Veterinary Medicine and Science最新文献

Background: Trypanosomosis is an economically significant livestock production constraint in 37 sub-Saharan African countries, including Ethiopia. Trypanosomosis requires a high annual budget to reduce Trypanosomosis infection and vector control.

Material and methods: A repeated cross-sectional study design was employed in four selected districts of the Gamo and Gofa zones to assess the prevalence of African animal trypanosomosis for over four years from 2019 to 2022, in dry and rainy seasons. About eleven kebeles were selected to bleed 2,567 cattle. Two hundred forty NGU traps were deployed for 2 days, 30 traps per season in each district, using a global positioning system (GPS). All cattle were local Zebu breed and were selected systematically from the eleven kebeles of the Zalla, Dara Mallo, Kucha, and Kucha Alfa districts. The risk factors recorded were analysed using Stata 14 software.

Results: The overall prevalence of bovine trypanosomosis across the study areas was 9.9% with a 95% confidence interval of 8.8%-11.1%. The responsible cause of Trypanosoma species was Trypanosoma congolense (84.3%), followed by mixed infections of T. vivax and T. congolense (11.1%), and T. vivax (4.7%). The study showed significant (p < 0.05) prevalence differences observed between districts, kebeles, altitudes, seasons, and study years using univariable logistic regression. Multivariable logistic regression analyses revealed that season, study year, skin coat colour, and body condition score were risk factors affecting bovine trypanosomosis in the study area. Infected and poor-body-conditioned animals showed significantly (p < 0.05) lower mean packed cell volume (PCV) than corresponding factors. The overall tsetse survey in wet and dry seasons showed proportions of 2075 (84.1%) and 386 (15.7%) Glossina spp. caught, with apparent densities of 8.65 and 1.61 flies per trap per day, respectively.

Conclusion: The study findings showed that trypanosomosis and tsetse flies were high in the study area and influenced by the season and study locations. Therefore, the disease requires improved control action to alleviate the problem in the area.

The hypothalamic-pituitary-adrenal axis responds to stress by releasing the adrenocorticotropic hormone which, in turn, stimulates the release of glucocorticoids (GCs). During acute stress events, the GCs' function is to maintain homeostasis. Short-term stress events trigger psychophysiological responses which are fundamental for survival in the natural world. Chronic stress occurs when the effect of stressors persists, and GCs secretion continues. The increase of GCs interacts with receptors in the brain triggering a negative feedback loop which inhibits the secretion of ACTH, consequently down-regulating GC production. Cortisol is the main GC in most mammals, including koalas. Cortisol is metabolised by the liver and bacterial enzymes in the intestine, and its metabolites are excreted via the faeces. In a previous study, where we used the tetrahydrocorticosterone) enzyme immunoassay (aka 50c EIA) for measuring faecal cortisol metabolites (FCMs) to assess stress in koalas, we did not detect a decrease in FCM values (negative feedback) after administration of prednisolone, an exogenous GC. Using the dexamethasone suppression test (DST), this study aimed at determining the ability of the feedback loop to decrease the concentration of plasma cortisol. This was achieved by measuring the values of plasma cortisol as well as FCMs using the 50c EIA in four koalas. No cortisol suppression was observed, rather an increase in plasma cortisol concentration in all koalas. This was also reflected in the increase of FCMs. An unresponsive feedback loop, and consequent prolonged high levels of plasma cortisol, is likely to increase koalas' susceptibility to diseases and it may impact their coping mechanism in nature.

This study investigates fluctuating asymmetry (FA) and directional asymmetry (DA) in the skulls of four cattle breeds: Eastern Anatolian Red, Southern Anatolian Red, Holstein and Simmental by using geometric morphometrics methods. A total of 89 skulls were analysed (Eastern Anatolian Red, n = 16; Southern Anatolian Red, n = 21; Simmental, n = 24; Holstein, n = 28) using 3D landmark based methods, including Procrustes superimposition, principal component analysis (PCA) and Procrustes ANOVA. PCA showed that the first two axes explained 32.39% of DA variation and 26.2% of FA variation, reflecting the multidimensional nature of cranial asymmetry. The results show that DA accounts for a greater proportion of total shape variation than FA, indicating a consistent asymmetry pattern across breeds. PCA revealed overlapping FA among breeds, with Holstein and Eastern Anatolian Red exhibiting greater variation, indicating higher developmental instability. FA, a marker of developmental instability, was most prominent along the horizontal (x-axis) and vertical (y-axis) planes, particularly in the nasal and orbital regions, suggesting mechanical loading as a possible influence. Procrustes ANOVA confirmed significant breed effects for skull shape (p < 0.0001), but asymmetry was not breed dependent. The analysis revealed that DA is primarily influenced by biomechanical factors, such as head posture, muscle attachments and habitual head movements, particularly in the occipital region. In contrast to masticatory structures, nasal asymmetry was linked to respiratory efficiency and environmental adaptation. These findings provide new insights into the role of genetic and environmental influences on cattle skull development and demonstrate the value of geometric morphometrics methods in capturing subtle morphological variation beyond traditional linear measurements.

Background and objectives: Epidemiological evidence suggests that vitamin D insufficiency is associated with human atherosclerosis and hypertension. The cardiovascular impacts of vitamin D are related to its influence on the effects of insulin, renin, lipid metabolism and inflammatory mediators. This study aimed to determine the impact of vitamin D on blood pressure, carotid tunica intima-media thickness, and lipid profile in healthy adult dogs.

Methods: Oral vitamin D3 (1000 IU) was administered to eight mixed-breed adult male dogs daily for 42 days. Serum 25-hydroxy vitamin D, high-density lipoprotein (HDL), low-density lipoprotein (LDL), very-low-density lipoprotein (VLDL), cholesterol, triglyceride, glucose angiotensin-converting enzyme (ACE) concentration, and blood pressure (systolic, diastolic, and mean), and were measured before treatment (day 0) and on days 14, 28, and 42.

Results: A sustained rise in serum 25(OH)D concentration was noted across the study periodm with significant increases noted between days 0 to 14, 14 to 28 and 28 to 42. Increasing serum triglyceride, LDL and VLDL concentrations and a reduction in diastolic blood pressure were documented over the study period. Serum triglyceride concentrations were higher on day 42 compared to days 0, 14, and 28. Serum LDL concentration was higher on day 28 and day 42 compared to day 0. VLDL concentration and diastolic blood pressure were higher on day 42 than on day 14 and day 28. There was no change in mean or systolic blood pressure, tunica intima-media thickness or in serum HDL or cholesterol concentration over the 42-day study period. The effect on blood glucose concentration was variable, with an initial reduction (from day 0 to 28) followed by a rebound increase (from day 28 to 42), resulting in no significant change at day 42 compared with day 0.

Conclusion: Oral administration of 1000 IU (40-67 IU/kg bodyweight) of vitamin D daily for 42 days resulted in a reduction in diastolic blood pressure and an increase in serum LDL, VLDL and triglyceride concentration. Additional studies are required to verify the findings and to further assess potential clinical implications.

Objective: This study evaluated the safety profile of tolfenamic acid following repeated oral administration in Japanese quails (Coturnix coturnix japonica) at doses of 2 and 8 mg/kg every 12 h for 7 days.

Methods: The 42 quails were randomly assigned to three groups. The first group (n = 6) received saline orally every 12 h for 7 days. The second (n = 18) and third (n = 18) groups were administered tolfenamic acid at doses of 2 and 8 mg/kg, respectively, orally every 12 h for 7 days, totalling 14 doses. The safety profile of tolfenamic acid was evaluated by haematological, biochemical and histopathological parameters.

Results: Haematological analysis revealed no significant differences across groups, except for a decreased mean corpuscular haemoglobin concentration in the 8 mg/kg group. Biochemical assessments indicated stable liver and kidney function markers, as no significant changes were observed in alanine aminotransferase, aspartate aminotransferase, total cholesterol, albumin or creatinine levels. However, histopathological examinations showed significant liver changes, including hydropic degeneration and bile duct proliferation, as well as renal tubular epithelial degeneration, particularly in the higher dose group. Notably, lymphoid tissue depletion was observed in the spleen of treated birds.

Conclusion: These findings indicate that tolfenamic acid administration does not adversely affect haematological or biochemical parameters. Although biochemical parameters remained normal, histopathological changes such as tissue damage may indicate early or subclinical injury that could impair organ function over time. These microscopic alterations might lead to long-term health issues in quails, even without biochemical abnormalities. Therefore, cautious dosing and regular tissue monitoring are important when using tolfenamic acid.

Despite their use in rural and urban transport systems, horses are often abandoned when they are aged and/or face health problems. Abandoned horses typically experience a miserable life, which is ethically unacceptable. This piece of work reports on the suffering of an abandoned cart horse and proposes strategies to improve the welfare of such horses. A type of pension program or provident fund and sanctuary should be established for working animals to lessen their suffering after abandonment. Comprehensive studies should be conducted to gather more data on the suffering of abandoned horses and to develop context-dependent solutions.

Background: The Arian broiler, an important native Iranian breed, shows heightened sensitivity to metabolic disturbances caused by lipopolysaccharide (LPS). This study evaluated whether glycyrrhizin could mitigate LPS-associated physiological disruptions.

Methods: In a controlled trial, 100 Arian broilers (21-day-old, mean weight 750 g) were randomly allocated into five experimental groups: (1) ICV glycyrrhizin dose-response assessment (1, 2 and 4 µg) evaluating feeding behaviour; (2) ICV LPS challenge (12.5, 25 and 50 ng) with 8-h monitoring of feed intake and cloacal temperature; (3) IP glycyrrhizin administration (12.5, 25 and 50 mg/kg) to assess effects on feed consumption; (4) IP glycyrrhizin + ICV LPS interaction study; and (5) ICV glycyrrhizin + LPS co-administration group.

Results: LPS administration induced characteristic biphasic temperature dysregulation, with significant hypothermia at 3 h (-1.3 ± 0.4°C vs. controls) followed by hyperthermia at 8 h (+1.1 ± 0.3°C), accompanied by feed intake reduction (p < 0.05). The findings indicated that feed intake increased significantly following the injection via both intraperitoneal and intracerebroventricular of glycyrrhizin in a dose-dependent manner (p < 0.05), but IP delivery (25 and 50 mg/kg) showed comparable effects with 20-30 min delayed onset. Co-administration completely prevented LPS-induced disturbances at optimal doses.

Conclusions: Glycyrrhizin counteracts LPS-induced thermoregulatory and feeding disturbances in Arian broilers through rapid-acting mechanisms. While the physiological improvements align with anti-inflammatory responses observed in other species, direct molecular evidence remains to be established.

Aim of study: This study aimed to evaluate the in ovo injection of nettle extract, mushroom extract and their mixture as natural anti-aromatase on sex reversal, histological changes in ovaries and testes and carcass characteristics of Ross 308 broiler chickens.

Area of study: Sex differentiation in avian species MATERIAL AND METHODS: A completely randomized block design used to allocate 500 fertilized eggs (Ross 308 strain) in five treatments (four replicates, 25 eggs per replication). Treatments included: an injection of nettle (URE), mushroom (AGE), mushroom and nettle extract (MIX), distilled water (PC) and no injected eggs (NC). The evaluation of ovarian and testicular tissues was done histologically.

Main results: In ovo injection of URE and MIX substances significantly lead to decreased total follicle numbers compared to positive controls (p = 0.01). The proportion of ovaries covered by connective tissue was similar to the testicular tunica albuginea in the URE, AGE and MIX groups, with coverage percentages of 75%, 50% and 62.5%, respectively, while control treatment showed 0% coverage (p = 0.0001). Hatched chickens from AGE group exhibited the highest germ/Sertoli cell ratio and germinal epithelial height in testicular tissue compared to the controls.

Research highlights: This study demonstrates that in ovo injection of flavonoid-based aromatase inhibitors derived from nettle and mushroom extracts, either individually or in combination, may induce mild effects on gonadal differentiation and structural changes of treated chickens. However, a final statement is subject to further research findings.

Background: The nutrient requirements of laying hens are not static but dynamic, changing throughout the day in response to the cyclic nature of egg formation.

Objectives: The current study aimed to evaluate the impact of the AM/PM feeding regimen (AM/PM-FR), which involved higher levels of protein, amino acids and available phosphorus, and lower levels of Ca in the morning diet, with the converse in the afternoon diet, on aged laying hens.

Methods: A total of 300, 74-week-old Hy-Line W36 laying hens were randomly assigned to a completely randomized design with 5 treatments, 6 replicates, and 10 hens per replicate. Experimental treatments included offering AM/PM-FR at 0% (control), 10%, 20%, 30% and 40% changing nutrient levels (CNL) between the morning (5:00 AM-2:00 PM) and evening (2:00 PM-5:00 AM) diets. The exposure program consisted of continuous lighting from 5:00 AM to 9:00 PM and darkness from 9:00 PM to 5:00 AM.

Results: The feed conversion ratio (FCR) and economic profit, income minus feed cost (IMFC), improved with a quadratic trend in response to increased CNL of AM/PM-FR. Throughout the entire experimental period, birds fed AM/PM-FR at 30% CNL showed improvements of 4.57% in FCR and 17.55% in IMFC compared to the control group. A lower incidence of egg fractures and a higher yolk crude protein concentration were observed with a linear trend in response to increased CNL of AM/PM-FR. By increasing CNL of AM/PM-FR, the total tract apparent mineral (Ca and phosphorus) and ether extract retention improved with quadratic and linear trends, respectively. Non-significant effects of the treatments were noted on egg quality, blood metabolites, bone mechanical properties and mineral contents.

Conclusions: It was concluded that the use of AM/PM-FR at 30% CNL in aged laying hens may facilitate the precision nutrition and thus improve production and economic performance.