Vitamins and selenium in bulk tank milk of organic and conventional dairy farms

Vitamins in milk are important for the human consumer, the calf and the cow. They are also important for the dairy industry because some of them affect the risk for off-flavour. Studies indicate that milk from organic and conventional dairy farms may differ in these aspects. The aim of this study was therefore to investigate whether there are differences in the concentration of vitamins and selenium in milk between organic and conventional farms in Sweden. Bulk tank milk was sampled in 20 organic and 20 conventional dairy farms at three occasions during the indoor season. Concentrations of α-tocopherol, β-carotene and retinol were determined by HPLC and selenium by hydrid generation inductively coupled plasma atomic emission spectrometry. Herd characteristics were collected by questionnaires and from the official milk recording scheme. Multivariable linear mixed models were used to evaluate the associations between milk composition and type of farm, while adjusting for potential confounders and the repeated observations within farm. Average levels of α-tocopherol, β-carotene, retinol and selenium were 0.84 µg/ml, 0.18 µg/ml, 0.32 µg/ml and 13.6 µg/kg, respectively. There were no differences between organic and conventional farms in β-carotene, retinol or selenium concentration. Concentration of α-tocopherol was also similar, but was significantly lower in organic farms if differences in amount of roughage were accounted for in the statistical model

Temperature, productivity, and heat tolerance: Evidence from Swedish dairy production

This study aims to identify the effects of temperature on dairy production and the heat tolerance of different dairy breeds under heat stress. Using farm and animal-level data from 1435 dairy farms throughout Sweden for 4 years (from 2016 to 2019), we find that a 7-day average of daily maximum temperatures above similar to 20 degrees C is associated with sharp declines in milk production. We then estimate the farm-level loss in contribution margin for a typical Swedish dairy farm for the year 2018, which consisted of long-lasting heatwaves and extended summer temperatures. We also estimate that, on average, there are no differences in the impact of heatwaves on milk losses for different dairy breeds but that there exists a trade-off between genetic milk production potential and heat tolerance of a dairy cow. The magnitude of this productivity-tolerance trade-off may differ across breeds, suggesting that the high-production potential animals of certain breeds may be less sensitive to heat stress. These findings have important implications in terms of adapting to heat stress, investing in mitigation measures, and development of future breeds that can ameliorate the current trade-off between production capacity of a cow and its heat tolerance

Pågående svenskt projekt: Djurhälsa i ekologiska mjölkbesättningar

I doktorandprojektet ”Djurhälsa i ekologiska mjölkbesättningar” som drivs vid Institutionen för kliniska vetenskaper, Fakulteten för veterinärmedicin och husdjursvetenskap på SLU studeras effekterna av ekologisk drift på hälsa och fruktsamhet i några olika delstudier

A participatory approach to design monitoring indicators of production diseases in organic dairy farms

Production diseases have an important negative effect on the health and welfare of dairy cows. Although organic animal production systems aim for high animal health levels, compliance with European organic farming regulations does not guarantee that this is achieved. Herd health and production management (HHPM) programs aim at optimizing herd health by preventing disease and production problems, but as yet they have not been consistently implemented by farmers. We hypothesize that one reason is the mismatch between what scientists propose as indicators for herd health monitoring and what farmers would like to use. Herd health monitoring is a key element in HHPM programs as it permits a regular assessment of the functioning of the different components of the production process. Planned observations or measurements of these components are indispensable for this monitoring. In this study, a participatory approach was used to create an environment in which farmers could adapt the indicators proposed by scientists for monitoring the five main production diseases on dairy cattle farms. The adaptations of the indicators were characterized and the farmers’ explanations for the changes made were described. The study was conducted in France and Sweden, which differ in terms of their national organic regulations and existing advisory services. In both countries, twenty certified organic dairy farmers and their animal health management advisors participated in the study. All of the farmers adapted the initial monitoring plan proposed by scientists to specific production and animal health situation on their farm. This resulted in forty unique and farm-specific combinations of indicators for herd health monitoring. All but three farmers intended to monitor five health topics simultaneously using the constructed indicators. The qualitative analysis of the explanations given by farmers for their choices enabled an understanding of farmers’ reasons for selecting and adapting indicators. This is valuable information for scientists involved in the design of HHPM programs. Advisors in the field also can benefit from this participatory approach because it transforms monitoring tools provided by scientists into farm-specific tools

Herd-level risk factors associated with cow mortality in Swedish dairy herds

An increase in on-farm mortality (euthanasia and death) in dairy herds has been reported in several countries in the last decade. This does not only imply possible problems with animal welfare, but it also causes economic losses to the farmer. The objective of this study was to evaluate time trends in on-farm dairy cow mortality in Sweden and identify potential herd-level risk factors. Data was retrieved on all Swedish dairy herds enrolled in the milk recording scheme between 2002 and 2010. Herds with a herd size of 40 dead or euthanized cows per 100 cow-years were excluded. Two different models were used: 1 multiple year analysis which included 6,898 herds during the period 2002 to 2010 and 1 single year analysis including 4,252 herds for the year 2010, where other variables that were not present during the entire multiple year study were analyzed. The outcome variable was the number of euthanized and dead cows per year and season. A negative binomial regression model, adjusted for clustering within herd, was applied to both models. Fixed effects in the multiple year analysis were breed, calving interval, herd size, milk yield, region, season, pasture period, and year. Fixed effects in the single year analysis were breed, calving interval, conventional vs. organic farming, herd size, housing system, milk yield, region, and season. The multiple year analysis demonstrated that MR gradually increased from 5.1 to 6.6 events per 100 cow-years during the study period. Swedish MR are consequently on par with, or even greater than, MR among dairy herds in other comparable countries. Higher mortality was associated with larger herd size, longer calving intervals, and herds that had Swedish Holstein as the predominant breed. Lower mortality was observed in herds with a higher herd average milk yield, during the fall and winter, and in organically managed herds. There were regional differences in mortality. An interaction between herd size and season was found in both models. Also, an interaction between housing system and milk yield was found in the single year analysis. This first assessment of on-farm mortality in Swedish dairy herds confirmed that the MR has increased over the last few years. The study also identified some herd-level risk factors

Biosecurity level and health management practices in 60 Swedish farrow-to-finish herds

Background: Biosecurity measures are important tools to maintain animal health in pig herds. Within the MINAPIG project, whose overall aim is to evaluate strategies to raise pigs with less antimicrobial use, biosecurity was evaluated in medium to large farrow-to-finish pig herds in Sweden. In 60 farrow-to-finish herds with more than 100 sows, the biosecurity level was evaluated using a previously developed protocol (BioCheck). In a detailed questionnaire, internal and external biosecurity was scored in six subcategories each. An overall score for biosecurity was also provided. Information regarding production parameters as well as gender and educational level of personnel working with the pigs was also collected. Descriptive statistics were used to examine the recorded data.Results: The median scores for external and internal biosecurity were 68 and 59, respectively, where 0 indicates total absence of biosecurity and 100 means maximal possible biosecurity. The subcategories for external and internal biosecurity that had the highest scores were "Purchase of animals" (external) and "Nursery unit"/"Fattening unit" (internal), while "Feed, water and equipment supplies" (external) and "Measures between compartments and equipment"/"Cleaning and disinfection" (internal) received the lowest scores. A female caretaker in the farrowing unit, a farmer with fewer years of experience and more educated personnel were positively associated with higher scores for some of the external and internal subcategories. In herds with < 190 sows, fattening pigs were mixed between batches significantly more often than in larger herds.Conclusions: The herds in this study had a high level of external biosecurity, as well as good internal biosecurity. Strong biosecurity related to the purchase of animals, protocols for visitors, the use of all-in, all-out systems, and sanitary period between batches. Still, there is room for improvement in preventing both the introduction of disease to herds (external) and the spread of infections within herds (internal). Systems for animal transport can be improved and with respect to internal biosecurity, there is especially room for improvement regarding hygiene measures in and between compartments, as well as the staff's working procedures between different groups of pigs

Ekomjölk – djurhälsa i ekologiska mjölkbesättningar

Målsättningen med projektet är: • Ökad generell kunskap om hälsoläget i ekologiska besättningar med mjölkproduktion. • Att bedöma om den officiella sjukdomsregistreringen är ett användbart redskap för att följa upp djurhälsan i ekologiska besättningar. • Att studera om en ekologisk foderstat ökar risken för ämnesomsättnings- och fertilitetsstörningar hos mjölkkor. Projektets nuvarande status: Första besättningsbesöken inom delstudie I har genomförts och besök 2 planeras just nu, medan delstudie II och III kommer att initieras inom kort

Detecting and predicting changes in milk homogeneity using data from automatic milking systems

To ensure milk quality and detect cows with signs of mastitis, visual inspection of milk by prestripping quarters before milking is recommended in many countries. An objective method to find milk changed in homogeneity (i.e., with clots) is to use commercially available inline filters to inspect the milk. Due to the required manual labor, this method is not applicable in automatic milking systems (AMS). We investigated the possibility of detecting and predicting changes in milk homogeneity using data generated by AMS. In total, 21,335 quarter-level milk inspections were performed on 5,424 milkings of 624 unique cows on 4 farms by applying visual inspection of inline filters that assembled clots from the separate quarters during milking. Images of the filters with clots were scored for density, resulting in 892 observations with signs of clots for analysis (77% traces or mild cases, 15% moderate cases, and 8% heavy cases). The quarter density scores were combined into 1 score indicating the presence of clots during a single cow milking and into 2 scores summarizing the density scores in cow milkings during a 30-h sampling period. Data generated from the AMS, such as milk yield, milk flow, conductivity, and online somatic cell counts, were used as input to 4 multilayer perceptron models to detect or predict single milkings with clots and to detect milking periods with clots. All models resulted in high specificity (98-100%), showing that the models correctly classified cow milkings or cow milking periods with no clots observed. The ability to successfully classify cow milkings or cow periods with observed clots had a low sensitivity. The highest sensitivity (26%) was obtained by the model that detected clots in a single milking. The prevalence of clots in the data was low (2.4%), which was reflected in the results. The positive predictive value depends on the prevalence and was relatively high, with the highest positive predictive value (72%) reached in the model that detected clots during the 30-h sampling periods. The misclassification rate for cow milkings that included higher-density scores was lower, indicating that the models that detected or predicted clots in a single milking could better distinguish the heavier cases of clots. Using data from AMS to detect and predict changes in milk homogeneity seems to be possible, although the prediction performance for the definitions of clots used in this study was poor

Explaining farmers' adoption of mastitis control practices using psychological constructs from the theory of planned behavior

Mastitis control options (MCOs) are management actions that are adopted to prevent mastitis in dairy herds. In this study, the psychological constructs attitude, subjective norms and perceived behavioral control are used to explain farmers' adoption of MCOs. So far, little research has used psychological constructs to explain adoption of MCOs. Based on recommendations by a Swedish dairy association (Va center dot xa) aimed at farmers, a total of 15 different management areas, representing MCOs for contagious and environmental bacteria, were used to characterize adoption behaviors. A total of 286 Swedish full-time farmers specializing in dairy production participated in the survey. Four different farmer groups were identified through a cluster analysis of similarities in how farmers adopted MCOs together with data on bulk milk somatic cell count and subjectively evaluated somatic cell counts on the farms. Regression analyses were performed to test whether the psychological constructs could explain differences in adoption across the MCO groups. Results revealed that farmers' decisions about which set of mastitis control options to adopt as preventive actions were explained by the farmers' perceived behavioral control of the situation and by differences in subjective norm. The attitude construct did not contribute to predicting the adoption of mastitis control options. Results suggest that work aimed at implementing MCOs should be complemented by programs specifically designed to improve the ability of farmers to use and/or combine MCOs to both alleviate and prevent mastitis. They also suggest that there is little to gain from programs aimed at fostering attitudes to prevent mastitis. We interpret the findings as indicating a need to strengthen perceived behavioral control as well as subjective norms among Swedish farmers' regarding their preventive work with mastitis. Understanding how to affect farmers' behavior, and thus reducing and controlling mastitis, will have positive effects on animal health and welfare in general