Farming practices in Sweden related to feeding milk and colostrum from cows treated with antimicrobials to dairy calves     

Anna Duse  Karin Persson Waller  Ulf Emanuelson  Helle Ericsson Unnerstad  Ylva Persson  Bj?rn Bengtsson 《Acta veterinaria Scandinavica》2013,55(1):49

Background

Milk produced by cows in receipt of antimicrobial therapy may contain antimicrobial residues. Such antimicrobial-containing waste milk must be withdrawn from human consumption and is therefore sometimes used as calf feed. Unfortunately, this approach might promote selection of antimicrobial resistant bacteria in the calves’ intestinal microbiota. The objectives of this study were therefore to obtain an overview of waste milk feeding practices on Swedish dairy farms and to investigate if these practices were associated with certain farm characteristics. A representative group of 457 Swedish dairy farmers participated in a web-based survey with questions about the use of colostrum and milk from cows treated with antimicrobials at dry off or during lactation, respectively, as calf feed.

Results

Colostrum (milk from the first milking after calving) and transition milk (milk from the second milking to the fourth day after calving) from cows treated with antimicrobials at dry off was fed to calves on 89% and 85% of the farms in the study, respectively. When antimicrobial therapy was given to cows during lactation, 56% of the farms fed milk that was produced during the course of treatment to calves, whereas milk that was produced during the subsequent withdrawal period was fed to calves on 79% of the farms. Surveyed farmers were less prone to feed such milk if the antimicrobial therapy was due to mastitis than other infections. In Sweden, a majority of antimicrobial treatments during lactation are systemic administration of benzylpenicillin and thus, the bulk of waste milk in Sweden is likely to contain residues of this drug. Feeding waste milk to calves was more common on non-organic farms, and on farms located in Southern Sweden, and was less common on farms with cows housed in cold free stalls barns.

Conclusions

Waste milk that may contain antimicrobial residues is, at least occasionally, used as feed for calves on a majority of surveyed Swedish dairy farms. Future work should focus on the effect of waste milk feeding on the occurrence of antimicrobial resistant bacteria in the calves’ intestinal microbiota.  相似文献   

Evaluation of Electrical Stunning of Atlantic Cod (Gadus morhua) and Turbot (Psetta maxima) in Seawater     

Bert Lambooij  Hanne Digre  Ulf Erikson  Henny Reimert  Dirk Burggraaf  Hans van de Vis 《Journal Of Aquatic Food Product Technology》2013,22(4):371-379

The aim of this study was to assess electrical stunning of Atlantic cod and turbot in seawater to develop a protocol for the process of stunning and killing. An induced general epileptiform insult (unconscious) had a duration of 40 ± 27 s (n =14) in cod (2.6 ± 0.5 kg) and 34 ± 18 s (n = 19) in turbot (520 ± 65 g). Seven cod and 3 turbot displayed a physical reaction, and 11 turbot registered an electroencephalogram (EEG) response to pain stimuli administered 30 s post-stun. The heart rate was 32 ± 6 beats/min in cod and 25 ± 7 beats/min in turbot prior to stunning. Post-stunning, the electrocardiogram (ECG) revealed fibrillation and reduced activity post-stun. EEG, ECG recordings, and behavioral observations indicate that when a bipolar square wave current was applied with a frequency of 133 Hz and 43% duty cycle side to side (turbot) and at 170 Hz and 33% duty cycle (cod) head to tail, both species were stunned in seawater at current densities of 3.2 A/dm² and 2.5 A/dm², respectively. For turbot, a 5 s exposure to electricity followed by chilling in ice water for 15 min is sufficient to prevent recovery. For cod, a killing method needs to be established.  相似文献   

Fish life history,angler behaviour and optimal management of recreational fisheries     

Fiona D Johnston  Robert Arlinghaus  Ulf Dieckmann 《Fish and Fisheries》2013,14(4):554-579

To predict recreational‐fishing impacts on freshwater fish species, it is important to understand the interplay between fish populations, anglers and management actions. We use an integrated bioeconomic model to study the importance of fish life‐history type (LHT) for determining (i) vulnerability to over‐exploitation by diverse angler types (generic, consumptive and trophy anglers), who respond dynamically to fishing‐quality changes; (ii) regulations [i.e., minimum‐size limits (MSLs) and licence densities] that maximize the social welfare of angler populations; and (iii) biological and social conditions resulting under such socially optimal regulations. We examine five prototypical freshwater species: European perch (Perca fluviatilis), brown trout (Salmo trutta), pikeperch (Sander lucioperca), pike (Esox lucius) and bull trout (Salvelinus confluentus). We find that LHT is important for determining the vulnerability of fish populations to overfishing, with pike, pikeperch, and bull trout being more vulnerable than perch and brown trout. Angler type influences the magnitude of fishing impacts, because of differences in fishing practices and angler‐type‐specific effects of LHT on angling effort. Our results indicate that angler types are systematically attracted to particular LHTs. Socially optimal minimum‐size limits generally increase with LHT vulnerability, whereas optimal licence densities are similar across LHTs. Yet, both regulations vary among angler types. Despite this variation, we find that biological sustainability occurs under socially optimal regulations, with one exception. Our results highlight the importance of jointly considering fish diversity, angler diversity and regulations when predicting sustainable management strategies for recreational fisheries. Failure to do so could result in socially suboptimal management and/or fishery collapse.  相似文献   

Diatom derived polyunsaturated aldehydes do not structure the planktonic microbial community in a mesocosm study     

Paul C  Reunamo A  Lindehoff E  Bergkvist J  Mausz MA  Larsson H  Richter H  Wängberg SÅ  Leskinen P  Båmstedt U  Pohnert G 《Marine drugs》2012,10(4):775-792

Several marine and freshwater diatoms produce polyunsaturated aldehydes (PUA) in wound-activated processes. These metabolites are also released by intact diatom cells during algal blooms. Due to their activity in laboratory experiments, PUA are considered as potential mediators of diatom-bacteria interactions. Here, we tested the hypothesis that PUA mediate such processes in a close-to-field mesocosm experiment. Natural plankton communities enriched with Skeletonema marinoi strains that differ in their PUA production, a plankton control, and a plankton control supplemented with PUA at natural and elevated concentrations were observed. We monitored bacterial and viral abundance as well as bacterial community composition and did not observe any influence of PUA on these parameters even at elevated concentrations. We rather detected an alternation of the bacterial diversity over time and differences between the two S. marinoi strains, indicating unique dynamic bacterial communities in these algal blooms. These results suggest that factors other than PUA are of significance for interactions between diatoms and bacteria.  相似文献   

Evaluation of two dairy herd reproductive performance indicators that are adjusted for voluntary waiting period     

Emma L?f  Hans Gustafsson  Ulf Emanuelson 《Acta veterinaria Scandinavica》2012,54(1):5

Background

Overall reproductive performance of dairy herds is monitored by various indicators. Most of them do not consider all eligible animals and do not consider different management strategies at farm level. This problem can be alleviated by measuring the proportion of pregnant cows by specific intervals after their calving date or after a fixed time period, such as the voluntary waiting period. The aim of this study was to evaluate two reproductive performance indicators that consider the voluntary waiting period at the herd. The two indicators were: percentage of pregnant cows in the herd after the voluntary waiting period plus 30 days (PV30) and percentage of inseminated cows in the herd after the voluntary waiting period plus 30 days (IV30). We wanted to assess how PV30 and IV30 perform in a simulation of herds with different reproductive management and physiology and to compare them to indicators of reproductive performance that do not consider the herd voluntary waiting period.

Methods

To evaluate the reproductive indicators we used the SimHerd-program, a stochastic simulation model, and 18 scenarios were simulated. The scenarios were designed by altering the reproductive management efficiency and the status of reproductive physiology of the herd. Logistic regression models, together with receiver operating characteristics (ROC), were used to examine how well the reproductive performance indicators could discriminate between herds of different levels of reproductive management efficiency or reproductive physiology.

Results

The logistic regression models with the ROC analysis showed that IV30 was the indicator that best discriminated between different levels of management efficiency followed by PV30, calving interval, 200-days not-in calf-rate (NotIC200), in calf rate at100-days (IC100) and a fertility index. For reproductive physiology the ROC analysis showed that the fertility index was the indicator that best discriminated between different levels, followed by PV30, NotIC200, IC100 and the calving interval. IV30 could not discriminate between the two levels.

Conclusion

PV30 is the single best performance indicator for estimating the level of both herd management efficiency and reproductive physiology followed by NotIC200 and IC100. This indicates that PV30 could be a potential candidate for inclusion in dairy herd improvement schemes.  相似文献   

Analytical models for splitting capacity of bottom rails in partially anchored timber frame shear walls based on fracture mechanics     

Giuseppe Caprolu  Ulf Arne Girhammar  Bo Källsner 《Wood material science & engineering》2017,12(3):165-188

Plastic design methods can be used for determining the load-carrying capacity of partially anchored shear walls. For such walls, the leading stud is not fully anchored against uplift and tying down forces are developed in the sheathing-to-framing joints and the bottom rail will be subjected to crosswise bending, leading to possible splitting failure of the rail. In order to use these plastic design methods, a ductile behaviour of the sheathing-to-framing joints must be ensured. In two earlier experimental programmes, the splitting failure capacity of the bottom rail has been studied. Two brittle failure modes occurred during testing: (1) a crack opening from the bottom surface of the bottom rail and (2) a crack opening from the side surface of the bottom rail. In this article, a fracture mechanics approach for the two failure modes is used to evaluate the experimental results. The comparison shows a good agreement between the experimental and analytical results. The failure mode is largely dependent on the distance between the edge of the washer and the loaded edge of the bottom rail. The fracture mechanics models seem to capture the essential behaviour of the splitting modes and to include the decisive parameters.  相似文献   

An indoor pelagic mesocosm facility to simulate multiple water-column characteristics     

Båmstedt  Ulf  Larsson  Henrik 《International Aquatic Research》2018,10(1):13-29

International Aquatic Research - Mesocosms are important research tools in aquatic ecology because they close the gap between laboratory studies at the individual or lower organization level and...  相似文献   

Development of a LC-MS/MS method for the analysis of enniatins and beauvericin in whole fresh and ensiled maize     

Sørensen JL  Nielsen KF  Rasmussen PH  Thrane U 《Journal of agricultural and food chemistry》2008,56(21):10439-10443

A LC-MS/MS method for the detection of beauvericin and the four enniatins A, A1, B, and B1 in maize and maize silage was developed. The method uses direct injection of maize extracts without any tedious and laborious cleanup procedures. The limit of quantification was determined at 13 ng g(-1) for beauvericin and at 17, 34, 24, and 26 ng g(-1) for enniatins A, A1, B, and B1, respectively. The method was used in surveys of the compounds in fresh maize samples collected at harvest in 2005 and 2006. All samples had the same distribution of the enniatins: B > B1 > A1 > A. Enniatin B was present in 90% of the samples in 2005 and in 100% in 2006 at levels up to 489 and 2598 ng g(-1), respectively. Beauvericin contamination was more frequently detected in 2006 than in 2005 (89 and 10%, respectively) and in higher amounts (988 and 71 ng g(-1), respectively). The occurrence of beauvericin and the four enniatins was examined in 3-month-old maize silage stacks from 20 different farms. As observed in fresh maize, enniatin B was the most abundant compound in ensiled maize and was found from 19 stacks at levels up to 218 ng g(-1). The stability of enniatin B in maize silage was assessed by analyzing samples from 10 of the silage stacks taken after 3, 7, and 11 months of ensiling. Enniatin B could be detected at all locations after 11 months and appeared to be stable during ensiling.  相似文献   

Prevalence of and factors associated with Brucella sero-positivity in cattle in urban and peri-urban Gulu and Soroti towns of Uganda     

Denis Rwabiita MUGIZI  Sofia BOQVIST  George William NASINYAMA  Charles WAISWA  Kokas IKWAP  Kim ROCK  Elisabeth LINDAHL  Ulf MAGNUSSON  Joseph ERUME 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(5):557-564

Brucellosis is a key zoonosis of major public health, animal welfare and economic significance, and is endemic in livestock in Uganda. A cross-sectional epidemiological study was carried out to estimate the sero-prevalence of brucellosis and identify factors associated with sero-positivity in cattle in urban and peri-urban Gulu and Soroti towns of Northern and Eastern Uganda, respectively. A total of 1007 sera and data on biologically plausible risk factors from 166 herds and their spatial locations, were collected from cattle reared in urban and peri-urban Gulu and Soroti towns of Uganda. The sera were analyzed using indirect ELISA and sero-positive reactors confirmed by competitive ELISA. Multivariable models were used to investigate for risk factors. The overall animal-level and herd-level sero-prevalence was 7.5% (76/1007, 95% Confidence Interval (CI): 6.15–9.4%) and 27.1% (45/166, 95% CI: 20.9–34.3%), respectively. Herd-level sero-prevalence was significantly (P<0.001) higher in Soroti than Gulu. In Gulu town, sero-positivity increased with an increase in herd size (P=0.03) and age (P=0.002), and was higher in cattle brought in from western Uganda (P<0.0001). In Soroti town, introduction of new cattle into a herd was significantly (P=0.027) associated with herd sero-positivity. There was a geographically differential risk (clustering) of Brucella sero- positivity in herds in Soroti, while sero-positivity was homogeneously distributed in Gulu. The data highlight brucellosis occurrence and major risk factors for its transmission in cattle in urban and peri-urban areas.  相似文献   

Managerial practices and factors influencing reproductive performance of dairy cows in urban/peri-urban areas of Kampala and Gulu,Uganda     

Kanyima M. Benon  David O. Owiny  Renée B?ge  Maria G. Nassuna-Musoke  Patrice Humblot  Ulf Magnusson 《Acta veterinaria Scandinavica》2015,57(1)

Background

Urban/peri-urban dairy production and sales has evolved as an adjustment to cope with food security and economic needs for urban dwellers in low-income countries and created an opportunity to transform from subsistence rural lifestyles of dairy farming to commercial engagement in towns. However, urban/peri-urban dairy farms differ in challenges from rural dairy farms and reproduction is important and critical for assuring sustainable economic output in both environments. Here we recorded for the first time differences between two geographically and economically different cities corresponding to different settings within the same country in managerial factors influencing reproductive performance in urban/peri-urban dairy cowherds.

Results

The urban/peri-urban dairy farmers in the capital Kampala were more often male (P = 0.002) and commercialized (P = 0.0025), more experienced (P = 0.0001) and practiced zero-grazing more often (P = 0.05) than in the regional municipality Gulu. Also, the milk production per herd and cow (P = 0.0005) and calving rate were (P = 0.0001) higher in Kampala and artificial insemination was more commonly (P = 0.002) used than in Gulu. There was no difference in abortion nor neonatal mortality rate between the two locations. Overall, calving rates were higher (P = 0.0003) in smaller (≤3 dairy cows) and open grazing (P = 0.003) herds. Abortion rates were higher among dairy herds practicing late (≥5 months) (P = 0.003) calf weaning and in herds with commercial purposes (P = 0.0001). Neonatal calf mortality was lower (P = 0.01) in small herds.

Conclusion

The study showed significant differences between Kampala and Gulu in reproductive performance and related husbandry factors for cows in the urban/peri-urban dairy farming systems. For several reproductive performance traits we found associations with husbandry and production traits, which should be taken into account when providing advice to the urban and peri-urban dairy farmers in the tropics.  相似文献