Foot Ash as a Means of Quantifying Bone Mineralization in Chicks

Three studies were conducted to evaluate foot ash as an alternative method to quantify the degree of bone mineralization in broiler chicks. In Experiment 1, the objective was to evaluate whether degree of bone mineralization would be reflected by foot ash in broiler chickens at 14 d of age. Birds receiving 0.24, 0.32, or 0.40% of dietary available phosphorus (AP) demonstrated significant differences in foot ash (10.93, 13.46, and 15.45%, respectively). In Experiment 2, we determined that the time required for a foot sample to dry to a constant weight at 105°C was 48 h. In Experiment 3, the objectives were to compare the response of bone mineralization to dietary phosphorus levels as reflected by foot ash and tibia bone ash and to evaluate the effect of fat extraction on the determination of these parameters. Broiler chicks were fed graded levels of AP (0.25, 0.30, 0.35, and 0.40%) from 1 to 14 d of age. Significantly different responses between each dietary AP level could be detected by any method used. A significant linear response was observed between dietary AP and percentage of extracted or unextracted tibia or foot ash, with determination coefficients above 90% found for all 4 methods used. Results confirmed that the dietary phosphorus levels affected bone mineralization and that the degree of mineralization could reliably be reflected by foot ash. The assay was found to be as reliable as the tibia bone ash in reflecting degree of bone mineralization in chicks during the first 14 d of age. Fat extraction did not affect the reliability of either assay.     

Postnatal Osteological Development of the Hyoid Bone in the New Zealand White Rabbit

This study augments knowledge of bone growth by observing the development of the hyoid bone in the New Zealand White rabbit. Preserved hyoid bones representing five different age periods, each period including five individuals and the total number of animals being 25, were fixed in 3.5% formaldehyde solution and 95% ethanol, followed by a pure acetone bath. They were then stained with an alcian blue–alizarin red combination. The mode of bone formation was intracartilaginous type ossification. While the basihyoideum and thyrohyoideum were observed to start ossifying first at prenatal stage, indicating that they are the main skeletal structures of the hyoid apparatus, the ceratohyoideum and lingual process began to ossify in the second and third periods. The separately occurring primary ossification centres fused completely among themselves in the fifth period. Because no further ossification centers were observed and the ossified parts continued the development and growth, the research was terminated after 10 weeks of age.     

肉鸡骨骼发育的调控机制

肉鸡骨骼发育主要是通过软骨内骨化完成的。在软骨内骨化的进程中,生长板软骨细胞经历增殖、肥大、转分化和软骨基质矿化等,最终成骨逐渐取代软骨原基,实现骨骼的线性延长。软骨内成骨是一个复杂精密的过程,由SOX9、RUNX2、MEF2C、OSX、TGF-β、BMP2、FGFs、IHH和PTHrP等多种信号因子和转录因子协调调控,这些调控因子由生长板不同区的软骨细胞表达或特异性的调控软骨细胞的增殖、分化及血管侵入等过程。在家禽养殖中,肉鸡常发腿病且治疗难度大,而有关肉鸡腿病发病机制的研究报道相对较少。本文综述了骨形成过程及具体的分子调控机制,为了解肉鸡腿病的发生以及提供有效治疗方案提供参考。     

Generalized Osteosclerosis in a Cat

A 12-year-old, neutered male, domestic long-hair cat was evaluated for a 6-month history of inspiratory stertor and epiphora. In computed tomography of the skull and pelvis, and radiographs of the thorax, right femur and stifle there was generalized osteosclerosis, with obliteration of the nasal turbinates and nasolacrimal duct obstruction. The cat also had a large fibrosarcoma involving the right pelvic limb. Osteosclerosis is a rare disorder that is poorly understood but has been described in several species. Various manifestations, potential causes, and radiologic findings of osteosclerosis are discussed.     

Ectopic pregnancy through a caesarean scar in a ewe

CASE HISTORY: A routine ultrasonographic examination for pregnancy diagnosis in a 3-year-old ewe revealed a normal embryo located in the uterine cavity and an abnormal mass located in the abdomen. At the time of examination, the ewe was 4.5?months pregnant, but 10?months previously she had undergone a caesarean section due to dystocia.

CLINICAL FINDINGS: The abnormal mass (12?cm × 8?cm) was located outside the uterine cavity; it was anechoic at the periphery, and in the centre there was an echogenic embryo-like structure. Exploratory laparotomy was performed, which revealed an ectopic pregnancy through the caesarean scar.

TREATMENT: The ectopic foetus was excised and the caesarean scar was repaired. The ewe made a complete recovery and the intrauterine pregnancy was completed to full-term, resulting in the birth of a healthy female lamb 35?days after the removal of the ectopic foetus.

CLINICAL RELEVANCE: Ectopic pregnancies have previously been described in ewes. As far as the authors are aware, this is the first report of an ectopic pregnancy through a caesarean scar in sheep or any other farm animal species.     

Effects of Rice Bran Inclusion on Performance and Bone Mineralization in Broiler Chicks

Rice bran, a by-product of the rice industry, is available for animal feeds. However, it has not been a common part of poultry rations in Argentina. Hydrolytic and oxidative rancidity development, phytate content, enzyme inhibitor, and high fiber content are the most important antinutritive factors cited as limiting factors for its use. An experiment utilizing 1-d-old male broiler chicks was conducted to determine the responses of zootechnical and bone mineralization parameters to diets with different concentrations of rice bran. The feed conversion and tibia ash were more sensitive than weight gain to detect antinutritive factors in rice bran. High concentrations of rice bran (in excess of 20%) produced a significant reduction in body weight. Furthermore, feed conversion and bone mineralization variables were impaired by feeding 10% rice bran diets. The adverse effects of rice bran on weight gain, feed conversion, and mineralization in the current studies suggest that rice bran should be included in broiler diets at a level between 10 and 20% if strategies are not used to decrease the antinutritive activity.     

绵羊高繁殖力候选基因BMPR-IA的研究

以骨形态发生蛋白受体IA（bone morphogenetic protein receptor IA，BMPR-IA）基因为候选基因，采用PCR—SSCP技术检测该基因在高繁殖力绵羊品种（小尾寒羊、湖羊）以及低繁殖力绵羊品种（多赛特羊、特克塞尔羊、德国肉用美利奴羊）中的单核苷酸多态性，同时研究该基因对小尾寒羊高繁殖力的影响。结果表明：在小尾寒羊中检测到AA、AB两种基因型，在湖羊中只检测到一种基因型BB，而在低繁殖力的3个绵羊品种中只检测到一种基因型AA。统计结果表明：小尾寒羊A等位基因频率为0．964，B等位基因频率为0．036。测序结果表明：BB型与AA型相比有6处核苷酸发生了突变。独立性检验表明：外尾寒羊与低繁殖力绵羊品种间基因型分布差异不显著（P〉0．05），而湖羊与小尾寒羊、低繁殖力绵羊品种间基因型分布差异极显著（P〈0．001）。AB基因型小尾寒羊平均产羔数比AA基因型多0．15只，但差异不显著（P〉0．05）。研究表明：BMPR-IA基因不是小尾寒羊和湖羊高繁殖力的主效基因。     

25-羟胆钙化醇与维生素D_3对北京鸭生产性能和骨骼发育的影响

试验选用2 160羽1日龄北京鸭,按4×3两因素设计随机分成12个处理,每处理6个重复;分别饲喂不同水平的25-羟胆钙化醇(25-OH-D3)(0、35、70、105μg/kg)与维生素D3(2 500、3 000、3 500 IU/kg)的日粮,探讨25-OH-D3在肉鸭日粮中的使用效果。结果表明:不同水平25-OH-D3对北京鸭生产性能没有显著影响;添加105μg/kg较35、70μg/kg显著降低45日龄北京鸭胸肌率(P<0.05);70、105μg/kg 25-OH-D3较35μg/kg显著提高了胫骨磷含量(P<0.05)。添加3 500、3 000 IU/kg维生素D3较2 500 IU/kg显著提高15～35日龄北京鸭日增重(P<0.05);添加3 500 IU/kg维生素D3较3 000、2 500 IU/kg显著提高14、45日龄胫骨钙含量(P<0.05)。25-OH-D3和维生素D3对14日龄胫骨中钙、磷含量和45日龄胫骨磷含量分别存在极显著(P<0.01)和显著(P<0.05)地交互作用。综合本试验可得出,北京鸭日粮中添加3 000 IU/kg维生素D3和70μg/kg 25-OH-D3效果最佳。     

Primary isolated osteoma cutis causing eyelid deformation and strabismus in a dog

Osteoma cutis describes bone formation in skin and is well documented in the medical literature, but veterinary reports are few. We report a single case of a juvenile samoyed that was referred for assessment of a superior eyelid anomaly. Exploratory surgery and histopathology revealed the presence of mature, lamellar bone within the superior eyelid. The histologic appearance was consistent with primary osteoma cutis. The presence of the ossification within the deep dermis of the eyelid was associated with an abnormal conformation causing trichiasis, keratitis and dorsal strabismus. Identification of the osseous lesion during surgery and its removal was curative with no recurrence of disease during the 32 month follow‐up period.     

Gastrografin as a Gastrointestinal Contrast Medium in the Cat

Gastrografin (diatrizoate meglumine and diatrizoate sodium solution) was used to evaluate its performance as a gastrointestinal-tract contrast medium in ten cats. It was administered through an orogastric tube to ketamine hydrochloridesedated, nonatropinized, mature cats at a dose rate of 22 mg/kg. Gastric emptying and largeintestinal filling were observed within 30–60 minutes in seven cats and in 120 minutes in the remaining three cats. The mucosal detail of the small intestine was poor, being represented by a homogeneous "halo" of decreased radiodensity surrounding the more radiodense intestinal luminal contents. The contrast medium refluxed into the esophagus in six cats. Some contrast medium precipitated in the stomach and small intestines in all ten cats. Urinary-tract opacification occurred in all cats and was first seen 60 minutes after Gastrografin was administered. Gastrografin satisfactorily opacifies the lumen of the gastrointestinal tract of cats. It has physical and physiologic characteristics that preclude its use for routine gastrointestinal contrast studies. These characteristics are reviewed in this article.     

Phosphorus equivalency of a Citrobracter braakii phytase in broilers

A study was conducted to evaluate the effects of phytase supplementation on growth performance, phosphorus availability, and bone mineralization in broilers. Three hundred fifty Cobb × Cobb 500 slow-feathering male broilers were placed in steel battery cages into 7 treatments with 10 replications of 5 chicks each. The treatments were: a positive control (PC) diet [0.42% nonphytate phosphorus (nPP)], 4 diets containing increases in nPP from dicalcium phosphate (0.14, 0.20, 0.26, and 0.32%), and 2 phytase supplemental levels [500 and 1,000 phytase units ( FYT)/kg] on the diet having 0.14% nPP. All diets contained 0.8% calcium. Growth performance and bone data were regressed against the 4 diets having increased nPP. The equations generated were replaced by the corresponding performance obtained with 2 phytase levels to estimate their nPP bioequivalence. An overall reduction in performance and bone mineralization was observed associated with a reduction in nPP. Linear fits provided the best adjustments for all responses with the exceptions of BW gain (BWG) and feed intake (FI). Adding phytase to the 0.14% nPP diet improved growth performance and bone mineralization (P < 0.001). Average bioequivalence nPP for each phytase level was dependent on the evaluated response with lowest and highest values at 500 FYT supplementation of 0.077 and 0.145 for toe P and femur Ca, respectively, whereas lowest and highest values at 1,000 FYT of 0.143 and 0.194 for BWG and toe ash. Averaging all values for 500 and 1,000 FYT provided estimations of 0.100 and 0.166 nPP, respectively.     

Bone fatigue and its implications for injuries in racehorses

Musculoskeletal injuries are a common cause of lost training days and wastage in racehorses. Many bone injuries are a consequence of repeated high loading during fast work, resulting in chronic damage accumulation and material fatigue of bone. The highest joint loads occur in the fetlock, which is also the most common site of subchondral bone injury in racehorses. Microcracks in the subchondral bone at sites where intra‐articular fractures and palmar osteochondral disease occur are similar to the fatigue damage detected experimentally after repeated loading of bone. Fatigue is a process that has undergone much study in material science in order to avoid catastrophic failure of engineering structures. The term ‘fatigue life’ refers to the numbers of cycles of loading that can be sustained before failure occurs. Fatigue life decreases exponentially with increasing load. This is important in horses as loads within the limb increase with increasing speed. Bone adapts to increased loading by modelling to maintain the strains within the bone at a safe level. Bone also repairs fatigued matrix through remodelling. Fatigue injuries develop when microdamage accumulates faster than remodelling can repair. Remodelling of the equine metacarpus is reduced during race training and accelerated during rest periods. The first phase of remodelling is bone resorption, which weakens the bone through increased porosity. A bone that is porous following a rest period may fail earlier than a fully adapted bone. Maximising bone adaptation is an important part of training young racehorses. However, even well‐adapted bones accumulate microdamage and require ongoing remodelling. If remodelling inhibition at the extremes of training is unavoidable then the duration of exposure to high‐speed work needs to be limited and appropriate rest periods instituted. Further research is warranted to elucidate the effect of fast‐speed work and rest on bone damage accumulation and repair.     

中草药复方防治肉鸡骨病的研究

为探明中草药复方对肉鸡骨病的防治效果,本研究选用160只1日龄健康科宝肉鸡,随机均分为8组,分别饲养至30和60日龄,由当归、枸杞、山药等8味中草药组成复方制剂,将中草药复方以高（0.6%）、中（0.4%）、低（0.2%）3个剂量组进行治疗试验,同时设置对照组饲喂基础饲粮,分别于30、60日龄时称重,采用生化分析仪检测骨代谢相关血液生化指标维生素D受体（VDR）、骨钙素（OT）、骨保护素（OPG）、碱性磷酸酶（ALP）,通过万能试验机进行三点弯曲试验,以弹性模量、屈服强度和最大应力为指标检测胫骨的骨强度,运用实时荧光定量PCR方法检测胸椎、腿软骨组织中骨保护素（OPG）、骨形态发生蛋白-2（BMP-2）、成骨细胞转录因子2（Runx-2）、细胞核因子κB受体活化因子（RANK）、细胞核因子κB受体活化因子配体（RANKL）、肿瘤坏死因子α（TNF-α）基因mRNA表达量的差异。结果显示,与对照组相比添加复方中草药组试验鸡后体重略增加;60日龄时血清中VDR、OT、OPG、ALP含量显著或极显著提高（P<0.05;P<0.01）;肉鸡的胫骨骨强度指标（弹性模量、屈服强度和最大应力）显著增加（P<0.05）,且弹性模量、屈服强度、最大应力3个指标均表现为30日龄高于60日龄,与血液生化指标相符;复方中草药可显著促进OPG、BMP-2、Runx-2基因表达（P<0.05）,显著抑制TNF-α、RANK、RANKL基因表达（P<0.05）。综合试验结果,兼顾活重和骨强度相关指标,复方中草药高剂量组是改善科宝肉鸡骨骼特性最优配方,且中草药复方通过提高血清中VDR、OT、OPG、ALP含量,调控OPG/RANK/RANKL系统维持骨吸收和骨形成两者动态平衡,促进骨形成的重要通路BMP-2/Smads/Runx-2中BMP-2和Runx-2基因的表达,同时抑制TNF-α基因表达,以达到改善科宝肉鸡骨骼特性,最终有效防治肉鸡的骨病。     

Agenesis and Dysgenesis of the Navicular Bone as Cause of Lameness and Malalignment in Two Foals

A three-week-old warmblood colt was referred for a two-week history of lameness on the left thoracic limb, and a two-month-old Quarter Horse–mix filly was referred for malaligned pelvic limbs since birth. The foals were diagnosed with agenesis and dysgenesis of the navicular bone, respectively. In this report, we present clinical signs, diagnostics, and postmortem workup of the two cases.     

Bone Mineral Changes in Dairy Cows: The Effect of Low and High Calcium Feeding During the High Yielding Period*

Bone mineral content in two coccygeal vertebrae of 14 cows of Swedish Red and White Breed were investigated using the dichromatic photon absorptiometry. The investigation started at parturition and continued for 120 days. Each animal received a controlled amount of hay, ensilage and concentrate, and the milk yield was measured and registered. Seven cows (group L) received Ca and P close to the ARC standard. The other seven cows (group H) received a 30 % higher amount of Ca and P (15–20 % above Swedish standard) than the ones in group L. The bone mineral content in group L decreased by 10 % up to 90 days postpartum, and thereafter increased. In group H, the mean bone mineral content increased.     

维生素K与动物骨骼发育研究进展

维生素K在动物骨骼发育中起着重要的作用,其机理主要是维生素K能够促进血清中骨钙素的羧化,羧化的骨钙素与羟基磷灰石的结合能力增强,促进了骨骼的矿化,从而改善骨骼质量。血清骨钙素的羧化程度是维生素K状态评定的一个新的敏感指标。为获得动物良好的骨骼质量和生产性能,应适当增加日粮中维生素K的添加量。