously reported by other investigators. An increase in the lactation average linear score of 1.0 was associated with a decrease of approximately 200 kg of milk per lactation. Limited carry-over effect of elevated SCC during the second lactation was found in the third lactation. For third lactation milk production, the effect of increased SCC during the preceding (second) lactation was only about 20 to 30% as much as the effect of SCC increases in the third lactation.

Animals↗
PubMed1991

Application of portfolio theory in decision tree analysis.

A general application of portfolio analysis for herd decision tree analysis is described. In the herd environment, this methodology offers a means of employing population-based decision strategies that can help the producer control economic variation in expected return from a given set of decision options. An economic decision tree model regarding the use of prostaglandin in dairy cows with undetected estrus was used to determine the expected return of the decisions to use prostaglandin and breed on a timed basis, use prostaglandin and then breed on sign of estrus, or breed on signs of estrus. The risk attributes of these decision alternatives were calculated from the decision tree, and portfolio theory was used to find the efficient decision combinations (portfolios with the highest return for a given variance). The resulting combinations of decisions could be used to control return variation.

Animals↗
PubMed1988

Herd composite somatic cell counts: average linear score and weighted average somatic cell count score and milk production.

The relationship between herd production weighted average somatic cell count (average of somatic cell count weighted by individual cow milk production) and average linear score (average of individual cow linear score somatic cell counts) was investigated using three models. The model with the highest R2 was log weighted average somatic cell count versus average linear score. Use of the regression model results to convert an average linear score to weighted average somatic cell count results in a bulk tank somatic cell count approximately twice that of conversion of a linear score somatic cell count when done on an individual cow basis. Rolling herd average milk decreased 190 kg as average linear score increased by 1.

Animals↗
PubMed1987

Economic impact of the use of prostaglandin to induce estrus in dairy cows.

An economic model concerning the value of using prostaglandin (PG) in dairy cows with nondetected estrus was developed. Considering numerous and varied assumptions, it was more profitable to treat cows with PG and to breed the cows at a detected estrus than it was not to treat the cows and to wait to breed the cows at a detected estrus. Generally, using timed artificial insemination, it was also more profitable to breed PG-treated cows than it was not to use PG. However, timed insemination was less profitable than was breeding PG-treated cows by artificial insemination at a detected estrus.

Animal Husbandry↗
PubMed1985

Economic decisions in veterinary practice: a method for field use.

A technique is presented that allows economic decision analysis, sensitivity analysis, and threshold analysis to be done rapidly in field situations. The method allows the practitioner to choose between 2 interventions with different costs and different probabilities of success. A graphic approach is presented, which speeds and simplifies the analysis.

Animals↗