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.

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.

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.

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.

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.

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.

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.].

Prevalence of Gastrointestinal Parasites in Small Ruminant Farms in Southern Spain.

The primary population of small ruminants in Spain is concentrated in the southern region, a critical area for the country's livestock production. Indirect economic losses can occur when this livestock is affected by gastrointestinal parasites. This study aimed to determine the prevalence of these parasites in small ruminant herds (159 sheep and 39 goats) through coprological analyses and conducted a survey on farmers' management practices related to gastrointestinal parasite control. The survey results revealed some important aspects: monitoring through coprological analyses is not a common practice; veterinarians are not typically involved in deworming plans; anthelmintic treatment in adults is often applied twice a year in sheep and once a year in goats; and finally, drug rotation was higher in sheep farms. Coprological analyses showed Eimeria spp. as the most common parasitic infection, followed by Strongyles infection. Other parasites like Moniezia spp., Trichuris spp., and D. dendriticum were less important, although their prevalence was higher in sheep than goats. This constitutes the first report on the epidemiological status of gastrointestinal parasites in small ruminants in southern Spain. Based on the survey findings, the introduction of certain management measures on farms could potentially mitigate parasite infections.

Essential Oils in Nellore Beef Cattle: In Vivo Impact on Rumen Emissions.

Essential oils (EOs), as rumen additives, decreased CH4 emissions in in vitro trials but results from in vivo studies are still limited. We investigated the effects of Origanum vulgare (OEO) and Thymus vulgaris (TEO) EOs on in vivo methane emissions from Nellore beef cattle. Six adult rumen-cannulated Nellore cattle were used in a double 3 × 3 Latin square design. Treatments consisted of three diets containing either 3 mL OEO per kg of concentrate, 3 mL TEO/kg of concentrate, or no EO addition. The experimental period consisted of three 21 d feeding periods and methane production was measured using the sulfur hexafluoride (SF6) technique from Day 16 to Day 21 of each feeding period. Intake, total apparent digestibility (dry matter as well as neutral and acid detergent fiber), and rumen parameters (pH, ammoniacal nitrogen concentration, and short-chain fatty acids) were also evaluated. The EOs did not decrease CH4 emissions and had no effect on rumen parameters.

Copra Meal: A Review of Its Production, Properties, and Prospects.

Copra meal, the byproduct of coconut oil production, has been widely available at low cost but has been underutilized, with huge portions still becoming waste. Extensive research on different species have been performed to improve its use as an alternative feed ingredient, aiming to reduce the impact of fluctuating feed prices in some parts of the world where coconut is a major commodity. As for any biological product, the physical and chemical properties of copra meal play a crucial role in its use and limitations. In the case of copra meal, studies have found that additional treatments are needed to improve its nutritional composition and make it readily and efficiently available for ruminant and monogastric animals, poultry, and aquaculture applications. This paper presents a summary of up-to-date information on the physical and chemical characteristics of the product, as well as discussions on the various methods employed to improve and optimize its biological value as animal feed. There have been limited studies that have explored other effective and economical means of utilizing copra meal outside the livestock and feed industry. Hence, this paper also aims to provide a lens on future prospects and diverse applications involving copra meal, as well as to present the gaps and challenges that have to be addressed to maximize its product value and biological potential.

No Evidence of Neutrophil Response Modulation in Goats after Immunization against Paratuberculosis with a Heat-Inactivated Vaccine.

Neutrophils are believed to play a role in the initial stages of paratuberculosis, and it has recently been demonstrated that vaccination can modulate their function via priming or through epigenetic and metabolic reprogramming (training). Modulation of the neutrophil response against Mycobacterium avium subspecies paratuberculosis (Map) through vaccination has been demonstrated in a rabbit model but not in ruminants. Therefore, in the present work, the effect of vaccination on the response of caprine neutrophils against Map was studied. Neutrophils were isolated from non-vaccinated (n = 7) and Gudair®-vaccinated goat kids (n = 7), before vaccination and 30 days post-vaccination. Then, several neutrophil functions were quantified ex vivo: cell-free and anchored neutrophil extracellular trap (NET) release, phagocytosis, and the differential expression of several cytokines and TLR2. The induction of cell-free NETosis and TLR2 expression by Map is reported for the first time. However, vaccination showed no significant effect on any of the functions studied. This suggests that the protection conferred by Gudair® vaccination is based on mechanisms that are independent of the neutrophil function modulation. Further research into the impact of alternative vaccination strategies or the paratuberculosis infection stage on ruminant neutrophil function could provide valuable insights into its role in paratuberculosis.

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.

Seroprevalence of infectious pathogens of zoonotic and veterinary importance in wild ruminants from Slovenia.

Introduction: Wildlife represents an increasingly important source of pathogens of medical and veterinary importance. Surveillance in wildlife offers an insight on current epidemiological status of selected pathogens and help to prevent spillovers to humans and livestock. Material and methods: Our study included 312 wild ruminants belonging to five species: Roe deer (n = 134), red deer (n = 113), Alpine chamois (n = 53), European mouflon (n = 10) and Alpine ibex (n = 2). Seven pathogens that may have profound effect on human/livestock health and economic viability of the farms were tested using serological methods. Results: Antibodies against Toxoplasma gondii, Neospora caninum, Coxiella burnetii, Brucella spp., Chlamydophila abortus, Mycobacterium avium subsp. paratuberculosis (MAP) and Mycobacterium bovis were detected in 34.62% (108/312), 0.96% (3/312), 2.24% (7/312), 0, 0.96% (3/312), 0, 0.64% (2/312) of animals tested, respectively. Because of low prevalences, risk factors were assessed only for T. gondii. Sex (female>male) and species (roe deer>red deer, roe deer>Alpine chamois) were significantly associated with the T. gondii positive outcome, while age was not. Discussion: Adult males had the lowest T. gondii prevalence which offers future research opportunities. The lower seroprevalence of most investigated pathogens suggests game meat, if properly cooked, as being relatively safe for human consumption. This is the first study investigating the seroprevalence and associated risk factors of selected pathogens in wild ruminants in Slovenia.

Inseminate without hormonal treatment in dairy sheep farms: exploring the consequences on the sustainability of several contrasted production systems.

Alternatives to hormonal treatments (HTs) in dairy sheep reproduction management are being explored in response to increasing societal concerns regarding animal welfare and food safety. However, hormone-free reproduction implies higher variability in flock performances and additional constraints for timely synchronised artificial insemination (AI) in the flock, impacting the diffusion of genetic progress. The use of the male effect, a well-known practice to induce synchronised oestrus, combined with precision tools (e.g., heat detector), is a plausible way to implement AI without HT in dairy sheep farms. To date, the consequences of such alternative reproduction management on the whole farm sustainability remain unknown. To anticipate these potential impacts, a multiagent model (REPRIN'OV) was used to simulate dairy sheep farms' sustainability indicators (biotechnical, economic, environmental and workload). A reproduction management scenario, including the use of the male effect followed by AI on the adult ewes (HFAI), was simulated and compared to the current reproduction management of four case study farms (Early_conv, Late_conv, Early_org and Late_org). They were selected to represent the different agricultural models (Conventional or Organic) and reproduction seasons (Early - during spring, out of ewes' natural reproduction season - or Late -from early summer to the end of autumn) of the Roquefort Basin's farms in Southern France. Simulation results showed that the HFAI scenario had different consequences depending on the farm's production system type. A negative effect on most key sustainability indicators of the Conv farms was observed, as a significant reduction in the fertility rate, in the proportion of young ewes born from AI (-54% in both farms; P < 0.05) and in the flock's milk production were observed; while the workload and greenhouse gas (GHG) emissions were increased compared to the initial scenario. In the Org farms, HFAI had neutral to positive effects on most indicators as the fertility, milk production of the flock, workload during milking and GHG emissions were barely affected by this scenario, while an increase in the proportion of young ewes born from AI was observed (+39% and + 43% in each farm, respectively; P < 0.05), allowing a better farm gross margin. Still, the workload during lambing was increased in Early_org (+18%; P < 0.05), as Early farms, tended to be more negatively impacted by HFAI than Late ones. Overall, our simulation approach provides interesting elements to exchange with stakeholders on how to progress towards a socially acceptable reproduction management system, for the dairy sheep sector.

Short communication: Goat mastitis and the formation of neutrophil extracellular traps (NETs).

Mastitis, an inflammation of the mammary gland affecting milk production and quality in dairy herds, is often associated with Staphylococcus spp. in goats. Neutrophils are crucial in combating infections by migrating into milk and deploying various defense strategies, including the release of neutrophil extracellular traps (NETs) composed of DNA, histones, and bactericidal proteins. This study investigated whether NETs are released by goat neutrophils stimulated in vitro by Staphylococcus aureus and Staphylococcus warneri, two common pathogens of goat mastitis. PMNs were isolated from blood from healthy adult goats. We evaluated goat NET formation by stimulating cells with: phorbol 12-myristate 13-acetate (PMA) as a positive control, cytochalasin for inhibition of actin polymerization, S. aureus, and S. warneri. NET formation was observed in response to chemical stimulation and bacterial presence, effectively trapping pathogens. Variations in NET formation between S. aureus and S. warneri suggest pathogen-specific responses. These findings suggest that the formation of NETs may be an important complementary mechanism in the defense against mastitis in goats. In conclusion, this study unveils a novel defense mechanism in goats, indicating the role of NETs against S. aureus and S. warneri in mastitis.

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.

Supplementing zebu cattle with crop co-products helps to reduce enteric emissions in West Africa.

In Africa, a wide variety of diets (forage + crop co-products or other agricultural by-products) is being used by livestock farmers in different production systems to adapt to climate change. This study aimed to assess the performance of various local feeding strategies on Sudanese Fulani zebu cattle. Two experiments were carried out on 10 steers aged initially 33 months (142 kg body weight - BW). The animals were fed eight different diets at an intake level of 3.2% LW in dry matter (DM), including two control diets of 100% rangeland forage (100% RF) and six experimental diets made up of forage and crop co-products (75:25 DM ratio). In the first experiment, the control diet was made up of rangeland forage (RF) and supplements consisted of four cereal co-products (CC), i.e. maize, sorghum, millet, and rice straws. In the second experiment, the control diet consisted of Panicum maximum (Pmax) hay, and the supplements tested were two legume co-products (LC), i.e. cowpea and peanut haulms. Each experiment lasted 3 weeks, including 2 weeks of adaptation to the diet and 1 week of data collection on individual animals (intake, apparent digestibility, and enteric methane). The NDF content of the diets was different within each experiment (p < 0.05). Among diets containing CC, DM intake [g/kg BW] was significantly higher (+31%; p = 0.025) for the diet containing rice straw than for the other diets, which showed similar levels to the RF diet. Among diets containing LC, intake was significantly higher (p = 0.004) than for the Pmax diet. Intake was higher for the peanut haulm diet than for the cowpea haulm diet. The DM digestibility was similar between the different diets in each experiment. Enteric methane (eCH4) yield [g/kg DMI] from the CC and LC-containing diets were reduced by an average of 23% and 20% compared to the RF and Pmax control diets respectively. Raising awareness among agro-pastoralists about the use of crop co-products offers real prospects for eCH4 emissions mitigation in the Sahel 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.

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.

Insights into Effects of Combined Capric and Lauric Acid on Rumen Bacterial Composition.

This study used next-generation sequencing to assess the impact of combined capric acid (C10) and lauric acid (C12) on the ruminal bacterial composition. Eight Holstein cows were randomly assigned to two groups using a cross-over design. The cows were fed two silage-based diets with the addition of either 100 g of stearic acid per cow per day (control), or 50 g of capric acid and 50 g of lauric acid per cow per day (C10 + C12). On day 18, 250 mL of rumen fluid was collected from each cow, and DNA was isolated, amplified, and sequenced. Treatment did not alter bacterial diversity indices, the relative abundance of archaea, nor the fiber-degrading microorganisms, except for a decrease in Fibrobacter (from 2.9% to 0.7%; p = 0.04). The relative abundance of Prevotellaceae decreased (from 39.9% to 29.6%; p = 0.009), which is notable because some members help to efficiently utilize ammonia by releasing it slowly into the rumen. Furthermore, the relative abundance of Clostridia increased (from 28.4% to 41.5%; p = 0.008), which may have aided the increased ammonia-nitrogen levels in the rumen, as this class contains hyperammonia-producing members. Our study reveals alterations in bacterial abundances with implications for rumen ammonia levels, offering insights into potential strategies for modulating rumen fermentation processes and methane production in ruminant livestock.