Mechanical Comparison of Two External Fixator Clamp Designs

Objective —To compare two external fixation clamp designs for their ability to resist movement of a fixation pin in relation to the connecting rod. Study Design —Two designs of external fixator clamps were attached to connecting rods mounted on a jig for mechanical testing. Fixator pins were placed perpendicular to the connecting rod. A mechanical testing machine was used to deflect each 3.2-mm pin at a distance that was 25 mm from the center of the clamp bolt. Both clamp designs were tightened to 4.4, 6.1, and 7.8 newton-meters (N m) torque, and loads were applied in a position ramp through 4 mm and resisting loads were measured. Two clamp orientations were used during load application, such that the deflection of the pin tended to tighten the clamp bolt or tended to loosen the clamp bolt. The tests were videotaped to determine mode of failure. Comparisons of the load/displacement curves for the two external fixator clamp designs were made using nonlinear equational curve fitting methods. The resultant plateau and rise coefficients were compared using analysis of variance. Results —Slippage of the pin in relation to the clamp occurred with the Kirschner-Ehmer clamp tightened to 4.4, 6.1, and 7.8 N-m, and slipping of the pin in relation to the clamp occurred with the experimental clamp design tightened to 4.4 and 6.1 N-m but not to 7.8 N-m. At 7.8 N-m, the 3.2-mm pin deformed plastically with the experimental clamp design. Increasing the torque of the clamp bolt resulted in superior plateau coefficients for both clamp designs. At each level of tightness and in each clamp orientation to applied pin load, the experimental clamp design provided greater plateau coefficients than did the Kirschner-Ehmer clamp design. At 7.8 N m of tightness, the Kirschner-Ehmer clamp and bolt bent, whereas only slight plastic deformation of the experimental clamp design occurred. Conclusions —The experimental external fixator clamp was more secure in resisting fixator pin movement at all levels of tightening compared with the Kirschner-Ehmer-type external fixator clamp. At 7.8 N m of tightening, the new clamp design did not allow slippage of the pin within the clamp. Clinical Significance—The experimental external fixator clamp should result in greater rigidity of fixator configurations, in addition to providing design features that allow addition of a clamp between two installed clamps, sleeved predrilling of pilot holes for all pins, measurement of pin depth, and placement of positive profile pins at all sites.     

Laparoscopic Gonadectomy in Two Intersex Warmblood Horses

Two phenotypically female Warmblood horses were presented at the Clinic for Horses owing to stallion-like behavior. One mare had an enlarged clitoris, whereas the other one showed no signs of ambiguous external genitalia. In both cases, intra-abdominal testicles were removed by laparoscopy. Hormone status, cytogenetic evaluation, and histopathological examination of the gonads were performed. One animal was diagnosed as having XX disorder of sexual development; the other one, as male pseudohermaphrodite.     

Laparoscopic Repair of Scrotal Hernia in Two Foals

Nonstrangulating indirect scrotal hernias were corrected in two 4-week-old Percheron foals by a laparoscopic technique. After laparoscopic reduction of herniated nonstrangulated small intestine each testes was retracted through the vaginal ring. The ligament of the tail of the epididymis was transected by electrocautery. The testicular vessels and nerves were isolated by cautery of the mesenteric portion of the mesorchium and then ligated. Staples were used to close the opening of the inguinal canal by apposing the peritoneal edges of the vaginal ring. Resection of umbilical stalk remnants via celiotomy performed in one foal after laparoscopic observation of enlargement of the right umbilical artery and urachus. No complications or recurrence of herniation had occurred 16 weeks after surgery.     

两种复合预混料对热应激奶牛产奶性能的影响

试验目的是观测两种不同配方的复合预混料在热应激条件下对中国荷斯坦奶牛产奶性能的影响。试验分为两组,每组7头,分别饲喂对照组(普通型预混料)和试验组(含抗热应激预混料)日粮,两种日粮基础配方相同,含预混料不同,平均温湿度指数(THI)为80.18±5.43。经32d的饲养试验表明:1、抗热应激功能型预混料较普通型预混料显著提高产奶量9%(P<0.05);2、两组间平均乳脂率、乳蛋白率、乳糖和非脂乳固体(SNF)无显著差异(P>0.05);3、试验期间平均产奶量与THI呈双曲线负相关关系(对照组Rc2=0.5365;试验组RT2=0.4894)(P>0.05)。     

杜长大、约滇陆不同杂交组合商品猪生长育肥试验研究

找出一种繁育方法的杂交品种商品猪,使能够较好适合云南蒙自县地理位置和当地农业生产特点,在相同营养水平和饲养管理条件下,对杜洛克×（长白×约克）（DLY）与约克×滇陆（YDL）两个不同杂交组合商品猪进行育肥饲养对比试验,测定指标为不同杂交组合试验猪的体重、日增重、饲料转化效率和活体背膘厚。结果表明,DLY与YDL育肥猪体重和日增重差异不显著（P〉0.05）;饲料转化率DLY（2.35∶1）优于YDL（2.52∶1）;背膘厚YDL（12.71 mm）大于DLY（10.96 mm）（P〉0.05）。结果显示,DLY杂交组合猪具有较快生长速度和较高瘦肉率,适合营养饲养水平和规模化程度较高的养猪场饲养;而YDL猪具有适应性强、耐粗饲和生长速度快等特点,较适合云南适度规模猪场和农村条件下饲养。     

两种复合酶对断奶仔猪生长性能、营养物质消化率和肠道形态的影响

试验旨在评价断奶仔猪玉米豆粕型日粮中两种复合酶制剂的添加效果。试验选用128头体重为(5.67±0.86)kg的健康杜×长×大三元杂交仔猪,按体重和性别完全随机区组分为4组,每组8个重复,每个重复(圈)4头猪(公母各半)。4个处理分别为:(1)正对照组(PC);(2)负对照组(NC);(3)复合酶A组(EA):NC+1g/kg复合酶A;(4)复合酶B组(EB):NC+1g/kg复合酶B。试验共28d,分两阶段饲养,分别于第0d,第7d和第28d准确称量每圈猪体重并记录饲料的摄入量,日粮均为粉料。结果表明,PC及加酶组后期和全期平均日增重极显著高于NC(P0.01),但各组前期平均日增重无显著差异;与NC相比,PC和加酶组前期和全期料重比显著改善(P0.05);日粮添加EA提高试验前后期能量、干物质和粗蛋白的表观消化率(P0.05),而EB仅提高后期能量、干物质和粗蛋白表观消化率(P0.05);PC和加酶组仔猪十二指肠绒毛高度、绒毛高度/隐窝深度显著高于NC(P0.05),EA组仔猪十二指肠隐窝深度显著低于NC和PC(P0.05),PC仔猪回肠绒毛高度显著高于NC(P0.05),但加酶组、PC、NC之间差异均不显著。由此得出,玉米豆粕日粮中添加复合酶可改善仔猪十二指肠的发育,提高营养物质消化率,从而改善仔猪的生长性能。     

2个四元杂交配套系商品猪屠宰性能的比较研究

试验通过对64头皮杜×长大和18头皮杜×长蓝四元杂交配套系商品猪进行屠宰测定,以比较胴体和肉质性状的优劣,旨在为进一步从事优质猪肉的生产提供依据。结果表明:①在活体性状方面,皮杜×长蓝的活体肌内脂肪含量(intramuscular fat content,IMF)肩部最厚处背膘厚和最后肋背膘厚均极显著高于皮杜×长大(P<0.01),而屠体重和日增重极显著低于皮杜×长大(P<0.01);②在胴体性状方面,皮杜×长蓝的肩部最厚处背膘厚极显著高于皮杜×长大(P<0.01),胴体长和眼肌面积极显著低于皮杜×长大(P<0.01);③在肉质性状方面,皮杜×长蓝的IMF、pH₁和大理石纹等指标均极显著高于皮杜×长大(P<0.01),肉色b指标极显著低于皮杜×长大(P<0.01),pH_{24 h}和滴水损失显著低于皮杜×长大(P<0.05),同时皮杜×长蓝的嫩度比皮杜×长大更好;④2种配套商品猪的肉色评分均在3~4之间,属于正常肉色;pH₁大于5.9,pH_{24 h}小于6.0,表明肉质正常;皮杜×长大的IMF在1.5%~2.0%之间,皮杜×长蓝的IMF高于2.0%;2个品种的剪切力均小于4 kg,属于消费者喜欢的类型。     

促卵素对高日龄产蛋鸡生产性能的影响

通过添加0．1％促卵素对449～532d的高日龄产蛋鸡进行试验。结果表明,试验组比对照组每日每只平均多产4．66g蛋,多增收0．01985元。随着日龄增加,差异越来越显著。表明促卵素对产蛋鸡具有延缓衰老、延长产蛋周期的作用。     

大蒜素对蛋鸡产蛋后期产蛋性能的影响

将240只55周龄、健康的巴布考克（B380）蛋鸡随机分为5组,在其基础日粮中分别添加0、0．05、0．1、0．15、0．2g／kg的大蒜素,观察其对蛋鸡生产性能的影响。试验结果表明：与对照组相比,在蛋鸡日粮中加入0．1g／kg的大蒜素可极显著提高平均蛋重（P〈0．01）,极显著降低料蛋比（P〈0．01）,显著降低蛋黄比色值（P〈0．05）。在蛋鸡日粮中加入0．1g／kg的大蒜素可极显著提高蛋鸡产蛋后期产蛋性能。     

麦洼牦牛两个不同毛色选育群产奶性能的分析

[目的]为麦洼牦牛新品系选育提供必要的技术支持。[方法]针对两个选育群,选择全天然放牧条件及每日挤奶一次,采用间隔10 d测定第2~3胎次共32头奶牛盛草期的挤奶量、乳常规营养成分和物理参数,应用含草场效应在内的固定模型比较分析方法。[结果]粉嘴黑体的选育群Ⅱ样本乳脂率高于纯黑毛色的选育群Ⅰ,而挤奶量低于后者,但差异不显著（P〉0.05）;个体间及个体相邻测定日间乳脂率有较大变异;乳脂率的草场效应显著（P〈0.05）。[结论]两个选育群产奶性能无显著差异（P〉0.05）;乳脂率较高而乳蛋白率较低;乳脂率性状具有提高的潜力,同时草场可以显著影响乳脂率;这还需要进一步研究支持。     

益生素对肉仔鸡生产性能的影响

选用240只AA肉仔鸡,随机分成4组,对照组饲喂基础日粮,试验组在基础日粮中分别添加杆菌肽锌(20mg/kg)、2%和3%的益生素,比较试验鸡的生产性能。结果表明:日粮中添加2%和3%的益生素可显著提高肉鸡的日增重、饲料效率、成活率、屠宰率(<0.05);益生素可替代抗生素杆菌肽锌提高肉鸡生产性能。     

两种方法治疗黄牛不孕症的比较研究

选择30头两个情期不孕的黄牛，随机分成两组，第一组用传统中药进行治疗，第二组用激素、维生素进行治疗。结果表明，第一组受胎率为53．3％，每二组受胎率为73．3％，第二组比第一组高20％（P＜0．05）。     

纤维素酶对肉鸡生产性能的影响

试验选用1日龄的艾维因肉雏鸡240只,随机分成4个组,分别饲喂不同水平的纤维素酶.试验共分为两期,第一期为1 ～28日龄,第二期为29～49日龄.结果显示：肉鸡28日龄和49日龄时,与对照组相比,试验组的日增重均有有显著（P＜0.05）或极显著（P＜0.01）升高,料重比显著（P＜0.05）或极显著（P＜0.01）降低.结果表明,添加不同浓度的纤维素酶可在一定程度上增加肉鸡日增重,提高肉鸡饲料转化率.     

日粮中添加巴尔麦氏对肉兔生长的影响

选择120只体重、日龄相近的新西兰白兔,随机分成四组,对照组日粮中不添加巴尔麦氏,试验Ⅰ组、试验Ⅱ组、试验Ⅲ组日粮中分别添加0.08%、0.10%、0.12%巴尔麦氏.结果表明:生长肉兔的日粮中添加巴尔麦氏能显著提高肉兔的日增重和饲料转化率,试验Ⅱ组、试验Ⅲ的日增重和料重比与对照组均存在显著(P＜0.05)或极显著的差异(P＜0.01);各组之间屠宰率无显著差异(P＞0.05);各试验组与对照组相比,发病死亡率明显下降;与对照组相比较,试验Ⅰ、试验Ⅱ、试验Ⅲ的经济效益分别提高了1.77%、13.21%、16.73%.巴尔麦氏可明显提高养兔效益,可进一步研究推广应用.     

日粮中添加天蚕素抗菌肽对母猪繁殖性能的影响

为探讨日粮中添加天蚕素抗菌肽对母猪生产性能的影响,试验选取32头二胎经产母猪,采用单因子完全随机设计,分为试验组和对照组,试验组从母猪分娩前30 d到产后21 d添加400 kg/mg天蚕素抗菌肽,对照组按猪场正常药物保健程序进行（母猪产前产后在饲料中添加阿莫西林400 kg/mg和支原净300 kg/mg）。结果表明,对照组的活仔率、健仔率均极显著低于试验组（P＜0.01）;试验组初生重、21 d体重、日增重和成活率均高于对照组,但差异不显著（P＞0.05）;试验组的腹泻率显著低于对照组（P＜0.05）。     

酵母及其培养物对反刍动物生产性能的影响

本文综述了国内外大量有关酵母培养物影响反刍动物生产性能的研究，主要探讨其对采食量、产奶量、增重的影响。     

利用DHI对两个奶牛场奶牛生产性能的综合分析

应用DHI(dairy herd improvement奶牛牛群改良)测定体系,对杨凌某奶牛场和西安某奶牛场2007年的5、6、7月份生产情况进行分析,结果表明:这两个牛场的奶牛患有严重的乳房炎或隐性乳房炎;泌乳高峰期到达时间晚;存在着潜在的奶量损失;产犊间隔过长。针对以上问题,提出了相应的改进措施。