Effects of particle size, ash content, and processing pressure on the bioavailability of phosphorus in meat and bone meal for swine

Meat and bone meal (MBM), when supplemented with tryptophan, is an excellent protein source for pigs. It is also a rich source of Ca and P, but some research has suggested that the bioavailability of P is variable. Three experiments were conducted to determine whether particle size, ash content, or processing pressure of MBM influences the bioavailability of P. Each experiment involved six replications of six treatments with individually penned pigs initially averaging 13 to 17 kg of BW. A low-P basal diet was fed with or without 0.1 or 0.2% added P (as-fed basis) from monosodium phosphate (MSP) or with three types of MBM added at levels that supplied 0.2% P (as-fed basis). The Ca level was 0.70%, and the lysine level was 0.95% in all diets. Pigs were allowed to consume their diets (meal form) on an ad libitum basis. At the end of the study, pigs were killed, and femurs and third and fourth metacarpals and metatarsals were removed for determination of breaking strength and ash content. Bone traits were regressed on added P intake for each P source, and slope-ratio procedures were used to estimate the bioavailability of P in MBM relative to that in MSP. In Exp. 1, a blended source of MBM ground to three particle sizes (amount that passed through 6-, 8-, or 12-mesh screens) was evaluated. In Exp. 2, low-ash MBM of porcine origin, high-ash MBM of bovine origin, and a 1:1 blend of the two sources were assessed. In Exp. 3, normally processed MBM was subjected to an additional 2.1 and 4.2 kg/cm2 of pressure for 20 min to determine whether excessive heat treatment would influence the bioavailability of P. Fineness of grind of MBM or processing pressure did not influence the relative bioavailability of P in this study; however, ash content of MBM affected P bioavailability. The relative availability of P in low-ash MBM of porcine origin (with composition typical of meat meal) was approximately 15 percentage units less than that in high-ash MBM of bovine origin. Overall, the bioavailability of P in MBM, relative to that in MSP, averaged 85%.     

Evaluation of cell-mediated immune responses and bacterial clearance in 6-10 months old water buffalo (Bubalus bubalis) experimentally vaccinated with four dosages of commercial Brucella abortus strain RB51 vaccine

Thirty water buffalo, obtained from a brucellosis-free farm, were used to evaluate cell-mediated immune responses and bacterial clearance in response to vaccination with Brucella abortus strain RB51 (RB51) in a dose-response study. The animals were randomly divided into five treatment groups. Groups I--V received the recommended dose (RD) of RB51 vaccine once, RD twice 4 weeks apart, double RD once, double RD twice 4 weeks apart and saline once, respectively. Cell-mediated immune response to RB51 was assessed by the histological examination of haematoxylin and eosin (H&E) stained sections of lymph nodes draining the sites of inoculation and by comparison of stimulation indices (SI) derived from gamma interferon (IFN-gamma) assay. A mixture of cytoplasmic proteins from B. melitensis B115 (brucellergene) was used as a specific antigenic stimulus to peripheral blood mononuclear cells (PBMC) and lymph node mononuclear cells (LNMC) up to 22 post-initial-inoculation week (PIW). Supernatants harvested at 18-24h after the in vitro antigenic stimulus were assayed for their IFN-gamma content by using a commercial sandwich enzyme-linked immunosorbent assay (ELISA) kit. Clearance of RB51 was assessed by the sequential immunohistochemical examination of sections of draining lymph nodes post-inoculation. There was no observable expansion of the deep cortex of lymph nodes on H&E sections indicating poor T-cell stimulation. All group V (control) water buffalo PBMC ELISA values were negative (SI<2.2) at all PIW sampling intervals. Overall PBMC IFN-gamma assay detected vaccinates from treatment groups' I--IV 67% (4/6), 83% (5/6), 33% (2/6) and 67% (4/6), respectively. LNMC IFN-gamma assay was unimpressive and there was a negative correlation (--.08) between the results of PBMC and LNMC of IFN-gamma assay. Clearance of RB51 occurred between 4 and 6 PIW in treatment groups I and III and between 6 and 12 PIW in groups II and IV. RB51 was not detected in any of the control animals at sampling intervals post-inoculation.     

Giant unruptured aneurysm of the left sinus of Valsalva in the left ventricular outflow tract of a young dog

A young adult, 28 kg, intact female Siberian husky-mixed breed dog was presented to the Veterinary Medical Teaching Hospital (VMTH) Emergency Service for evaluation of a dysrhythmia and an abnormal cardiac structure. The dog had been adopted from an animal shelter approximately 3 months before presentation. The dog occasionally showed exercise intolerance, and the owners suspected that she had impaired vision. Initial clinical signs appeared 2 days before presentation during strenuous activity—the dog uncharacteristically stopped and lay down while tachypneic. The dog produced dark liquid feces and was lethargic and anorexic overnight.     

Evaluation of surveillance and sample collection methods to document freedom from infectious bovine rhinotracheitis in cattle populations

OBJECTIVES: To assess the sensitivity of the current surveillance program used in Denmark for detecting outbreaks of infectious bovine rhinotracheitis (IBR) at the herd level and to evaluate the impact of alternative sample collection strategies on the sensitivity of the system in an acceptable time frame. SAMPLE POPULATION: Data from the Danish Central Husbandry Register on cattle of 24,355 and 25,233 beef herds and on 13,034 and 12,003 dairy herds in the years 2000 and 2001, respectively. PROCEDURES: Surveillance programs were evaluated under current sample collection conditions and under 3 alternative scenarios by use of simulation modeling. Data from the current detection component of the surveillance system were used as input, taking into consideration the sensitivity and specificity of bulktank milk and serologic testing. RESULTS:The current system identifies infected dairy herds within a 3-month period with desired accuracy largely because of the test characteristics and number of bulk-tank milk samples. The system is less likely to detect infected beef herds in a timely manner because surveillance in beef herds depends solely on serologic testing at the time of slaughter. The efficiency of surveillance in dairy cattle herds was not decreased substantially when the slaughter-surveillance component was omitted. CONCLUSIONS AND CLINICAL RELEVANCE:Geographically targeted sample collection during the high-risk season (winter) was predicted to increase the probability of rapid detection of IBR infection in cattle. This approach can be used for assessing other surveillance systems to determine the best strategies for detection of infected herds.     

Histomorphometric analysis of the proximal portion of the femur in dogs with moderate osteoarthritis

OBJECTIVE: To describe the histomorphometric properties of epiphyseal and metaphyseal trabecular bone of the proximal portion of the femur of dogs with moderate osteoarthritis. SAMPLE POPULATION: Proximal portions of a femour from 24 dogs. PROCEDURE: The proximal portion of a femur was obtained from each dog. Eleven and thirteen specimens were sectioned in the transverse and coronal planes, respectively. Three evenly spaced sections from each specimen were chosen, surface stained, and digitized, and the stained areas were preferentially selected. Custom software was used for histomorphometric analysis of each section. A mixed-model analysis was used to evaluate the effect of slice location and region on 6 parameters, and a Fisher protected t test was used when differences were detected. RESULTS: There was a significant difference between the femoral head and femoral neck for all parameters tested. In coronal sections, the femoral neck was significantly more anisotropic than the femoral head. In transverse sections, the craniolateral region of the femoral neck was significantly more anisotropic than the caudomedial and craniomedial regions. CONCLUSIONS AND CLINICAL RELEVANCE: There is a predictable cancellous microarchitecture in the proximal portion of femurs from dogs with moderate osteoarthritis. Trabeculae are more numerous, thicker, and closer together but more randomly arranged in the femoral head than in the femoral neck. Dogs with moderate osteoarthritis had an increase in trabecular anisotropy in the craniolateral region of the femoral neck. However, there was no corresponding increase in trabecular alignment of the proximomedial region of the femoral head. Results support an association between trabecular alignment and the progression of osteoarthritis.     

Ex vivo investigation of the use of hydrothermal energy to induce chondrocyte necrosis in articular cartilage of the metacarpophalangeal and metatarsophalangeal joints of horses

OBJECTIVE: To evaluate the use of hydrothermal ablation of articular cartilage for arthrodesis in horses through investigation of the effects of joint lavage with physiologic saline (0.9% NaCI) solution (80 degrees C) for various treatment times on chondrocyte viability in the articular cartilage of the metacarpophalangeal and metatarsophalangeal joints of cadaveric horse limbs. Sample Population-7 pairs of metacarpophalangeal and 8 pairs of metatarsophalangeal joints from 8 Thoroughbreds. PROCEDURE: The horses were euthanatized for reasons unrelated to musculoskeletal disease. On a random basis, 1 joint of each pair underwent intra-articular lavage for 5, 10, or 15 minutes with heated saline solution (80 degrees C); the other joint underwent sham treatment of similar duration with saline solution at 22 degrees C (control). Cartilage samples from the distal articular surface of metacarpus III (or metatarsus III), the proximal surface of the proximal phalanx, and the lateral and medial proximal sesamoid bones were assessed for chondrocyte viability via confocal microscopy and viability staining following enzymatic digestion. RESULTS: Compared with the control joints, findings of both viability assays indicated that the percentage of sites containing viable chondrocytes in heat-treated joints was decreased.Treatment hazard ratios of 0.048 (confocal microscopy) and 0.2 (digestion assay) were estimated. Histologically, periarticular soft tissues had minimal detrimental effects after heat treatment. CONCLUSIONS AND CLINICAL RELEVANCE: Ex vivo intra-articular lavage with saline solution at 80 degrees C resulted in the death of almost all articular chondrocytes in the joint. This technique may be a satisfactory method for extensive cartilage ablation when performing arthrodesis by minimally invasive techniques.     

疏花疏果提高鸭梨质量

鸭梨是大形梨果之一。在锦西地区多栽植在山地,由于管理粗放,产量极不稳定,质量较低,常因“大年”座果率高,结实过多,出现大量的小果,经济价值降低。为了稳产,提高果品质量,我们在沙河营公社上喂牛厂大队第二生产长对鸭梨进行了疏花疏果效果的调查研究。这个队在     

应用扫描电子显微镜对杨木及其塑合材抗腐性的研究

毛白杨(Populus tomentosa)与加杨(P.canadensis)都是速生树种,但材质较差,属于不抗腐的木材,如经浸注液浸注和热聚合处理成为塑合材后,便可提高其抗腐性。七十年代以来.扫描电镜已成为各学科领域中一种先进的研究工具,具有放大范围广、分辨率高、能直接观察到试样的立体三维图像,以及试样制备较为简便等显著优点。木材的细胞壁主要是由纤维素与木素组成,具有坚固性,在试样制备过程中,即使处在高度脱水和高度真空喷镀的条件下,也不容易萎缩变形,适合作扫描电镜的材料。因