An alternative strategy to reduce methane (CH₄) emissions from livestock is biochar, a porous carbonaceous material produced through the pyrolysis of biomass. This study aimed to evaluate the effects of biochars derived from walnut shell, almond shell, and apricot shell on rumen fermentation and CH₄ production under in vitro conditions. The experiment used a completely randomized design in an in vitro fermentation system with four treatments: a control diet without biochar and the control diet supplemented with 1% (based on total substrate dry matter) walnut, almond, or apricot shell biochar. Gas production was measured at multiple time points, and fermentation parameters were analyzed after 24 h of incubation. Walnut shell biochar increased gas production throughout the incubation period, whereas apricot shell biochar decreased it compared to the control (P < 0.05). While pH remained unaffected, apricot shell biochar significantly reduced ammonia nitrogen (NH₃-N) (P < 0.05). Furthermore, apricot and almond shell biochars significantly reduced protozoa counts (P < 0.05). Notably, walnut shell biochar significantly increased total volatile fatty acids (VFA) and propionate concentrations (P < 0.05), and enhanced in vitro dry matter degradability (DMD) (72.3% vs. 65.3% in the control) (P < 0.05). All biochar treatments significantly reduced CH₄ production (P < 0.05), with the greatest reduction observed with walnut shell biochar (77.2 vs. 90.9 mL/g DM; approximately 15% reduction). Overall, walnut shell biochar showed the most favorable effects by enhancing in vitro DMD, increasing total VFA and propionate concentrations, and achieving the greatest reduction in CH₄ production.
This study investigated associations between the hormone cortisol, the neurotransmitters dopamine and serotonin, immunoglobulin A (IgA), heart rate (HR), rectal temperature (RT) and cow behavior pattern in relation to production stress, stress around calving, human handling and adaptation to the milking robot system. Blood samples of 315 Holstein-Friesian cows from five farms with AMS were taken within 14 d after calving (blood sampling date 1 (= BS1) to assess physiological responses during the early postpartum period, followed by human behavioral assessments at blood sampling date 2 (= BS2). Indicators for cow reactions to human handling at BS2 included measurements for the avoidance distance (AD) and scores for the tolerance to tactile interaction (TTI). Dopamine, serotonin and IgA were measured by ELISA tests, and cortisol concentrations were determined by radioimmunoassay. HR and RT as physiological stress indicators were recorded before blood sampling. Associations between blood and physiological biomarkers under different stressors were inferred via generalized linear mixed model applications. In model group 1, analyzing the effects of blood and physiological biomarkers at BS1 on the same biomarkers at BS1, serotonin significantly (P < 0.001) influenced dopamine, and vice versa. Model group 2, examining the effects of behavioral traits on blood and physiological biomarkers at BS2, revealed a significant effect of TTI (P < 0.001) on HR. In model group 3, assessing the effects of biomarkers at BS1 on the same biomarkers at BS2, dopamine, serotonin, IgA and HR at BS1 significantly (P < 0.001) predicted the corresponding biomarker at BS2. In model group 4, effects of daily milk yield on blood and physiological biomarkers at BS2, were non-significant (P > 0.05). In conclusion and from a practical farming perspective, AMS behavioral indicators showed diverse patterns in relation to stress biomarkers, suggesting an index trait for behavioral assessment in a technical environment.
Canine parvovirus (CPV) remains one of the most important causes of infectious gastroenteritis and mortality in puppies worldwide despite the widespread availability of effective vaccines. Although vaccination has substantially reduced disease incidence since the introduction of modified-live vaccines, CPV continues to circulate globally, and cases of parvoviral enteritis are still reported in both vaccinated and unvaccinated dogs. These observations have generated ongoing debate regarding the relative contribution of viral, host, and management factors to vaccination failure.This narrative review provides an updated synthesis of CPV epidemiology, vaccination strategies, causes of vaccine failure, and recent advances in prevention and treatment. Particular attention is given to major controversies surrounding antigenic variation, maternally derived antibody (MDA) interference, host-related factors, and vaccination protocol compliance. The review examines the emergence and global spread of CPV-2a, CPV-2b, and CPV-2c and critically evaluates experimental and field evidence regarding their impact on vaccine efficacy. While concerns regarding antigenic mismatch have accompanied the emergence of CPV variants, current evidence indicates that commercially available modified-live vaccines provide substantial cross-protection against circulating strains, including CPV-2c. In contrast, MDA interference, incomplete vaccination schedules, inadequate population immunity, improper vaccine handling, and high environmental infectious pressure appear to account for most reported vaccination failures.The review also discusses the concept of the immunity gap and the evolution of international vaccination recommendations, including administration of repeated vaccine doses until at least 16 weeks of age and an additional booster at approximately 26 weeks in selected high-risk situations. Recent advances in passive immunotherapy, including CPV-specific monoclonal antibodies and hyperimmune plasma, are also reviewed.Particular emphasis is placed on African epidemiological settings, where limited surveillance systems, variable vaccination coverage, sustained environmental viral circulation, and frequent deviations from international vaccination guidelines may contribute to persistent disease burden. Morocco is presented as a representative example of these challenges because, despite the availability of effective vaccines, veterinarians continue to encounter frequent cases of parvoviral enteritis and apparent vaccination failure in the absence of structured surveillance and pharmacovigilance systems. By integrating recent experimental, clinical, and epidemiological evidence, this review aims to clarify the mechanisms underlying CPV vaccination failure and to identify priorities for improving disease prevention and control in Africa and other regions facing similar epidemiological constraints.
Minimally invasive techniques allow tissue sampling while limiting procedural invasiveness. This study compared the quality of biopsy samples obtained through laparoscopically guided core needle (16G or 18G), laparoscopic pancreatic forceps or laparoscopic cup forceps with teeth for sampling non-grossly enlarged cecocolic lymph nodes in dog cadavers. Three techniques were performed in randomized order across 17 fresh cadavers, collecting three specimens per technique (153 total specimens, yielding 51 technique-level histological assessments). Sample collection time, observer-reported perceived difficulty, and a composite histological sample-adequacy score (0-14) were evaluated. Core needle biopsy required longer collection time than both forceps techniques (adjusted p = 0.002 for both comparisons). Perceived difficulty was lowest for pancreatic forceps, followed by cup forceps with teeth, and highest for core needle biopsy (all adjusted p ≤ 0.004). Both pancreatic forceps and cup forceps with teeth yielded higher composite adequacy scores than core needle biopsy (adjusted p = 0.019 and 0.006, respectively), whereas the two forceps did not differ (p = 0.504). Core needle biopsy was associated with greater fragmentation, lower structural preservation, and more histopathological changes limiting interpretation. Exploratory comparisons showed no differences between 16G and 18G needles. In this cadaveric model, both laparoscopic forceps techniques provided shorter collection times, lower perceived difficulty, and superior histological sample adequacy than laparoscopically guided core needle biopsy. Clinical safety and disease-specific diagnostic performance warrant further evaluation.
Mastitis is a multifactorial disease with major consequences for production, animal welfare, and public health, yet it remains less studied in goats than in cows. Moreover, reports of antimicrobial resistance among bacteria isolated from mastitic goats are scarce. In Ethiopia, treatment decisions for mastitis largely rely on empirical clinical experience rather than routine antimicrobial susceptibility testing. To address this gap, a cross-sectional study was conducted from November to December 2024 in Waghimra, Amhara, Ethiopia, to identify the major bacterial causes of mastitis and to evaluate their antimicrobial susceptibility patterns. Bacterial isolation, identification, and antimicrobial susceptibility testing followed standard protocols, and statistical analyses were performed using Stata 17 and WHONET software. The overall goat-level mastitis prevalence was 24.69% (98/397), comprising 2.52% (10/397) clinical and 22.28% (88/395) subclinical mastitis. Staphylococcus spp. (47/129; 36.43%) was the predominant isolate, followed by E. coli (12/129; 9.30%) and Klebsiella spp. (3/129; 2.33%). All Staphylococcus isolates were resistant to ampicillin (37/37; 100%) and showed considerable resistance to tetracycline (16/37; 43.24%), but remained highly susceptible to kanamycin (36/37; 97.30%), chloramphenicol, and gentamicin (35/37; 94.59% each). E. coli and Klebsiella spp. were highly susceptible to most antimicrobials tested, except ampicillin. Multidrug resistance was detected in 13.46% (7 out of 52) of isolates, occurring exclusively among Staphylococcus spp. Subclinical mastitis, mainly caused by Staphylococcus spp., was highly prevalent in the study area, showing complete ampicillin resistance and considerable tetracycline resistance. These findings have important implications for milk production, animal welfare, and public health, given local raw milk consumption.
This study aimed to evaluate whether pregnancy loss during early, mid, or late gestation periods is associated with parity, uterine health, or season of breeding in a Mexican intensive, temperate semi-arid production system. In a retrospective cohort observational study (n = 772), primiparous and multiparous cows with a retained placenta and/or metritis were categorized as having uterine disease (UTD), whereas cows without these conditions were categorized as healthy (HLT). Two seasons of breeding were considered: dry (November-April) and rainy (May-October). Pregnancy loss was classified into three gestation periods: early (33 to 42 days, n = 772), mid (43 to 110 days, n = 706), and late (111 to 202 days, n = 599). Data were analyzed using multivariate logistic regression and Cox proportional hazard regression models. Overall, cows that experienced uterine disease had a higher risk of losing their pregnancy during the early (P = 0.0280), mid (P = 0.0441), and late (P = 0.0340) evaluation periods compared to healthy cows. Concurrently, multiparous cows exhibited a higher risk of pregnancy loss during the mid (P = 0.0048) period compared to primiparous cows. The Cox proportional hazard model indicated that the probability of remaining pregnant over time was consistently lower for UTD cows (P = 0.0010) and multiparous cows (P = 0.0006) compared to their healthy and primiparous counterparts, respectively. In conclusion, postpartum uterine diseases and multiparity are critical risk factors that compromise long-term pregnancy maintenance in dairy cattle managed under intensive, temperate semi-arid production systems in Mexico.
Transition milk is an important part of a newborn calf's nutrition, and its positive effects on the calf's health could be attributed, among others, to its fatty acid (FA) profile. Transition milk can be collected via automated milking systems (AMS). This study aimed to evaluate changes in FA profile of transition milk in dependence on parity, the number of milkings, and the between-milking interval when using AMS for its collection. The on-farm observation was conducted on 18 Czech Fleckvieh cows in a confined system that were in their first (7 cows), second (5 cows), or third or higher parity (6 cows). Starting from the second milking, cows were milked in AMS. Milk was sampled at each milking within 4 days postpartum and analysed for its FA profile using two-dimensional gas chromatography with a vacuum ultraviolet detector. The FA profile changed gradually with the increasing number of milkings postpartum. The relative content of short-chain and long-chain FA increased (P < 0.05) at the expense of medium-chain FA, and the content of monounsaturated FA increased at the expense of saturated FA (P < 0.001). Parity affected mainly the content of butyric, myristic, stearic, and oleic acids (P < 0.05). The interval between milkings did not have a pronounced effect on the FA profile, as only slight changes in the concentration of lauric and linolelaidic acids were observed (P < 0.05). When using AMS, cows’ parity and milking number seem to be the main factors influencing the FA profile of transition milk.
Tryptophan (TRP) and serotonin (5-HT) play important biological roles, including neurotransmission. However, the preservation and quantification of TRP and 5-HT in blood samples are challenging due to their instability. In addition, methods for their determination in biological samples using high-performance liquid chromatography with fluorescence detection (HPLC-FLD) remain limited. This study aimed to develop methods for the preservation and quantification of 5-HT and TRP in blood using HPLC-FLD. Mobile phases with different pH values (3.5, 4.0, and 4.5) and methanol-to-buffer ratios (25:75, 20:80, and 15:85) were evaluated. A stability study using different preservatives (perchloric acid, oxalic acid, oxalic acid + glycine, EDTA, EDTA + perchloric acid, Na2S2O5, Na2S2O5 + EDTA, 15% methanol, and 30% methanol) and storage temperatures was conducted. TRP and 5-HT concentrations were determined in whole blood, serum, heparinized plasma, and EDTA plasma. The optimized mobile phase consisted of methanol and KH2PO4 buffer (pH 3.5) at a 20:80 ratio. Intraday and interday precision were 2.20% and 4.43% for TRP, and 2.36% and 4.96% for 5-HT, respectively. Mean accuracy was 105.2% for TRP and 99.4% for 5-HT. Serum samples preserved with 30% methanol showed no significant changes (P > 0.05) in TRP and 5-HT concentrations when stored at −20°C or −80°C. TRP exhibited minor variation among blood fractions, whereas 5-HT was higher in serum. The proposed analytical method is sensitive and reliable for quantifying TRP and 5-HT in blood. Methanol (30%) effectively preserved TRP and 5-HT during frozen storage for at least 56 days.
This study was conducted to evaluate effects of direct-fed microbials (DFM) and zinc-methionine (ZM) as well as their potential interaction and dose response of ZM as nutritional strategies to improve growth performance, blood metabolites, rumen fermentation characteristics, and apparent nutrient digestibility in preweaning Holstein calves. Seventy-two newborn Holstein calves (4 d of age, BW = 38.6 ± 6.27 kg) were assigned to a 2 × 3 factorial arrangement of treatments with DFM at 2 levels (0 or 5 g/calf/d) and ZM at 3 levels (0, 422, and 632 mg/calf/d). Main effects of DFM and ZM increased body weight, final body weight and dry matter intake. As ZM dose increased, body weight increased both linearly and quadratically, while final body weight increased quadratically and dry matter intake increased linearly. Main effect of DFM increased average daily gain. Withers height increased with main effects of DFM and ZM, whereas heart girth increased with main effects of DFM and ZM and also DFM × ZM interaction. Hip width increased by ZM main effect. Zinc-methionine level increased heart girth both linearly and quadratically but increased hip width quadratically and withers height linearly. In plasma, DFM main effect increased glucose, total protein, and cholesterol, whereas ZM main effect increased albumin. Plasma albumin increased linearly in response to ZM level. According to our results, DFM and ZM can be considered as effective additives to improve growth performance in preweaning dairy calves. No consistent evidence was found that combined DFM and zinc supplementation might enhance calf performance.
Three key signatures — microbial, nutritional, and epigenetic — are pivotal in nutrigenomics, mediating poultry responses to nutritional signals, such as low-protein diets (LPDs) and lysine restriction (LR). These multidimensional signatures — encompassing bacterial, archaeal, and fungal taxonomy, functional genes, and metabolomic profiles (short-chain fatty acids; SCFAs) — orchestrate host metabolism, immunity, and feed conversion ratio (FCR). This PRISMA-ScR scoping review synthesizes multi-omics evidence showing that LPDs shift cecal fermentation toward saccharolytic pathways, enriching butyrate-producing taxa (Ruminococcaceae, Lachnospiraceae) while suppressing Proteobacteria and toxic proteolytic metabolites (ammonia, branched-chain fatty acids). LR elevates Actinobacteria/Synergistetes, triggers microbial nitrogen limitation, and reconfigures SCFA profiles through cross-feeding, thereby activating host nutrient sensors (mTOR downregulation, GCN2 upregulation) to prioritize immunity and FCR gains. Methanogenic archaea (Methanobrevibacter) fine-tune hydrogen economies, although diet-induced changes require deeper exploration. Key signatures forecast performance, featuring optimized Firmicutes/Bacteroidetes ratios and ureolytic genes (gdhA/glnA) as markers of protein resilience and profiles for breed-specific responses. SCFAs drive epigenetics (HDAC suppression, histone acetylation) and immunometabolism (Treg expansion, NF-κB dampening), bridging microbiome to host benefits via gut-liver interplay. Emerging applications span next-generation probiotics (NGPs) and live biotherapeutic products (LBPs), tailored from signature consortia (L. reuteri + B. velezensis) or archaeal agents, to sustain diet-induced states in antibiotic-free regimens. Major gaps persist in causal multi-omics validation, breed-specific responses, standardized baselines, and archaeal contributions. Integrating LPD/LR with tailored NGPs/LBPs promises precision nutrition strategies that enhance nitrogen utilization, reduce emissions, and improve welfare. Gnotobiotic, FMT, and AI trials are essential for translating microbial signatures into scalable flock-level precision management.
This study examined the impact of varying concentrations of Clostridium butyricum on growth, nutrient digestibility, intestinal morphology, serum profiles, and gut microbiota in weaned piglets. A total of 210 healthy 34-day-old weaned piglets (Duroc × Landrace × Yorkshire) with an initial body weight of 8.89 ± 0.11 kg were randomly assigned to five groups (six replicates per group, seven piglets per replicate). The control group received a basal diet, while the experimental groups (T1-T4) received the basal diet supplemented with 2 × 10⁸, 5 × 10⁸, 1 × 10⁹, and 2 × 10⁹ CFU/kg of Clostridium butyricum, respectively. The trial lasted 28 days. The T4 group had higher apparent total tract digestibility of dry matter, organic matter, and gross energy compared to the control grou (P < 0.05). Apparent nutrient digestibility in weaned piglets rose linearly and quadratically with Clostridium butyricum level (P < 0.05). Supplementation with Clostridium butyricum enhanced antioxidant activities including superoxide dismutase, catalase, total antioxidant capacity, and glutathione peroxidase levels while reducing malondialdehyde concentration (P < 0.05). In both linear and quadratic models, serum SOD activity in weaned piglets increased linearly, whereas CAT activity followed a quadratic pattern throughout the experiment (P < 0.05). It also improved immunoglobulin levels and reduced pro-inflammatory cytokines such as tumor necrosis factor-α, interleukin-1β, interleukin-6, and interleukin-8 (P < 0.05). Additionally, the T1 group and the T4 group promoted the enrichment of norank_f__Butyricicoccaceae and Ruminococcus_gauvreauii_group, respectively (LDA >2, P < 0.05). In conclusion, Clostridium butyricum supplementation improves intestinal morphology, antioxidant capacity, immune status, and gut microbiota in weaned piglets.
To address the digitalization of poultry farming and demand for precise chick management, this study developed deep learning models for facial biometric recognition in Xianghuang chickens, an indigenous yellow-feathered breed from Hengyang, Hunan. A unified dataset of 6,024 images (frontal and profile views) was compiled to evaluate five architectures—ResNet-50, ResNet-101, MobileNetV2, EfficientNet-B0, and EfficientNet-B0+CBAM—on two tasks: individual identification and sex classification.For individual identification, all models performed excellently. Under frontal views, Top-1 accuracy exceeded 98% and Top-5 surpassed 99%, with no significant inter-model differences (p> 0.05). Profile views were slightly more challenging, but Top-1 accuracy remained above 94%. Grad-CAM visualization revealed models focused on key facial regions (nasal, periocular, beak), confirming facial features’ utility for identification. Sex classification using facial features alone was unsatisfactory. The highest accuracy was 71.01% (ResNet-50, profile view), with all models showing overfitting (generalization gap > 2%) and stagnant validation accuracy. This stems from subtle sexual dimorphism in slow-growing chicks and imaging variability. This study constructed the first labeled facial dataset for Xianghuang chickens, filling a gap in poultry facial recognition research. While demonstrating deep learning’s potential for non-contact chick identification under controlled conditions, it highlights biological limitations in early sex determination via facial morphology alone.
Small ruminant production contributes directly to SDG 2 (Zero Hunger) and SDG 1 (No Poverty). This study examines the impact of veterinary and ethnoveterinary practices on small ruminant farm performance. Using primary data from 400 smallholder farmers and applying a multinomial endogenous switching regression model, the study estimates the effects of integrated veterinary and ethnoveterinary medicinal practices on herd size, mortality rates, and net farm income. The results indicate that joint adoption of ethnoveterinary and conventional veterinary practices yields superior performance outcomes relative to exclusive reliance on either system. Specifically, the results reveal that treating small ruminants with veterinary medicinal practices (VM) in isolation increased herd size by 24% (5 animals) as compared to 28% (6 animals) when VM is combined with ethnoveterinary medicinal practices (EVM). Joint adoption of EVM and VM was found to significantly reduce ruminant mortality rate by 9% per year, and improved net farm income by 72% relative to sole usage of VM, which reduces mortality rate by 7% and increases farm net income by 27%. Counterfactual estimates further reveal that non-adopters would have achieved significantly higher productivity and income levels under joint adoption. The findings underscore the complementarities between indigenous knowledge systems and formal veterinary services. Policy efforts aimed at strengthening small ruminant productivity should therefore promote integrative animal health strategies through extension training, institutional support, and inclusive service delivery models. By demonstrating the performance-enhancing effects of hybrid animal health systems, this study contributes to the literature on sustainable livestock management and inclusive agricultural transformation in sub-Saharan Africa.
Genetic improvement of show-jumping competition results has a clear breeding goal which is to produce horses that can repeatedly clear technically demanding courses at maximum height, resulting in placement results. However, how to achieve this, and thus how to accurately choose breeding candidates, is far from straightforward due to the heterogeneity of competition outcomes. In this study, we analyzed Fédération Équestre Internationale (FEI) competition records from 19,232 horses together with pedigree data to evaluate novel phenotypes suitable for international genetic evaluations. Traditional traits (maximum height jumped, total prize money won, number of competitions) were analyzed together with composite ratios (clear-round ratio and placement ratio), modeled both across career and within 5-cm FEI height categories (1.20–1.60 m). Using animal models and binomial threshold models in ASReml, we estimated heritability, repeatability, and genetic correlations. Maximum height achieved in career showed moderate heritability (h² = 0.22), while earnings and number of competitions displayed low heritability and modest repeatability. Composite ratios modeled over career had low heritability (h²obs = 0.02–0.08) and moderate repeatability, whereas analyses within height categories revealed substantially higher heritabilities (h²obs up to 0.59), especially in mid-level classes (1.35–1.45 m). Genetic correlations were high between adjacent heights, but weaker between the lowest and elite levels, suggesting partly distinct genetic determinants across competition classes. These findings indicate that FEI-restricted composite phenotypes, especially mid-height ratios, provide informative and heritable indicators for breeding programs.
Low air quality and the presence of harmful gases such as ammonia can have detrimental effects on the health and welfare of pigs. Excessive concentrations of these gases are particularly common in negative pressure ventilated barns found in conventional husbandry systems. There are various devices and guidelines available for measuring harmful gases in such environments. In this study, ammonia and carbon dioxide were measured using three different devices. Measurements were taken across four production cycles in six pens at two different heights (0.6 m, within test pens; 1.5 m, representing human working height).The measurement results for ammonia and carbon dioxide obtained with the three different methods differed significantly from one another. Comparison of the two measurement heights revealed no significant difference for ammonia. However, measurement height had a significant effect on carbon dioxide concentrations. Furthermore, the location of the sampling points (test pens) within the compartment significantly influenced the measured concentrations of both ammonia and carbon dioxide, indicating spatial variability.When assessing air quality in a barn, it is advisable to use two different measurement systems for ammonia and carbon dioxide to ensure reliable results. Measuring ammonia does not necessarily have to be performed at animal height, as its vertical distribution was found to be uniform within the compartment. However, the location of the sampling points significantly influenced both ammonia and carbon dioxide concentrations. Therefore, measurements should be conducted at multiple locations within a compartment to capture spatial variability and to determine the most appropriate position for stationary sensors.
Endoparasites remain major constraints on equine health and productivity in Ethiopia; however, epidemiological data from northwestern regions are limited. This study investigated the occurrence, parasite diversity, infection intensity, and risk factors associated with endoparasite infections in equines in northwestern Ethiopia. A cross-sectional study was conducted using coprological examinations complemented by postmortem inspections. Standard parasitological techniques were employed, and multivariable logistic regression analysis was used to identify predictors of infection. Data were analyzed using SPSS version 27. Overall, 411 of 720 equines were infected, giving an overall prevalence of 57.1% (95% CI: 53.5-60.7). Endoparasite infections were common, with Strongyle spp. (23.5%; 95% CI: 20.5-26.7) and Parascaris spp. (10.1%; 95% CI: 8.1-12.7) identified as the predominant parasites. Postmortem examination revealed a diverse range of endoparasites, including gastrointestinal and respiratory nematodes, cestodes, trematodes, and botfly larvae. Most infections were of low to moderate intensity. Multivariable analysis showed that species, age, body condition score, and season were significantly associated with infection (p ≤ 0.05). Young equines were at higher risk compared with older animals (AOR = 2.80; 95% CI: 1.63-4.80; p < 0.001). Equines with poor (AOR = 9.13; 95% CI: 5.04-16.52) and medium (AOR = 3.84; 95% CI: 2.28-6.46) body condition scores were significantly more likely to be infected than those in good condition (p < 0.001). Donkeys had a significantly lower likelihood of infection than horses (AOR = 0.18; 95% CI: 0.05-0.62; p = 0.007), while infection risk was higher during the wet season compared with the dry season (AOR = 2.72; 95% CI: 1.93-3.83; p < 0.001). Sex was not significantly associated with infection status. In conclusion, endoparasite infections are widespread among equines in the study area and are strongly influenced by host characteristics and seasonal factors. These findings provide baseline epidemiological evidence to inform targeted parasite control strategies, with priority given to young equines, animals in poor body condition, and wet-season interventions.
Fixed-time laparoscopic artificial insemination (FT-LAI) using frozen-thawed semen can accelerate genetic improvement in goats, but its efficiency depends on appropriate ovulation synchrony and effective use of cryopreserved spermatozoa. Controlled internal drug release (CIDR) devices and intravaginal fluorogestone acetate sponges are widely used progestogen-based synchronisation tools. However, their comparative performance under tropical field conditions, particularly when reduced sperm doses are used for LAI, remains insufficiently defined. A 2 × 2 factorial field trial was conducted in 175 multiparous Boer × Thai native does to compare synchronisation method (CIDR vs. intravaginal sponge) and insemination dose (150 × 106 vs. 60 × 106 progressively motile spermatozoa). Does received a 13-day intravaginal progestogen treatment followed by 250 IU eCG at device removal, and FT-LAI was performed during the expected periovulatory period. Pregnancy diagnosis was conducted by transrectal ultrasonography at Day 42 post-insemination. Follicular size and ovulatory status were assessed laparoscopically at insemination. CIDR-treated does had a higher pregnancy rate than sponge-treated does (76.1% vs. 59.0%; p = 0.024; OR = 2.21, 95% CI: 1.15-4.22). Sperm dose did not significantly affect pregnancy rate (150 × 106 (72.1%) vs 60 × 106 (65.4%), p = 0.452; OR = 1.36, 95% CI: 0.70-2.64). The interaction between synchronisation method and sperm dose was not significant. Laparoscopic observation at insemination showed that the CIDR-treated group had a higher proportion of does with recent ovulation (33.8% vs. 3.6%; p < 0.0001) and slightly larger right ovarian follicles (6.15 ± 1.41 vs. 5.80 ± 1.21 mm; p = 0.00054). These findings indicate that CIDR-based synchronisation yields greater follicular readiness at insemination and higher early pregnancy outcomes compared with sponges, while using the lower sperm dose did not significantly reduce Day 42 pregnancy rates under the present study conditions. The protocol has potential practical relevance for improving genetic resource use in tropical goat production systems.
