薰衣草精油替代饲用抗生素对肉仔鸡生产性能和胴体品质的影响

[目的]研究日粮中添加薰衣草精油替代饲用抗生素对肉仔鸡生产性能及胴体品质的影响.[方法]将300只1日龄AA肉仔鸡随机分成4个处理组(每组设3个重复,每个重复25只),对照组饲喂基础日粮加抗生素,试验Ⅰ组、Ⅱ组、Ⅲ组日粮为基础日粮,分别添加薰衣草精油0.4、0.8、1.2(0～2周)和0.2、0.4和0.6 mL/kg(3 ～6周).[结果]日粮中添加薰衣草精油与添加抗生素比较,对肉仔鸡的平均日增重、料重比、死淘率和胴体品质等生产性能指标的影响不显著(P＞0.05);除了试验组Ⅲ的腿肌率与抗生素组相比有显著降低外(P＜0.05),其它胴体品质指标与抗生素组相比无显著性差异(P＞0.05).试验组的平均死淘率(0.86;)低于抗生素组的死淘率(3.1;);试验组Ⅰ比抗生素组日增重提高了1.87; (P ＞0.05),料重比降低了0.53; (P ＞0.05).[结论]从肉仔鸡41 d末重、料重比、死淘率等指标综合评定来看,用薰衣草精油替代肉仔鸡饲用抗生素是可行的,0～2周和3～6周日粮中分别添加薰衣草精油0.4和0.2 mL/kg的效果较好.     

Evaluation of compression generated by self compressing Orthofix bone pins and lag screws in simulated lateral humeral condylar fractures.

A simulated lateral humeral condylar fracture was created in each of the 52 humeri collected from 26 dogs. One humerus from each pair was stabilized with a 2.0 mm cortical bone screw which was inserted in lag fashion. The other humerus from each pair was stabilized with a 2.2 mm threaded diameter Orthofix pin inserted across the condyle. Prior to each repair, an antirotational K-wire was placed and then the Pressurex Sensitive film was inserted in the osteotomy site in order to determine the compressive pressure (MPa), compressive force (KN), and area of compression (cm(2)) achieved during fixation. The maximum insertional torque achieved before stripping was measured for each implant. The mean compression generated by insertion of a 2.0 mm lag screw was 20.36 +/- 1.51 MPa compared to 18.88 +/- 1.76 MPa generated by a 2.2 mm Orthofix pin (p < 0.003). The mean area of compression generated by insertion of a 2.0 mm lag screw was 2.39 +/- 1.29 cm(2), compared to 1.16 +/- 0.84 cm(2) generated by insertion of a 2.2 mm Orthofix pin (p < 0.0001). The mean compressive force (compression x area compressed) generated by insertion of a 2.0 mm lag screw was 4.96 +/- 2.90 Kn, compared to 2.20 +/- 1.65 Kn generated by insertion of a 2.2 mm Orthofix pin (p < 0.0001). The mean insertion torque to failure for the lag screws was 0.49 +/- 0.07 NM, compared to 0.91 NM +/- 0.18 NM generated by the Orthofix pins (P < 0.0001). Both repair methods are likely to be acceptable for the repair of similar fractures in small breed dogs.     

Kinetic and kinematic gait analysis in dogs.

Kinetic and kinematic gait analysis provides objective, quantifiable, and repeatable information on normal and abnormal gait in dogs. Data collection requires specialized equipment, and techniques must be carefully controlled to ensure that accurate measurements are obtained. Force-plate and kinematic analysis is currently used primarily as a research tool to study various gait abnormalities and objectively assess treatment efficacy. As future research identifies characteristic changes associated with specific types of lameness, the use of gait analysis to evaluate individual clinical patients with lameness should become more valuable. Specialized gait analysis techniques may eventually enable veterinarians to accurately diagnose subtle lameness, better evaluate dogs with resolving lameness, and accurately select the appropriate time to return an athletic dog to exercise after recovery from an injury.     

Association of a Pasteurella haemolytica-like organism with enteritis in swine.

A Pasteurella haemolytica-like organism was isolated from the intestines of 28 swine with clinical, gross, or microscopic evidence of enteritis. In 15 cases, other known enteric pathogens were also demonstrated, and in 13 cases, no other pathogens were detected. The mean age of affected animals was 44 days. Most of the animals had clinical evidence of diarrhea. Gross enteric lesions were present in 17 of 21 cases. Microscopic lesions were present in 24 of 26 cases. A diffuse or segmental moderate to severe necrotizing enteritis was the most common lesion in cases in which only the Pasteurella haemolytica-like organism was isolated. Biochemical tests gave results consistent with Pasteurella haemolytica, and 5 of 15 isolates met criteria for biotype A. Negative results were found with an indirect haemagglutination procedure for P. haemolytica.     

Intestinal strangulation caused by intra-abdominal lipomas in a dog.

Pedunculated, intra-abdominal lipomas caused intestinal strangulation in a Doberman Pinscher. The dog was treated surgically to remove the lipomas and the devitalized intestine but died soon after surgery. Histologic evaluation confirmed the diagnosis of lipoma.     

Trifluoromethylketones as possible transition state analog inhibitors of juvenile hormone esterase

A series of compounds containing the trifluoromethylketone group have been synthesized utilizing either a modified Grignard procedure or by reacting selected aliphatic bromides or tosylates with the Collman reagent [Na₂Fe(CO)₄]. When tested in vitro as inhibitors of crude juvenile hormone esterase from the hemolymph of the cabbage looper, Trichoplusia ni (Noctuidae), the most active compounds were trifluoromethylketones possessing either a juvenoid-like structure or a straight aliphatic chain. The logarithm of the inhibitory potency of the aliphatic compounds was proportional to their chain length, up to 1,1,1-trifluorotetradecan-2-one (I₅₀ = 1 × 10^?7M). This powerful inhibition was found to be highly selective for JHE, reversible, competitive by Lineweaver-Burk analysis, and was characterized by high affinity of the inhibitor for the esterase (K_i = 3.2 × 10^?9M, K_m JH III = 2 × 10^?7M). Other trifluoromethylketones were shown to be inhibitors of T. ni α-naphthylacetate esterase and bovine trypsin. By analogy with the mechanism of trypsin action, trifluoromethylketones are probably potent inhibitors due to their resemblance to a tetrahedral transition state on the reaction coordinate to the acylated enzyme.     

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