Transmission and quantification of verocytotoxin-producingEscherichia coliO157 in dairy cattle and calves

2008 ◽  
Vol 137 (1) ◽  
pp. 114-123 ◽  
Author(s):  
J. M. SCHOUTEN ◽  
E. A. M. GRAAT ◽  
K. FRANKENA ◽  
F. VAN ZIJDERVELD ◽  
M. C. M. DE JONG
Keyword(s):  
Escherichia Coli ◽  
Dairy Cows ◽  
Field Study ◽  
Dairy Herd ◽  
Infectious Period ◽  
Basic Reproduction Ratio ◽  
Transmission Experiment ◽  
Reproduction Ratio ◽  
Susceptible Population ◽  
Previous Summer

SUMMARYData from a field study of 14 months duration in a naturally colonized dairy herd and data from an experiment with calves were used to quantify transmission of verocytotoxin-producingEscherichia coli(VTEC O157) in cattle. For the latter, two groups of 10 calves were randomly assigned and put out in one of two pastures. From each group, five animals were experimentally inoculated with 109c.f.u. O157 VTEC and, considered infectious, put back in their group. Each of the susceptible contact calves became positive within 6 days of being reunited. The estimate of the basic reproduction ratio (R0) in the experiment was 7·3 (95% CI 3·92–11·5), indicating that each infectious calf will infect seven other calves on average during an assumed infectious period of 28 days in a fully susceptible population. TheR0among dairy cows appeared to be about 10 times lower (0·70, 95% CI 0·48–1·04). After the transmission experiment, six contact-infected animals that were shedding continuously during the experiment were housed in a tie stall during winter. After 40 days, all six tested negative for O157 VTEC. In June, after a period of 34 weeks in which the heifers remained negative, they were put out in a clean and isolated pasture to observe whether they started shedding again. On each pasture that was infected with O157 VTEC during the transmission experiment the previous summer, newly purchased susceptible calves were placed. None of the heifers or calves started shedding during 14 weeks, indicating that both the heifers and the previously contaminated pasture did not function as reservoir of O157 VTEC.

scholarly journals Estimation of the basic reproduction ratio (R0) for Shiga toxin-producing Escherichia coli O157:H7 (STEC O157) in beef calves

2004 ◽  
Vol 132 (2) ◽  
pp. 291-295 ◽  
Author(s):  
W. W. LAEGREID ◽  
J. E. KEEN
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Escherichia Coli O157 ◽  
Basic Reproduction Ratio ◽  
Serum Samples ◽  
Reproduction Ratio ◽  
Beef Calves ◽  
Beef Cow ◽  
Blocking Elisa ◽  
Deterministic Methods

To understand the dynamics of transmission of Shiga toxin-producing Escherichia coli O157:H7 (STEC O157) in beef calves, serum samples were obtained from calves in a beef cow-calf herd approximately every 6 weeks from birth until weaning for three consecutive years. The presence of specific anti-O157 antibodies in these serum samples was detected using a blocking ELISA assay incorporating an anti-O157 monoclonal antibody. Using seroconversion data, the basic reproduction ratio (R0) was estimated for each of the three years as well as in aggregate using both deterministic and Martingale methods. R0 for STEC O157 infection in range beef calves by deterministic methods varied from 2·9–5·6, with an average of 4·3 (95% CI 2·8–5·9). Martingale estimates of R0 ranged from 3·5–7·4, or 5·3 (95% CI 3·9–6·6), for data from all three years. Given the above estimate of R0, it is predicted that 65–86% of a herd of calves must be effectively vaccinated, or must be rendered non-susceptible through other means, to eliminate STEC O157 infection from a herd.

scholarly journals Estimating transmission parameters of F4+ E. coli for F4-receptor-positive and -negative piglets: one-to-one transmission experiment

2004 ◽  
Vol 132 (6) ◽  
pp. 1039-1048 ◽  
Author(s):  
P. L. GEENEN ◽  
J. Van der MEULEN ◽  
A. BOUMA ◽  
M. C. M. De JONG
Keyword(s):  
Linear Models ◽  
Infectious Period ◽  
Transmission Experiment ◽  
Reproduction Ratio ◽  
E Coli ◽  
Transmission Parameters ◽  
Secondary Infections ◽  
One To One ◽  
The Difference ◽  
Adhesion Site

F4+ Escherichia coli is an important agent of post-weaning diarrhoea in piglets. Piglets that express an adhesion site for F4+ E. coli in their small intestine (F4R+) shed higher numbers of F4+ E. coli than piglets lacking this site (F4R−). We hypothesized that F4R+ piglets are more infectious and more susceptible for F4+ E. coli. This implies that in populations with F4R+ and F4R− piglets, the transmission would be dependent on the frequency of both types of animals. To quantify the difference in infectiousness and susceptibility, a one-to-one transmission experiment was performed with 20 pairs consisting of one inoculated and one contact piglet. Based on the contact infections observed, transmission parameters were estimated with generalized linear models. F4R+ piglets were infectious for other piglets and the reproduction ratio (R0) for homogeneous F4R+ populations, that is the average number of secondary infections that one F4R+ pig will cause during its entire infectious period in a population of susceptible F4R+ individuals only, was estimated as 7·1. F4R+ piglets were more susceptible than F4R− piglets and reducing the fraction of F4R+ piglets of a population will reduce transmission. It was calculated that in order to prevent major outbreaks of F4+ E. coli (R0<1), the fraction of F4R+ piglets must be lower than 0·14.

114 What Is the Impact of Dairy Influence Cattle on the Traditional Beef Industry Structure?

2021 ◽  
Vol 99 (Supplement_1) ◽  
pp. 38-39
Author(s):  
Bradley J Johnson ◽  
Luke Fuerniss
Keyword(s):  
Dairy Cows ◽  
Dairy Herd ◽  
The United States ◽  
Reproductive Technologies ◽  
Industry Structure ◽  
Data Availability ◽  
Beef Production ◽  
Feed Conversion ◽  
Beef Industry ◽  
The Impact

Abstract The U.S. cow inventory includes approximately 31 million beef cows and 9 million dairy cows, so flow of cattle from dairies into beef production influences the traditional beef industry structure. Dairy-influenced cattle have historically entered the beef supply chain as cull cows and calf-fed Holstein steers. Culled dairy cows account for approximately half of the cows harvested in the United States annually. Fed steers and heifers of dairy influence are estimated to account for 15% of annual steer and heifer slaughter. Advancements in data availability, genomics, and reproductive technologies have enabled more precise selection of dairy replacement heifers and more pregnancies to be allocated to a terminal sire. Recently, the use of beef semen to breed dairy cows that are not desirable for producing replacement heifers has become more widespread. Beef-on-dairy calves are often moved to calf ranches shortly after birth where they are weaned and grown before transitioning to traditional grow yards or feedlots. In comparison to traditional range beef production, calves of dairy origin are weaned at a younger age, have more restricted mobility early in life, and are fed a delivered ration for a greater number of days. While carcasses of dairy-originated fed cattle excel in subcutaneous leanness and marbling, calves originating from dairies typically experience greater morbidity, poorer feed conversion, and poorer dressed yields compared to native fed cattle. Future opportunities to optimize beef production from the dairy herd include refining sire selection to consistently produce high quality calves, reducing variation in calfhood management, and identifying optimal nutrition and growth technology programs for calves from dairies.

Comparing the performance of Holstein and Friesian dairy cows on British dairy farms

2002 ◽  
Vol 2002 ◽  
pp. 18-18
Author(s):  
G. E. Pollott ◽  
J. D. Leaver
Keyword(s):  
Dairy Cows ◽  
Dairy Herd ◽  
Dairy Farms ◽  
Dairy Herds ◽  
The Uk ◽  
Friesian Cows

In recent years there has been an influx of Holstein genes into the UK dairy herd, largely achieved by a ‘grading up’ process using imported Holstein semen on Friesian cows. The research reported here investigates this process using performance records from UK dairy herds.

scholarly journals Mathematical analysis of a within-host model of SARS-CoV-2

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Bhagya Jyoti Nath ◽  
Kaushik Dehingia ◽  
Vishnu Narayan Mishra ◽  
Yu-Ming Chu ◽  
Hemanta Kumar Sarmah
Keyword(s):  
Stability Analysis ◽  
Basic Reproduction Number ◽  
Reproduction Number ◽  
Basic Reproduction Ratio ◽  
Viral Kinetics ◽  
Reproduction Ratio ◽  
Biological Implication ◽  
Infection Models ◽  
Kinetics Of ◽  
The Basic Reproduction Number

AbstractIn this paper, we have mathematically analyzed a within-host model of SARS-CoV-2 which is used by Li et al. in the paper “The within-host viral kinetics of SARS-CoV-2” published in (Math. Biosci. Eng. 17(4):2853–2861, 2020). Important properties of the model, like nonnegativity of solutions and their boundedness, are established. Also, we have calculated the basic reproduction number which is an important parameter in the infection models. From stability analysis of the model, it is found that stability of the biologically feasible steady states are determined by the basic reproduction number $(\chi _{0})$ ( χ 0 ) . Numerical simulations are done in order to substantiate analytical results. A biological implication from this study is that a COVID-19 patient with less than one basic reproduction ratio can automatically recover from the infection.

Effects of feeding peas to high-producing dairy cows

1995 ◽  
Vol 75 (4) ◽  
pp. 625-629 ◽  
Author(s):  
R. R. Corbett ◽  
L. A. Goonewardene ◽  
E. K. Okine
Keyword(s):  
Dairy Cows ◽  
Milk Production ◽  
Milk Yield ◽  
Milk Fat ◽  
Dairy Herd ◽  
Protein Source ◽  
Canola Meal ◽  
Stage Of Lactation ◽  
Nutrient Analyses ◽  
Protein Milk

The effect of substituting peas for soybean and canola meals as a protein source in a high-producing dairy herd was studied in 66 Holstein cows, divided into two groups based on stage of lactation, parity, level of milk production and days in milk. Two 18.5% crude protein grain concentrate diets were formulated based on the nutrient analyses of the forages available. The control grain mix contained standard protein sources, principally soybean and canola meal (SBM\CM) while the test grain mix was formulated to contain approximately 25% field peas as the major source of protein. Both grain rations were formulated to the same nutrient specifications and balanced for undegradable protein. The duration of the trial was 6 mo during which grain feeding levels were adjusted monthly based on milk yield. For cows in early lactation, 4% fat-corrected milk yield was higher (P < 0.05) for cows fed pea based concentrates (31.3 kg d−1) than for cows fed SBM\CM supplement (29.7 kg d−1). Fat-corrected milk yield was not affected by source of protein in mid- and late-lactation cows. Fat-corrected milk production was not different (P > 0.05) for cows fed SBM\CM compared with cows fed the pea supplement when cows across all stages of lactation were included in the analyses. Milk fat percent was significantly higher (P < 0.05) for early- and mid-lactation cows fed the pea supplement. The results suggest that peas can be substituted for SBM\CM as a protein source for high-producing dairy cows. Key words: Dairy cow, pea, soybean and canola meal supplement, undegradable protein, milk production

scholarly journals The Global Behavior of a Periodic Epidemic Model with Travel between Patches

2012 ◽  
Vol 2012 ◽  
pp. 1-12
Author(s):  
Luosheng Wen ◽  
Bin Long ◽  
Xin Liang ◽  
Fengling Zeng
Keyword(s):  
Epidemic Model ◽  
Transmission Rate ◽  
Global Behavior ◽  
Uniform Persistence ◽  
Basic Reproduction Ratio ◽  
Globally Asymptotically Stable ◽  
Reproduction Ratio ◽  
Periodic Transmission ◽  
Theoretical Results ◽  
Disease Free

We establish an SIS (susceptible-infected-susceptible) epidemic model, in which the travel between patches and the periodic transmission rate are considered. As an example, the global behavior of the model with two patches is investigated. We present the expression of basic reproduction ratioR0and two theorems on the global behavior: ifR0< 1 the disease-free periodic solution is globally asymptotically stable and ifR0> 1, then it is unstable; ifR0> 1, the disease is uniform persistence. Finally, two numerical examples are given to clarify the theoretical results.

scholarly journals Factors Affecting Milk Flow Traits in Dairy Cows: Results of a Field Study

2007 ◽  
Vol 90 (3) ◽  
pp. 1159-1167 ◽  
Author(s):  
A. Sandrucci ◽  
A. Tamburini ◽  
L. Bava ◽  
M. Zucali
Keyword(s):  
Dairy Cows ◽  
Field Study ◽  
Factors Affecting ◽  
Milk Flow

scholarly journals Detection of the extended spectrum β-lactamase produced by Escherichia coli from dairy cows by using the Vitek-2 method in Tulungagung regency, Indonesia

2020 ◽  
Vol 34 (1) ◽  
pp. 203-207
Author(s):  
Akyun R. Putra ◽  
Mustofa H. Effendi ◽  
Setiawan Koesdarto ◽  
Suwarno Suwarno ◽  
Wiwiek Tyasningsih ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Dairy Cows ◽  
Extended Spectrum ◽  
Vitek 2

scholarly journals Transmission of bovine herpesvirus 1 within and between herds on an island with a BHV1 control programme

2003 ◽  
Vol 130 (3) ◽  
pp. 541-552 ◽  
Author(s):  
J. J. HAGE ◽  
Y. H. SCHUKKEN ◽  
H. SCHOLS ◽  
M. A. MARIS-VELDHUIS ◽  
F. A. M. RIJSEWIJK ◽  
...  
Keyword(s):  
The Netherlands ◽  
Bovine Herpesvirus ◽  
Control Programme ◽  
Basic Reproduction Ratio ◽  
Bovine Herpesvirus 1 ◽  
Reproduction Ratio ◽  
Animal Contact ◽  
Major Outbreak ◽  
Herpesvirus 1

Transmission of bovine herpesvirus 1 (BHV1) within and between herds was studied on the island of Ameland, The Netherlands. There were 50 herds with 3300 head of cattle on the island. Herds were divided into three groups: (1) only containing seronegative cattle, (2) containing seronegative cattle and vaccinated seropositive cattle, and (3) containing only vaccinated cattle. All 23 herds in groups 1 and 2 were monitored. Three major outbreaks of BHV1 infections were observed due to the introduction of infectious cattle. Another major outbreak was most likely induced by reactivation of latent BHV1 in seropositive cattle. The basic reproduction ratio within these herds was estimated at least 4. Only one of these outbreaks led to three secondary outbreaks in susceptible herds in which all cattle were seronegative. These outbreaks were most likely due to respectively, direct animal contact, human transmission, and aerogenic transmission. The basic reproduction ratio between herds in this study was estimated to be 0·6.

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