Animals最新文献

The global demand for fish oil (FO) is increasing while its supply is decreasing, which has limited its use in aquafeeds. Research on alternative terrestrial oils (TOs) for commonly cultured fish species in Bangladesh is limited. This research involved a 70-day feeding experiment to assess the effectiveness of replacing FO with TOs in the diet of Gangetic catfish (Mystus cavasius). Five diets were formulated: a control diet (D1) with fish meal and FO, and four diets replacing FO with soybean oil (D2), black soldier fly larvae oil (D3), palm oil (D4), or a mixed oil combination (D5) of 50% black soldier fly larvae oil, 25% soybean oil, and 25% palm oil. A total of 675 fish (0.5 g each) were distributed in 15 100 L aquariums (45 fish/aquarium) and fed to satiation twice daily. Fish fed with Diet D5 showed significantly higher growth, followed by those fed with D3, D4, and D1, while D2 resulted in significantly lower growth. Fish on the D5 diet consumed the most feed, followed by those on the D3 and D2 diets, with similar feed intake levels for those on the D1 and D4 diets. FCR, FCE, and PER were not significantly affected by dietary oil sources. Whole-body lipid content (p < 0.05) was significantly lower in the D3 group and higher in the D2 group, while other groups showed intermediate values. The fatty acid composition in the fish reflected their diets: significantly higher n-3 LC-PUFA (EPA + DHA) content was observed in the D1 group, followed by the D4 and D3 groups, and fish fed with D2 and D5 showed significantly lower values. Alpha-linolenic acid C18:3n-3) was significantly higher in the D2 group, followed by the D3, D1, and D4 groups, with the D5 group having a significantly lower value. Total MUFA was significantly higher in D4, followed by D1, D5, and D3; the D2-fed group showed a significantly lower value. Lauric acid (C12:0) was significantly higher in D3, followed by D5; other groups showed significantly lower values. Feed physical properties were significantly influenced by oil type, with water stability, pellet durability, and palatability being significantly highest in the D2 and D5 diets, followed by D3 and D4, with D1 being the lowest. Fish on the D1 and D5 diets had a significantly higher condition factor (CF) compared to fish on the D2 diet. Considering the growth and overall performance in the current study, we concluded that under the current dietary composition, TOs can effectively replace FO in the diets of Gangetic catfish, with mixed oils, black soldier fly larvae oil, and palm oil being the most promising alternatives.

Developing new haptic communication tools to enhance communication between dogs and their handlers during field operations has garnered interest in recent years. It is a promising field that could ameliorate dog-handler interactions in the field while addressing practical challenges, such as the need for discrete communication during operations. When extended to the public, such technology could improve communication with impaired dogs. With this review, we aim to (1) give an overview of dogs' understanding and discrimination of haptic signals, (2) highlight the need to investigate the possible impact of such tools on dogs' welfare, as well as (3) point out current caveats and future research directions.

Accurate clutch-frequency estimates are essential for assessing population abundance and reproductive output in sea turtles. Traditional nighttime beach-monitoring approaches, however, often underestimate clutch frequency by missing nesting events occurring outside patrolled beaches. Here, we integrated long-term beach monitoring (2009-2016) with satellite telemetry to estimate the clutch frequency of loggerhead turtles (Caretta caretta) nesting at Praia do Forte, Bahia, Brazil. A total of 593 females were identified along a 5 km monitored beach segment, and transient individuals represented 42.4% ± 3.9 SD of seasonal records. A 2-year remigration interval was the most frequent. The observed clutch frequency (OCF) averaged 3.1 ± 1.2 SD clutches per female, while the estimated clutch frequency based on beach monitoring alone (ECF_BM) averaged 3.9 ± 1.5 SD. For the subset of satellite-tracked females (n = 12), integration of residency length derived from telemetry increased the estimate to 5.6 ± 0.7 SD clutches per female (ECF_BMST). Statistical comparisons confirmed significant differences among estimation methods. These findings align with previous studies, demonstrating that clutch frequency is substantially underestimated when relying solely on beach monitoring. Incorporating satellite telemetry, therefore, provides a more accurate assessment of reproductive output and has important implications for population modelling and the conservation of loggerhead turtles in Brazil.

Significant differences in reproductive performance exist between meat-type ducks (e.g., Qiangying Duck, QD) and laying-type ducks (e.g., Shaoxing Duck, SD). The molecular mechanisms underlying these differences, particularly concerning ovarian development and function, remain incompletely understood. This study aimed to comprehensively characterize the ovarian transcriptomes of these two duck types, focusing on differential gene expression and post-transcriptional regulatory events. We performed an integrated full-length transcriptome analysis of ovarian tissues from these two breeds using PacBio SMRT and Illumina sequencing. Bioinformatic analyses, including functional annotation, differential expression analysis, and the identification of APA events, were used. We discovered substantial breed-specific differences in alternative polyadenylation (APA), with SD ducks exhibiting significant 3'UTR shortening in 3799 genes and 3'UTR lengthening in 1626 genes compared to QD. The integrated analysis of differential gene expression and APA events highlighted key genes related to steroid hormone synthesis (HMGCS1, DHCR24), lipid metabolism (SCD), signal transduction (HRAS), and antioxidant defense (SOD1). The functional enrichment implicated critical pathways such as mitochondrial energy metabolism, oxidative phosphorylation, and fatty acid degradation. Our study provides a comprehensive atlas of post-transcriptional regulation in the duck ovary and reveals APA as a crucial process of gene regulation. APA may contribute to the differential ovarian function and egg-laying capacity between meat and laying ducks, thus offering valuable targets for genetic selection.

Microcystin-LR (MC-LR), produced by Cyanobacteria, is being detected in many types of waters, posing a universal threat to aquatic animals. However, there have been few comprehensive endpoints assessed, including oxidative stress, transcriptome changes, intestinal microbiota, and histopathology, in anurans exposed to MC-LR. In this study, all these effects of MC-LR on Chinese brown frog (Rana chensinensis David, 1875) tadpoles were investigated by exposing the tadpoles to MC-LR at different concentrations (0, 0.1, 1.0, 5.0, and 10.0 μg/L) for 7 days. Our results revealed that treatment of tadpoles with the high MC-LR dosage (10.0 μg/L) induced a significant increase in malondialdehyde (MDA) content and decreases in superoxide dismutase (SOD) activity, glutathione peroxidase (GPx) activity, and total antioxidant capacity (TAC). RNA-seq analysis of the liver showed that the number of differentially expressed genes (DEGs) was 2361 under lower MC-LR stress (1.0 μg/L), while the number of DEGs increased to 3185 under higher MC-LR stress (10.0 μg/L). Gene Ontology analysis showed that several biological processes and molecular functions related to digestion were enriched in both MC-LR treated groups, such as digestion, serine-type endopeptidase activity, and serine-type peptidase activity. KEGG enrichment analysis also indicated that the digestion for pancreatic secretion, protein digestion and absorption, and fat digestion and absorption pathways were significantly enriched in the treatment groups. Additionally, the bacterial richness was elevated by MC-LR exposure. At the phylum level, treatment with MC-LR changed the relative abundances of Desulfobacterota, Fusobacteriota, and Actinobacteriota. At the genus level, MC-LR caused significant alterations in the abundances of 23 genera. Furthermore, examination of sections obtained from the livers and intestines of tadpoles in the treatment groups showed damaged histological structure. The knowledge from this study will have potential value for understanding the mechanisms related to MC-LR toxicity in anurans.

This study evaluated the clinical bactericidal efficacy and safety of a novel chlorine dioxide teat disinfectant compared to a traditional iodine glycerin disinfectant in dairy cows. The randomized controlled trial included long-term natural exposure (100 cows) and teat surface disinfection (40 cows) experiments. Key metrics assessed were somatic cell count (SCC), teat skin health (dryness, roughness, hyperkeratosis), and bacterial reduction rates against Staphylococcus aureus, Escherichia coli, and Streptococcus spp. Results demonstrated that the chlorine dioxide teat disinfectant achieved comparable to iodine glycerin disinfectant in controlling the rate of SCC exceeding the threhold (3.57% vs. 4.50% at day 10; p > 0.05), teat skin dryness, end roughness, and hyperkeratosis severity showed no significant differences over time or between iodine glycerin (control) and chlorine dioxide teat disinfectant groups (all p > 0.05). Notably, quantitative bacteriological assessment revealed significantly higher log₁₀ reduction values for chlorine dioxide teat disinfectant (2.14) versus iodine glycerin controls (1.93; p < 0.05). Microbiological evaluation further demonstrated complete pathogen eradication (100.00%) by chlorine dioxide across all isolates (S. aureus, E. coli, Streptococcus spp.), whereas iodine glycerin achieved 99.84-100.00% bactericidal rates. The findings suggest that chlorine dioxide teat disinfectant is a sustainable and effective alternative to iodine glycerin disinfectant, offering robust antimicrobial activity, improved teat condition, and reduced residue concerns. Further multicenter studies are warranted to validate these outcomes under diverse herd management conditions.

Expanded and intensified agriculture is a major driver of habitat loss for endangered species such as the Oriental White Stork (Ciconia boyciana), making wildlife-friendly farming an increasingly important approach for reconciling biodiversity conservation with agricultural development. Building on a 2018 feasibility study in the Sanjiang Plain, this research employs a choice experiment to examine how preferences for Oriental White Stork-friendly farming have evolved among urban consumers and residents of stork habitats under expanding green consumption and increasing experience with environmentally friendly farming. The results reveal pronounced preference heterogeneity and persistent cognitive separation between wildlife conservation and agricultural production, particularly among urban consumers, despite a stable group being willing to pay a premium for stork-friendly products. Rural residents' decisions remain largely economically driven, though younger farmers with prior experience in environmentally friendly practices show more positive attitudes. Significant urban-rural differences suggest policy complementarities, whereby price-oriented incentives may encourage price-sensitive farmers to adopt green agriculture, while intrinsically motivated farmers require support through an Oriental White Stork-oriented value chain. Overall, the findings demonstrate that Wildlife-Friendly Farming cannot be effectively promoted through a one-size-fits-all approach; instead, stratified, group-specific policy and market mechanisms are essential for aligning producer incentives with consumer demand and supporting the long-term viability of biodiversity-friendly agricultural systems.

Chinese rice-field eel rhabdovirus (CrERV) is a serious epidemic pathogen of Chinese rice-field eel and causes severe economic losses to aquaculture. However, there are no commercial drugs presently available to control CrERV infection. Eugenol is a bioactive compound extracted from clove plants and exhibits potential antiviral activity. In the study, the antiviral activity of eugenol against CrERV was investigated in Chinese rice-field eel (Monopterus albus). Eugenol reached the highest inhibition rate of 96.6% at 40 mg/L in Chinese rice-field eel kidney cells (CrEK). Notably, eugenol exhibits antiviral activity by directly targeting CrERV and additionally confers prophylactic effects against infection via its action on CrEK cells. The results of exploring the viral invasion cycle demonstrated that eugenol primarily exerted its antiviral effect during the middle stage and late stage (12 h and 24 h) of viral infection. In addition, eugenol inhibited CrERV-induced apoptosis of CrEK cells, maintained mitochondrial membrane potential levels, maintained physiological cellular morphology and structure, and protected cells from loss of cellular morphology, formation of apoptotic vesicles, and cell fragmentation. For the in vivo study, eugenol increased the survival rate of CrERV-infected rice-field eel by 56% and 48%, in prevention experiments and treatment experiments, respectively. Concurrently, eugenol significantly reduced viral loads and induced the upregulation of anti-inflammatory and antioxidant genes, indicating its potential for immunoregulation. In summary, eugenol holds potential for both preventing and treating CrERV infections in the aquaculture context.

Male infertility in dromedary camels lacks objective diagnostic tools. This study evaluated the combined diagnostic value of testicular Doppler ultrasonography and semen biomarkers in 68 infertile (azoospermic, n = 21; oligozoospemic, n = 47) and 9 fertile male camels. All animals underwent a breeding soundness evaluation; computer-assisted semen analysis; color Doppler of the supratesticular artery; and a seminal plasma assessment for semenogelin I (SEM I), semenogelin II (SEM II), extracellular matrix protein 1 (ECM1), and testis-expressed protein 101 (TEX101). Infertile camels showed significantly impaired semen quality (p < 0.001). All four biomarkers were significantly lower in the infertile groups than controls (p = 0.001). Doppler indices indicated impaired testicular perfusion, with higher resistive and pulsatility indices (p = 0.003; p = 0.009) and lower velocity parameters (p < 0.001) in infertile animals. Biomarkers were strongly intercorrelated and negatively correlated with Doppler indices. ECM1 was the only significant predictor of infertility from the regression analysis (p = 0.031). Among the oligozoospemic camels stratified by motility, the >50% motility group had significantly higher SEM I and SEM II concentrations (p < 0.002). Integrating Doppler ultrasonography with biomarker profiling provides complementary diagnostic indicators for male camel infertility.

Prevalence of LPS in Gram-negative bacterial udder infections determines mastitis severity and disease prognosis. This pilot study explores the notion that milk-soluble (s) LPS/IgG complex levels in dairy cows link mastitis severity to intramammary Gram-negative infections during early lactation. Milk, within a single herd, was analysed from (i) 34 early lactating cows with acute mastitis and (ii) milk selected from peak lactation cows displaying either healthy (SCC < 100 × 10³ cells/mL, n = 146) or subclinical mastitis (SCC > 150 × 10³ cells/mL, n = 135) characteristics. Milk was assessed for (i) sLPS/IgG using an "in-house" ELISA, (ii) udder inflammation using LDH activity, and (iii) bacterial presence applying on-farm and standard microbiological laboratory techniques. Mean milk sLPS/IgG absorbances in acute mastitis cows were higher than those detected in healthy and subclinical mastitis cows, with mean differences of 0.35 (95% CI, 0.28 to 0.42) and 0.36 (95% CI, 0.28 to 0.44), respectively. On day 1 of acute mastitis, sLPS/IgG levels in milk containing only Gram-positive bacteria ranged from OD 0.04 to 0.14 (median = 0.1). In contrast, sLPS/IgG levels ranging from OD 0.27 to 1.42 (median = 0.58) and from 0.02 to 1.67 (median = 0.21) were detected in milk containing only Gram-negative bacteria or both Gram-negative and Gram-positive bacteria (i.e., polymicrobial), respectively. Furthermore, differential milk sLPS/IgG absorbance profiles (observed during the testing period days 1-3) were observed in cows with acute mastitis caused by Gram-positive, Gram-negative or polymicrobial infections. Our preliminary findings support the notion that milk sLPS/IgG complexes provide a link between mastitis severity and intramammary Gram-negative infections in dairy cows during early lactation.