Intensive Dairy Research Articles

Influence of diverse pasture species and reduced nitrogen fertiliser inputs on soil health on four irrigated Canterbury dairy pastures

Maintaining and improving the health of pastoral soils is important to enable the provision of ecosystem services for sustainable production. We investigate the impacts of increasing pasture species diversity and reducing nitrogen (N) fertiliser inputs on pasture productivity and the flow on effects for soil health on four irrigated dairy farms in Canterbury. The soils had generally good health prior to pastures being resown. During the establishment of both simple and diverse pastures there was a decline in Olsen P, soil organic carbon (C), total N and potentially available N to below target levels. In the year following pasture establishment there was no difference in herbage accumulation between the simple and more diverse pastures under irrigation. For both simple and diverse pastures, grass species contributed approximately 50%, legumes 15%, and herbs 20% of the total dry matter harvested. Although there was a reduction in pasture growth as N fertiliser inputs were reduced, legume content did not decline significantly and differences in soil health were not observed at this stage. Despite the farms being intensive dairy systems, the data suggests good soil health prior to pasture establishment. Hence maintaining soil health as well as its restoration following disturbance present opportunities for these farms.

The most common diseases in intensive dairy cattle farms in the Mediterranean region

This study was conducted in an intensive dairy cattle farm with a capacity of 200 lactating cow in the Mediterranean region. In this study, 2-year health records in the farm were systematically analysed. The common diseases seen in the records were determined and the recurrence status and the periods of occurrence were determined. Based on the information obtained from the records of the farm , the most common diseases and the diseases that affect the efficiency of the farm the most were determined and evaluated here. In the results, it was understood that the most common diseases treated in the dairy farming operating in the Mediterranean region in a period of 2 years were mastitis, lameness, reproductive problems and metritis.

Association Between Dairy Production System and Milk Functionality Based on Analysis of miRNAs in Exosomes from Milk.

Dairy farming practices significantly affect the nutritional and functional properties of milk. This study compares miRNAs in milk exosomes from extensive and intensive dairy systems and explores their potential implications for human consumers. Extensive systems are believed to produce milk of higher quality with better animal welfare compared to intensive systems. Milk samples from eight extensive and nine intensive dairy farms were analysed. Milk-derived extracellular vesicles were isolated through sequential ultracentrifugation and characterised through Dynamic Light Scattering and Nanosight to determine the size and the concentration of the extracellular vesicles, in addition to immunoblotting to ensure the presence of exosome-specific proteins in their membrane. miRNA levels were quantified using RT-qPCR, and metabolic pathways associated with miRNAs showing significant differences between farm groups were analysed. EVs from extensive farms had higher concentrations. Notably, bta-miR-451 levels were significantly higher in milk from extensive farms (p = 0.021). Like human miRNA hsa-miR-451, it is linked to pathways related to Parkinson's disease and cancer. Our research suggests that milk production in extensive systems not only provides socioeconomic and environmental benefits but may also have positive effects on human health. Further research is warranted to explore the bioactive potential of these miRNAs and their implications for human health.

Impact of Feed Bunk Space on the Prevalence of Torsion and Foreleg Distal Asymmetry in Holstein Cows.

Leg torsion and distal asymmetry (LTDA) among cows reared on intensive farms in the Comarca Lagunera region of northern Mexico may be indicative of underlying health concerns. To ascertain whether the incidence of LTDA is associated with trough measurements and with productive, reproductive, and disease variables, the prevalence of LTDA was determined in lactating dairy cows. The data were derived from two intensive dairy farms in northern Mexico (G60: 2043 cows in 13 pens with 142.0 m of linear feed bunk space and 65.0 m of pen depth; G100: 2227 cows in 12 pens with 215.0 m of linear feed bunk space and 49.0 m of pen depth). The cows were observed over the course of a week to identify any macroscopic lesions indicative of LTDA. Cows exhibiting lesions were assigned a value of "1", while those without lesions were assigned a value of "0". Furthermore, data regarding other limb diseases (LDs) were collected and subjected to analysis. A comparison was conducted to ascertain the impact of reproductive, productive, and feed bunk size variables on the prevalence of LTDA and other LDs. To ascertain the prevalence of LTDA and LDs, a chi-squared test was employed. The prevalence of LTDA was found to be 27.6% (G60: 31.4%, G100: 22.4%). No association was identified between LTDA and the variables included in the study. However, a correlation was identified between LDs and the following variables: total width, distance from the edge, width from the feed bunk to the tramp, and the presence of a manure crust on the walls. Principal component analysis (PCA) was conducted to examine the correlation between LDs and various factors at the farm and pen levels. The findings indicated that the distance from the feed bunk to the trough, the presence of manure crusts on the walls, and the breeding time were associated with LDs in G100, as well as in three of the twelve pens (302, 306, and 308) within G100. The findings suggest that the prevalence of LDs is associated with an increase in the width of the feed bunk and the width of the manure crust on the walls, particularly in pregnant cows. The results permit the conclusion that LTDA and LDs are associated with the measurements of the feed bunks, the absence of manure cleaning of the feed bunks, and gestation. This association gives rise to significant health issues for Holstein cows on these farms, with more than one in four cows affected. To reduce the prevalence of LTDA in lactating dairy cows, it is recommended that the standard measurements for feed bunk design be adhered to. This will reduce the prevalence of LTDA and LDs, promote the cleaning protocols to avoid the accumulation of manure crusts, and facilitate close monitoring of pregnant cows, thereby alleviating the impacts of these foot pathologies on animal welfare.

A semi-quantitative risk model for dairy farms to pinpoint and break source-pathway connections between nutrient sources and open drainage channel sections

IntroductionOn intensive grassland dairy farms in high rainfall areas with poorly drained soils, networks of open drainage channels linked to in-field drainage systems are needed to enable farm operations. Nitrogen and phosphorus point and diffuse sources may be connected to this open drainage channel network along surface and subsurface pathways, with negative impacts upon delivery to the downstream aquatic system.MethodsThis study developed a semi-quantitative risk assessment model by: (1) selecting parameters (categorical or continuous) representing the nutrient transfer continuum and (2) scoring (relative magnitude and impact) the risk of nutrient source connectivity and delivery for every open drainage channel section across seven dairy farms.Results and DiscussionA Risk Index Classification System consisting of low, medium, high, or very high-risk class was developed, with high or above requiring a mitigation plan. Results showed that 23%, 68%, 9% and 0% of all open drainage channels on study farms were identified as low, moderate, high and very high-risk, respectively. A range from 2% to 25% per farm of the open drainage channels was classified as high-risk that potentially needed mitigation, although none was identified as very high-risk. Two-thirds of the high-risk open drainage channels were connected to the farmyards, with potential for high nutrient loss from point sources. A combined approach of source management and targeted breaking of the pathway (e.g., in-channel filters, water diversion bars) may help minimise nutrient losses from high risk open drainage channels on poorly draining soils.

Effects of High-Grain Diet on Performance, Ruminal Fermentation, and Rumen Microbial Flora of Lactating Holstein Dairy Cows.

The objectives of the current study were to evaluate the fluctuations in production performance, rumen fermentation, and microbial community in lactating dairy cows fed a high-grain diet (HG). In this study, 16 healthy Holstein lactating dairy cattle with similar milk yields of 16.80 ± 4.30 kg/d, days in milk 171.44 ± 23.25 days, and parity 2.2 ± 1.5 times were selected and randomly allocated into two groups. One group was fed a low-grain diet (LG; 40% concentrate, DM basis; n = 8), and the other group was fed a high-grain diet (HG; 60% concentrate, DM basis; n = 8). The experiment lasted 6 weeks, including 1 week for adaptation. The experimental results showed that the milk fat content in the milk of lactating cows in the HG group was significantly reduced (p < 0.05), and the milk urea nitrogen (MUN) content showed an increasing trend (0.05 < p < 0.10) compared with the LG group. Compared with the LG group, rumen fluid pH was significantly decreased after feeding a high-grain diet, and contents of total volatile fatty acids (TVFA), acetate, propionate, and butyrate were significantly increased (p < 0.05). The acetate/propionate significantly decreased (p < 0.05). HG group significantly increased the abundance of Prevotella and Bacteroides in rumen fluid while significantly reducing the abundance of Methanobrevibacter and Lachnospiraceae ND3007_group (p < 0.05). Microorganisms with LDA scores > 2 were defined as unique, with the bacterial genus Anaerorhabdus_furcosa_group identified as a biomarker for the LG group, and the unique bacterial genus in the HG group were Prevotella, Stenotrophomonas, and Xanthomonadaceae. The prediction results of microbial function showed that a total of 18 KEGG differential pathways were generated between the two treatment groups, mainly manifested in metabolic pathways, signal transduction, and the immune system. In conclusion, the HG group promoted rumen fermentation by altering the microbial composition of lactating cows. Our findings provide a theoretical basis for the rational use of high-grain diets to achieve high yields in intensive dairy farming.

Postponing first colostrum collection: impact on immunoglobulin G in goat colostrum

This experiment was motivated by the need to understand the impacts of delaying the first colostrum collection on immunoglobulin G (IgG) concentrations in goat colostrum, addressing a gap in caprine-specific research, despite its significance in dairy farming. Concurrently, we examined the relationship between colostral IgG, total protein (TP) and Brix values. Two colostrum samples were collected from 56 Saanen goats, one from each udder half. The first sample was collected from the right teat immediately postbirth, and the second sample was collected from the left teat at one of the predetermined postpartum intervals: 0, 4–6, 8–10, or 12–14 h postpartum, each time interval comprising 14 goats. Colostral IgG was determined by ELISA, Brix was determined by digital refractometry, and TP was determined by the Bradford protein method. Sperman’s correlations and Lin’s concordance correlation coefficient were used to determine the direction and strength of the association and to assess agreement (prediction accuracy) between methods, respectively. Receiver operator characteristic analysis was used to determine Brix and TP thresholds for predicting good-quality colostrum using several cut-offs (20, 30, 40, and 50 g/L IgG). Mean (± SD) for colostral IgG, Brix, and TP were 54 ± 22.6 g/L, 22 ± 5.0%, and 12 ± 2.8 g/dL, respectively. The statistical analysis did not provide evidence of a significant impact of time of first collection (up to 14 h postpartum), on IgG, Brix, and TP. Brix and IgG values exhibited both a high degree of correlation (r = 0.89–90) and concordance (ρc = 0.89–90), indicating a strong and reliable relationship between the two measurements. The prevalence of samples ≥ 20, 30, 40, and 50 g of IgG/L were 96, 88, 71, and 54%, respectively. Optimal Brix and TP thresholds predicting IgG ≥ 20, 30, 40, and 50 g/L IgG were 13.8, 17.5, 20.1, and 22.5%, and 6.8, 9.3, 10.8, and 11.1 g/dL, respectively. Increasing the IgG threshold resulted in lower sensitivity but higher specificity for estimating colostral IgG using Brix or TP values. The present findings indicate that delaying the first colostrum collection up to 14 h postpartum did not result in conclusive changes in colostral IgG concentration, Brix values, or total protein levels. Our results also confirm the reliability of Brix refractometry as an on-farm tool for estimating IgG concentrations in goat colostrum. These results are particularly relevant to intensive dairy systems, offering insights to enhance colostrum management and task prioritisation, especially during the bustling kidding periods.

Potential of slurry from intensive dairy cattle farms for paulownia and populus trees, as organic fertilizer: i. effect on production

Intensive dairy cattle breeding have a relevant social and economic impact in Portugal, particularly in the northern region. This activity generates a high flow of livestock effluents (slurry), rich in important nutrients for plant growth, which can be introduced into forest production systems. These effluents can provide a good alternative to mineral fertilizers, not only from an economic perspective, but also from the point of view of soil fertility resilience. In the present study, the effect of increasing doses of slurry on tree growth was evaluated in clones of Paulownia and Populus, as they are genotypes that have a high efficiency in the mobilization of soil nutrients and in the capture of CO2 from the atmosphere, as well as high biomass calorific value. To this end, a demonstration field was installed, where the trees were planted with the compasses of: 2.5 x 1.5 m and 2.5 x 0.75 m, respectively for Paulownia and for Populus. In the field, the following treatments were performed: T0 - no fertilization, either mineral or organic; T1 - amount of slurry equivalent to 85 kg of N ha-1; T2 - amount of slurry equivalent to 170 kg of N ha-1; T3 - amount of slurry equivalent to 340 kg of N ha-1, either with or without inoculation prior to transplantation, with mycorrhizal arbuscular fungi and plant growth-promoting bacteria. Results evidenced a positive effect of the slurry application, both in the diameter at breast height and in total stand height, showing its fertilizing potential which should later be assessed on the ability to constitute an alternative or, simply, a complement to mineral fertilization.

A Review of the Effects of Stress on Dairy Cattle Behaviour.

In this narrative review, the authors summarise the relationship between stress and behaviour and how dairy cattle cope with stressors. Based on the available literature, the most common stressors in intensive dairy cattle farming, such as pain, disease, heat stress, poor comfort caused by technology, and social stress, are surveyed. The authors describe how these stressors modify the behaviour of dairy cattle, influencing their feeding patterns, social interactions, and overall well-being. Additionally, the review explores the effectiveness of various coping mechanisms employed by dairy cattle to mitigate stress, including physiological adaptations and behavioural responses. This review is a valuable resource for understanding and grading stress in dairy cattle through behavioural reactions. Elucidating the intricate interplay between stressors and behaviour offers insights into potential interventions to improve animal welfare and productivity in dairy farming. Furthermore, this review highlights areas for future research, suggesting avenues for more comprehensive behavioural studies to enhance our understanding of stress management strategies in dairy cattle.

Low-performance diagnosis of covered anaerobic lagoons as a waste management strategy in the intensive dairy industry

ABSTRACT Covered anaerobic lagoons (CALs) are Latin America's main livestock waste treatment systems. Mexico has 680 CALs that present low biogas yields (0.05 m3 m−3 digester d−1) and low COD removal rates (< 60%). This work focused on diagnosing CAL´s low performance in dairy farms by determining and analyzing operational parameters. Seven CALs located in the main dairy basin of Mexico were analyzed. The sampling areas for each CAL were the supernatant, the active zone, settled sludge, and digester inlet and outlet. The variation of the process parameter values corroborated that CALs appeared stratified and not working as expected. The sludge zone, comprising 50–58% of total solids content and 1–15% of total CALs volume, showed an elemental compounds content suitable for organic fertilizer (340, 48, and 5 kg t−1 of C, N, and S, respectively). However, this zone contained, at least, 85% of the slowly hydrolysable material; the methanogenic potential was less than 87 mL CH4 g VS−1, and the C/N ratio ranged from 4.9 to 17, outside of the optimal range. The biogas produced did not exceed 60% of methane content and more than 3000 ppm of H2S. The sludge zone significantly influences the lagoon's dynamics since it is a nutrient sink. Furthermore, the lack of agitation is the leading cause for the low energy yield and the low removal of organic matter rate. This work provides valuable information to address the operational problems within the CALs improving our understanding that shall allow proposing reactivation alternatives.

Assessing the feasibility of test-and-cull and test-and-segregation approaches for the control of high-prevalence bovine tuberculosis in Ethiopian intensive dairy farms

Bovine tuberculosis (bTB) is endemic and has a substantial impact on the livestock sector in Ethiopia and other low and middle-income countries (LMICs). With a national emphasis on dairy farm intensification to boost milk production and spur economic growth, the incidence of bTB is anticipated to rise. However, Ethiopia, like other LMICs, lacks a comprehensive national bTB control strategy due to the economic and social infeasibility of traditional test-and-cull (TC) approaches. To inform the development of such a strategy, we evaluated the effectiveness and feasibility of TC and test-and-segregation (TSg) strategies for bTB control on Ethiopian dairy farms. A TC approach was used at Farm A [N = 62; comparative cervical test (CCT) > 4 mm, starting prevalence 11.3%] while TSg was implemented at Farm B (N = 45; CCT > 4 mm, prevalence 22.2%), with testing intervals of 2–4 months. Both strategies achieved a reduction in bTB prevalence to 0%, requiring seven rounds of TC over 18 months at Farm A, and five rounds of TSg over 12 months at Farm B’s negative herd. The results show that adopting more sensitive thresholds [CCT > 0 mm or single cervical test (SCT) > 2 mm] during later rounds was pivotal in identifying and managing previously undetected infections, emphasizing the critical need for optimized diagnostic thresholds. Cost analysis revealed that TC was approximately twice as expensive as TSg, primarily due to testing, labor, and cow losses in TC, versus construction of new facilities and additional labor for TSg. This underscores the economic and logistical challenges of bTB management in resource-limited settings. Taken together, our study highlights an urgent need for the exploration of alternative approaches including TSg and or vaccination to mitigate within herd transmission and enable implementation of bTB control in regions where TC is not feasible.

Dynamic Prediction of Total N and P Contents in Slurry from Dairy Farms under Different Treatment Processes Using Near-Infrared Spectroscopy

Nutrient content fluctuation in dairy production slurry is highly influenced by the various treatment processes applied in the Chinese dairy sector. The dynamic measurement of these contents is critical for the practical and efficient field application of slurry subjected to various processes. In the study, a total of 715 slurry samples were collected from 24 intensive dairy farms in Tianjin subjected to three typical treatment processes. Descriptive statistical analysis, principal component analysis, and partial least square regression were used to investigate the variation in total nitrogen (TN) and total phosphorus (TP) contents, spectral characteristics, and the performance of the prediction model of the slurry under the processes, respectively. Results revealed significant differences in both TN and TP contents along with the spectra for the slurry subjected to different treatment processes. All the inter-process models showed poor performance, and the results were worse compared to the intra-process models. Among the intra-process models for TN, the optimally performing models were the Pac fusion model (R2pred = 0.82; RPD = 2.38) and the single model Pa (R2pred = 0.83; RPD = 2.31). Among the intra-process models for TP, the optimum results were seen for Pab (R2pred = 0.77; RPD = 2.07) and Pa (R2pred = 0.79; RPD = 2.30). Taking different treatment processes into consideration is essential to establish flexible models that can be adaptive for diversified scenarios. This would be helpful to improve the tracking monitor measures, efficiently guide the land application of slurry, and support the sustainable development of animal farming and environmental conversation.

Understanding dairy farmers' trade‐offs between environmental, social and economic sustainability attributes in feeding systems: The role of farmers' identities

AbstractThere is scope for improving the sustainability of intensive dairy farms through the uptake of sustainable production practices such as more grass‐based feeding systems. Such feeding systems can reduce feed‐food competition and the environmental impacts of feed production, among other farm‐level and societal benefits. However, empirical research on how farmers' feed choices mis(align) with sustainability transitions and the associated drivers is limited. This paper explores the trade‐offs that farmers make between the environmental, social and economic sustainability impacts of grass‐based feeding systems based on data from Swedish dairy farmers. Using an identity‐based utility framework and a hybrid latent class model, we find substantial heterogeneity in dairy farmers' trade‐offs between feed‐related sustainability attributes: greenhouse gas emissions, biodiversity, animal welfare, feed self‐sufficiency, feed cost and milk yield. Furthermore, our findings demonstrate that farmers who are strongly interested in the environmental and social sustainability impacts of their dairy feeding systems, beyond economic gains, are motivated mainly by their pro‐environmental and pro‐social identities. Overall, our findings imply that identity‐enhancing interventions are promising policy instruments for encouraging the uptake of more grass‐based feeding systems.

Nitrogen loss partitioning and emissions in intensive subtropical hybrid dairy systems

Nitrogen loss partitioning and emissions in intensive subtropical hybrid dairy systems

Study on the Constraints and Practical Knowledge for Intensive Dairy Cattle Farming in Mongolia

The given text highlights the importance of managing the intensive farming of Mongolian dairy cattle effectively to improve the quality of dairy products and promote the livestock industry's comprehensive development. The livestock industry is a crucial pillar of Mongolia's economy, contributing about 12% to the annual GDP. However, Mongolia's dairy industry has not been fully developed, and there has been a significant increase in the quality and demand for dairy products in recent years due to urbanization. The text also discusses the challenges faced by Mongolian livestock farming, such as the extensive farming practices, harsh winters, and lack of management and planning. The author suggests standardizing the standards for large-scale ranch management operations and practical operations of modern ranch management systems to enhance the livestock industry's intensification, scaling, organization, socialization, and industrialization. The text also highlights the need to improve the management level of breeders, plan the construction of breeding farms rationally, strengthen the inspection efforts of relevant departments, and enhance technical research to address the problems existing in intensive management. Overall, the text provides a comprehensive study on developing the livestock industry and promoting the healthy and sustainable development of the livestock economy.

The effectiveness of a virtual fencing technology to allocate pasture and herd cows to the milking shed

Virtual fencing technology provides an opportunity to rethink the management of intensive grazing systems in general, yet most studies have used products developed and applied to more extensive livestock systems. This research aimed to assess the application of a virtual fencing technology developed for the intensive pastoral dairy industry. The Halter system uses 2 primary cues, sound and vibration, and one aversive secondary cue, a low energy electrical pulse, to confine cows to a pasture allocation and remotely herd cows. Two groups of 40 mid-lactation multiparous dairy cows were studied (Bos taurus, predominantly Friesian and Friesian × Jersey, parity 1-8). Cows were milked twice per day and provided 9 kg pasture DM/day in a 24-h allocation, supplemented with 7 kg silage and 6 kg grain DM/day. Training to the Halter system occurred over 10 d after which cows were managed with the technology for a further 28 d. The type and time of cues delivered was recorded by each collar and communicated via a base-station to cloud data storage. Cows took less than a day to start responding to the sound cues delivered while held on a pasture allocation and were moving to the milking parlor without human intervention by d 4 of training. On training d 1, at least 60% of sound cues resulted in an electrical pulse. Across training d 2-10, 6.4% of sound cues resulted in a pulse. After the 10-d training period, 2.6% of sound cues resulted in a pulse. During the management period, 90% of cows spent ≤1.7 min/d beyond the virtual fence, received ≤ 0.71 pulse/d in the paddock and received ≤ 1 pulse/d during virtual herding to the parlor. By the final week of the management period, 50% of cows received zero pulses/week in the paddock and 35% received zero pulses/week during virtual herding. The number of pulses delivered per day and the pulse:sound cue ratio was lower in this study than that previously reported using other virtual fencing technologies. We conclude that the Halter technology is successful at containing lactating dairy cows in an intensive grazing system as well as at remotely herding animals to the milking parlor.

Climate and environmental effects of nutritional mitigation options to reduce enteric methane in dairy cattle: A life cycle assessment

Nutritional mitigation strategies represent an option to reduce enteric methane emissions from ruminants, but these strategies must not have undesirable side effects.Therefore, the present study aimed to analyze the environmental effects of supplementation of typical dairy cow feeding rations in Denmark (S0) with 20 g extra fatty acids per kg dry-matter (S1), 10 g nitrate per kg dry-matter (S2), and 60 mg 3-nitrooxypropanol (3-NOP) per kg dry-matter (S3). A cradle-to-farm gate life cycle assessment approach was used, where fifteen environmental impacts were assessed to capture the environmental effects. Pairwise Monte Carlo simulations were conducted to identify statistically significant results.It was found that the climate impact per kg of milk decreased for all the strategies (−7 % in S1 and S2 and −13 % in S3) compared to S0. Furthermore, lower land use and land use change emissions were determined by the partial replacement of soybean meal with cracked rapeseed (in S1) or nitrate (in S2). The reduction in the level of enteric methane also contributed to decreases in the toxicity-related impacts of organic chemicals in S1. The use of nitrate in S2 also involved a decrease in the use of soybean meal, which contributed to decreases in the land use impacts. In strategies S2 and S3 increases in other environmental impacts were observed compared to S0 because of the manufacturing of nitrate or 3-NOP, or higher N excretion and emission at supplementation with nitrate.It was concluded that S3 was more effective in reducing the climate (and human-toxicity impacts of organic substances) impacts, while S1 caused small decreases in a wider range of environmental impacts. The present study has an important contribution to quantifying a wide range of environmental effects for intensive dairy and regarding the implementation of nutritional strategies in dairy cattle to reduce enteric methane.

Modeling the environmental impacts of Asparagopsis as feed, a cow toilet and slurry acidification in two synthetic dairy farms

Intensive dairy farming, particularly enteric fermentation and manure management, is a major contributor to negative impacts on the local and global environment. A wide range of abatement measures has been proposed to reduce livestock-related emissions, yet the individual and combined effects of these innovations are often unknown. In this study, we performed an attributional life cycle assessment of three innovative measures modeled in two synthetic German dairy farm systems: Feeding of the seaweed Asparagopsis, installing an in-house cow toilet system, and performing on-field slurry acidification. These measures were modeled both individually and in combination to account for single and cumulative effects and compared to a reference scenario under current practices. Our results showed that feeding high levels of Asparagopsis and the combination of all three measures were most effective at reducing global warming potential (20–30 %), while only the latter mitigated eutrophication (6–9%) and acidification potential (14–17 %). The cow toilet required additional adapted manure management (separated storage and injection of urine) to effectively reduce eutrophication (8–10 %) and acidification potential (19–23 %) and to decrease global warming potential (3–4%) and abiotic depletion (4–5%). Slurry acidification slightly affected all considered environmental impact categories. All three measures involved trade-offs, either between LCA impact categories (global warming potential vs. abiotic depletion), the location of impacts (off- vs. on-farm), or the emission reduction in individual gases (ammonia vs. nitrous oxide). Measure combinations could compensate for the observed trade-offs. Our study highlights the potential of novel abatement measures but also shows the interdependencies of measures in different stages. This calls for a revisiting of current priorities in funding and legislation, which often focus on single objectives and measures (e.g. ammonia reduction) toward the preferential use of measures that are effective without driving trade-offs or improving resource efficiency.

Prevalence and molecular characterization of Cryptosporidium spp., Enterocytozoon bieneusi, and Giardia duodenalis in dairy cattle in Ningxia, northwestern China.

Cryptosporidium spp., Enterocytozoon bieneusi, and Giardia duodenalis are common intestinal pathogens that infect humans and animals. To date, research regarding these three protozoa in the Ningxia Hui Autonomous Region (Ningxia) has mostly been limited to a single pathogen, and comprehensive data on mixed infections are unavailable. This study aimed to evaluate the zoonotic potential of these three protozoa. In this study, small subunit ribosomal RNA (SSU rRNA) and 60 kDa glycoprotein (gp60) genes of Cryptosporidium; internal transcribed spacer (ITS) gene of E. bieneusi; and SSU rRNA, glutamate dehydrogenase (gdh), triosephosphate isomerase (tpi), and beta-giardin (bg) genes of G. duodenalis were examined. DNA extraction, polymerase chain reaction, and sequence analysis were performed on fecal samples collected from 320 dairy cattle at three intensive dairy farms in Ningxia in 2021 to determine the prevalence and genetic characteristics of these three protozoa. The findings revealed that 61.56% (197/320) of the samples were infected with at least one protozoan. The overall prevalence of Cryptosporidium was 19.38% (62/320), E. bieneusi was 41.56% (133/320), and G. duodenalis was 29.38% (94/320). This study identified four Cryptosporidium species (C. bovis, C. andersoni, C. ryanae, and C. parvum) and the presence of mixed infections with two or three Cryptosporidium species. C. bovis was the dominant species in this study, while the dominant C. parvum subtypes were IIdA15G1 and IIdA20G1. The genotypes of E. bieneusis were J, BEB4, and I alongside the novel genotypes NX1-NX8, all belonging to group 2, with genotype J being dominant. G. duodenalis assemblages were identified as assemblages E, A, and B, and a mixed infection involving assemblages A + E was identified, with assemblage E being the dominant one. Concurrently, 11 isolates formed 10 different assemblage E multilocus genotypes (MLGs) and 1 assemblage A MLG and assemblage E MLGs formed 5 subgroups. To the best of our knowledge, this is the first report on mixed infection with two or three Cryptosporidium species in cattle in Ningxia and on the presence of the C. parvum subtype IIdA20G1 in this part of China. This study also discovered nine genotypes of E. bieneusis and novel features of G. duodenalis assemblages in Ningxia. This study indicates that dairy cattle in this region may play a significant role in the zoonotic transmission of Cryptosporidium spp., E. bieneusi, and G. duodenalis.

Partial herd hoof trimming results in a higher economic net benefit than whole herd hoof trimming in dairy herds.

Sole ulcers, a common cause of lameness is the costliest non-infectious foot lesion in dairy cows and one of the most prevalent non-infectious foot lesions in freestall housing systems. Costs associated with sole ulcers are treatment costs, plus increased labor and decreased productivity and fertility. Routine hoof trimming is part of a strategy to manage sole ulcers. However, hoof trimming strategies differ among farms. The two most frequently applied strategies are: 1) partial herd hoof trimming with a 2-month interval between trims; and 2) whole herd hoof trimming at 6-month intervals. A Markov model was developed to investigate whether every 2 months partial herd hoof trimming or whole herd hoof trimming every 6 months was the most cost-effective strategy to avoid costs associated with sole ulcers. In this model, the net benefits for a 100-cow herd and the average productive life span of a dairy cow in intensive dairy systems of 3 years were evaluated. Partial herd hoof trimming was the most cost-effective strategy 100% of the time compared to whole herd hoof trimming, with a difference in 3-year net benefits of US$4,337 (95% CI: US$2,713-US$5,830). Based on sensitivity analyses, variables that were the sources of the biggest uncertainty in the model were herd size, the probability of being trimmed in a partial herd trim, and the prevalence of sole ulcers. To further investigate the impacts of herd size and of probability of being trimmed, various scenario analyses were conducted. With increasing herd size, the difference in net benefits in favor of partial herd hoof trimming increased even more. Scenario analyses about the probability of getting trimmed all indicated that targeted intervention increased the difference in net benefits in favor of partial herd hoof trimming. However, if the selection of cows to be trimmed in a partial herd trim was random, the whole herd hoof trimming strategy became cost-effective. Therefore, targeted selection and early intervention are necessary to decrease costs associated with sole ulcers.