Animal Production Research Articles

Digitalisation opportunities for livestock welfare monitoring with a focus on heat stress

Rising global temperatures due to climate change pose an increased risk of heat stress (HS) in livestock, which requires accurate prediction methods to improve animal welfare and mitigate heat-related economic losses. In this literature review, we aimed to critically examine the potential of digitalisation in precision livestock farming from the perspective of assessing heat stress in cattle. Particular attention was paid to the possibility of using sensors to record changes in behaviour, physiological parameters, and feed and water consumption as predictors for detecting and preventing heat stress and its consequences in animals. The use of already proven sensors, such as those that record animal behaviour, to assess physiological parameters related to heat stress may be promising, using innovative data processing technologies, which requires additional investigation in future studies. Precision livestock farming (PLF) technologies that enable real-time monitoring of herds under specific conditions, such as disease or stress, play a key role in increasing the efficiency of herd management. Sensors, cameras, microphones, GPS, accelerometers and RFID tags are commonly used to collect data on animal behaviour and physiological parameters, helping to detect stress. Machine learning algorithms applied to sensor data can distinguish between different states of declining cow welfare, helping farmers make quick decisions. In summary, the integration of sensors, artificial intelligence and precision devices can help prevent heat stress in farm animals, improving animal welfare and productivity, while mitigating the negative effects of heat stress caused by climate change.

Effects of microencapsulated plant essential oils on growth performance, immunity, and intestinal health of weaned Tibetan piglets.

Plant essential oils (PEOs) have received significant attention in animal production due to their diverse beneficial properties and hold potential to alleviate weaning stress. However, PEOs effectiveness is often compromised by volatility and degradation. Microencapsulation can enhance the stability and control release rate of essential oils. Whether different microencapsulation techniques affect the effectiveness remain unknown. This study aimed to investigate the effects of PEOs coated by different microencapsulation techniques on growth performance, immunity, and intestinal health of weaned Tibetan piglets. A total of 120 Tibetan piglets, aged 30 days, were randomly divided into five groups with four replicates, each containing six piglets. The experimental period lasted for 32 days. The groups were fed different diets: a basal diet without antibiotics (NC), a basal diet supplemented with 10 mg/kg tylosin and 50 mg/kg colistin sulfate (PC), 300 mg/kg solidified PEO particles (SPEO), 300 mg/kg cold spray-coated PEO (CSPEO), or 300 mg/kg hot spray-coated PEO (HSPEO). The results showed that supplementation with SPEO, CSPEO, or HSPEO led to a notable decrease in diarrhea incidence and feed to gain ratio, as well as duodenum lipopolysaccharide content, while simultaneously increase in average daily gain, interleukin-10 (IL-10) levels and the abundance of ileum Bifidobacterium compared with the NC group (p < 0.05). Supplementation with SPEO, CSPEO, or HSPEO significantly elevated serum immunoglobulin G (IgG) levels and concurrently reduced serum lipopolysaccharide and interferon γ levels compared with the NC and PC groups (p < 0.05). Serum insulin-like growth factor 1 (IGF-1) levels in the SPEO and HSPEO groups significantly increased compared with the NC group (p < 0.05). Additionally, CSPEO and HSPEO significantly reduced jejunum pH value (p < 0.05) compared with the NC and PC groups (p<0.05). Additionally, Supplementation with HSPEO significantly elevated levels of serum immunoglobulin M (IgM) and interleukin-4 (IL-4), abundance of ileum Lactobacillus, along with decreased serum interleukin-1 beta (IL-1β) levels compared with both the NC and PC groups. Our findings suggest that different microencapsulation techniques affect the effectiveness. Dietary supplemented with PEOs, especially HSPEO, increased growth performance, improved immune function, and optimized gut microbiota composition of weaned piglets, making it a promising feed additive in piglet production.

Effect of Seed Rate on Forage Yield, and Nutritional Value of Sudan Grass and Vetch Mixtures in Ethiopia: A Review

The livestock feed resources in Ethiopia are classified as natural pasture, crop residues, improved pasture and forage, agro-industrial by-products, and also hay production of which the first two feed resources are the major feed contributors for the livestock production in Ethiopia but they are lacking in protein and minerals. Natural pastures contribute about 80-85 of animal feed in Ethiopia, including naturally occurring grasses, legumes, shrubs, hurbs, and tree foliages. Crop residue is one of the feed resources used for animal production in Ethiopia and is available in those areas in which livestock and crop production are practiced. Around 30 million tonnes of DM of agricultural crop residues are produced annually on the national scale, of which 70% are used as animal feed. The major agro-industrial by products commonly used in Ethiopia are obtained from different agro-industries. The nutritional values of agro-industrial by products are excellent but their productivity is small, limited, and limited to few farms in urban and peri-urban areas and they contribute much less to livestock feed. Furthermore, traditional livestock feed supply mainly depends upon natural pasture and crop residues, which have low crude protein and other chemical composition. However, there is tremendous potential to alleviate feed shortages using improved forage production. To fulfill this gap, producing a stable improved forage in the livestock sector is mandatory. For that reason, the legume and grass intercropping system are important to increase biomass production and forage yield. Hence, Sudan grass (Aden gode) known with its plant height than other cultivars and vetch (&amp;lt;i&amp;gt;Vicia dasycarpa&amp;lt;/i&amp;gt;) have greater plant height and creeping growth habit that enable compatible to larger grass species and they are selectable forages to enhance the forage yield and quality under similar times.

Short-Term Effects of Heat Stress on Cow Behavior, Registered by Innovative Technologies and Blood Gas Parameters.

Heat stress (HS) is one of the key factors affecting an animal's immune system and productivity, as a result of a physiological reaction combined with environmental factors. This study examined the short-term effects of heat stress on cow behavior, as recorded by innovative technologies, and its impact on blood gas parameters, using 56 of the 1070 cows clinically evaluated during the second and subsequent lactations within the first 30 days postpartum. Throughout the experiment (from 4 June 2024 until 1 July 2024), cow behavior parameters (rumination time min/d. (RT), body temperature (°C), reticulorumen pH, water consumption (L/day), cow activity (h/day)) were monitored using specialized SmaXtec boluses and employing a blood gas analyzer (Siemens Healthineers, 1200 Courtneypark Dr E Mississauga, L5T 1P2, Canada). During the study period, the temperature-humidity index (THI), based on ambient temperature and humidity, was recorded and used to calculate THI and to categorize the data into four THI classes as follows: 1-THI 60-63 (4 June 2024-12 June 2024); 2-THI 65-69 (13 June 2024-18 June 2024); 3-THI 73-75 (19 June 2024-25 June 2024); and 4-THI 73-78 (26 June 2024-1 July 2024). The results showed that heat stress significantly reduced rumination time by up to 70% in cows within the highest THI class (73 to 78) and increased body temperature by 2%. It also caused a 12.6% decrease in partial carbon dioxide pressure (pCO2) and a 32% increase in partial oxygen pressure (pO2), also decreasing plasma sodium by 1.36% and potassium by 6%, while increasing chloride by 3%. The findings underscore the critical need for continuous monitoring, early detection, and proactive management to mitigate the adverse impacts of heat stress on dairy cow health and productivity. Recommendations include the use of advanced monitoring technologies and specific blood gas parameter tracking to detect the early signs of heat stress and implement more timely interventions.

Dhurrin in Sorghum: Biosynthesis, Regulation, Biological Function and Challenges for Animal Production.

Sorghum (Sorghum bicolor) holds a significant position as the fifth most vital cereal crop globally. Its drought resistance and robust biomass production, coupled with commendable nutritional value, make sorghum a promising choice for animal feed. Nevertheless, the utilization of sorghum in animal production faces hurdles of dhurrin (a cyanogenic glycoside) poisoning. While dhurrin serves as a protective secondary metabolite during sorghum growth, the resulting highly toxic hydrogen cyanide poses a significant threat to animal safety. This review extensively examines the biometabolic processes of dhurrin, the pivotal genes involved in the regulation of dhurrin biosynthesis, and the factors influencing dhurrin content in sorghum. It delves into the impact of dhurrin on animal production and explores measures to mitigate its content, aiming to provide insights for advancing research on dhurrin metabolism regulation in sorghum and its rational utilization in animal production.

Seven hundred and ninety-seven metagenome-assembled genomes from the goat rumen during early life

The rumen microbiome plays an important role in providing energy and protein to the host. Manipulation of rumen microbiome during early life may have a long-term beneficial effect on the health, growth performance, and feed efficiency of ruminants. To better understand the profiles and functional potentials of rumen microbiome in young ruminants, metagenomic binning was performed to investigate the rumen microbiome of goat kids from one to 84 days of age. A total of 797 metagenome-assembled genomes (MAGs) were recovered from the rumen of 42 Laiwu black goat kids. Our findings provide fundamental knowledge of the rumen microbiome during early life based on metagenomic binning, which may provide insights into effective strategies to achieve long-term beneficial effects on animal health and production.

Computer Vision-Based cybernetics systems for promoting modern poultry Farming: A critical review

As global demands on the poultry production and welfare both intensify, the precision poultry farming technologies such as computer vision-based cybernetics system is becoming important in addressing the current issues related to animal welfare and production efficiencies. The integration of computer vision technology has become a catalyst for transformative change in precision farming, particularly concerning productivity and welfare. This review paper delineates the central role of computer vision in precision poultry farming, focusing on its applications in non-contact monitoring methods that employ advanced sensors and cameras to enhance farm biosecurity and bird observation without disturbance. We delved into the multifaceted advancements such as the utilization of convolutional neural networks (CNNs) for behavior analysis and health monitoring, evidenced by the high accuracy sorting of eggs and identification of health concerns within target-dense farm environments. The review paper underscores advancements in precision agriculture, including accurate egg weight estimation and egg classification within cage-free systems, paralleling the poultry sector’s evolution towards more ethical farming practices. Moreover, it addresses the progress in poultry growth monitoring and examines case studies of commercial farms, showcasing how these innovations are being practically applied to enhance productivity and animal welfare. Challenges remain, particularly in terms of environmental variability and data annotation for deep learning models. Nevertheless, the review emphasizes the scope for future innovations like voice-controlled robotics and virtual reality applications, which have the potential to enhance poultry farming to new levels of efficiency, humanity, and sustainability. The insights assert that the continued exploration and development in computer vision technologies are not only instrumental for the poultry sector but also offer a blueprint for agricultural enhancement at large.

Current application of proteomics in the veterinary field – a short summary and literature review

The biomedical research field’s continuous search for innovative technologies has led to improved disease diagnosis, novel drug discovery, and therapeutic interventions, all aimed at enhancing animal and human health alike. In this context, proteomics has emerged as a critical new technology, focusing on detailed examinations of protein composition, abundance, structure, function, and interactions. Proteomics, the study of the entire set ofproteins expressed by an organism, plays a crucial role in disease diagnosis, drug discovery, and therapeutic interventions in both human and animal health. Proteomics in veterinary medicine and animal health is an evolving field that holds significant promise for fundamental and applied discoveries related to the biology and pathology of domestic and companion species. It encompasses a broad spectrum of applications, including disease diagnosis, comparative medicine, pharmacology, nutrition, reproductive biology, livestock production,and pathology. By analysing protein profiles and interactions, proteomics contributes to enhancing animal health, welfare, and productivity across various fields of veterinary research and practice. Experimental proteomics in domestic animals offers advantages over the use of rodents, such as the ability to conduct multipletime-series samplings of biological samples for extensive analysis, allowing for the investigation of experimental and natural disease processes. This review highlights the current application of proteomics in veterinary medicine, focusing on its potential to advance diagnostics, research, and treatments in veterinary science. The current limitations of proteomics are also discussed.

In vivo anthelmintic activity of Combretum mucronatum schumach & Thonn leaf extract against Haemonchus contortus in goats

Parasitic infections with gastrointestinal nematodes are a serious problem for the health and welfare of domestic animals and negatively affect the economics of animal production. Haemonchus contortus is a haematophagous nematode of small ruminants responsible for significant mortality and morbidity. In addition, the widespread resistance to synthetic anthelmintic drugs emphasizes the urgent need of alternative treatment options against haemonchosis. This work aims to investigate the anthelmintic activity of an hydroethanolic Combretum mucronatum leaf extract (CMLE) against Haemonchus contortus in goats. Goats were artificially infected with 3500 third-stage larvae of H. contortus, and 21 days later, treated with CMLE (1000, 500, 250 mg/kg) for 4 consecutive days. Different parameters such as faecal egg count reduction, weight and haematocrit were monitored during the experimental period. The number of eggs per gram of faeces (EPG) was concentration-depended lower and significantly reduced compared to the untreated control (p < 0.0001). The effect of the highest CMLE dose (4 ×1000 mg/kg body weight) was similar to the effect of albendazole (1 ×5 mg/kg of body weight). The ED50 and ED90 values calculated were 189.17 and 392.33 mg/kg body weight respectively. ED50 and ED90 values were time-dependent. Moreover, CMLE improved haematocrit and weight of goats in dose-dependent and time-dependent manner. These results showed that CMLE could be used for haemonchosis treatment in small ruminants.

Applying life cycle assessment to European high nature value farming systems: Environmental impacts and biodiversity

CONTEXTLife Cycle Assessment (LCA) remains a method of choice for assessing the environmental performance of agricultural systems. However, it is rarely applied to multifunctional extensive production systems, in which livestock use, apart from animal production, maintains a continuous disturbance that sustains the diversity of habitats and species. OBJECTIVEThis study aims to assess the environmental impact and biodiversity of extensive ruminant production on semi-natural grasslands (SNG), that is, High Nature Value (HNV) farming across Europe. We collected data from a total of 41 HNV farms in five countries (Finland, Estonia, Spain, Greece, and France) that produce beef, sheep, and goats, and that incorporate (to a varied degree) semi-natural and permanent pastures into production. METHODSWe used LCA to assess the potential environmental impact of HNV farms according to global warming potential (GWP100), fossil resource scarcity (FRS), water scarcity (WS) and land use (LU), by using the Solagro Carbon Calculator and OpenLCA software. We assessed biodiversity based on the expert scoring system of SALCA-BD. We compared impacts on per area and per product basis across the farms, and related them to the productivity. RESULTS AND CONCLUSIONSResults revealed a considerable variation in all environmental impacts among HNV farms, explained mostly by the type of ruminants, main product (meat or milk) and the production level. GWP100 per unit in beef product in France was almost twice as high as that in boreal and 3 times more than in Spain, while sheep systems in Greece varied 7-fold for meat. Sheep systems consistently had the highest GWP100, while goat systems used the most land, fossil fuel and water. Small ruminant production in Spain had both the highest land occupation and biodiversity values. Biodiversity was at its highest on farms utilising only SNG for production, which, however, related negatively to the farms' production output. Enteric fermentation accounted for 32% of overall emissions. SIGNIFICANCEThis study makes a novel contribution towards a better understanding of the environmental performance and production capacity of HNV farming systems that are often used as examples of multifunctional and sustainable ruminant-based production.

Navigating the Landscape of Tick Diversity: Integrating Molecular Approaches for Enhanced Control Measures.

The emergence and spread of infectious diseases, particularly zoonotic diseases originating from wildlife, pose significant threats to global health and economy. This review examines the pivotal role of ticks as vectors in transmitting pathogens to humans, livestock, and wildlife and the use of molecular techniques in their identification. Tick infestations result in economic losses through reduced animal productivity, anemia, and quality deterioration of hides. Furthermore, ticks serve as reservoirs for a wide range of pathogens including viruses, bacteria, fungi, protozoa, and nematodes, contributing to the transmission of diseases such as Crimean-Congo hemorrhagic fever, tick-borne encephalitis, and African swine fever among others. The interface between wildlife, livestock, and humans facilitates the transmission of zoonotic pathogens, exacerbated by nomadic and pastoralist lifestyles that promote interactions between wildlife and domestic animals. This movement of animals across landscapes enhances the dispersion of tick vectors, increasing the risk of pathogen exposure for diverse populations. Historically, tick identification in sub-Saharan Africa has relied on morphological characteristics despite limitations such as species overlap and variability. Molecular techniques offer a more precise means of species identification, providing critical data for effective tick and pathogen management strategies. Integrating molecular approaches into tick research enhances our understanding of tick diversity, distribution patterns, and pathogen dynamics. This knowledge is essential for developing targeted interventions to mitigate the impact of tick-borne diseases on public and veterinary health worldwide.

Preclinical Efficacy of Cap-Dependent and Independent mRNA Vaccines against Bovine Viral Diarrhea Virus-1.

Bovine viral diarrhea virus (BVDV) is an RNA virus associated with severe economic losses in animal production. Effective vaccination and viral surveillance are urgent for the prevention and control of BVDV infection. However, the application of traditional modified live vaccines and inactivated vaccines is faced with tremendous challenges. In the present study, we describe the preclinical efficacy of two BVDV mRNA vaccines tested in mice and guinea pigs, followed by a field trial in goats, where they were compared to a commercial vaccine (formaldehyde inactivated). The two mRNAs were engineered to express the envelope protein E2 of BVDV-1, the most prevalent subtype across the world, through a 5' cap-dependent or independent fashion. Better titers of neutralizing antibodies against BVDV-1 were achieved using the capped RNA in the sera of mice and guinea pigs, with maximum values reaching 9.4 and 13.7 (by -log2), respectively, on the 35th day post-vaccination. At the same time point, the antibody levels in goats were 9.1 and 10.2 for the capped and capless RNAs, respectively, and there were no significant differences compared to the commercial vaccine. The animals remained healthy throughout the experiment, as reflected by their normal leukogram profiles. Collectively, our findings demonstrate that mRNA vaccines have good safety and immunogenicity, and we laid a strong foundation for the further exploitation of efficient and safe BVDV vaccines.

Editing microbes to mitigate enteric methane emissions in livestock.

Livestock production significantly contributes to greenhouse gas (GHG) emissions particularly methane (CH4) emissions thereby influencing climate change. To address this issue further, it is crucial to establish strategies that simultaneously increase ruminant productivity while minimizing GHG emissions, particularly from cattle, sheep, and goats. Recent advancements have revealed the potential for modulating the rumen microbial ecosystem through genetic selection to reduce methane (CH4) production, and by microbial genome editing including CRISPR/Cas9, TALENs (Transcription Activator-Like Effector Nucleases), ZFNs (Zinc Finger Nucleases), RNA interference (RNAi), Pime editing, Base editing and double-stranded break-free (DSB-free). These technologies enable precise genetic modifications, offering opportunities to enhance traits that reduce environmental impact and optimize metabolic pathways. Additionally, various nutrition-related measures have shown promise in mitigating methane emissions to varying extents. This review aims to present a future-oriented viewpoint on reducing methane emissions from ruminants by leveraging CRISPR/Cas9 technology to engineer the microbial consortia within the rumen. The ultimate objective is to develop sustainable livestock production methods that effectively decrease methane emissions, while maintaining animal health and productivity.

Environmental factors and management practices associated with beef cattle carcass quality in the mid-west of Brazil.

The "Precoce MS" program, established by the Brazilian government in Mato Grosso do Sul in 2017, aims to encourage beef producers to harvest animals at younger ages to enhance carcass quality. About 40% of the beef produced in the state now comes from this program, which offers tax refunds ranging from 49% to 67% based on carcass classification and production system. Despite the program success, with participants delivering younger animals (with a maximum of 4 incisors), there remains significant variability in carcass quality. This paper investigates management practices and environmental factors affecting farm performance regarding carcass quality. Data from all animals harvested between the beginning of 2017 and the end of 2018 were analyzed, totaling 1,107 million animals from 1,470 farms. Farm performance was assessed based on the percentage of animals achieving grades "AAA" and "AA." Each batch of harvested cattle from each farm was categorized into two groups: high farm performance (HFP, with more than 50% of animals classified as "AAA" or "AA") and low farm performance (LFP, with less than 50% classified as such). A predictive logistic model was developed to forecast farm performance (FP) using 14 continuous and 15 discrete pre-selected variables. The most effective model, obtained through backward stepwise variable selection, had an R 2 of 0.18, accuracy of 71.5%, and AUC of 0.715. Key predictors included animal category, production system type, carcass weight, individual identification, traceability system, presence of a feed plant, location, and the Normalized Difference Vegetation Index (NDVI) from the 12-mo average before harvest. Developing predictive models of carcass quality by integrating data from commercial farms with other sources of information (animal, production system, and environment) can improve our understanding of production systems, optimize resource allocation, and advance sustainable animal production. Additionally, they offer valuable insights for designing and implementing better sectorial, social, and environmental policies by public administrations, not only in Brazil but also in other tropical and subtropical regions worldwide.

Selection for yield in elephant-grass forage genotypes using GGE Biplot analysis

Elephant grass is among the most used forages in intensive animal production systems due to its high productive potential, carrying capacity and nutritional quality. Because of the existing interaction between genotypes and environments, it is essential to select and develop materials that are not only high-yielding but also adaptable and stable. In this context, this study was developed to analyze the performance and select genotypes of elephant grass simultaneously for dry matter yield, performance stability and adaptability. Fifty-three elephant grass genotypes with forage potential were evaluated in four environments (rainy and dry seasons in years 1 and 2), defined according to the time at which the harvests occurred. A randomized-block design with two replicates was adopted. Dry matter yield (t.ha-1) was measured at each assessment (harvest). Adaptability and genotypic stability were evaluated using the GGE biplot methodology and R software. In the overall classification, genotypes 53, 22, 29, 17 and 33 showed the best average performance. Regarding dry matter yield, adaptability and phenotypic stability, genotype 53 was classified as the ideotype.

Direct Observation of Feeding Behavior of Adult Tabanidae (Diptera) on Beef Cattle from Khon Kaen Province in Thailand.

Tabanidae (horse flies and deer flies) are hematophagous insects that cause direct and indirect damage to animal production. The aims of this study were to determine the preferred site, time of day, and duration of tabanid feeding on beef cattle and identify factors related to infestation by tabanids. The population of tabanids was surveyed on certain body parts of the beef cattle (fore udder, tail, navel, leg, dewlap, body, and under) during the morning hours (9.00-10.30 a.m.), midday (12.00-13.30 a.m.), and afternoon (15.30-17.00 p.m.) every day for 10 days. The findings showed that two genera, Tabanus Linnaeus, 1758, and Chrysops Meigen, 1803, landed on the cows. The leg was statistically significantly the most frequent landing site for tabanids (15.067 ± 7.54) compared with other parts. The average feeding duration for each insect was 2.76 ± 1.77 min. The results showed that a significant number of tabanids were present during midday, as compared with the morning and afternoon. Temperature was found to be positively associated with fly abundance. A regression model was derived in this study (y = 4.23x - 116.09). This information is important for tabanid control and prevention in beef cattle.

Functionalized Graphene-Based Biosensors for Early Detection of Subclinical Ketosis in Dairy Cows

Precision livestock farming is one method of improving the productivity, health, and well-being of animals. Advanced diagnostic tools including biosensors can play a key role in the management of livestock operations. Detection of ketosis, a metabolic disease that occurs in early lactation dairy cows due to the negative energy balance, is one potential on-farm use of biosensors. Beta–hydroxybutyrate (βHB) is an excellent biomarker for ketosis monitoring in dairy cows because βHB is one of the main ketones produced during this metabolic state. In this report, we develop a low-cost, Keto-sensor (graphene-based sensor) for the detection and quantification of βHB concentrations in less than a minute. In this device, graphene nanosheets were layered onto a screen–printed electrode (SPE), and then a stabilized enzyme (Beta–hydroxybutyrate dehydrogenase, NADH, and glycerol) was used to functionalize the graphene surface enabled by EDC–NHS conjugation chemistry. The Keto-sensor offers an analytical sensitivity of 10 nM and a limit-of-detection (LoD) of 0.24 nM within a detection range of 0.00001-3.0 mM. Spike testing indicates that the Keto-sensor can detect βHB in serum samples from bovines with subclinical ketosis. The Keto-sensor developed in this study shows promising results for early detection of subclinical ketosis on farms.

Prevalence of bovine trypanosomosis and tsetse fly density in Loka Abaya and Derara districts in Sidama Regional State, Ethiopia.

Animal trypanosomosis is a significant livestock disease with economic and social repercussions, reducing the supply of animal products and restricting the utilization of animals for traction and transportation. In Ethiopia, it is prevalent and poses a major hindrance to the advancement of animal production. This repeated cross-sectional study was aimed at assessing seasonal variation in bovine trypanosomosis prevalence and tsetse fly density and identifying the potential risk factors in the Loka Abaya and Derara districts of the Sidama National Regional State. Blood samples were collected from 964 cattle, 484 samples during the dry season, and 480 during the wet season. The buffy coat method was employed to analyze these samples. Furthermore, 78 standard NGU traps were set up at various locations in the two districts during both seasons for entomological investigation. The overall apparent prevalence of trypanosomosis was 9% (95% CI 7.3-11.0), without a significant difference (p > 0.05) between the dry season (7.4%) and wet season (10.6%). The apparent prevalence was significantly higher in Loka Abaya (11.8%) than in Derara (6.3%) district (OR = 2.04; p = 0.003) and in cattle with black coat color (29%) than in mixed color (6.8%) (OR = 5.3; p < 0.001). The majority of infections were caused by Trypanosoma congolense (70%), followed by T. vivax (29%), and mixed infections (1%) with the two species. The average packed cell volume (PCV) was significantly (p < 0.0001) lower in infected animals (20.7 ± 4%) compared to uninfected ones (25.5 ± 5.4%), in cattle examined during the dry season (24.1 ± 6%) versus the wet season (26.1 ± 4.7%), in cattle sampled from the Loka Abaya district (24.2 ± 5.5%) versus Derara district (26 ± 5.3%), and in cattle with poor body condition (23.6 ± 5.7%) compared to those with good body condition (26.5 ± 5.3%). A total of 5282 flies were captured during the study, with 4437 (84%) being tsetse flies (Glossina pallidipes), 439 (8.3%) Tabanids, 190 (3.6%) Stomoxys spp., and 216 (4.1%) Musca spp. The apparent density (AD) of G. pallidipes was 28.4 flies/trap/day, showing no statistically significant difference between wet (32.1) and dry (24.6) seasons (p > 0.05). The AD of G. pallidipes was significantly (p < 0.001) higher in the Loka Abaya district (57.3) than in the Derara district (0.9). The study highlights a moderate trypanosomosis apparent prevalence and high AD of G. pallidipes, showing significant variation between the study districts but no seasonal difference. The observed apparent prevalence of trypanosomosis and tsetse fly density notably affects animal health and productivity. As a result, strategies for vector control like insecticide-treated targets, trypanocidal medications for infected animals, and community-based initiatives such as education and participation in control programs are recommended.

Conventional and unsupervised artificial intelligence analyses identified risk factors for antimicrobial resistance on dairy farms in the province of Québec, Canada

Antimicrobial resistance (AMR) is one of the greatest threats to global health worldwide and is threatening not only humans, but also animal production systems, including dairy farms. The objective of this paper was to describe risks factors associated with AMR on dairy farms in Québec, Canada. This observational cross-sectional study included 101 commercial dairy farms and took place between the springs of 2017 and 2018 for a one-year period. We explored risk factors such as farm practices and producer's knowledge (measured using a questionnaire), antimicrobial use (quantified using veterinary invoices), and the presence of Salmonella Dublin (tested by serology). We evaluated AMR with fecal Escherichia coli retrieved from pre-weaned calves and lactating cows using the following outcomes: the presence of extended-spectrum-β-lactamase/AmpC resistance and the number of resistances to antimicrobial classes. We used logistic regression models to evaluate the association between each risk factor and the 2 outcomes for the 2 types of samples (pre-weaned calves and lactating cows). Furthermore, we explored the relationships between these risk factors utilizing data dimensionality reduction and hierarchical clustering. Outputs of these analyses were used as regressors for AMR in regression models. While the results for univariate analyses were ambiguous, the unsupervised analysis naturally categorized the sample of farms according to their health/treatment status (dimension 1, explaining 12.9% of the variance) and herd size (dimension 2, explaining 7.8%). Three clusters of farms were identified (cluster 1: mainly healthy herds and low ceftiofur users, cluster 2: relatively high ceftiofur users, cluster 3: farms with a higher incidence of diseases and higher antimicrobial treatment rates). Dimension 1 and cluster membership were statistically associated with the presence of extended-spectrum-β-lactamase/AmpC resistance in lactating cows and in pre-weaned calves. Dimension 1 was also statistically associated with the number of resistances in lactating cows and in pre-weaned calves. This study highlights the complexity of analyzing risk factors associated with AMR. Our results suggest that the herd health status and the AMU-related practices used are associated with AMR in dairy farms. However, prospective studies are needed to confirm a causal relation.

Assessment of dry matter yield, nutritional value, and calf weight gain in Mombaza-Kudzu pasture associations.

O Objective: To evaluate the biomass production, nutritional value and animal production of an association with fabaceae species and grasses with grazing calves. Design/Methodology/Approach: The study compared Mombaza (Megathyrsus maximus) – Kudzu (Pueraria phaseoloides) association pasture against a Mombaza in monoculture control. Ten calves, five in each pasture type, were grazed in rotation for seven months. Dry matter yield, proportion of Kudzu in the association, protein, neutral detergent fiber (NDF), acid detergent fiber (ADF), ash, and daily weight gain were evaluated every 36 days. Results: Dry matter yield did not differ between pasture types, but varied by sampling dates, being higher at the onset of the rainy season (May 20th). The proportion of Kudzu in the association was low, decreasing from 8.42% to 1.71% over the study period. Lignin content increased in the association during the driest month (April). Daily weight gain was 978 g in the monoculture pasture and 678 g/day in the association, with no significant difference. Study Limitations/Implications: The low persistence of the fabaceae in the association limits the nutritional value of the pasture, consequently, the improvement of grazing animal production. Findings/Conclusions: During the drought season, both pastures exhibited the highest protein concentration and the greatest weight gain at the beginning of this period. However, the association did not result in greater weight gains due to the low persistence of the fabaceae.