农林科学最新文献

Aims: To investigate the effect of injection of trace mineral supplement (TMS) 14-28 days before calving on white blood cell count (WBCC) and function, serum antioxidant capacity (SAC) and reactive oxygen species (ROS) in pasture-fed cattle after calving.

Methods: On each of two South Island, seasonally calving, pastoral dairy farms,1 month before dry-off, a random sample of 150 multiparous cows predicted to calve within 7 days of the herd's planned start of calving (PSC) were stratified on individual somatic cell count, age, breed and expected calving date. On each farm, 14-24 days before PSC, 60 selected cows were randomly assigned for TMS (Zn, Mn, Se, Cu) injection, and 60 were controls. All 240 cows were contemporaneously injected with hydroxocobalamin, and controls with Se. Blood samples were collected pre-injection and 3, 12 and 40 days after calving. Phagocytic activity, count and proportion of neutrophils, lymphocytes and monocytes, WBCC, ROS, SAC were measured. Plasma concentrations of Se, Cu and glutathione peroxidase (GPx) were monitored from a random subset of animals. Differences attributable to TMS were estimated using mixed-multivariable Bayesian analysis, expressed as mean and highest density interval (HDI).

Results: Three and 40 days after calving, TMS-treated cows had 0.36 (90% HDI = 0.00-0.77) x 10⁹ and 0.25 (90% HDI = 0.00-0.55) x 10⁹ fewer neutrophils/L. Neutrophils comprised 6 (90% HDI = 0-11)% and 4 (90% HDI = 0-8)% less of the WBCC, and the neutrophil count was 14 (90% HDI = 0-27)% and 9 (90% HDI = 0-18)% less than controls. However, 3 days after calving, there were 7 (95% HDI = 2-12)% more cells phagocytosing and 2,900 (95% HDI = 2,600-3,200) more bacteria ingested/cell. Twelve and 40 days after calving, TMS-treated cows had 0.65 (95% HDI = 0.17-1.17) x 10⁹ and 0.28 (95% HDI = 0.00-0.59) x 10⁹ more lymphocytes/L. Lymphocytes comprised 10 (95% HDI = 3-18)% and 5 (95% HDI = 0-9)% more of the WBCC, and the lymphocyte count was 30 (95% HDI = 11-51)% and 9 (95% HDI = 0-9)% more than controls. There were no meaningful differences in ROS, SAC, ROS/SAC, other white blood cells, or WBCC. Plasma Cu, Se and GPx concentrations were above recommended thresholds.

Conclusions: Pre-calving TMS injection was associated with differences in white blood cell population and function that may reduce the risk of disease.

Abbreviations: BHOB: Beta-hydroxybutyrate; GPx: Glutathione peroxidase; HDI: Highest density interval; MESF: Molecules of equivalent soluble fluorophore; OSi: Oxidative stress index; PSC: Planned start of calving; ROPE: Region of probable equivalence; ROS: Reactive oxygen species; SAC: Serum antioxidant capacity; THI: Temperature humidity index; TMS: Trace mineral supplement; WAIC: Widely applicable information criterion; WBCC: White blood cell count.

In this study, malt was produced from quinoa seeds using different ultrasound treatment with different intensities (20%, 60%, and 100%), ultrasound times (5, 10, and 15 minutes), and soaking times (2, 6, and 10 hours) at a frequency of 20 kHz. The seeds were soaked in water at 25 °C during exposure to ultrasound waves. The results showed that an increase in soaking time led to a higher malting yield and percentage of soluble solids (°Brix), followed by a downward trend. This trend was intensified by longer exposure to ultrasound waves at higher intensities. The interaction effect of ultrasound wave and soaking time on physicochemical properties showed a downward trend, followed by an upward trend in cold-water and hot-water extract yields, reducing sugar, soluble nitrogen, color, and Kolbach index, with increasing levels of the variables. Finally, quinoa malt treated with an ultrasound intensity of 100% for 15 minutes and soaked for 6hours exhibited the best physicochemical characteristics.

Canine lymphoma represents a biologically and metabolically heterogeneous group of neoplasms that arise from malignant transformation of lymphoid cells. An accurate diagnosis is crucial because of its impact on survival. Current diagnostic methods include clinical laboratory tests and imaging, most of which are invasive and lack sensitivity and specificity. Interestingly, recent work in cancer patients focuses on the search for biomarkers for diagnosis, investigation of treatment response mechanisms, treatment efficacy and prognosis and the discovery of tumour metabolic pathways using metabolomic analysis. In this study, we compare the metabolite profiles in serum from 37 dogs with multicentric lymphoma (22 B-cell lymphomas/LB, 9 CD45+ T-cell lymphomas/LTCD45+, 6 CD45- T-cell lymphomas/LTCD45-) and 25 healthy dogs using ¹H nuclear magnetic resonance spectroscopy (NMR). ¹H NMR-based metabolite profiling analysis recognised lipids and 22 metabolites, with 16 of them altered, and was shown to be an effective approach for differentiating samples from dogs with lymphoma and healthy controls based on principal component analysis of the NMR data. We also investigated variations in the serum metabolome between immunophenotypes and the control group through pairwise comparisons of the healthy against the LB, LTCD45+ and LTCD45- groups, respectively which showed similar metabolomic profiles. In addition, there were significant differences in the levels of five individual metabolites based on the univariate statistical analysis. Our results showed alterations in energy, protein and lipid metabolism, suggesting glucose, lactate, N-acetyl glycoproteins (NAGs), scyllo-inositol and choline as possible new candidate biomarkers in canine multicentric lymphoma.

Canine mast cell tumours (MCTs) are one of the most common skin cancers of dogs. Surgical removal is the primary treatment, but recurrence and metastasis can occur even with low-grade tumours. As a result, new treatment strategies are being sought. We tested the potential of several oncolytic viruses (OVs) to infect and kill a cell line isolated from a canine MCT. Employing a resazurin-based metabolic assay and flow cytometry technology, we used recombinant vesicular stomatitis virus (rVSV-Δm51), avian orthoavulavirus-1 (AOaV-1), and Orf viruses in our assessment. Our study aimed to evaluate the potential of oncolytic virotherapy in treating canine cancers. We found that MCT-1 cells showed different sensitivities to the OVs, with rVSV-Δm51 showing the most promising results in vitro. These findings suggest that further investigation into using OVs for treating canine MCTs is needed, although clinical efficacy is yet to be determined.

Aims: To describe rates of and reasons for culling and mortality of ewes between breeding and mid-lactation on New Zealand sheep farms; to investigate associations of these variables with farm demographic variables; and to describe rates of and reasons for culling of ewes at weaning.

Methods: Participants were a convenience sample of 34 farms from across New Zealand. Demographic data were initially collected for each farm via a questionnaire administered in-person to the flock owner or manager. During approximately 8 months from breeding to mid-lactation, ewe tally, culling and mortality data were collected and used to calculate various parameters related to flock performance and to investigate associations. During the main ewe-culling event at weaning, ewe-culling data were collected from 29/34 flocks participating in the study.

Results: There was considerable variation between flocks, but the between-flock mean replacement percentage was 29.2 (SD 5.0)%. Overall, a between-flock mean of 10.5 (SD 4.6)% of ewes presented for breeding were culled or dead/missing by mid-lactation and thus did not rear any lambs. Additionally, from 27 flocks that reported data on ewes' success at rearing lambs, a between-flock mean of 3.9 (SD 2.5)% of ewes that remained alive at mid-lactation failed to rear any lambs, resulting in an overall between-flock mean loss of 23.1 (SD 6.3) potential lambs per 100 ewes. Two-thirds of ewe mortalities between breeding and mid-lactation occurred during the lambing period. Model results showed flocks with higher pregnancy scanning percentages had lower rates of culling and mortality between breeding and mid-lactation. However, apart from farm contour, from breeding to mid-lactation there were no associations for culling and mortality with farm size, flock size, number of ewes per labour unit, whether ewe hoggets (7-9 months of age) were presented for breeding, or duration of the breeding period. A between-flock mean of 16.5 (SD 8.3)% of ewes present at weaning were culled, and among mixed-age ewes, the most common reasons for culling at this time were age, incisor teeth defects and udder defects.

Conclusions: To reduce unnecessary ewe culling and mortality, attention should be focused on maximising conception rates, ensuring judicious culling decisions, optimising body condition score, and identifying farm-specific causes of death over the lambing period to facilitate targeted intervention strategies.

Clinical relevance: Identifying why and when ewes exit flocks, and comparing it with the data presented here, will facilitate the development of flock-specific interventions to reduce ewe culling and mortality.

Aim: To assess whether the fluoride concentration in the humeri of first-lactation, 2-year-old dairy cows with a spontaneous humeral fracture is significantly different from that of first-lactation, 2-year-old dairy cows without a humeral fracture.

Methods: Two studies were conducted, the first with nine bone samples from 2-year-old, first-calving dairy cows with a humeral fracture (all from the Waikato region) age-matched with seven control bone samples from the Waikato, Bay of Plenty and Manawatū-Whanganui regions. The second study used 26 bone samples from 2-year-old, first-lactation dairy cows with a humeral fracture (from the Otago, Canterbury, Southland, West Coast, Waikato and Manawatū-Whanganui regions) age-matched with 14 control bone samples (all from the Manawatū-Whanganui region or unknown). Control bone samples were from first-lactation, 2-year-old dairy cows that did not have humeral fractures. Bone fluoride concentration was quantified for all samples.

Results: The median fluoride concentration of humeri from first-lactation, 2-year-old dairy cows with a humeral fracture was significantly higher than humeri from unaffected control cows in both studies. In Study 1, the median bone fluoride concentration was 599 (IQR 562.7-763.5) mg/kg from case cows and 296.6 (IQR: 191.2-391.7) mg/kg from control cows (p < 0.001), and in Study 2 the median bone fluoride concentration from case and control cows was 415 (IQR: 312.5-515) mg/kg and 290 (IQR: 262.5-410) mg/kg (p = 0.04) respectively.

Conclusions and clinical relevance: Although there are limitations to this study due to the unbalanced regional distribution of cases and controls, the results indicate that sub-clinical fluoride toxicosis may be linked to spontaneous humeral fractures in first-lactation dairy cows in New Zealand. Further research is required to determine if bone fluoride concentrations play a role in the pathogenesis of these fractures.

Aims: To assess the feasibility and safety of a locking cortical pearl plate system for the repair of lumbar vertebral fractures and luxation in cats using an ex vivo feline model.

Methods: This cadaveric study of the lumbar vertebral column (L1-L7) involved 28 Domestic Short-hair cats without vertebral column pathology. Surrounding soft tissue was removed, except for the paravertebral musculature, joint capsules, and ligaments associated with the L1-L7 vertebrae. To determine whether the application of a 2.0-mm, 69-mm-long, 12-hole locking cortical pearl plate (LCPP) and screws was feasible, the dimensions of the feline lumbar vertebral bodies (length, width, and height) were measured using CT imaging. Width and height were evaluated at five locations along the length of the vertebrae with implant corridors (cor 1-cor4) located in between. Following CT, plates were applied to the vertebral columns. After implantation, another CT scan was performed to evaluate plate positions, screw trajectories, screw implantation angles, and vertebral canal breaching. Implantation was classified according to the modified Zdichavsky scoring system for vertebral canal penetration and grade I and IIa defined as acceptable.

Results: A total of 371 screws were inserted into the lumbar vertebral bodies, and breaching occurred in 32 cases (8.6%), of which 29 (90.6%) were at L6 and L7. The median angle of inserted screws was 61.6° (min 53.4°, max 76.3°). Aside from one location, no significant angle deviations were observed between breaching (median 62.8°; min 53.4°, max 76.3°) and non-breaching (median 61.2°; min 53.8°, max 74.7°) screws. All 267 screws implanted in L1-L5 were graded I or IIa (acceptable). In contrast, low rates of acceptable implantation were achieved for L6 (52/60; 86.7%) and L7 (24/44; 54.4%), caused by clustering of breachings in corridor 3 of the two vertebrae.

Conclusions: Application of the LCPP immediately proximal to the transverse processes and ventral to the pedicles with a screw implantation angle of 60° is feasible and appears safe for L1-L5, resulting in a low number of vertebral canal breaches and a high rate of acceptable implantations.

Clinical relevance: The 2.0-mm, 69-mm-long, 12-hole LCPP can be considered an acceptable option for treating feline vertebral fractures and luxations of L1-L5. It cannot be recommended for use in corridor 3 of L6 or L7 due to the high risk of breaching the vertebral canal.

In order to find the optimal share of barley seedling powder (BSP) to improve the rheological properties of wheat dough and physico-chemical properties of steamed bread (SB), BSP was added with wheat flour at various proportions (2-10%). Results showed that with the increasing amount of BSP additive, the farinograph index (86.33-123), dough stability (9.37-12.63 min), and dough development time (6.23-7.63 min) in blend flour increased. Similarly, with the increasing BSP, SB became darker and more greenish, and the total flavonoid content increased. The content of chlorophyll-b, and total chlorophyll demonstrated a faster increase than that of chlorophyll-a. The hardness and chewability of SB improved as well whereas the springiness increased first and then decreased. The best springiness and gumminess of SB were found with 2% and 8% BSP additives respectively. 2%, 4%, and 6% addition of BSP resulted in a slight fluctuation in the bound water quantity than 8% and 10% BSP additive. No new compound formation was confirmed by Infrared analysis and there was only a heat and mass transfer process. Results from this study indicated that SB with improved quality attributes can be prepared from wheat flour fortified with BSP at 2-4%.

This study analysed pesticide residues in cauliflower (Brassica oleracea botrytis) and bitter gourd (Momordica charantia), two widely consumed vegetables in Bangladesh, and assessed the associated human health risks. Vegetables were analysed using a modified QuEChERS extraction, followed by gas chromatography with flame thermionic and electron capture detectors. Results showed that in 36.7% of the samples pesticide residues were detected, 90.9% of which exceeding the MRLs of the European Commission, so highlighting serious food safety concerns. Multiple residues were detected in some samples, with chlorpyrifos being the most common present, followed by diazinon, dimethoate and quinalphos. Human health risks, calculated by estimated daily intake and hazard index, indicated potential non-carcinogenic risks from the present pesticides. This study may assist policymakers and authorities in developing strategies for safe vegetable production and quality monitoring to ensure food safety.

The formation and occurrence of acrylamide in carbohydrate-rich foods has been extensively studied over the course of the past few decades. However, the emergence of plant-based meat alternatives presents a new challenge in this field. The aim of this study was to evaluate the levels of acrylamide in commercially available plant-based meat alternatives before and after heat treatment. Trace levels of acrylamide were detected in all samples before heat-treatment, while the concentrations increased in 11 samples out of 16 after heat-treatment. The highest concentration of acrylamide increased from 65.7 ± 6.6 µg kg^-1 before to 119 ± 12 µg kg^-1 after heat-treatment. Principal component analysis (PCA) indicated that besides macronutrient composition, the use of additives and processing techniques have a strong influence on acrylamide formation in plant-based meat alternatives. The latter was supported by the analysis of self-made meat alternative models that were prepared using only the base ingredients.