Publications - Publications

Microbial aetiology, antibiotic susceptibility and pathogen-specific risk factors for udder pathogens from clinical mastitis in dairy cows

Duse, A., Persson Waller, K., Pedersen, K. — Mon, 26 Jul 2021 08:57:37 +0200

Design and selection of engineered lytic proteins with Staphylococcus aureus decolonizing activity

Gutiérrez, D., Rodríguez-Rubio, L., Ruas-Madiedo, P., et al. — Tue, 14 Sep 2021 08:57:37 +0200

The potential of using E. coli as an indicator for the surveillance of antimicrobial resistance (AMR) in the environment

Anjum, M., Schmitt, H., Börjesson, S., et al. — Fri, 29 Oct 2021 08:57:37 +0200

Defining the scope of the European Antimicrobial Resistance Surveillance network in Veterinary medicine (EARS-Vet): a bottom-up and One Health approach

Mader, R., Bourély, C., Amat, J., et al. — Wed, 12 Jan 2022 08:57:37 +0100

Microbiological Diagnoses on Clinical Mastitis—Comparison between Diagnoses Made in Veterinary Clinics versus in Laboratory Applying MALDI-TOF MS

Boye Astrup, L., Pedersen, K., Farre, M. — Sat, 19 Feb 2022 08:57:37 +0100

Review and Analysis of National Monitoring Systems for Antimicrobial Resistance in Animal Bacterial Pathogens in Europe: A Basis for the Development of the European Antimicrobial Resistance Surveillance Network in Veterinary Medicine (EARS-Vet)

Mader, R., Munoz Madero, C., Aasmäe, B., et al. — Fri, 22 Apr 2022 08:57:37 +0200

Herd-level prevalence of Mycoplasma bovis in Swedish dairy herds determined by antibody ELISA and PCR on bulk tank milk and herd characteristics associated with seropositivity

Hurri, E., Ohlson, A., Lundberg, Å., Aspan, A., Pedersen, K., Tråvén, M. — Wed, 27 Apr 2022 08:57:37 +0200

Association between antibiotic consumption and resistance in mink production

Kvist Nikolaisen, N., Fertner, M., Corvera Kløve Lassen, D. ., et al. — Sat, 09 Jul 2022 08:57:37 +0200

Pilot testing the EARS-Vet surveillance network for antibiotic resistance in bacterial pathogens from animals in the EU/EEA

Lagrange, J., Amat, J., Ballesteros, C., et al. — Mon, 22 May 2023 08:57:37 +0200

Digestibilité iléale et totale apparentes des nutriments chez le porc en croissance : effet de la granulation, de la xylanase et de la présence de coproduits

Chassé, É. ., Guay, F., Létourneau-Montminy, M. — Tue, 01 Jan 2019 08:57:37 +0100

The effects of antibiotic use on the dynamics of the microbiome and resistome in pigs

Wegener Tams, K., Larsen, I., Elvekjær Hansen, J., et al. — Tue, 01 Aug 2023 08:57:37 +0200

Facteurs affectant la température corporelle et le gain de poids de porcelets nouveau-nés

Chassé, É. ., Guay, F. — Wed, 01 Jan 2020 08:57:37 +0100

Impact de l’ajout d’enzymes sur la digestibilité iléale des carbohydrates chez le porc en croissance selon la taille et la fréquence de repas

Chassé, É. ., Guay, F., Létourneau-Montminy, M. — Fri, 01 Jan 2021 08:57:37 +0100

Impact of diet type and xylanase supplementation on the ileal digestibility of nutrients, and growth performance in growing-finishing pigs

Chassé, É. ., Dickner-Ouellet, L., Pomar, C., Guay, F., Létourneau-Montminy, M. — Fri, 01 Jan 2021 08:57:37 +0100

Effect of pelleting on nutrients and energy digestibility in growing pigs fed corn-soybean meal-based diet or diet containing corn distillers dried grains with solubles (cDDGS), wheat middlings and bakery meal

Chassé, É. ., Guay, F., Létourneau-Montminy, M. — Fri, 01 Jan 2021 08:57:37 +0100

High- or low-fibre diet, meal size and frequency: Effect on ileal and total tract digestibility and mean retention time in growing pigs

Chassé, É. ., Guay, F., Létourneau-Montminy, M. — Sun, 01 Jan 2023 08:57:37 +0100

Impact of enzyme inclusion on the digestibility of protein, amino acids, calcium and phosphorus in growing pigs depending on meal size, frequency and sampling period

Chassé, É. ., Guay, F., Létourneau-Montminy, M. — Sun, 01 Jan 2023 08:57:37 +0100

Genomic analyses of Streptococcus uberis reveal high diversity but few antibiotic resistance genes

Myrenås, M., Fasth, C., Persson Waller, K., Pedersen, K. — Wed, 01 Jan 2025 08:57:37 +0100

Survival of livestock-associated methicillin-resistant Staphylococcus aureus CC398 on different surface materials

Tuominen, K., Frosth, S., Pedersen, K., Rosendal, T., Sternberg Lewerin, S. — Fri, 17 Mar 2023 08:57:37 +0100

Chapter 8 : Understanding and optimizing the use of prebiotics in pig nutrition

Chassé, É. ., Knudsen, K. E. B., Hedemann, M. S., Canibe, N., Razmgah, N. — Mon, 01 Jan 2024 08:57:37 +0100

Foderstrategier til pattegrise i farestalden

Hald, M. — Sat, 09 Nov 2024 08:57:37 +0100

Effect of rape seed fat and saturated fat on milk production and enteric methane, when added to diets with different ratios between grass-clover and maize silage

Børsting, C. F., Lashkari, S., Kjeldsen, M. H. — Sun, 01 Sep 2024 08:57:37 +0200

The effect of an essential oil blend on performance, feed efficiency, methane emission and rumen microbiome in lactating dairy cows

Børsting, C. F., Noel, S. J., Lashkari, S., Hellwing, A. L. F. — Sun, 01 Sep 2024 08:57:37 +0200

Development of Livestock-Associated Methicillin-Resistant Staphylococcus aureus (LA-MRSA) Loads in Pigs and Pig Stables During the Fattening Period

Pedersen, K., Nielsen, M. W., Fertner, M. E., Espinosa-Gongora, C., Bækbo, P. — Fri, 01 Nov 2024 08:57:37 +0100

Livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) is widespread in European pig production and poses an occupational hazard to farm workers and their household members. Farm workers are exposed to LA-MRSA through direct contact with pigs and airborne transmission, enabling bacteria to be carried home in the nose or on the skin. Consequently, it is important to consider LA-MRSA in a one-health context, studying human exposure by examining LA-MRSA levels in pigs, air, and dust in the farm environment. In this investigation, LA-MRSA levels were quantified in nasal swab samples from the pigs, air samples, and dust at three different time points in a farm rearing pigs from approx. 30 kg until slaughter. Sampling was repeated across seven batches of pigs, resulting in the analysis of 504 nasal swab samples, alongside air and dust samples. LA-MRSA was cultured and quantified on MRSA2 agar plates. Findings revealed significant batch-to-batch variation and a significant 94.1% decrease in LA-MRSA levels during the rearing period. Despite this decline, all nasal swab samples tested positive, with the highest level reaching 353,000 cfu in a sample. Among the 42 air samples, LA-MRSA levels were low to moderate, with a maximum of 568 and an average of 63 cfu/m³. In the 28 dust samples collected during the second and third sampling periods, LA-MRSA counts were high, reaching up to 37,272 cfu/g, with an average of 17,185 cfu/g. The results suggest that while LA-MRSA levels in pigs decrease with age, reaching low levels before slaughter, the bacterium remains highly abundant in dust, posing an occupational hazard to farm workers.

Setting Up Horses for a Good Life

Christensen, J. W. — Fri, 01 Mar 2024 08:57:37 +0100

Phenotypic traits related to methane emissions from Holstein dairy cows challenged by low or high forage proportion

Kjeldsen, M. H., de Evan Rozada, T., Noel, S. J., et al. — Sun, 01 Dec 2024 08:57:37 +0100

Limited literature is available identifying phenotypical traits related to enteric methane (CH₄) production from dairy cows, despite its relevance in relation to breeding for animals with a low CH₄ yield (g/kg DMI) and the derived consequences hereof. This study aimed to investigate the relationships between CH₄ yield and different animal phenotypes when 16 second-parity dairy cows, fitted with a ruminal cannula, were fed 2 diets differing in forage/concentrate ratio in a crossover design. The diets had either a low forage proportion (35% on DM basis; F35) or a high forage proportion (63% on DM basis; F63). Gas exchange was measured by means of indirect calorimetry. Spot samples of feces were collected, and indigestible NDF (INDF) was used as an internal marker to determine total-tract digestibility. In addition, ruminal evacuations, monitoring of chewing activity, determination of ruminal VFA concentration, analysis of relative abundance of methanogens, and measurement of liquid passage rate were performed. Statistical differences were analyzed by a linear mixed model with diet, DIM, and period as fixed effects, and cow as random effect. The random cow estimates (RCE) were extracted from the model to get the Pearson correlations (r) between RCE of CH₄ yield and RCE of all other variables measured, in order to identify possible phenotypes related to CH₄ yield. Significant correlations were observed between RCE of CH₄ yield and RCE of OM digestibility (r = 0.63) and ruminal concentrations of valeric acid (r = −0.61), acetic acid (r = 0.54), ammonium (r = 0.55), and lactic acid (r = ‒0.53). Additionally, tendencies were observed for correlations between RCE of CH₄ yield and RCE of H₂ yield in g/kg DM (r = 0.47, P = 0.07), and ruminal isobutyric acid concentration (r = 0.43, P = 0.09). No correlations were observed between RCE of CH₄ yield and RCE of ruminal pool sizes, milk data, urinary measurements, or chewing activity. Cows had a lower DMI and ECM when they were fed F63 compared with F35. Cows fed F63 had higher NDF digestibility, CH₄ emissions (g/d, g/kg of DMI, and g/kg of ECM), ruminal concentration of acetic acid, ruminal pH, degradation rate of digestible NDF (DNDF, %/h), and longer rumen retention time (h). Rumination and total chewing time (min/kg DMI) were also higher for cows fed F63. The results in the present study emphasize the positive relation between a cow's ability to digest OM and their CH₄ emissions. The derived consequences of breeding for lower CH₄ emission might be cows with lower ability to digest OM, but more studies are warranted for further documentation of this relationship.

Oral Conflict Behaviour is a Potential Indicator of Oral Lesions in Dressage Horses

Christensen, J. W., Uldahl, M. — Fri, 01 Mar 2024 08:57:37 +0100

Corrigendum to “Effects of heat stress on feed intake, milk yield, milk composition, and feed efficiency in dairy cows

Chen, L., Thorup, V. M., Kudahl, A. B., Østergaard, S. — Sun, 01 Dec 2024 08:57:37 +0100

This article contained in error in Table 5, in which “lactation stage” appeared instead of “THI.” The correct sentence table reads as follows, with the correction noted in bold. The authors regret the error.

Impact of Growth Rate on the Welfare of Broilers

Riber, A. B., Wurtz, K. E. — Fri, 01 Nov 2024 08:57:37 +0100

Selection for the more efficient production of broilers has resulted in rapid growth rates. The aim was to review the existing knowledge on the effect of growth rate on broiler welfare. Genotypes with faster growth rates consistently demonstrate poorer gait scores and increased prevalence of disorders affecting their legs than slower-growing genotypes. Reduced mobility places faster-growing broilers at an increased risk of developing contact dermatitis, as they spend increased durations sitting in contact with litter. Poor walking ability, heavy body weights, and conformational differences such as proportionally larger breast muscle in genotypes with faster growth can impact a bird’s ability to walk and navigate the environment, making it difficult to access resources and express natural behaviors. Faster growth has also been associated with poor cardiovascular health, increased susceptibility to heat stress, increased prevalence of mortality, ascites, as well as multiple breast muscle myopathies. Feed restriction, a practice associated with hunger and frustration, may be used to control the growth of broiler breeders, with birds having higher growth potential typically experiencing higher restriction levels. Overall, there is strong evidence that fast growth rates negatively impact welfare, and that slower-growing genotypes show significantly improved welfare. Furthermore, some evidence suggests that even minor reductions in growth rate can lead to welfare improvements.

The potential of using keel bone fracture in laying hens to investigate bone pain in a high mineral turnover, late mineralizing bone – a research plan.

Sun, 10 Mar 2024 08:57:37 +0100

Effects of feeding whole-cracked rapeseeds, nitrate, and 3-nitrooxypropanol on composition and functional properties of the milk fat fraction from Danish Holstein cows

Thu, 01 Aug 2024 08:57:37 +0200

The aim of this study was to determine the individual
and combined effects of supplementing fat with wholecracked
rapeseed (FAT), nitrate (NITRATE), and 3-nitrooxypropanol
(3-NOP) on compositional and functional
properties of milk fat. An 8 × 8 incomplete Latin square
design was conducted with 48 lactating Danish Holstein
cows over 6 periods of 21 d each. Eight diets were 2 ×
2 × 2 factorially arranged: FAT (30 or 63 g crude fat/kg
DM), NITRATE (0 or 10 g nitrate/kg DM), and 3-NOP
(0 or 80 mg 3-NOP/kg DM), and cows were fed ad libitum.
Milk samples were analyzed for general composition,
fatty acids (FA) and thermal properties of milk
fat. Milk fat content was decreased by supplementing
fat but increased by 3-NOP. The changes in FA composition
were mainly driven by the FAT × 3-NOP interaction.
Fat supplementation shifted milk FA composition
toward a lower content of SFA and greater contents of
MUFA and PUFA, whereas these effects became smaller
in combination with 3-NOP. However, 3-NOP had no
effects on SFA, MUFA, or PUFA in low-fat diets. Fat
supplementation lowered solid-fat content in milk fat
because of the decreased SFA content. The onset crystallization
temperature of milk fat was decreased by
3-NOP when supplemented in low-fat diets. According
to the FAT × 3-NOP interaction, supplementation of fat
without 3-NOP shifted the peak temperature of the lowmelting
fraction of milk fat toward low temperature as a
result of a decreased proportion of C16:0 and increased
proportions of C18:1 cis-9, C18:1 trans-11, C18:2 cis-9,
and CLA cis-9,trans-11. In conclusion, no additive effects
were observed among FAT, NITRATE, and 3-NOP
on chemical and thermal properties of milk fat, and fat
supplementation largely changed milk FA composition,
which in turn affected the thermal properties of milk fat.

Invited review

Vaarst, M., Ritter, C., Saraceni, J., et al. — Sun, 01 Dec 2024 08:57:37 +0100

Qualitative research related to humans, dairy cows, calves, and farming has been published by scientists from a variety of disciplines in many journals targeting dairy science audiences. We aimed to investigate how scientific communities other than those working in dairy science describe, analyze, and discuss dairy farming, because we found it important to bring this research to the attention of dairy scientists. In total, 117 articles were identified as involving one or more qualitative research methods in relation to dairy cattle. The review brought out a wealth of perspectives, new insights, and discussions related to dairy cattle, farmers, farming, and the sector, and in relation to societal issues and food and ecological landscapes. A broad range of qualitative research methods were used, and the literature targeted issues at the animal, farm, societal, food system, and landscape levels. Some raised critical questions about existing structures, highlighted unfairness in the industry, or pointed to new potential futures and contemporary agendas. We expect that it will be inspirational and stimulating for researchers to review new sources of literature and suggest a closer interdisciplinary collaboration among researchers from different disciplines for the future development of research involving dairy cattle. Further, it could be relevant and even necessary to engage in such interaction to avoid increasing polarization around future development of the sector—for example, related to climate change or how industrialization seems to push inequity or ignore the agency of animals themselves. Exploring perspectives of farming from different angles could enrich the outcomes of future dairy research.

Untargeted urine metabolomics suggests that ascorbic acid may serve as a promising biomarker for reduced feed intake in rabbits

Marín-García, P. J., Piles, M., Sánchez, J. P., et al. — Sun, 01 Dec 2024 08:57:37 +0100

Feed restriction is a common nutritional practice in rabbit farming; however, decreased feed intake can also signal potential digestive disorders at an early stage. This study endeavors to investigate the impact of feed restriction on selected productive traits and the urinary metabolome of juvenile rabbits across diverse genetic backgrounds. Our objective is to identify potential biomarkers capable of detecting periods of fasting. A total of 48 growing rabbits were used from two genetic types: Prat line (selected for litter size at weaning, n = 24) and Caldes line (selected for post-weaning growth rate, n = 24). At 60 days of age, a digestibility trial was carried out. Changes in productive traits (through bioelectrical impedance analysis, live weight control, average daily gain, energy, and protein retention) were evaluated when the animals were fed ad libitum from 60 to 64 days of age and when the same animals were subjected to feed restriction (50% of maintenance energy requirements) from 70 to 74 days of age, in a split-plot trial. In addition, untargeted urine metabolomics analysis was performed at both periods (ad libitum vs. restricted). Although some differences between genetic lines were observed in the animals’ performance traits (average daily gain and retention of energy and protein), no differences in the urine metabolome were found between genetic types. However, feed restriction caused notable changes in the metabolome. When the animals were subjected to feed restriction, they had higher levels of ascorbic acid (P = 0.001) and p-cresol sulphate (P = 0.058) and lower levels of pyrocatechol sulphate/hydroquinone sulphate (P < 0.001), resorcinol sulphate (P = 0.002), enterolactone sulphate (P < 0.001), enterolactone (P < 0.001), kynurenic acid (P = 0.0002), proline betaine (P < 0.001), pipecolic acid betaine (P < 0.001), xanthurenic acid (P < 0.001) and quinaldic acid (P < 0.001) than the same animals when they were fed ad libitum. This study proposes urine ascorbic acid as potential biomarker for fasting events in rabbits. As urine ascorbic acid is the sole metabolite that significantly increases in the restricted group, it offers promising indicator for early detection and targeted management of digestive disorders in rabbits.

Potential of 2 northern European brown seaweeds (Fucus serratus and Fucus vesiculosus) as enteric methane inhibitors in dairy cows

Thorsteinsson, M., Chassé, ., Curtasu, M. V., et al. — Sun, 01 Dec 2024 08:57:37 +0100

The 2 brown seaweeds, Fucus serratus and Fucus vesiculosus, have demonstrated antimethanogenic properties in vitro with reductions in CH₄ production ranging from 53 to 63%. This study aimed to investigate the effects of the 2 Fucus seaweeds on enteric CH₄ emissions, DMI, ECM, and nutrient digestibility when fed to dairy cows. The experiment was conducted using 4 multicannulated lactating Danish Holstein dairy cows, which over 3 experimental periods received either: (1) basal diet (CON; diet without any seaweed), (2) basal diet diluted with 4% (DM basis) Fucus serratus (SER), or (3) basal diet diluted with 4% (DM basis) Fucus vesiculosus (VES); resulting in one complete 3 × 3 Latin square and one incomplete 3 × 3 Latin square. Each period lasted 21 d and consisted of 14 d of adaptation, followed by 3 d of digesta sampling, and 4 d of gas exchange measurements using respiration chambers. Milk yield and feed intake were recorded daily. Blood samples were collected on d 15 and 17. All parameters were statistically analyzed using a mixed procedure of R. Opposite to what we had expected, neither of the 2 Fucus seaweeds reduced CH₄ emissions from the dairy cows as daily CH₄ production was significantly higher for both Fucus treatments compared with CON. Additionally, CH₄ yield (g CH₄/kg DMI) and intensity (g of CH₄/kg ECM) were significantly higher for SER compared with CON. Milk yield, DMI, and total-tract digestibility were unaffected by the treatments; however, SER resulted in lower milk protein yield (kg/d) and lower milk and blood plasma urea concentrations compared with CON. In conclusion, neither SER nor VES showed potential as methane-mitigating feed additives when fed to dairy cows at an inclusion level of 4% of DM. The inclusion of the 2 brown seaweeds had no effects on DMI, milk yield, or total-tract digestibility.

Chlorella and vegetable oil inclusion in diets for growing rabbits

Bordignon, F., Trocino, A., Marín García, P. J., et al. — Sun, 01 Dec 2024 08:57:37 +0100

The inclusion of microalgae in livestock diets has been shown to enhance animal productivity, immune response, and meat quality. However, the role of chlorella (Chlorella vulgaris) in growing rabbit nutrition has been scarcely explored, with available studies focusing on low inclusion levels (<1%) and their effects on rabbit growth and immune response. This study evaluated the growth performance, nutrient digestibility, plasma metabolites, caecal fermentative activity, and caecal microbiota composition of growing rabbits fed diets with different inclusion levels of chlorella and crude fat. A total of 648 mixed-sex Grimaud crossbred rabbits (33 d of age; 841 ± 140 g live weight) were fed six experimental diets (96 rabbits per diet for the growth trial) based on a bifactorial design with three dietary inclusion levels of chlorella (0, 1, and 2%) and two levels of crude fat (3 and 5%) obtained by the inclusion of soybean oil (1 and 3%, respectively). The trial lasted 38 days until slaughter. From 47 to 51 days of age, 72 rabbits (12 per diet) were submitted to a digestibility trial. At 51 days of age, samples of plasma and caecal content were collected from 36 rabbits (six rabbits per diet) to analyse plasma metabolites, caecal fermentations, and caecal microbiota. Rabbit live weight at 71 days of age (2 700 g, on average), weight gain (48.8 g/d) and feed conversion ratio (3.27) were unaffected by chlorella inclusion, while feed conversion ratio improved (−5%; P < 0.001) with an increase of crude fat from 3 to 5%. The digestibility of ADF (23.2 vs 20.9%; P < 0.05) and crude fat (83.8 vs 85.6%; P < 0.01) improved with the inclusion of chlorella at 2%, as well as the digestibility of crude fat (82.4 vs 86.9%; P < 0.001) and gross energy (57.3 vs 58.7%; P < 0.001) with crude fat inclusion at 5%. Plasma non-esterified fatty acids decreased (−19%; P < 0.05) in diets with 5% crude fat. Neither chlorella nor crude fat inclusion levels affected other plasma metabolites, caecal fermentations, or caecal microbiota. Overall, the inclusion of chlorella up to 2% in diets for growing rabbits did not significantly affect diet nutritional value, animal performance, or caecal activity. On the other hand, increasing crude fat to 5% improved the overall feed efficiency.

Measuring the Response Diversity of Ecological Communities Experiencing Multifarious Environmental Change

Fri, 01 Nov 2024 08:57:37 +0100

The diversity in organismal responses to environmental changes (i.e., response diversity) plays a crucial role in shaping community and ecosystem stability. However, existing measures of response diversity only consider a single environmental variable, whereas natural communities are commonly exposed to changes in multiple environmental variables simultaneously. Thus far, no approach exists to integrate multifarious environmental change and the measurement of response diversity. Here, we show how to consider and quantify response diversity in the context of multifarious environmental change, and in doing so introduce a distinction between response diversity to a defined or anticipated environmental change, and the response capacity to any possible set of (defined or undefined) future environmental changes. First, we describe and illustrate the concepts with empirical data. We reveal the role of the trajectory of environmental change in shaping response diversity when multiple environmental variables fluctuate over time. We show that, when the trajectory of the environmental change is undefined (i.e., there is no information or a priori expectation about how an environmental condition will change in future), we can quantify the response capacity of a community to any possible environmental change scenario. That is, we can estimate the capacity of a system to respond under a range of realistic or extreme environmental changes, with utility for predicting future responses to even multifarious environmental change. Finally, we investigate determinants of response diversity within a multifarious environmental change context. We identify factors such as the diversity of species responses to each environmental variable, the relative influence of different environmental variables and temporal means of environmental variable values as important determinants of response diversity. In doing so, we take an important step towards measuring and understanding the insurance capacity of ecological communities exposed to multifarious environmental change.

Resistomes from oxytetracycline-treated pigs are readily transferred to untreated pen mates

Tams, K. W., Larsen, A. R., Pedersen, K., et al. — Sun, 01 Dec 2024 08:57:37 +0100

Pork is currently a major part of Danish food export and is also a key dietary source of protein across the world. Industrial pork production, however, comes with high antibiotic usage in many countries, including Denmark. This has created consumer demand for meat Raised Without Antibiotics (RWA). Previous work has demonstrated that levels of antibiotic resistance genes (ARGs) are indeed increased in antibiotically treated animals, but also suggest that these ARGs are transferred to untreated pen-mates. In a Danish commercial farm, we studied four groups of physically separated pigs: one group of only antibiotic treated pigs (n = 20), one group of only untreated pigs (n = 30 total, n = 15 analysed), and one group combining treated (n = 15) and untreated pigs (n = 15). These groups were followed for 16 weeks during which all pigs were profiled for both their faecal microbiome (through 16 S rRNA gene sequencing) and resistome (by use of a high-throughput qPCR platform targeting 82 ARGs and their variants). We found that the resistome of treated pigs was substantially enriched in resistance genes compared to untreated pigs but, importantly, observed that untreated pigs co-reared with treated pigs had levels of resistance genes approaching their treated pen mates, suggesting that the treated enterotype is readily transferred to the untreated animal. From this, we conclude that mixing of treated and untreated pigs causes spill-over of antibiotic resistant bacteria and/or resistance genes from treated pigs when these are co-reared. To optimize RWA production, treated and untreated pigs should be physically separated to limit the proliferation of ARGs.

Forb-rich silage feeding increases milk n-3 and n-6 fatty acid content in practical dairy farming: results from three Danish organic farms

Lashkari, S., Bonefeld Petersen, M. ., Jensen, S. K. — Wed, 11 Sep 2024 08:57:37 +0200

Milk production and milk fatty acid (FA) composition were followed in three Danish commercial organic dairy farms where grass clover silage was substituted with a forb-rich silage. Farms A, B, and C included a total of 50, 189, and 235 lactating dairy cows, and 20 cows in each herd were selected to record the productive performance and milk composition. In all farms, 70% of diets were grass clover silage, and during the experiment, forb-rich silage gradually replaced grass clover silage during the 2–4 weeks, where after cows were fed the forb-rich silage diets for additional 2 weeks. The data were separately analyzed in each farm. Milk production at farms A and B was not affected by diet change, but milk production at farm C decreased by 1.7 kg energy corrected milk (ECM)/cow in cows fed the forb-rich silage. Regardless of farm, the proportion of C18:3n-3, C18:2n-6, and conjugated linoleic acid (CLA) isomers in milk from cows receiving the forb-rich silage increased compared to cows fed grass clover silage based diets. The results indicate the possibility for further increase in the content of poly-unsaturated fatty acids (PUFA) in organic milk by substituting grass clover silage with forb-rich silage.

Behaviour of Cows with Johne’s Disease (Paratuberculosis)

Charlton, G., Churches, J., Bleach, E. C. L., Thorup, V. M. — Mon, 11 Nov 2024 08:57:37 +0100

Johne’s disease (JD) significantly reduces the welfare of cattle worldwide. As changes in lying and feeding behaviours are considered important tools for assessing health and early detection of diseases, the aim of this study was to compare lying and feeding behaviours of JD-positive (JD5) and JD-negative (JD0) cows around peak lactation. The cows were fitted with an accelerometer-based sensor to record step counts and lying behaviour. They were also fitted with a pressure-based halter from approximately 56 d post-partum to collect feeding and rumination data. Every 3 months, the cows were milk sampled to test for naturally occurring JD using an ELISA. JD5 cows [n = 14 (two positive results in any four consecutive ELISAs)] were matched to JD0 cows [n = 14 (consecutive negative ELISAs)] based on lactation stage, parity, age, and milk yield. Of the 28 cows, 9 JD5 and 9 JD0 cows provided sensor data for analysis. JD5 cows spent 1.7 h/d less lying compared to JD0 cows. No differences in time spent eating were found; however, JD5 cows spent 1.1 h/d longer ruminating and produced 80 more feed boluses/d than JD0 cows around week 8 of lactation. The reason JD5 and JD0 cows behave differently around peak lactation is unclear and therefore warrants further investigation focusing on behaviour, milk yield, and feed intake among cows with JD.

Effects of astragalus polysaccharide on immune responses of porcine PBMC stimulated with PRRSV or CSFV

Zhuge, Z. Y., Zhu, Y. H., Liu, P. Q., et al. — Mon, 09 Jan 2012 08:57:37 +0100

Background: Astragalus polysaccharide (APS) has been used as an immunomodulator that can enhance immune responses, whereas the immunomodulatory effects of APS on porcine peripheral blood mononuclear cells (PBMCs) exposed to porcine reproductive and respiratory syndrome virus (PRRSV) and classical swine fever virus (CSFV) have not been investigated. Methodology/Principal Findings: Porcine PBMCs were cultured in complete RPMI media in the presence of the R98-strain of PRRSV (5×10 ⁴ TCID ₅₀/ml) or C-strain of CSFV (10 ³ TCID ₅₀/ml) with or without APS. The expression of mRNA for CD28, cytotoxic T-lymphocyte antigen 4 (CTLA-4), transforming growth factor-β (TGF-β), interleukin 2 (IL-2) and IL-10 was assayed by TaqMan real-time RT-PCR. The expression of mRNA for CD28 and CTLA-4 increased at 24 h after stimulation of PBMCs with CSFV and the increased production of CTLA-4 was confirmed by western blot analysis, whereas the increases were inhibited by the addition of APS. In addition, APS alone upregulated IL-2 and TGF-β mRNA expression in PBMCs and the addition of APS had the capacity to prevent a further increase in IL-2 mRNA expression in PBMCs during CSFV or PRRSV infection, but had no effect on TGF-β mRNA expression. The production of tumor necrosis factor-alpha (TNF-α) increased at 12 h after stimulation with PRRSV or CSFV, but not with PRRSV plus APS or CSFV plus APS, whereas the addition of APS to PBMCs infected with PRRSV or CSFV promoted IL-10 mRNA expression. Conclusions: We suggested that APS had immunomodulatory effects on cells exposed to PRRSV or CSFV. It might be that APS via different mechanisms affects the activities of immune cells during either PRRSV or CSFV infection. This possibility warrants further studies to evaluate whether APS would be an effective adjuvant in vaccines against PRRSV or CSFV.

Effect of nitrate supplementation on diurnal emission of enteric methane and nitrous oxide

Wang, W., Larsen, M., Weisbjerg, M. R., Hellwing, A. L.F., Lund, P. — Fri, 01 Nov 2024 08:57:37 +0100

The objective of this study was to investigate the effect of nitrate supplementation on diurnal enteric methane (CH₄) and nitrous oxide (N₂O) emissions in dairy cows. Four Danish Holstein dairy cows fitted with ruminal cannulas were used in a 2 × 2 crossover design with 2 periods of 14 d duration. Cows were fed ad libitum with 2 experimental diets based on either urea or nitrate (8.6 g of NO₃⁻/kgofDM) supplementation. Samples of ruminal fluid, blood, and rumen headspace gas samples were collected. Gas exchange was measured in respiration chambers during a 96-h period. Emission of N₂O was calculated from the ratio between CH₄ and N₂O in the rumen headspace and the measured CH₄ emission. Nitrate supplementation resulted in a lower daily CH₄ production (g/d), CH₄ yield (g/kg of DMI), and CH₄ per kilogram of fat- and protein-corrected milk yield; a tendency of lower CH₄ intensity (g/kg ECM); and higher daily hydrogen (H₂) production, H₂ yield, and daily N₂O production compared with urea supplementation. The only difference in ruminal VFA composition was a higher valerate proportion in cows receiving nitrate compared with urea supplementation. In conclusion, nitrate compared with urea supplementation reduced CH₄ production, mainly just after feeding, but also increased N₂O production.

Notat vedrørende miljø- og klimateknologier – screening af teknologier. Del 1

Nørremark, M., Hansen, M. J., Adamsen, A. P. S., et al. — Mon, 25 Nov 2024 08:57:37 +0100

Klovbeskæring øger overlevelsen

Thomsen, P. T. — Thu, 01 Aug 2024 08:57:37 +0200

Flyt nakkebommen, når kvier flyttes

Thomsen, P. T. — Sun, 01 Sep 2024 08:57:37 +0200

Højere ydelse, når goldkøer kommer på græs

Thomsen, P. T. — Fri, 01 Nov 2024 08:57:37 +0100

Early-life cow-level risk factors for sole ulcers in primiparous dairy cows

Thomsen, P. T., Houe, H. — Fri, 01 Nov 2024 08:57:37 +0100

Dietary protein requirement of hyper-prolific sows in late gestation

Johannsen, J. C., Sørensen, M. T., Bruun, T. S., Feyera, T. — Sun, 01 Dec 2024 08:57:37 +0100

This study aimed to determine the protein requirement of hyper-prolific sows in late gestation. Forty-eight multiparous sows were assigned to one of six dietary treatments according to body weight (BW; 287 ± 5 kg) on d 84 of gestation and parity (3.8 ± 0.1) and fed 3.3 kg/d from d 84 to 108 of gestation. Five dietary treatments had increasing concentrations of dietary protein [expressed as standardized ileal digestible (SID) lysine (Lys); 3.05 to 6.90 g/kg]. The sixth treatment (high-cAA) had reduced crude protein (CP) relative to Lys concentration and was supplemented with crystalline amino acids (AA), so that the concentration of the supplemented AA matched that of the diet containing 6.90 g/kg of SID Lys and the remaining essential AA matched that of the diet containing 3.05 g/kg of SID Lys. Sow BW and backfat thickness (BF) were measured and blood was sampled on d 84, 96 and 108 of gestation and weekly during lactation. Deuterium oxide was injected on d 84 and 108 of gestation and on d 3 and 28 of lactation to estimate sow body composition. A nitrogen (N) balance was conducted on d 107 of gestation. At the onset of farrowing, colostrum and blood were sampled from the sows and number and birth time of live- and stillborn piglets, and birth weight of liveborn were recorded. Piglets were weighed and colostrum sampled at 12, 24, and 36 h after the onset of farrowing, and thereafter weekly weighing and milk sampling during lactation. From d 84 to 108 of gestation sow BW increased with SID Lys until reaching a plateau at 5.63 g/kg of SID Lys (P = 0.02) and sow BF had a polynomial relationship with SID Lys, which peaked at 4.85 g/kg of SID Lys (P = 0.04). On d 107 of gestation, N retention and utilization increased linearly with SID Lys and reached plateaus at 5.60 (P < 0.001) and 5.07 g/kg of SID Lys (P < 0.01), respectively. Reproductive parameters were not affected by dietary treatments and there were no indications of carry-over effects to lactational performance. During the treatment period, sows fed the high-cAA diet had higher BW (P < 0.01) and body protein (P = 0.02) gain than sows fed 3.05 g/kg of SID Lys and on d 107 of gestation they had reduced excretion of urea and N in urine (P < 0.001 for both) relative to sows fed 6.90 g/kg of SID Lys. Also, compared to any other treatment, the plasma concentration of sows fed the high-cAA diet gradually decreased during the treatment period (P < 0.01), indicating reduced AA oxidation. In conclusion, a SID Lys concentration of 4.85 to 5.07 g/kg (16.0 to 16.7 g/d) from d 84 to 108 of gestation ensures optimal utilization of N and maximizes BF gain in hyper-prolific sows. Piglet and litter birth weight and sow milk yield were unaffected by dietary concentration of SID Lys. Feeding late gestating sows diets with reduced CP relative to Lys and supplemented with crystalline AA, improved N balance, with no indications of impaired reproductive and subsequent lactational performance or reduced maternal gain, suggesting that the AA composition of the high-cAA diet met the sows’ requirement for essential AA.

Consecutive mating of black soldier fly males to produce full- and half-sibling offspring

Jensen, K., Thormose, S., Noer, N. K. ., et al. — Mon, 01 Jan 2024 08:57:37 +0100

In animal breeding programs, utilizing quantitative genetic designs such as full/half sibling design is fundamental. This however demands that mating can be controlled, including having individual males mating with several females. In the literature, black soldier fly (BSF) males and females are reported to have to gather in lekking groups to engage in competitive displays and courtship rituals before they will mate. This lekking behavior is described as crucial for establishing suitable mating conditions, and mating of BSF pairs or individual sires is therefore assumed impossible. We show that an individual virgin male can be successfully mated with an individual virgin female. Furthermore, we show that an individual male can mate several virgin females, in our experiment up to four, consecutively within up to four hours and produce eggs and offspring with each mated female. Our findings pave the way for moving beyond mass selection to now include pedigree information in BSF breeding. This has the potential to allow selection for multiple traits simultaneously, control inbreeding, and increase rates of selection responses compared to phenotypically based mass selection.

Will the use of DON detoxification of feed using sodium metabisulfite and sodium sulfite increase the level of sulfite in feed?

Nørgaard, J. V. — Mon, 18 Nov 2024 08:57:37 +0100

Neighborhood Disadvantage and Birth Outcomes Among Refugees

Fri, 01 Nov 2024 08:57:37 +0100

OBJECTIVE: To examine the association between neighborhood socioeconomic disadvantage and birth outcomes among refugee women in Denmark, leveraging a natural experiment. METHODS: This register-based study included 15 118 infants born to women who arrived in Denmark as refugees during 1986 to 1998, when a dispersal policy was in place that quasirandomly assigned newcomers to neighborhoods with varying degrees of socioeconomic disadvantage. Neighborhood disadvantage was measured using a composite index representing neighborhood-level income, education, unemployment, and welfare assistance. These data were linked to individual-level birth register data. Outcomes included low birth weight, preterm birth, and small-for-gestational-age infants. Associations between neighborhood disadvantage at resettlement and birth outcomes up to 20 years after resettlement were examined using multivariable regressions adjusting for characteristics of the women at resettlement. RESULTS: Each SD of increase in neighborhood disadvantage was associated with an 18% increase in low birth weight risk (0.61 percentage points [pp], 95% confidence interval [CI]: 0.19-1.02), 15% increase in preterm birth risk (0.64 pp, 95% CI: 0.22-1.07), and 7% increase in small-for-gestational-age risk (0.78 pp, 95% CI: 0.01-1.54) 5 years after resettlement. Results did not differ after adjusting for urbanicity and conational density, but associations were attenuated after adjusting for municipality-level fixed effects, suggesting that local government characteristics may partially explain the associations. CONCLUSIONS: Resettling in a disadvantaged neighborhood is associated with higher risk of adverse birth outcomes among refugee women. This highlights how policy decisions affecting settlement of refugees can have long-term consequences, including on the health of the next generation.