Deposition and clearance of radiolabelled monodisperse polystyrene spheres in the calf lung

Two groups of three calves were exposed to monodisperse aerosols of radiolabelled polystyrene spheres measuring 3.3 microns in aerodynamic diameter (SD 0.3 micron). Although the spheres preferentially deposited in the trachea and major bronchi, 72 per cent of the total radioactivity deposited was found in lung tissue beyond the major bronchi. Mean alveolar deposition, estimated from the end retention value after mucociliary clearance, was 34 per cent in the group of bull calves and 52 per cent in the group of heifer calves. Alveolar deposition increased from 47 to 56 per cent (P less than 0.05) in heifer calves treated with oestradiol. Mucociliary clearance of the spheres was unaffected by repeated exposure to the experimental aerosol and the overall mean mucociliary clearance rate constant was 1.28 (+/- 0.43) h-1 (half-life 32 minutes). Clearance curve profiles tended to be characteristic for individual calves but variation in mucociliary clearance rates within calves was high and on occasions clearance rate inexplicably fell to 10 to 50 per cent of the maximum achievable value for the calf. Neither mucociliary clearance rate nor alveolar deposition was affected by a change in climate from 14 degrees C, 87 per cent relative humidity to 5 degrees C, 75 per cent relative humidity. Both alveolar deposition and mucociliary clearance of the spheres could be manipulated using a beta-adrenergic treatment.     

The effects of a β2-agonist (clenbuterol), and anti-bacterial drugs (trimethoprim with sulphadiazine; oxytetracycline) on calf mucociliary clearance

A non-invasive radio-aerosol technique was employed to study mucociliary clearance patterns in three groups of four calves of different ages. The initial clearance pattern, the percentage cleared in 1 h, and the percentage cleared between 1 and 19 h were used as indices of clearance efficiency. (Percentage retention at 19 h was used as an index of alveolar deposition.) These measurements were recorded in a series of experiments designed to investigate the effects of: clenbuterol (given as a single intravenous injection, 0.75 microgram/kg); a combination of trimethoprim and sulphadiazine-TMPS (administered by intramuscular injection twice daily for 3 days: 2.5 mg/kg trimethoprim; 12.5 mg/kg sulphadiazine) alone, or with a supplementary injection of clenbuterol; and oxytetracycline (administered by intramuscular injection twice daily for 3 days; 3 mg/kg). Clenbuterol alone tended to increase clearance rate, although this effect did not achieve statistical significance. The combination of TMPS with clenbuterol produced results similar to those of clenbuterol alone. Neither TMPS nor oxytetracycline had any significant effect on indices of mucociliary clearance. Differences were observed between calves of different age groups, particularly in clearance phases between 1 and 19 h.     

The calf reo-like virus (rotavirus) vaccine: an ineffective immunization agent for rotaviral diarrhea of piglets.

Rotavirus, in a commercially available calf vaccine, did not replicate in newborn colostrum-free piglets inoculated orally with one half of a calf dose. Gross and microscopic examination of these vaccinated piglets revealed no lesions consistent with rotaviral infection and vaccinated piglets were susceptible to challenge by porcine rotavirus. Challenged piglets vomited, had diarrhea and became severely dehydrated. Rotavirus was visualized in their gut fluid. Villi in the small intestines were shortened, blunted and fused. Rotaviral antigens were seen in enterocytes.     

Brain abscess in a Japanese black calf: utility of computed tomography (CT)

Computed tomography (CT) was used for diagnosis of brain abscess in a 6-month-old, Japanese black calf presented with neurological dysfunction, compulsive circling and vision disturbance. CT images showed asymmetric lateral ventricles, and presence of intra-cranial multiple low absorption lesions surrounded by capsule suggestive of abscess in the right cerebral hemisphere. Postmortem examination revealed marked swelling of right cerebral hemisphere and olfactory bulb. Multilocular large abscess containing creamy pus was found to occupy most area of periventricular and lateral ventricle. Fusobacterium necrophrum was isolated from the abscess contents as the causative agent. These results demonstrate that CT is useful tool for tentative diagnosis of bovine brain abscess.     

Variables in estimation of adipocyte size and number with a particle counter

Porcine adipose tissue slices were fixed with osmium tetroxide and cells released by treatment with urea. Cell size and number were determined by an instrumental method using a particle counter. Storage of adipose tissue samples as frozen slices or in osmium, in post-osmium saline, in urea or in post-urea Triton all tended to produce less acceptable results than obtained with fresh tissue slices. Various storage conditions either tended to diminish cell size, to produce small particles or to cause aggregation. Repeatabilities of cell number, cell diameter and cell volume from multiple samples obtained from one anatomical location within an animal (perfect repeatability = 1) were .39, .52 and .65, respectively. Repeatabilities of instrument determinations were greater than .98 for cell number, cell diameter and cell volume. Cell number may be estimated from particle counts or indirectly from average size. Particle count number and that calculated from mean cell diameter were similar, whereas cell numbers estimated from mean cell volumes were smaller. Different adipose tissue depots and backfat layers had divergent cell size, making extrapolation to whole-animal cell number complex.     

原料粒度对家禽消化和生产性能的影响

饲料工业很少关注蛋白类原料（如豆粕、肉粉等）的粒度，因其在出厂时已经粉碎，但需要控制谷物等的粒度。     

Detection of coronavirus in calf faeces with a haemadsorption-elution-haemagglutination assay (HEHA)

A simple and rapid procedure has been developed for the detection of bovine coronaviruses in faecal specimens. The method consists of adsorption of the virus onto mouse erythrocytes at 4°C, removal of unadsorbed material and elution of adsorbed viral material at 37°C. The eluate is then used in a haemagglutination test. Specificity of the reaction is checked by a blocking assay. No non-specific reactions have been observed. The sensitivity of the test appeared to be better than that of the electron microscope, at least when crude faecal extracts are used. By ultracentrifugation of the eluates the sensitivity of the assay can be further improved.     

Identification of a bisegmented double-stranded RNA virus (picobirnavirus) in calf faeces

To determine the incidence of rotavirus infection among dairy herds in the State of S?o Paulo, Brazil, 576 faecal samples obtained from calves aged 1-45 days with and without diarrhoea, reared on 63 dairy cattle farms, were analyzed. Polyacrylamide gel electrophoresis (PAGE) identified 28 samples positive for group A rotavirus, while four samples, two diarrhoeic and two non-diarrhoeic, showed a bisegmented genome with a typical picobirnavirus pattern. Electron microscopy revealed spherical virus particles with a diameter of 37 nm and without a defined surface structure. The present study is the first report of a bisegmented virus identified in cattle in Brazil.     

近红外光谱技术(NIRS)测定玉米粉碎粒度的研究

试验研究了近红外光谱技术(NIRS)快速测定玉米粉碎粒度的应用。建立的近红外定量预测模型定标决定系数(RC2)为0.9463,相对标准差(RSD)为6.5619%,相对分析误差(RPD)为4.3771,定标结果较好;并对模型的预测能力进行了验证,其中验证决定系数(RV2)为0.9186,相对标准差为6.8646%,相对分析误差为4.0856,预测能力较好,表明近红外技术具有较高的准确度。实验研究结果对饲料生产过程中粉碎粒度的控制具有重要的实际意义。     

Analysis of fecal nutrients and particle size in captive proboscis monkeys (Nasalis larvatus) fed seasonal dietary foliage at a Japanese zoo

One male and three female captive proboscis monkeys (Nasalis larvatus) were used as test animals to compare fecal nutrients after being fed seasonal foliage. Foliage and fecal samples were collected during three seasons (spring, summer, and winter). We analyzed crude ash (CA), ether extract (EE), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), and acid detergent lignin (ADL). In addition to the above components, for the fecal samples, we examined total fecal nitrogen (TFN), nitrogen in fecal NDF (NDF-N), metabolic fecal nitrogen (MFN), and particle size distribution (MPS). Seasonal differences in foliage components were observed, with NDF and ADF being lowest in spring (p < 0.05). Fecal NDF and ADF also tended to be lowest in spring. Further, the distribution of fecal particle size indicated that MPS tended to increase in winter. The mean fecal NDF content (47.4%) for all three seasons measured in this study was as much as 1.3 times lower than previously reported values in free-ranging specimens. These data provide useful information that can be used to find some suitable food items for the endangered highly folivorous monkeys in captivity.     

Anatomically corrected malposition (ACM) with subpulmonary infundibulum in a calf: clinico-morphologic case report.

A Japanese black calf with cyanosis, tachycardia, tachypnea and systolic murmur died of hypoxemia and cardiac insufficiency on the 38th day after birth. We could not establish the diagnosis during it's life. However, anatomically corrected malposition (ACM) with ventricular septal defect was confirmed at autopsy. There was situs solitus of the viscera and atria with atrio-ventricular discordance and ventriculo-arterial concordance. The ventricles demonstrated l-loop, i.e. on the right-sided ventricle there was a markedly enlarged morphologic left ventricle, and on the left-sided ventricle there was a hypoplastic morphologic right ventricle with a stenotic tricuspid valve and Ebstein-like deformity. The right posterior aorta originated from the left ventricle. The pulmonary artery arose from the left-sided right ventricle via infundibulum. There was a fibrous continuity between the aortic and mitral valve. We considered that this is the first reported case of bovine ACM.