Swiss Dairy Research Articles

Identification of genomic regions affecting nitrogen excretion intensity in Brown Swiss dairy cows

Dairy cows with a lower nitrogen excretion intensity (Nexi) excrete less nitrogen, ammonia (NH3) and nitrous oxide (N2O), a highly potent greenhouse gas (GHG), per kg of milk produced and therefore represent a lower environmental impact while maintaining food security. To date, the genomics background of Nexi is unknown. Here we performed a genetic association study, overlap analysis and functional enrichment analysis for Nexi in 875 genotyped dairy cows with 2,147 lactations from 200 herds. We identified 1456 single nucleotide polymorphisms (SNPs) that significantly affect Nexi. We found 140 SNPs overlapping with 148 protein-coding genes. The MAN1A1 gene is a strong candidate gene for Nexi. Genotype CC of rs42786248, the most significantly associated SNP located in the MAN1A1 gene, had higher Nexi than genotypes AA (p < 0.001) and AC (p < 0.001). We identified 33 genes involved in biological processes related to nitrogen metabolism. Our results form the basis for further research on the genomics background of Nexi. The identified SNPs serve as potential targets for selective breeding programs, aimed at reducing Nexi and associated NH3 and N2O emissions in cattle production, thus contributing to more environmentally sustainable milk production.

Grazing intensity and associated frequency of human contact, and horn status, influence activity on pasture, physiological pre-slaughter reactions and meat quality in beef heifers

Meat quality is influenced by many factors related to the animal, such as its genetics and health status, farm management, and slaughter and processing conditions. The present study aimed to investigate the effects and interactions of grazing intensity and horn status on behaviour, physiological pre-slaughter stress status and meat characteristics of beef heifers. The study involved 32 horned and 32 disbudded F1 crossbred (Limousin ☓ Swiss Dairy breed) heifers during summer grazing on mountain pastures. Half of the heifers of each horn status were assigned to one of two grazing systems, balanced for live weight, dam and behavioural reactivity: grazing at either high (HI) or low (LI) grazing intensity. HI groups grazed in 3 times smaller paddocks and changed the paddock three times more often than LI groups. The effects of horn status and grazing intensity on physical activity on pasture, pre-slaughter stress and meat quality of the m. longissimus thoracis were studied. Compared to HI heifers, LI Heifers walked more when on pasture, showed greater stress levels before stunning, and their meat had greater water losses and greater early troponin levels. The varying pre-slaughter stress levels may be attributed to the differing frequency of human contact resulting from the differing frequency of paddock changes and may explain part of the effects on meat quality. Compared to disbudded heifers, horned heifers had faster heart rates at the abattoir, and their meat had lower cooking loss and was less juicy. Pre-slaughter heart rates showed robust correlations with various meat quality indicators. The study shows that both horn status and grazing management, including human contact, influence meat quality. Part of the effects may be related to different pre-slaughter physiological reactions, which subsequently influence meat quality.

Cubicle design and dairy cow rising and lying down behaviours in free-stalls with insufficient lunge space

Cubicle partitions divide the resting area of free-stalls into individual lying places for cows, thereby facilitating the maintenance of good hygiene and reducing competition by separating animals. The forward lunge space in lying cubicles is often insufficient for a natural head lunge movement during rising. Cubicles with open frame partitions and a flexible neck strap aim to alleviate this welfare issue. The open partition frame facilitates lateral space sharing (using space of neighbouring cubicles for the head lunge movement) and the flexible neck strap is presumably less painful upon collision. In an observational study, we investigated the lying behaviour of free-stall housed dairy cows in this ’permissive’ cubicle type with open frame partitions and a flexible neck strap positioned relatively high above the lying surface compared to ’restrictive’ cubicles with partitions with more bar work in the lateral lunge space and a lower-positioned rigid neck rail. The study was conducted on commercial Swiss dairy farms with exclusively wall-facing lying cubicles of either the permissive (four farms) or restrictive (six farms) type. The forward lunge space on these farms ranged from 55 to 70 cm, which we considered insufficient for adult cows to lunge their heads forward. On each farm, 18–20 lactating dairy cows were selected. In total, 188 animals were used in the statistical analysis. Over 1.5 days, rising and lying down movements were videotaped, and the prevalence of atypical behaviours during these movements was recorded. In addition, we determined the daily lying duration, the lying frequency, and the mean lying bout duration using accelerometers mounted on the left hind leg. The data was analysed in relation to the cubicle type (permissive or restrictive). In the permissive cubicle type, staggered head lunge movements during rising and displays of hesitance before lying down were less prevalent. The lying frequency was higher, and daily lying duration was longer in the permissive cubicle type, although these estimates should be interpreted with caution due to the short data collection period. The results of this study suggest that the permissive cubicle with open partitions and a high-positioned flexible neck strap may improve conditions for dairy cows to rise and lie down. A permissive cubicle design may therefore improve cow welfare in free-stalls with insufficient forward lunge space, where increasing lunge space is not feasible.

Product differentiation, quality, and milk price stability: The case of the Swiss cheese market

AbstractWe investigate potential linkages between product and quality differentiation in the cheese markets and raw milk producer prices. We analyze the co‐movements of producer prices of milk delivered to cheese processing channels with different differentiation strategies, namely industrial, artisanal, and artisanal cheese with geographical indications (GI) in the Swiss dairy market. We find that overall, product and quality differentiation in cheese markets helps milk producers achieve higher and more stable prices. Additional GI protection does not guarantee further enhancement of producer prices. Rather, its effectiveness may depend largely on the strength of GI protection and the governance of producer organizations.

Welfare in Swiss dairy heifers: Comparative assessment of skin lesions in two housing systems

During summer, dairy heifers are often managed extensively in Switzerland. This applies to 2 different types of husbandry systems across the country, i.e., to heifers on alpine transhumance pastures and to heifers on pastures belonging to a year-round lowland farm. In contrast to heifers, dairy cows are more intensively farmed and spend more time in confinement. The prevalence of skin lesions (e.g., hock injuries) in dairy cows is high. The aim of this study was to record the prevalence of skin lesions in heifers and to possibly determine the time of occurrence of these lesions. To this end, heifers from both husbandry systems (alpine pastures vs. year-round lowland farm pastures) were inspected both visually and through palpation, and findings were compared. Inspection took place in fall, i.e., at the end of the alpine pasturing season before descent to the lowlands. Of the 480 heifers included on a total of 28 farms, skin lesions were found in 13.1% of individuals. Skin lesions commonly associated with barn design (e.g., injuries on the dewlap or hock injuries) and skin lesions on the pelvis were most frequently detected, equally distributed among husbandry systems. In conclusion, the prevalence of skin lesions among Swiss dairy heifers appears to be lower for compared with dairy cows, at least as measured in the fall before heifers transition to the main dairy herd. Accordingly, deploying measures to reduce skin lesions is more efficient on dairy farms than in heifer raising systems.

Enhancing culling decisions in Swiss dairy farming: Introducing a tool for improved replacement choices

Making improved replacement decisions for dairy cattle is a complex and crucial task for farmers. Research suggests that the ideal economic productive lifespan of a cow is typically between 5 and 6 lactations, yet real-world practices fall short of this potential. Farmers often face suboptimal decisions owing to the intricate nature of the culling process, which involves numerous economic and non-economic factors that vary between farms. This complexity is compounded by a lack of comprehensive information on the economic implications of culling decisions. To address this challenge, we present an algorithm and tool designed for Swiss dairy farmers, aiming to simplify and optimize their culling decisions. This algorithm, inspired by previous models, leverages a Markov chain approach to calculate anticipated survival probabilities, considering factors such as pregnancy. Key aspects of this tool include assigning a monetary value, known as the ``cow value,'' to each cow based on expected survival and monthly revenue. The cow value allows farmers to rank all cows comprehensively, aiding in the identification of less productive cows that merit replacement. The algorithm considers the diverse production systems and breed variations in Swiss dairy farming. It factors in variables such as the cost of acquiring replacement heifers, milk prices, protein and fat contents, fertility, and health. This tool offers Swiss dairy farmers valuable insights, especially in larger herds, where culling decisions may be less evident. By providing economic implications of culling choices, the algorithm optimizes average herd life and enhances farmers' income.

Diagnostic performance of Mycoplasmopsis bovis antibody ELISA tests on bulk tank milk from dairy herds

BackgroundTesting of bulk tank milk (BTM) for Mycoplasmopsis bovis (previously Mycoplasma bovis) antibodies is increasingly popular. However the performance of some commercially available tests is unknown, and cutoff values possibly need to be adjusted in light of the purpose. Therefore, the aim of this study was to compare the diagnostic performance of three commercially available M. bovis antibody ELISAs on BTM, and to explore optimal cutoff values for screening purposes. A prospective diagnostic test accuracy study was performed on 156 BTM samples from Belgian and Swiss dairy farms using Bayesian Latent Class Analysis. Samples were initially classified using manufacturer cutoff values, followed by generated values.ResultsFollowing the manufacturer’s guidelines, sensitivity of 91.4%, 25.6%, 69.2%, and specificity of 67.2%, 96.8%, 85.8% were observed for ID-screen, Bio K432, and Bio K302, respectively. Optimization of cutoffs resulted in a sensitivity of 89.0%, 82.0%, and 85.5%, and a specificity of 83.4%, 75.1%, 77.2%, respectively.ConclusionsThe ID-screen showed the highest diagnostic performance after optimization of cutoff values, and could be useful for screening. Both Bio-X tests may be of value for diagnostic or confirmation purposes due to their high specificity.

Prevalence of Painful Lesions of the Digits and Risk Factors Associated with Digital Dermatitis, Ulcers and White Line Disease on Swiss Cattle Farms.

The first aim of this study was to calculate the prevalence of painful lesions of the digits ("alarm" lesions; ALs) in Swiss dairy herds and cow-calf operations over a three-year study period. The following ALs were included in the calculation: the M2 stage of digital dermatitis (DD M2), ulcers (U), white line fissures (WLF) of moderate and high severity, white line abscesses (WLA), interdigital phlegmon (IP) and swelling of the coronet and/or bulb (SW). Between February 2020 and February 2023, digit disorders were electronically recorded during routine trimmings by 40 specially trained hoof trimmers on Swiss cattle farms participating in the national claw health programme. The data set used consisted of over 35,000 observations from almost 25,000 cows from 702 herds. While at the herd-level, the predominant AL documented in 2022 was U with 50.3% followed by WLF with 38.1%, at the cow-level, in 2022, it was DD M2 with 5.4% followed by U with 3.7%. During the study period, within-herd prevalences of ALs ranged from 0.0% to a maximum of 66.1% in 2020. The second aim of this study was to determine herd- and cow-level risk factors associated with digital dermatitis (DD), U and white line disease (WL) in dairy cows using data from 2022. While for DD, analysed herd-level factors appeared to have a greater effect on the probability of its occurrence, the presence of U and WL was mainly associated with the analysed cow-level factors. The risk for DD increased with a higher herd trimming frequency. Herds kept in tie stalls had a lower risk for DD and WL and a higher risk for U compared to herds kept in loose housing systems. Herds with predominantly Holstein Friesian cows as well as Holstein Friesian cows had a higher risk for the occurrence of DD compared to herds and cows of other breeds. With increasing parity, cows had a higher risk of developing U and WL, whereas for DD, parity was negatively associated with prevalence. Cows trimmed during the grazing period had a higher risk of U and WL than cows trimmed during the housing period. These findings may contribute to improve management measures affecting the health of the digits in farms with structures similar to those evaluated in the current study, such as small herds with frequent access to pasture. Further research is warranted to demonstrate how measures addressing the current results combined with those of individual herd risk assessments might contribute to an improvement in the health of the digits in the respective dairy herds.

Seroprevalence of Mycobacterium avium subsp. paratuberculosis in Swiss dairy herds and risk factors for a positive herd status and within-herd prevalence.

Bovine paratuberculosis (PTB) is a chronic enteric disease caused by Mycobacterium avium subsp. paratuberculosis (MAP). Control of PTB is important given its negative economic consequences and the potential zoonotic role of MAP in Crohn's disease in humans. To determine the seroprevalence of MAP in Swiss dairy herds and to identify risk factors associated with seropositive herd status and high within-herd seroprevalence, 10,063 serum samples collected from cattle over 12 months of age in 171 Swiss dairy farms were analyzed using a commercial ELISA test. Eight herds were excluded due to non-interpretable ELISA results. Risk factors associated with seropositive herd status and high within-herd seroprevalence were investigated with regression models using results from a questionnaire on management practices possibly associated with the introduction or spread of MAP in the remaining 163 herds. Univariable logistic regression was performed, carrying forward for multivariable regression analysis when p < 0.2. The calculated between-herd true seroprevalence was 3.6% (95% CI, 0.96-8.4%). Due to the low within-herd seroprevalence, it was not possible to calculate the true seroprevalence at animal level; the apparent within-herd seroprevalence ranged from 2.3 to 5.5% with a median of 3.6% in nine positive farms. Herd size (p = 0.037) and the common grazing of lactating cows with cows from other herds (p = 0.014) were associated with seropositive herd status, while heifers sharing alpine pasture with dairy cattle from other herds were associated with a decreased probability of the herd to test seropositive (p = 0.042). Reliable identification of significant risk factors associated with MAP spread and high seroprevalence of PTB within seropositive herds was not possible due to low observed seroprevalence within herds and low sensitivity of the ELISA test. These results highlight the limitation of serology for MAP diagnosis in small herds with low infection prevalence.

Feed-food and land use competition of lowland and mountain dairy cow farms

Dairy cows and other ruminants contribute to human nutrition as they are able to convert feed components containing human inedible fibre concentrations (e.g. roughage and by-products from the food processing industry) into valuable animal-sourced food. A number of crops often fed to dairy cows (e.g. soy or cereals) are however potentially edible by humans too. Additionally, land used to grow dairy cattle feed may compete with crop production for human consumption. Two different methods to assess the competition between feed consumption of dairy cows and human food supply were thus refined and tested on 25 Swiss dairy farms. With respect to the potential human edibility of the feeds used in dairy production, the human-edible feed conversion ratio (eFCR) was applied. The land use ratio (LUR) was used to relate the food production potential, per area of land utilised, with the dairy production output. Low to medium eFCR, with values ranging from 0.02 to 0.68 were found, as an average proportion of 0.74 of total DM intake consisted of roughage. In contrast, we found relatively high LUR (0.69–5.93) for most farms. If the land area used to produce feed for cows was used for crop production (applying a crop rotation), 23 of the 25 farms could have produced more edible protein and all farms more human-edible energy. Indicator values strongly depend on the underlying scenarios, such as the human-edible proportion of feeds or the suitability of land and climate for crop production. Reducing the amount of human-edible feeds in dairy farming by feeding by-products from the food processing industry and improving forage quality may be suitable strategies to reduce eFCR, but relying on low-opportunity cost feeds may restrict milk performance level per cow. On farm level, improving overall efficiency and therefore using less land (especially area suitable for crop production) per kg product decreases LUR. However, the most promising strategy to mitigate land use competition may be to localise dairy production to land areas not suitable for crop production. Both methods (eFCR and LUR) should be used in parallel. They offer an opportunity to holistically evaluate the net contribution of dairy production to the human food supply under different environmental conditions and stress the importance of production systems well suited to specific farm site characteristics.

Assessing farmer willingness to participate in a subsidized veterinary herd health management program.

Zoonoses, such as COVID-19, can cause pandemics with many fatalities. Therefore, livestock keepers should attach great importance to livestock disease control. Veterinarians can support farmers in this task through a structured veterinary herd health management (VHHM) program. The dissemination of these programs remained low, and Swiss policy makers planned to launch a subsidy program for VHHM. To inform policy making ex-ante, a survey of 1600 Swiss dairy farmers was conducted to determine whether they are willing to participate and how much they are willing to pay. Contingent evaluation with a discrete choice format elicited willingness to pay (WTP). As a rather high share of farmers who would not participate was expected, a spike model was applied with a single-bounded discrete choice (SBDC) model. Only 47% of the farmers had a positive WTP. Mean WTP in the SBDC was CHF 10.47 per cow and year and in the spike model CHF 57.96. Participation would increase with higher subsidy levels. If the government pays 20% of the costs and farmers pay CHF 96 per cow per year, 23.6% of farms would participate. If the subsidy increases to 80% (CHF 24 for farmers), 40.4% would participate. A logistic regression indicates younger and older farmers, those with lower veterinary costs, and those who consider VHHM relevant only for farms with problems are less likely to participate.

Analysis of Dairy Cow Behavior during Milking Associated with Lameness

The detection of lame cows is a challenging and time-consuming issue for dairy farmers. Many farmers use the milking time to monitor the condition of their animals. Because lame cows often show increased stepping when standing to relieve pressure on aching claws, we investigated whether lame cows showed increased activity in the milking parlor. On 20 Swiss dairy farms, 647 cows were scored on lameness with a five-point locomotion score and categorized as clinical lame and non-lame cows in order to see if there are differences in behavior between these two groups (non-lame = scores 1 and 2; lame = scores 3, 4, and 5). During one evening milking, the behavior of the cows was analyzed. A three-dimensional accelerometer, attached to the milking cluster, detected the hind leg activity indirectly via the movements of the milking unit. Additionally, head movements, as well as weight shifting and the number of steps with the front legs, were analyzed from video recordings. Owing to a high percentage of false positive hind leg activities in some milkings measured by the sensor, only 60% of the collected data were evaluated for behavior (356 cows/milkings on 17 farms). Twenty-seven percent of the investigated cows were classified as lame. The lameness prevalence was increasing with increasing parity. Lame cows showed a higher hind leg activity during milking as well as a higher frequency of front steps and weight shifting events during their stay in the milking parlor than non-lame cows. No relation between the status of lameness and the number of head movements could be seen. Observation of increased stepping and weight shifting of individual animals during milking by the farmer could be used as an additional indicator to detect lame cows, but further investigations are required.

Cost-effectiveness of farm- vs. regional-level climate change mitigation policies

Abstract Agriculture is a significant source of global greenhouse gas (GHG) emissions, making reduction targets crucially needed. Worldwide, countries have set agricultural GHG reduction goals and discussed methods to reach them. A crucial aspect is, whether the policy target level is set at the individual farm or at a regional level. In this context, we assess the advantages regarding cost-effectiveness and GHG-reduction potential of targets at the regional level. First, we use the bioeconomic farm-level model FarmDyn to simulate the changes in income and GHG emissions of 65 Swiss dairy farms. Secondly, we develop an optimization algorithm to compare the efficiency and efficacy of these two target approaches. Our analysis reveals that regional targets, which consider the heterogenous abatement costs of the sector, are more cost-efficient than farm-level ones. Specifically, they enable a 10 per cent GHG reduction at 88 per cent lower costs, suggesting they might be a more cost-effective alternative to taxation.

MOCOS-associated renal syndrome in a Brown Swiss cattle.

A recessive form of MOCOS-associated xanthinuria type II is described in Tyrolean grey cattle. A similar case was identified in a 5-month-old Brown Swiss calf with hoof overgrowth, rough coat, urine sediment, and pneumonia. To characterize the disease phenotype, to evaluate its genetic etiology, and to determine the prevalence of the deleterious allele in the Brown Swiss population. An affected calf, its parents, and 65 441 Swiss dairy cattle. The affected animal was clinically examined and necropsied. Microarray genotyping was used to determine the genotypes and to assess the frequency of the MOCOS allele in a Brown Swiss control cohort. Ultrasonography revealed hyperechoic renal pyramids with multifocal distal shadowing and echogenic sediment in the urinary bladder. Necropsy revealed suppurative bronchopneumonia and urolithiasis. Histology revealed numerous nephroliths with multifocal chronic lymphohistiocytic interstitial infiltrates, fibrosis, tubular degeneration, chronic multifocal glomerulonephritis with sclerosis, and bilateral hydronephrosis. Dysplastic changes were observed in the corium of the claw and the cornea. Genetic testing identified the homozygous presence of a known MOCOS frameshift variant in the case. Both parents were heterozygous and the prevalence of carriers in genotyped Brown Swiss cattle was 1.4% (342/24337). The findings were consistent with the diagnosis of a recessive renal syndrome similar to xanthinuria type II described in Tyrolean grey cattle. The prevalence of the deleterious MOCOS allele is low in the Brown Swiss breed. However, mating of carriers should be avoided to prevent further losses.

Effects of graded levels of dietary pomegranate peel on methane and nitrogen losses, and metabolic and health indicators in dairy cows

This study aimed to quantify the effects of dietary inclusion of tannin-rich pomegranate peel (PP) on intake, methane and nitrogen (N) losses, and metabolic and health indicators in dairy cows. Four multiparous, late-lactating Brown Swiss dairy cows (796 kg body weight; 29 kg/d of energy corrected milk yield) were randomly allocated to 3 treatments in a randomized cyclic change-over design with 3 periods, each comprising 14 d of adaptation, 7 d of milk, urine, and feces collection, and 2 d of methane measurements. Treatments were formulated using PP that replaced on a dry matter (DM) basis 0% (control), 5%, and 10% of the basal mixed ration (BMR) consisting of corn and grass silage, alfalfa, and concentrate. Gaseous exchange of the cows was determined in open-circuit respiration chambers. Blood samples were collected on d 15 of each period. Individual feed intake as well as feces and urine excretion were quantified, and representative samples were collected for analyses of nutrients and phenol composition. Milk was analyzed for concentrations of fat, protein, lactose, milk urea N, and fatty acids. Total phenols and antioxidant capacity in milk and plasma were determined. In serum, the concentrations of urea and bilirubin as well as the activities of alanine aminotransferase (ALT), aspartate aminotransferase, glutamate dehydrogenase, alkaline phosphatase, and γ-glutamyl transferase were measured. The data were subjected to ANOVA with the Mixed procedure of SAS, with treatment and period as fixed and animal as random effects. The PP and BMR contained 218 and 3.5 g of total extractable tannins per kg DM, respectively, and thereof 203 and 3.3 g of hydrolyzable tannins. Total DM intake, energy corrected milk, and methane emission (total, yield, and intensity) were not affected by PP supplementation. The proportions of C18:2n-6 and C18:3n-3 in milk increased linearly as the amount of PP was increased in the diet. Milk urea N, blood urea N, and urinary N excretion decreased linearly with the increase in dietary PP content. Total phenols and antioxidant capacity in milk and plasma were not affected by the inclusion of PP. The activity of ALT increased in a linear manner with the inclusion of PP. In conclusion, replacing up to 10% of BMR with PP improved milk fatty acid composition and alleviated metabolic and environmental N load. However, the elevated serum ALT activity indicates an onset of liver stress even at 5% PP, requiring the development of adaptation protocols for safe inclusion of PP in ruminant diets.

Influence of dietary fiber content and horn status on thermoregulatory responses of Brown Swiss dairy cows under thermoneutral and short-term heat stress conditions

In the present experiment, 10 horned and 10 disbudded mid-lactating Brown Swiss cows were included in a crossover feeding trial with a hay or hay and concentrate diet. The effects of dietary neutral detergent fiber (NDF) content and horn status on thermoregulatory responses under thermoneutral and short-term heat stress conditions were studied, as both are considered to ease the cow's thermoregulation under an environmental heat load. Cows received either ad libitum hay and alfalfa pellets (85:15, C-, NDF content: 41.0%) or restricted amounts of hay and concentrate (70:30, C+, NDF content: 34.5%). The level of restriction applied with the C+ diet was determined from pre-experimental ad libitum intakes, ensuring that both diets provided the same intake of net energy for lactation (NEL). For data collection, cows were housed in respiration chambers for 5 d. The climatic conditions were 10°C and 60% relative humidity (RH), considered thermoneutral (TN) conditions (temperature-humidity index (THI): 52) for d 1 and 2, and 25°C and 70% RH, considered heat stress (HS) conditions (THI: 74), for d 4 and 5. On d 3, the temperature and RH were increased gradually. Compared with TN, HS conditions increased the water intake, skin temperature, respiration and heart rates, and endogenous heat production. They did not affect body temperature, feed intake, or milk production. Lowering dietary fiber content via concentrate supplementation lowered methane and increased carbon dioxide production. It did not mitigate physiological responses to HS. Although the responses of horned and disbudded cows were generally similar, the slower respiration rates of horned cows under HS conditions indicate a possible, albeit minor, role of the horn in thermoregulation. In conclusion, future investigations on nutritional strategies must be conducted to mitigate mild heat stress.

Elucidation of the Bovine Intramammary Bacteriome and Resistome from healthy cows of Swiss dairy farms in the Canton Tessin.

Healthy, untreated cows of nine dairy herds from the Swiss Canton Tessin were analyzed three times within one year to identify the most abundant species of the intramammary bacteriome. Aseptically collected milk samples were cultured and bacteria identified using MALDI-TOF. Of 256 cows analyzed, 96% were bacteriologically positive and 80% of the 1,024 quarters were positive for at least one bacterial species. 84.5% of the quarters were healthy with somatic cell counts (SCC) < 200,000 cells/mL, whereas 15.5% of the quarters showed a subclinical mastitis (SCC ≥ 200,000 cells/mL). We could assign 1,288 isolates to 104 different bacterial species including 23 predominant species. Non-aureus staphylococci and mammaliicocci (NASM) were most prevalent (14 different species; 73.5% quarters). Staphylococcus xylosus and Mammaliicoccus sciuri accounted for 74.7% of all NASM isolates. To describe the intramammary resistome, 350 isolates of the predominant species were selected and subjected to short-read whole genome sequencing (WGS) and phenotypic antibiotic resistance profiling. While complete genomes of eight type strains were available, the remaining 15 were de novo assembled with long reads as a resource for the community. The 23 complete genomes served for reference-based assembly of the Illumina WGS data. Both chromosomes and mobile genetic elements were examined for antibiotic resistance genes (ARGs) using in-house and online software tools. ARGs were then correlated with phenotypic antibiotic resistance data from minimum inhibitory concentration (MIC). Phenotypic and genomic antimicrobial resistance was isolate-specific. Resistance to clindamycin and oxacillin was most frequently observed (65 and 30%) in Staphylococcus xylosus but could not be linked to chromosomal or plasmid-borne ARGs. However, in several cases, the observed antimicrobial resistance could be explained by the presence of mobile genetic elements like tetK carried on small plasmids. This represents a possible mechanism of transfer between non-pathogenic bacteria and pathogens of the mammary gland within and between herds. The-to our knowledge-most extensive bacteriome reported and the first attempt to link it with the resistome promise to profoundly affect veterinary bacteriology in the future and are highly relevant in a One Health context, in particular for mastitis, the treatment of which still heavily relies on antibiotics.

Quantifying the impact of farmers' social networks on the effectiveness of climate change mitigation policies in agriculture

AbstractTo reduce agricultural greenhouse gas (GHG) emissions, farmers need to change current farming practices. However, farmers' climate change mitigation behaviour and particularly the role of social and individual characteristics remains poorly understood. Using an agent‐based modelling approach, we investigate how knowledge exchange within farmers' social networks affects the adoption of mitigation measures and the effectiveness of a payment per ton of GHG emissions abated. Our simulations are based on census, survey and interview data for 49 Swiss dairy and cattle farms to simulate the effect of social networks on overall GHG reduction and marginal abatement costs. We find that considering social networks increases overall reduction of GHG emissions by 45% at a given payment of 120 Swiss Francs (CHF) per ton of reduced GHG emissions. The per ton payment would have to increase by 380 CHF (i.e., 500 CHF/tCO2eq) to reach the same overall GHG reduction level without any social network effects. Moreover, marginal abatement costs for emissions are lower when farmers exchange relevant knowledge through social networks. The effectiveness of policy incentives aiming at agricultural climate change mitigation can hence be improved by simultaneously supporting knowledge exchange and opportunities of social learning in farming communities.

Energy Transitions in the Food Sector: The Economic Viability of Low-carbon Technologies in the Swiss Dairy Industry

Swiss dairy products are globally sought after but their production requires relatively large amounts of process heat, often generated from oil and gas. Low-carbon electricity- and biomass-based solutions exist but were often regarded as economically not viable in the past. Therefore, we evaluate the economic viability of low-carbon technologies for the Swiss dairy industry for scenarios of low and high fossil fuel prices in Europe, and its sensitivity to emission cost pathways. Results show a clear cost advantage of heat pumps and biomass boilers going forward, driven particularly by expected future gas prices.

Action‐ versus results‐based policy designs for agricultural climate change mitigation

AbstractReducing agricultural greenhouse gas (GHG) emissions is key to achieve overall climate policy goals. Effective and efficient policy instruments are needed to incentivize farmers' adoption of on‐farm climate change mitigation practices. We compare action‐ and results‐based policy designs for GHG reduction in agriculture and account for farmers' heterogeneous behavioral characteristics such as individual farming preferences, reluctance to change and social interactions. An agent‐based bio‐economic modeling approach is used to simulate total GHG reduction, overall governmental spending and farm‐level marginal abatement cost of Swiss dairy and beef cattle farms under both action‐ and results‐based policy designs. We find that total governmental spending associated with the compared policy designs depends on the cost and benefits of the considered measures as well as behavioral characteristics of farmers. More precisely, if farmers are reluctant to change, additional incentives are needed to increase adoption of a win‐win measure. In such a case, targeting the payment on the cost of that particular measure (action‐based design) instead of paying a uniform amount for abated emissions (results‐based design) can lower governmental spending for agricultural climate change mitigation. Farm‐level marginal cost of reducing GHG emissions are lower with results‐based payments independent of the cost of measures. Moreover, we find that farmers' individual preferences and reluctance to change substantially lower the adoption of mitigation measures and hence overall GHG reduction potential of farms.