Evaluation of commercial ELISA kits' diagnostic specificity for FAST diseases in wild animals.

Wild animals, sharing pathogens with domestic animals, play a crucial role in the epidemiology of infectious diseases. Sampling from wild animals poses significant challenges, yet it is vital for inclusion in disease surveillance and monitoring programmes. Often, mass surveillance involves serological screenings using enzyme-linked immunosorbent assay (ELISA) tests, typically validated only for domestic animals. This study assessed the diagnostic specificity of commercially available ELISA tests on 342 wild ruminant serum samples and 100 from wild boars. We evaluated three tests for foot-and-mouth disease: two for Peste des petits ruminants, two for Rift Valley fever and one for Capripox virus. Diagnostic specificity was calculated using the formula True Negative/(False Positive + True Negative). Cohen's kappa coefficient measured agreement between tests. Results showed high specificity and agreement across all tests. Specificity for foot-and-mouth disease (FMD) ranged from 93.89% for Prionics to 100% for IDEXX, with IDvet showing 99.6%. The highest agreement was between FMD IDvet and IDEXX at 97.1%. Rift Valley fever (RVF) tests, Ingezim and IDvet, achieved specificities of 100% and 98.83%, respectively. The optimal specificity was attained by retesting single reactors and inactivating the complement.Contribution: Commercially available ELISA kits are specific for foot-and-mouth disease and similar transboundary animal diseases and can be used for highly specific wild animal testing.

Efficiency of recombinant Ybgf in a double antigen-ELISA for the detection of Coxiella antibodies in ruminants.

Q fever is a zoonosis whose main reservoirs are domestic ruminants. Surveillance in these species is carried out mainly with serological tests, which, however, have limited diagnostic performance, and their manufacturing requires laboratories equipped with high biosafety requirements for antigen production. Recombinant ELISAs do not depend on these requirements and, being based on a single antigen, can reduce potential false positivity by identifying antibodies specific to a phase of infection. The aim of this study was to apply a new technology (dual antigen test) to a recombinant protein (Ybgf), an antigen produced in recombinant form and already used in previous studies for the design of an indirect ELISA. The successfully produced recombinant antigen was used to coat 96-well plates and, at the same time, another antigen aliquot was conjugated with HRP to obtain an HRP-conjugated Ybgf. After setting the test conditions, the results obtained with the recombinant double antigen test were compared with those obtained with a commercial assay (considered as reference assay) testing a total of 514 ruminant samples (280 goats and 234 cattle). A concordance of 86.2 and a Cohen's Kappa value of 0.72 were obtained, with no significant difference between the two species tested. Notably, the test proved to be highly specific, having correctly identified 250 out of 253 animals. This research represents an additional effort to use recombinant antigens to enhance serological methods in veterinary medicine. In a "one-health scenario", improving the performance of serological tests used in veterinary practice also means improving the surveillance of this infection.

Seroprevalence and contributing factors of transboundary animal diseases in sheep and goats: a study in Peninsular Malaysia.

Diseases caused by small ruminant lentiviruses, Mycobacterium avium ssp. paratuberculosis (MAP), Schmallenberg virus, and peste des petits ruminants virus (PPR) is globally recognised as serious threats to the ruminant industry due to their potential to spread rapidly across boundaries. Despite their global distribution and negative impacts on ruminant production, there is a gap in knowledge of the current trends in their epidemiology among sheep and goat populations in Peninsular Malaysia. This study was therefore designed to fill the gap of knowledge concerning the seroprevalence and contributing factors of CAEV, paratuberculosis, SBV, and PPRV among small ruminants from selected flocks in Selangor, Negeri Sembilan, and Pahang states in Peninsular Malaysia. A cross-sectional study design was used to collect animal data and blood samples for serological assays simultaneously. The ID Screen (ID.VET, France) indirect ELISA screening tests were used to detect serum antibodies directed against CAEV/MVV (VISNAS Ver 0922), paratuberculosis (PARAS Ver 0516), SBV (SBVC Ver 1114) and PPRV (PPRC Ver 0821). There was 45.4% (95% CI = 40.74-50.74), 6.8% (95% CI = 4.66-9.69), 27.8% (95% CI = 23.35-32.77), and 2.6% (95% CI = 1.11-0.51) true seroprevalence for CAEV, paratuberculosis, SBV, and PPR, respectively. Geographical location and species were the risk factors for CAEV and paratuberculosis, while the management system and age of small ruminants were the risk factors for SBV. The present study is the first to document a large-scale seroprevalence of MAP and PPR infection among sheep and goat flocks in Peninsular Malaysia. The presence of PPRV and MAP antibodies among small ruminant flocks is signalling current or previous exposure to the pathogens or cross reactions with similar antigens. This finding further suggests the potential for future outbreaks of these devastating diseases among sheep and goats in Malaysia. The high seroprevalence of CAEV and SBV among small ruminants indicates high levels of exposure to the viruses in the environment, which is a potential threat to production.

Development and application of a novel extraction protocol for the monitoring of microplastic contamination in widely consumed ruminant feeds.

Plastics and, in particular, microplastics (MPs) (< 5 mm) are emerging environmental pollutants responsible for interconnected risks to environmental, human, and animal health. The livestock sector is highly affected by these contaminants, with 50-60 % of the foreign bodies found in slaughtered domestic cattle being recognized as plastic-based materials. Additionally, microplastics were recently detected inside ruminant bodies and in their feces. MPs presence in ruminants could be explained by the intensive usage of plastic materials on farms, in particular to store feeds (i.e. to cover horizontal silos and to wrap hay bales). Although feed could be one of the main sources of plastics, especially of microplastics, a specific protocol to detect them in ruminant feeds is not actually present. Hence, the aim of this study was to optimize a specific protocol for the extraction, quantification, and identification of five microplastic polymers (high-density polyethylene, low-density polyethylene, polyamide fibers/particles, polyethylene terephthalate and polystyrene) from feeds typically used in ruminant diets (corn silage, hay, high protein feedstuff and total mixed ration). Several combinations of Fenton reactions and KOH digestion were tested. The final extraction protocol involved a KOH digestion (60 °C for 24 h), followed by two/three cycles of Fenton reactions. The extraction recoveries were of 100 % for high-density, low-density polyethylene, polyamide particles, and polystyrene and higher than 85 % for polyethylene terephthalate and polyamide fibers. Finally, the optimized protocol was successfully applied in the extraction of microplastics from real feed samples. All the feeds contained microplastics, particularly polyethylene, thus confirming the exposure of ruminants to MPs.

Control of Coxiella burnetii shedding in a dairy goat herd by annual offspring vaccination.

A Coxiella burnetii vaccination program, targeting only doelings, was introduced on a German goat farm to curb bacterial shedding. In 2018, adults were vaccinated with a C. burnetii Phase I vaccine at three-weeks apart following pathogen diagnosis, with a booster administered six months later due to sustained high shedding. From 2018 to 2021, doelings received two vaccine doses without any further boosters. To assess the program's efficacy, vaginal swabs from up to 40 animals per age group were collected during kidding seasons from 2019 to 2022. Bulk tank milk (BTM) samples were gathered monthly from January 2018 to October 2022 to monitor herd-level shedding. Real-time PCR analysis determined genome equivalents in all three sample types. Serum samples were taken before the initial immunization and during the post-kidding season from up to 40 goats per age group annually from 2018 to 2022. Phase-specific ELISAs determined IgG Phase I and Phase II antibodies. Additionally, two serum samples per age group from 2022 were analyzed using a neutralization assay. A few goats continued shedding small quantities during subsequent kidding seasons. Although positive BTM samples decreased, they displayed an undulating trend. Most age groups exhibited robust IgG Phase I responses and lower IgG Phase II levels post immunization. Mean IgG levels remained elevated until the study ended compared to pre-vaccination levels in most age groups. Additionally, neutralizing antibodies were present regardless of IgG response. Overall, double vaccination induced lasting antibody levels, but did not entirely prevent C. burnetii shedding. The resilience of the observed humoral immune activity requires further investigation.

Effect of feeding a blackseed meal-sericea lespedeza leaf meal pellet on gastrointestinal nematode and coccidia infection and animal performance in young goats.

Gastrointestinal nematode (GIN) infection poses the most significant obstacle to the sustainable development of small ruminant (sheep and goat) farming globally. Resistance of GINs to synthetic anthelmintic drugs has led to rising interest in exploring alternative methods for parasite control, such as the utilization of bioactive plants with anti-parasitic properties. In this investigation, black seed (Nigella sativa), a shrub high in secondary antioxidant compounds, and sericea lespedeza (Lespedeza cuneata), a perennial legume high in tannins with anti-parasitic properties were combined to determine if two bioactive plants containing different types of secondary compounds can provide a stronger anti-parasitic effect than sericea lespedeza alone. In a 49-day trial, naturally parasitized 6-7-month-old intact male Spanish goats (n = 15/treatment) were fed pelletized feeds encompassing sericea lespedeza leaf meal (SL), a combination of black seed meal (BS) and sericea lespedeza leaf meal (BS-SL - 75 % SL, 25 % BS), or alfalfa (Medicago sativa, control parasitized; CONP), with an additional group of dewormed kids given the alfalfa pellets (Control treated; CONT). Weekly measurements of animal weights and samples of blood and feces were collected to determine the packed cell volume (PCV), GIN fecal egg counts (FEC), and coccidia fecal oocyte counts (FOC), respectively. All animals were processed at the end of the trial (60 total), with adult Haemonchus contortus worms recovered from the abomasum of each goat for counting and sex determination. Carcass weights were recorded after processing. Goats given the SL and BS-SL treatments had lower FEC (P<0.05) than the parasitized alfalfa (CONP) goats. At the end of the study, the SL and BS-SL groups' FOC values were lower (P < 0.05) than the CONT and CONP groups. A rise in PCV values was seen over time for all groups; SL, BS-SL, and CONT animals exhibited higher PCV values (P < 0.05) in comparison to the CONP goats. The parasitized goats fed SL-only pellets showed greater feed intake and animal body weights (P < 0.05) compared to goats fed BS-SL or alfalfa pellets. However, the treatments had no effect on the weight of the goats' carcasses. Although the H. contortus adult worm counts in the CONT goats (alfalfa-dewormed) were lower (P < 0.05) than in the CONP goats (alfalfa-parasitized), they did not differ from the SL or BS-SL animals. This study indicates that sericea lespedeza leaf meal pellet diet, either by itself or in combination with black seed meal, showed promising results as an anthelmintic and may prove to be an effective alternative to exclusive use of conventional deworming drugs. The addition of black seed did not appear to enhance the effectiveness of sericea lespedeza in this study.

Erratum: Livestock feed resources used as alternatives during feed shortages and their impact on the environment and ruminant performance in West Africa: a systematic review.

[This corrects the article DOI: 10.3389/fvets.2024.1352235.].

Epidemiological factors conditioning sarcoptic mange spreading in wild boar (Sus scrofa).

Sarcoptic mange is a widely distributed disease, with numerous potential hosts among domestic and wild animals. Nowadays it is considered a neglected re-emergent infection in humans. As a difference with domestic pigs, and even with several clinical cases reported in some European countries, it seems that Eurasian wild boars (Sus scrofa) have a low susceptibility to clinical mange. However, because of a case of confirmed transmission from Spanish ibex (Capra pyrenaica) to wild boar in the province of Tarragona, we planned a large-scale ELISA survey in the neighboring Valencian Community (SE Spain). We compared 419 wild boar sera from different management systems (fenced vs. open game estates), different ages (piglets, juveniles, and adults), with different behaviour (gregarious females of all ages and male piglets vs. solitary juveniles and adult males), from areas with different wild boar densities, different wild ruminant densities and different sarcoptic mange epidemiologic situations. The whole prevalence of antibodies against sarcoptic mange in the tested wild boars was 10.5%. No significant differences were found when comparing fenced and free ranging wild boars, males and females, gregarious vs. solitary individuals or among different ages. However, wild boar density was a relevant factor. In areas with a hunting bag of <1 wild boar/km2, considered as a low density of suids, the seroprevalence was 2.94%, but rose to 11.52% in high density districts, constituting a significant difference (p = 0.037). Low wild boar populations would act as a protective factor (OR 0.233; p = 0.049) against coming into contact with the mite. The wild ruminant densities or their sarcoptic mange status did not show any effect on wild boars seroprevalence against this disease. These results reinforce the suggested host-taxon Sarcoptes scabiei specificity and the independence of host-species foci.

Review: Update of nutritional requirements of goats for growth and pregnancy in hot environments.

Goats play an important role in the agricultural business, providing valuable income sources through producing high-quality animal protein. They are widespread livestock for rural households due to their inherent resiliency, adaptability to many environments, and suitability in sustainable production systems. While goats are reared in highly diverse environments, a great portion of their population is reared in hot environments. Heat stress is known to affect goats' productive and reproductive performance negatively. However, goats can remarkably thrive in harsh conditions due to physiological, metabolic, and molecular adaptive mechanisms. In the face of it, in the last decades, the nutrition of goats, particularly their nutritional requirements, has received special attention. Research groups worldwide have dedicated their efforts to updating feeding systems for goats. Our objective was to present the recent findings on the energy and nutrient requirements of growing and pregnant goats in hot environments. Energy and protein requirements for the maintenance and growth of goats are influenced by sex and genotype only when mature weight is not considered in the models. Sex and genotype affect the efficiency of energy use for growth but do not affect the efficiency of protein use. Major mineral requirements for maintenance and growth are not affected by sex, except for magnesium. However, the phosphorus, sodium, and potassium requirements of goats raised in hot environments differ from those in the feeding systems. This difference may be related to the adaptation mechanisms goats employ to cope with the hot environmental conditions. Regarding requirements for pregnancy, there was no effect of days of pregnancy on the energy or protein requirements. The efficiency of metabolizable energy utilization for pregnancy increased with the progress of pregnancy. Mineral accretion for pregnancy differs between single and twin pregnancies and, irrespective of pregnancy type, the mineral requirements increase as pregnancy progresses. The differences between the estimated dietary requirements of goats raised in hot environments and the most widely adopted feeding systems suggest that these goats may be using energy and nutrients to cope with heat stress and other stressors associated with hot environments. The recent findings on energy, protein, and mineral requirements of growing and pregnant goats can be an important resource of information for enhancing feeding systems worldwide.

Prevalence of Helminths in Small Ruminant Farms and Evaluation of Control Practices Used to Counter Anthelmintic Resistance in Southern Italy.

Anthelmintic resistance in small ruminants is a serious worldwide problem. To reduce their spread, it is essential to know the prevalence of helminths on farms and the control practices adopted. As these studies in the Calabria region of southern Italy are fragmentary and outdated, a study on the prevalence of helminths in small ruminant holdings in this area has been conducted. The measures implemented to control helminths were also evaluated through questionnaires administered to farmers. In particular, on 90 farms (45 sheep and 45 goats), 1800 faecal samples from 900 sheep and 900 goats were collected in the spring. Using the FLOTAC dual technique, parasitological examinations demonstrated the presence of gastrointestinal nematodes in 100% of sheep and goat farms, followed by Nematodirus spp. (84.44% sheep and 48.89% goats), Moniezia spp. (73.33% sheep and 35.56% goats), Trichuris ovis (48.89% sheep and 42.22% goats), lungworms (28.89% sheep and 42.22% goats), Strongyloides papillosus (40% sheep and 26.67% goats), Dicrocoelium dendriticum (13.33% sheep and 26.67% goats), Calicophoron daubneyi (6.67% sheep and 31.11% goats), Fasciola hepatica (6.67% sheep and 4.44% goats), and Skrjabinema ovis (4.44% sheep and goats). The questionnaires showed that 82% and 85% of the farmers had applied pasture rotation, and that 93.3% and 86.6% had used anthelmintics in the previous year for sheep and goats, respectively. Only 24.4% of sheep farmers and 11.3% of goat farmers had carried out parasitological tests prior to treatments. The most used classes of anthelmintics were macrocyclic lactones and benzimidazoles, and only in 21.6% and 15.6%, for sheep and goats, respectively, was drug rotation carried out. These results denote that helminths represent a health problem for small ruminants and highlight a lack of knowledge of parasite control strategies among farmers. In these conditions, anthelmintic resistance phenomena could develop over time. Therefore, it is necessary to implement all possible strategies for the control of helminths, and to prevent the spread of anthelmintic resistance phenomena on farms in southern Italy.

Tracking melioidosis in Iran: Utilizing abattoir-based surveillance as a One Health approach.

BACKGROUND: Burkholderia pseudomallei, an environmental saprophyte bacterium, causes melioidosis in humans and animals. It was first discovered in Iran between 1967 and 1976 in small ruminants, equines, environments and humans. No subsequent studies have been conducted to determine the existence and prevalence of this pathogen in the country. OBJECTIVES: The present study aims to monitor the presence of B. pseudomallei in the ruminant population of the Golestan province of Iran, which largely depends on pastures. The ruminants can serve as sentinels to indicate the presence of the bacteria in the environment and its potential impact on human health in the One Health triad. METHODS: Liver and lung abscesses from domestic sheep, cattle and goats in three industrial and three conventional slaughterhouses were sampled and analysed using 23S ribosomal DNA polymerase chain reaction (rDNA PCR) with primers CVMP 23-1 and CVP-23-2 for B. pseudomallei, Burkholderia cepacia and Burkholderia vietnamiensis, as well as B. pseudomallei-specific TTS1 real-time PCR, along with microbiological and biochemical assays. RESULTS: Out of the 97 animals sampled, only 14 (15%) tested positive for 23S rDNA PCR. However, the follow-up evaluation using TTS1 real-time PCR and microbiological and biochemical assays did not confirm the presence of B. pseudomallei in the samples. CONCLUSIONS: Although B. pseudomallei was not detected in the current survey, conducting abattoir-based surveillance of ruminants is a cost-effective One Health approach to monitor pathogenic Burkholderia. Developing standards of clinical and laboratory good practices for Burkholderia infections is crucial for One Health surveillance.

Acute atrazine intoxication in heifers: Case report and toxicological studies.

Atrazine is a triazine organochloride herbicide, frequently used in different agricultural activities. Rare acute intoxication with atrazine is reported in production animals, and its metabolism in mammals is unknown. We report a spontaneous case of atrazine acute intoxication in 16.1% animals of a 168-beef heifer herd exposed to the herbicide at a farm located in Buenos Aires province, Argentina. Affected heifers showed different neurological signs and died suddenly, similar to the previous natural atrazine intoxication report. During autopsy, no gross lesions were observed. Different body fluids and tissues samples were collected during postmortem examination. No relevant histopathological findings were observed. High levels of atrazine and its metabolites were detected in different fluids and tissues by ultra-liquid chromatography high performance coupled to triple quadrupole mass spectrometry. These findings suggest ruminal or hepatic metabolization of atrazine in the exposed cattle. This is the first report of quantification and distribution of atrazine and its metabolites in intoxicated mammals providing relevant information for diagnostic purposes.

Assessment of health problems of sheep and goats based on ante-mortem and post-mortem inspection at Addis Ababa Abattoir, Ethiopia.

Introduction: Ethiopia has a rapidly growing small ruminant sector, which faces low productivity due to husbandry practices and poor health condition of the animals. A study was conducted in Ethiopia's largest municipal abattoir with the objective to assess the health problems of sheep and goats presented for slaughter using standard ante-mortem and post-mortem methodology. Methods: A cross-sectional study using systematic random sampling was conducted on 384 sheep and 384 goats from January to July 2014. Results: Soiled skin (69.1%), poor body condition (24.3%), and nostril discharge (19.5%) were common among both species at ante-mortem examination. Gross lesions were frequent in livers (39.7%) and lungs (37.2%), while pneumonia (18.1%) and adhesions (13.8%) were frequent in the lungs of sheep and goats, indicating stress-related illness. Parasitic lesions, especially fasciolosis (19.3%) and hydatid cysts (8.1%) were significantly more common in sheep livers (p 0.05). The direct financial loss from lesions in both species was 1,077,015 ETB or 53,851 USD per year, most of which was estimated to occur from carcass bruising. Discussion: The findings indicate that reducing parasite burden and preventing carcass bruising through improved handling could significantly increase the profitability of the small ruminant meat sector in Ethiopia.

Morphological and molecular data confirm the occurrence of Paramphistomum leydeni (Trematoda: Paramphistomidae) in ruminants from Southern Brazil.

Species belonging to the family Paramphistomidae Fischoeder, 1901, commonly known as "rumen flukes", are a group of parasites frequently related to Brazilian livestock production. They inhabit the digestive tract of ruminants and have recognized pathogenicity during the early stages of infection, which can be responsible for economic losses. These trematodes are often associated with Southern Brazil, a region heavily focused on animal farming, which also makes it ideal for the life cycle of paramphistomes. Despite their aforementioned importance, studies regarding their distribution, molecular taxonomy and biology are still scarce in the country. In the present study, rumen flukes collected from cattle (n = 22) and sheep (n = 3) from 9 batches of ruminants from the cities of Jaguarão, Pelotas and Rio Grande, state of Rio Grande do Sul, Brazil, between May and July 2022, were subjected to morphological and molecular study. The microscopic analysis of histological and manual cuts revealed diagnostical traits compatible with Paramphistomum leydeni Näsmark, 1937, including the presence of tegumental papillae, pharynx of the liorchis type and acetabulum of the leydeni type. Molecular data corroborated the morphological identification, with ITS-2 and cox-1 sequences here obtained presenting 100% and 96.8-99.8% similarity, respectively, to P. leydeni samples previously characterized in different countries from Asia, Europe, and South America. Intensity of infection ranged from 5 to 458 and 1 to3 specimens of P. leydeni in sampled cattle and sheep, respectively. The present study contributes to a better understanding of the taxonomy of the flukes involved in cattle and sheep paramphistomosis in Brazil, suggesting that P. leydeni could be the main paramphistome species found in ruminants in the studied region.

Recommendations on visit duration and sample number requirements for an automated head chamber system.

Automated head chamber systems (AHCS; GreenFeed, C-Lock Inc., Rapid City, SD) increasingly are being used for measuring the gas flux of unrestrained cattle. There are a wide range of recommendations for what constitutes a "good" visit (i.e., duration) to an AHCS and how many visits are required for the AHCS to quantify gas fluxes accurately and precisely. Accordingly, the purpose of this experiment was to investigate the effects of visit duration thresholds and the subsequent effects of these thresholds on the number of visits needed to provide adequate estimates of carbon dioxide (CO2) and methane (CH4) emissions, and oxygen (O2) consumption by beef cattle. This analysis utilized data from three previously published experiments with grazing beef steers and one experiment with finishing beef steers, with 103 steers total. When comparing all available visits, there was excellent agreement [Lin's concordance correlation coefficient (CCC) ≥ 0.96] between visits ≥ 3 min in duration and those ≥ 2 min for the three gases in all four experiments. When data from all four experiments were pooled, there was excellent agreement between visits ≥ 3 min and those ≥ 2 min and ≥ 1 min for all gases (CCC ≥ 0.96). These results suggest that estimates from visits ≥ 2 min are like those from visits ≥ 3 min. Next, we investigated if including visits ≥ 2 min or ≥ 1 min would increase the minimal number of visits required to provide excellent agreement with the "gold-standard" (mean of all visits ≥ 3 min). For this, we used only one of the experiments and randomly selected visits per animal ranging from n = 5 to 60, in increments of 5. The sole experiment was used because all animals had more than 60 visits. We then assessed the agreement between the "gold-standard" (mean of all visits ≥ 3 min [144 ±â€…55.01 visits per steer]) estimates of CO2, O2, and CH4. The minimum number of visits required to achieve excellent agreement (CCC ≥ 0.90) to the "gold-standard" estimate for all gases was 30 visits ≥ 3 min in duration, or 40 visits ≥ 2 min in duration. Visits ≥ 1 min in duration did not achieve excellent agreement, even when 60 were used. Based on these results, we recommend excluding visits < 3 min in duration with 30 minimum visit records per animal. However, if researchers choose to implement a 2-min visit duration threshold then 40 visit records are needed per animal.

GreenFeed systems (C-Lock Inc., Rapid City, SD) are being increasingly used for measuring carbon dioxide (CO2) and methane (CH4) emissions and oxygen consumption (O2) of free-roaming cattle. These systems utilize averages of multiple visits to provide estimates of daily gas flux. There currently exists a range of recommendations for what constitutes a "good" visit to GreenFeed. Additionally, the number of recommended visits required to achieve adequate estimates of these gas fluxes appears to be dependent on the minimum visit duration that is used. To date, there has been only one experiment that has investigated visit duration and the recommended number of visits for CO2 and CH4 emissions and to our knowledge this has not been assessed for O2 consumption. Based on the results of this experiment, we recommend using a 3-min minimum visit duration threshold with 30 visit records per animal. If researchers choose to use a 2-min visit duration threshold, then 40 visit records per animal are recommended.

Effects of dietary supplementation with alkaline mineral complex on in vitro ruminal fermentation and bacterial composition.

Introduction: Dairy industry growth faces challenges in China due to inadequate forage, leading to high-concentrate diets and potential rumen issues. Buffering agents, like sodium bicarbonate, play a crucial role in stabilizing rumen pH. Alkaline Mineral Complex (AMC), a liquid additive with a pH of 14, shows promise in supporting dairy cow health and mitigating heat stress through ionization. Methods: This experiment was aimed to study the effect of adding AMC to total mixed ration (TMR) on in vitro ruminal fermentation and bacterial composition. AMCat 1, 2, 4, and 8 mL/kg was added to the substrate (0.5 g TMR). Nutrient digestibility was measured after 48 h fermentation, and fermentation parameters and microbial composition were measured after 48 h fermentation. Results and discussion: The results of the experiment indicated that: The different concentrations of AMC showed a significant impact on time taken for gas production to reach 1/2 of the total gas production (HT) parameters (p < 0.05). Linear pH increase occurs at 6 and 24 h with rising AMC concentration (p < 0.05), showing a quadratic trend at 12 h (p < 0.05). The optimal buffering effect on rumen acid-base balance was observed at a 2 mL/kg concentration of AMC. Microbial diversity analysis indicated that there was no significant change in α-diversity with different AMC concentrations (p > 0.05). The microbial level demonstrated no significant difference in species diversity of rumen fluid bacteria among the various AMC concentration treatment groups compared to the control group, further supporting that the advantage of adding AMC in stabilizing the rumen environment without altering the structure of the rumen microbiota. Besides, the addition of AMC significantly increased the concentrations of acetate, propionate, total fatty acids (TVFA), and NH3-N, suggesting that AMC contributed to enhancing the energy and nitrogen utilization efficiency in ruminants. Based on the above detection indicators, we recommend that the most favorable concentration is 2 mL/kg.

Potential to reduce methane production of using cultivated seaweeds supplementation to reshape the community structure of rumen microorganisms.

Methane is a short-lived greenhouse gas but has a far greater warming effect than carbon dioxide. At the same time, the livestock sector serves as a large contributor to global emissions of anthropogenic methane. Herein, this work aimed to use cultivated seaweed supplementation to reduce methane emissions and investigate the potential influencing mechanism. To evaluate the feasibility, two cultivated seaweeds, Laminaria japonica Aresch, and Porphyra tenera, along with the enzymatic hydrolysates derived from L. japonica, underwent in vitro trials, and they were both added into corn silage feed (CSF) with different concentrations (1%, 5%, and 10% of CSF) for methane reduction evaluation. The results indicated that >75% and 50% reductions in methane production were observed for the seaweeds and seaweed enzymatic hydrolysates in 9- and 30-day, respectively. Combined high-throughput sequencing and multivariate analysis revealed that supplementation with seaweed and seaweed enzymatic hydrolysates had a notable impact on the prokaryotic community structure. Mantel tests further revealed that significant correlations between the prokaryotic community and methane accumulation (P < 0.05), implying the prokaryotic community plays a role in reducing methane emissions within the rumen. Correspondingly, the networks within the prokaryotic community unveiled the crucial role of propionate/butyrate-producing bacteria in regulating methane emissions through microbial interactions. The predicted function of the prokaryotic community exhibited a significant reduction in the presence of the narB gene in seaweed-supplemented treatments. This reduction may facilitate an increased rate of electron flow toward the nitrate reduction pathway while decreasing the conversion of H2 to methane. These results indicated the supplementation of cultivated seaweeds and the enzymatic hydrolysates has the potential to reshape the community structure of rumen microbial communities, and this alteration appears to be a key factor contributing to their methane production-reduction capability.

Unveiling of the Co-Infection of Peste des Petits Ruminants Virus and Caprine Enterovirus in Goat Herds with Severe Diarrhea in China.

Here, we report the discovery of two viruses associated with a disease characterized by severe diarrhea on a large-scale goat farm in Jilin province. Electron Microscopy observations revealed two kinds of virus particles with the sizes of 150-210 nm and 20-30 nm, respectively. Detection of 276 fecal specimens from the diseased herds showed the extensive infection of peste des petits ruminants virus (63.77%, 176/276) and caprine enterovirus (76.81%, 212/276), with a co-infection rate of 57.97% (160/276). These results were partially validated with RT-PCR, where all five PPRV-positive and CEV-positive specimens yielded the expected size of fragments, respectively, while no fragments were amplified from PPRV-negative and CEV-negative specimens. Moreover, corresponding PPRV and CEV fragments were amplified in PPRV and CEV double-positive specimens. Histopathological examinations revealed severe microscopic lesions such as degeneration, necrosis, and detachment of epithelial cells in the bronchioles and intestine. An immunohistochemistry assay detected PPRV antigens in bronchioles, cartilage tissue, intestine, and lymph nodes. Simultaneously, caprine enterovirus antigens were detected in lung, kidney, and intestinal tissues from the goats infected by the peste des petits ruminants virus. These results demonstrated the co-infection of peste des petits ruminants virus with caprine enterovirus in goats, revealing the tissue tropism for these two viruses, thus laying a basis for the future diagnosis, prevention, and epidemiological survey for these two virus infections.

Advancements in Understanding and Enhancing Antioxidant-Mediated Sperm Cryopreservation in Small Ruminants: Challenges and Perspectives.

Cryopreservation poses significant challenges to the preservation of sperm integrity and function, particularly in small ruminants where cryodamage is pronounced. This review explores the molecular mechanisms underlying sperm cryodamage and strategies for improving cryopreservation outcomes, with a focus on the role of antioxidants. Cryopreservation-induced alterations in proteins and RNA transcripts critical for sperm function, including motility, capacitation, fertilization, and embryo development, are discussed. Proteomic, transcriptomic, and epigenomic advancements have provided valuable insights into these mechanisms, offering potential biomarkers for predicting sperm freezability and enhancing cryopreservation strategies. Combining technologies such as mass spectrometry and flow cytometry allows for a comprehensive understanding of molecular and cellular changes induced by the freezing-thawing process. However, challenges remain in optimizing cryoprotectant formulations and antioxidant supplementation to improve post-thaw sperm fertility. Further research is needed to explore a wider range of novel cryoprotectants, antioxidants, and proteins for cryopreservation media, as well as to validate their efficacy in enhancing sperm viability and function. Additionally, investigations into the effects of cryopreservation on RNA transcripts and epigenetic factors in small ruminant species are warranted to advance our understanding of sperm preservation. Overall, this review highlights the importance of antioxidants in mitigating cryodamage and underscores the need for continued research to refine cryopreservation protocols and improve reproductive outcomes in small ruminants.