Уточнить поиск
Результаты 1-10 из 12
A pilot study on the effect of a novel feed additive containing exogenous enzymes, acidifiers, sodium butyrate and silicon dioxide nanoparticles on selected cellular immune indices and body weight gains of calves
2021
Szacawa, Ewelina | Dudek, Katarzyna | Bednarek, Dariusz | Pieszka, Marek | Bederska-Łojewska, Dorota
The rearing of calves is a difficult period for farmers due to health problems to which the animals are prone this time. Since the use of antibiotics as growth promoters has been forbidden, various innovative feed additives have been tested in many countries around the world. In this study, experimental (E) calves were supplemented with a novel feed additive consisting of the pancreatic-like enzymes protease and lipase, a fat-coated mixture of organic fumaric, malic, citric and sorbic acids, sodium butyrate and silicon dioxide nanoparticles. Control (C) calves received feed without additive. During the supplementation, white blood cell (WBC) counts with leukocyte differentiation, percentages of B lymphocytes and T lymphocytes and their subpopulations, phagocytic activity and oxidative burst of circulating monocytes and granulocytes were examined. Body weight (b.w.) gains of the calves were also monitored. The WBC counts in the E and C calves were within the reference ranges throughout the study. In the analysis of the percentages of the lymphocyte subpopulations, phagocytic activity and oxidative burst, no statistically significant differences were reported between the E and C groups. However, higher average daily body weight gains were obtained for the E calves. The study revealed that the examined feed additive did not modulate the immune response of the calves significantly. The tendency to higher daily average b.w. gains in the E calves than in the C calves suggests a beneficial effect of this feed additive.
Показать больше [+] Меньше [-]Acute and sub-chronic toxicity study of recombinant bovine interferon alpha in rodents
2021
Yu, Hai-Yang | Gao, Dong-Mei | Zhou, Wei | Xia, Bing-Bing | He, Zhi-Yuan | Wu, Bo | Jiang, Min-Zhi | Wang, Mingli | Zhao, Jun
Recombinant bovine interferon alpha (rBoIFN-α) has been demonstrated to have antiviral activity. However, no conduct of acute or chronic toxicity tests has been reported. Specific pathogen-free Sprague Dawley rats were administered doses at different concentrations through intraperitoneal or intravenous injection. After the administration (single for an acute toxicity test over 14 days or daily for a sub-chronic toxicity test over 30 days), the rats’ behaviour and other indicators and the degree of toxic reaction were continuously monitored. Blood was collected for haematological and serum biochemical examinations. At the end of the experiments, the rats were sacrificed for necropsy and histopathological tissue analysis. The external performance, behaviour characteristics, and changes in body temperature and body weight of the rats in each subgroup were comparable to the normal control subgroup. Except for a few cases, there were no lesions in the viscera’s pathological structures, and the blood parameters and biochemical indicators were not noticeably different from those of the control subgroup. This study suggests that rBoIFN-α seems to be safe for rats, and its use may foster the development of the cattle industry in China by protecting livestock health.
Показать больше [+] Меньше [-]Randomized, placebo-controlled, 28-day safety and pharmacokinetics evaluation of repeated oral cannabidiol administration in healthy dogs
2021
Vaughn, Dana M. | Paulionis, Lina J. | Kulpa, Justyna E.
OBJECTIVE To determine the safety and pharmacokinetics of various doses of plant-derived cannabidiol (CBD) versus placebo following repeated oral administration. ANIMALS 20 healthy adult Beagles. PROCEDURES In a randomized, blinded, placebo-controlled trial, dogs were randomized to 5 groups balanced in body weight and sex (n = 4 dogs/group) and received a CBD (1, 2, 4, or 12 mg/kg; from cannabis extract) or placebo oil formulation PO once daily for 28 days. Outcome variables were assessed through daily health observations, veterinary examinations, CBC, and serum biochemical analysis. Blood samples were collected at various time points to estimate 24-hour pharmacokinetic profiles of CBD and selected metabolites (7-carboxy-CBD and 7-hydroxy-CBD). RESULTS Repeated CBD administration was well tolerated by dogs, with no clinically important changes in measured safety outcomes. Veterinary examinations revealed no clinically important abnormal findings. Adverse events were mild in severity. Relative to placebo administration, CBD administration at 12 mg/kg/d resulted in more gastrointestinal adverse events (mainly hypersalivation) and significantly higher serum alkaline phosphatase activity. Total systemic exposure to CBD increased on a dose-dependent basis following both acute (first dose) and chronic (28 days) administration. Within each CBD dose group, repeated administration increased total systemic exposure to CBD 1.6- to 3.3-fold. The 24-hour trough plasma CBD concentrations were also dose dependent, with a steady state reached following 2 weeks of administration. CONCLUSIONS AND CLINICAL RELEVANCE Repeated, daily oral administration of the CBD formulation led to dose-dependent increases in total systemic exposure to CBD and 24-hour trough plasma concentrations in healthy dogs. These findings could help guide dose selection.
Показать больше [+] Меньше [-]Cardiopulmonary effects and recovery characteristics associated with 2 sedative protocols for assisted ventilation in healthy neonatal foals
2021
Kerr, Carolyn L. | Keating, Stephanie C. J. | Arroyo, Luis G. | Viel, Laure
Neonatal foals may require prolonged sedation to permit ventilatory support in the first few days of life. The objective of this study was to evaluate and compare the cardiopulmonary effects and clinical recovery characteristics of 2 sedative/analgesia protocols in healthy foals receiving assisted ventilation. Foals were randomized to receive dexmedetomidine, butorphanol, and propofol (DBP) or midazolam, butorphanol, and propofol (MBP) during a 24-hour period. Infusion rates of dexmedetomidine, midazolam, and propofol were adjusted and propofol boluses administered according to set protocols to maintain optimal sedation and muscle relaxation. Ventilatory support variables were adjusted to preset targets. Physiologic variables were recorded, cardiac output (CO) measured (thermodilution), and arterial and mixed venous blood collected for gas analysis at intervals up to 24 hours. Foals in group DBP received dexmedetomidine [2.4 ± 0.5 μg/kg body weight (BW) per hour], butorphanol (13 μg/kg BW per hour), and propofol (6.97 ± 0.86 mg/kg BW per hour), whereas foals in group MBP received midazolam (0.14 ± 0.04 mg/kg BW per hour), butorphanol (13 μg/kg BW per hour), and propofol (5.98 ± 1.33 mg/kg BW per hour). Foals in the DBP group received significantly more propofol boluses (9.0 ± 3.0) than those in the MBP group (4.0 ± 2.0). Although physiologic variables remained within acceptable limits, heart rate (HR), mean arterial pressure (MAP), and cardiac index (CI) were lower in foals in the DBP group than in the MBP group. Times to sternal recumbency, standing, and nursing were significantly shorter in the DBP than MBP group. We found that MBP and DBP protocols are suitable to assist ventilatory support in neonatal foals, although MBP results in a prolonged recovery compared to DBP.
Показать больше [+] Меньше [-]Comparison of the bacteriostatic effects of quaternary ammonium compounds and their combinations on a dairy farm environment and the microbial contamination of dairy products
2021
Chen, Nannan | Liu, Shanshan | Liu, Yu | Bai, Tongtong | Jia, Lihua | Wang, Li | Yue, Shan | Wu, Chenhua | Huang, Wenjing | Gao, Li | Fu, Jinlei | Liu, Siyu | Zhao, Tong | Li, Juan | Zhang, Yuntao | Zhu, Zhanbo
Disinfection is key for controlling microbial contamination and ensuring the safe production of milk and dairy products. In this study, we developed a new disinfection method using quaternary ammonium surfactant N-dodecyl-2-(pyridin-1-yl) acetamide chloride as the main component to form a bactericidal complex with either chlorhexidine acetate or glutaraldehyde, and we evaluated the bactericidal effects, safety, and clinical application value of the compound disinfectants. An in vivo acute oral toxicity assay in mice showed an LD50 > 5000 mg/kg body weight without abnormality in pathological tissue sections. Comparison with commercially available products also showed that they have outstanding bactericidal effects. Clinical trials proved that the compound disinfectants have excellent bactericidal effects on the air and ground of the dairy farm and on the skin of cattle, especially in a dairy farm environment. Our findings confirm that the new compound disinfectants have excellent bactericidal performance and are safe to use as disinfectants to prevent mastitis and contamination of the cattle farm environment.
Показать больше [+] Меньше [-]Repeatability, reproducibility, and reference intervals for indices of right atrial longitudinal strain derived from speckle-tracking echocardiography in healthy dogs
2021
Morita, Tomoya | Nakamura, Kensuke | Osuga, Tatsuyuki | Takiguchi, Mitsuyoshi
OBJECTIVE To determine repeatability, reproducibility, and reference intervals of indices of right atrial longitudinal strain (RALS) derived from speckle-tracking echocardiography (STE) in dogs without heart disease. ANIMALS 110 client-owned dogs and 10 laboratory Beagles. PROCEDURES To determine intraobserver within-day (repeatability) and interobserver (reproducibility) coefficients of variation, RALS during ventricular systole (ϵS), ventricular early diastole (ϵE), and atrial systole (ϵA), as derived with STE, were obtained by 2 investigators for 5 randomly selected client-owned dogs and analyzed by linear regression. Reference intervals were estimated from the results of all dogs. Correlations between RALS indices (ϵS, ϵE, and ϵA) and sex, age, body weight, heart rate, and blood pressure were determined. RESULTS RALS derived from STE showed good intraobserver within-day repeatability and interobserver reproducibility, with coefficients of variation of < 20%. Both ϵS and ϵE were significantly negatively correlated with age, but ϵA was not correlated with age. Indices were not correlated with sex, body weight, or blood pressure. CONCLUSIONS AND CLINICAL RELEVANCE RALS indices derived from STE were repeatable and reproducible and were affected by the age of dogs without heart disease. Age should be considered in the interpretation of RALS indices in clinical settings. Further studies are needed to apply RALS indices for assessing dogs with heart disease.
Показать больше [+] Меньше [-]Comparison of intra− and postoperative variables between laparoscopic and open ovariectomy in rabbits (Oryctolagus cuniculus)
2021
Kabakchiev, Claudia | Singh, Ameet | Dobson, Samantha | Beaufrere, Huges
OBJECTIVE To compare intraoperative and short-term postoperative variables pertaining to laparoscopic ovariectomy (LapOVE) and open ovariectomy (OVE) in rabbits (Oryctolagus cuniculus). ANIMALS Twelve 4− to 5-month-old female New Zealand White rabbits. PROCEDURES Rabbits were randomly assigned to undergo LapOVE (n = 6) or OVE (6), with a vessel-sealing device used to seal and transect the ovarian pedicles. Laparoscopic ovariectomy was performed with a 3-port approach. Variables were measured during surgery (surgery and anesthesia times and incision lengths) and for up to 7 days after surgery (food consumption, feces production, body weight, vital parameters, blood glucose and cortisol concentrations, abdominal palpation findings, facial grimace scale scores, and ethograms). RESULTS Mean surgery (43.2 vs 21.7 minutes) and anesthesia (76.2 vs 48.8 minutes) times were longer and mean incision length was shorter (24.0 vs 41.5 mm) for LapOVE versus OVE. No significant differences in postoperative variables were identified between groups. During LapOVE, small intestinal perforation occurred in 1 rabbit, which was then euthanized. Postoperative complications for the remaining rabbits included superficial incisional dehiscence (LapOVE, 1/5; OVE, 2/6), subcutaneous emphysema (LapOVE, 1/5; OVE, 0/6), and seroma formation (LapOVE, 1/5; OVE, 0/6). CONCLUSIONS AND CLINICAL RELEVANCE Surgery time for LapOVE was twice that of OVE, and LapOVE resulted in unique complications in rabbits. No evidence of a reduction in pain or faster return to baseline physiologic status was found for LapOVE. Further evaluation of LapOVE in rabbits is warranted, with modification to techniques used in this study or a larger sample size.
Показать больше [+] Меньше [-]Assessment of the effect of horseshoes with and without traction adaptations on the gait kinetics of nonlame horses during a trot on a concrete runway
2021
Wang, Pengju | Takawira, Catherine | Taguchi, Takashi | Niu, Xiao | Nazzal, Munir D. | Lopez, Mandi J.
OBJECTIVE To assess the effect of horseshoes with and without traction adaptations on the gait kinetics of nonlame horses during a trot on a concrete runway. ANIMALS 5 nonlame adult light-breed horses. PROCEDURES Kinetic data were obtained for each horse when it was trotted across a force platform within a concrete runway unshod (control) and shod with standard horseshoes; standard horseshoes with high profile–low surface area calks, with low profile–high surface area calks, and coated with a thin layer of tungsten carbide (TLTC); and plastic-steel composite (PSC) horseshoes. Kinetic data were obtained for the control treatment first, then for each of the 5 shoe types, which were applied to each horse in a random order. Kinetic variables were compared among the 6 treatments. RESULTS Body weight distribution did not differ among the 6 treatments. Compared with the control, the greatest increase in forelimb peak vertical force was observed when horses were shod with PSC shoes. In the hind limbs, the greatest increase in peak braking force was observed when horses were shod with PSC shoes, followed by the TLTC and low profile–high surface area calked shoes. The PSC shoes yielded the greatest coefficient of friction in both the forelimbs and hind limbs. Stance time was longest when horses were shod with standard shoes. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that PSC and TLTC shoes provided the best hoof protection and traction and might be good options for horses that spend a large amount of time traversing paved surfaces.
Показать больше [+] Меньше [-]Point shear wave elastography of the liver in healthy adult cats
2021
Park, Saechol | Choi, Jeongwoo | Kim, Kyeonga | Oh, Donghyun | Yoon, Junghee | Choi, Mincheol
OBJECTIVE To evaluate stiffness of the liver parenchyma in healthy adult cats by means of point shear wave elastography (PSWE). ANIMALS 18 client-owned adult (1- to 6-year-old) healthy cats. PROCEDURES Echogenicity and echotexture of the liver parenchyma were assessed by means of conventional B-mode ultrasonography. The shear wave velocity (Vs) of the right and left portions of the liver were measured by means of PSWE. RESULTS B-mode ultrasonography revealed no abnormalities in echotexture or echogenicity of the liver parenchyma in any cat. Mean (95% CI) Vs in the liver parenchyma was 1.46 m/s (1.36 to 1.55 m/s) for the right portion, 1.36 m/s (1.26 to 1.47 m/s) for the left portion, and 1.43 m/s (1.35 to 1.51 m/s) overall. The difference in mean Vs between the 2 portions of the liver was significant. No significant correlation was found between Vs and body weight or between Vs and the depth at which this variable was measured. CONCLUSIONS AND CLINICAL RELEVANCE Quantitative PSWE of the liver was feasible in healthy adult cats. The obtained values for Vs may be useful for interpretation of and comparison with values measured in cats with liver disease. Additional research is needed to explore the potential usefulness of PSWE for diagnostic purposes.
Показать больше [+] Меньше [-]Impact of meloxicam on respiratory virus titers and health outcomes when administered concurrently with a modified live respiratory vaccine in abruptly weaned beef steers
2021
Homerosky, Elizabeth R. | Jelinski, Michael J. | Dorin, Craig
Abruptly weaned crossbred steer calves (N = 271) were used in a randomized, blinded 2-arm clinical trial to assess the impact of a long-acting non-steroidal anti-inflammatory drug on bovine herpesvirus type 1, bovine respiratory syncytial virus, parainfluenza virus type 3, and coronavirus titers and health outcomes when administered concurrently with a modified live respiratory vaccine upon arrival at a feedlot. Treatment groups included a control (saline; n = 135) and an experimental group (injectable meloxicam; n = 136). Viral antibody titers and body weight were measured on arrival, day 7, and day 21, along with a final weight on day 45. Body weight and antibody titers for all viruses increased over time (P < 0.001); however, there were no differences by treatment group or a significant group × time interaction when evaluated using repeated measures analysis of variance. Interestingly, the use of meloxicam was associated with increased treatment risk (P < 0.05). In conclusion, the administration of meloxicam may adversely affect health; however, a decreased vaccine response is likely not a contributing factor.
Показать больше [+] Меньше [-]