Comparison of the trotting gaits of Labrador Retrievers and Greyhounds

OBJECTIVE: To compare the trotting gaits of Labrador Retrievers and Greyhounds to determine whether differences in locomotion are attributable to differences in their manner of moving or to body size and shape differences between these 2 breeds. ANIMALS: 8 healthy 5-month-old Greyhounds and 5 healthy Labrador Retrievers between 6 and 18 months old. PROCEDURE: A series of 4 force platforms was used to record independent ground reaction forces on the forelimbs and hind limbs during trotting. Values of stride parameters were compared between breeds before and after normalization for size differences. Standard values of absolute and normalized stride period and stride length were determined from linear regressions of these parameters on relative (normalized) velocity. Forces were normalized to body weight and compared at the same relative velocity. RESULTS: Greyhounds used fewer, longer strides than the Labrador Retrievers to travel at the same absolute speed. After normalization for body size differences, most measurable differences between breeds were eliminated. Subtle differences that did persist related to proportion of the stride that the forefoot was in contact with the ground, timing of initial hind foot contact relative to initial forefoot contact, and distribution of vertical force between the forelimbs and hind limbs. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that apparent differences in the trotting gait between Labrador Retrievers and Greyhounds are mainly attributable to differences in size, and that dogs of these 2 breeds move in a dynamically similar manner at the trot.     

Incidence of and breed-related risk factors for gastric dilatation-volvulus in dogs

OBJECTIVE: To compare incidence of and breed-related risk factors for gastric dilatation-volvulus (GDV) among 11 dog breeds (Akita, Bloodhound, Collie, Great Dane, Irish Setter, Irish Wolfhound, Newfoundland, Rottweiler, Saint Bernard, Standard Poodle, and Weimaraner). DESIGN: Prospective cohort study. ANIMALS: 1,914 dogs. PROCEDURE: Owners of dogs that did not have a history of GDV were recruited at dog shows, and the dog's length and height and depth and width of the thorax and abdomen were measured. Information concerning the dogs' medical history, genetic background, personality, and diet was obtained from owners, and owners were contacted by mail and telephone at approximately 1-year intervals to determine whether dogs had developed GDV or died. Incidence of GDV based on the number of dog-years at risk was calculated for each breed, and breed-related risk factors were identified. RESULTS AND CLINICAL RELEVANCE: Incidence of GDV for the 7 large (23 to 45 kg [50 to 99 lb]) and 4 giant (> 45 kg [> 99 lb]) breeds was 23 and 26 cases/1,000 dog-years at risk, respectively. Of the 105 dogs that developed GDV, 30 (28.6%) died. Incidence of GDV increased with increasing age. Cumulative incidence of GDV was 5.7% for all breeds. The only breed-specific characteristic significantly associated with a decreased incidence of GDV was an owner-perceived personality trait of happiness.     

Parameter estimates for direct and maternal genetic effects on yearling, eighteen-month, and slaughter weights of Korean native cattle

Data collected by the National Livestock Research Institute of the Rural Development Administration of Korea were used to estimate genetic parameters for yearling (YWT, n = 5,848), 18-mo (W18, n = 4,585), and slaughter (SWT, n = 2,279) weights for Korean Native cattle. Nine animal models were used to obtain REML estimates of genetic parameters: DP-2 included genetic, uncorrelated dam, and residual random effects; DQ-2 included genetic, sire x region x year-season interaction, and residual random effects; DPQ-2 was based on DQ-2 but included both interaction and dam effects; DMP-2 was based on DP-2 but with dam effect partitioned to include maternal genetic and permanent environmental effects; and DMPQ-2 was based on DMP-2 but also included sire interaction effects. Those five models included two fixed factors: region x year-season and age of dam x sex effects. Models DP-3, DQ-3, DPQ-3, and DMPQ-3 were based on DP-2, DQ-2, DPQ-2, and DMPQ-2 but included as a third fixed factor whether or not identification of the sire was known. Estimates of heritability with DMPQ-3 for YWT, with DPQ-3 for W18 and SWT when analyzed with single-trait analyses were .14, .11, and .17, respectively, and were nearly the same with bivariate analyses. Estimate of maternal heritability for YWT from single-trait analysis was .04, with estimates for other traits near zero. For bivariate analyses, the estimate for YWT was .01. With single trait analysis, estimate of the direct-maternal genetic correlation for YWT was negative (-.81). Estimates of direct genetic correlations between YWT and W18, YWT and SWT, and W18 and SWT were .99, 1.00, and .97, respectively. Estimates of environmental correlations varied from .60 to .81; the largest was between W18 and SWT. Including a fixed factor for whether sire identification was missing or not missing reduced the estimate of heritability for slaughter weight. The results suggest that the sire x region x year-season interaction is important for yearling weight and may be needed in a model for slaughter weight. Maternal effects may be of slight importance for yearling weight but of no importance for W18 and SWT. Models for national cattle evaluations for Korean Native cattle for YWT should be considered that include maternal genetic and permanent environmental as well as sire x region x year-season interaction effects, but those effects seem not to be needed for models for W18 and SWT. Not much reranking of sires occurred when ranked was based on the different models for W18 and SWT.     

Tacrolimus-FK506 induced immunosuppression in gnotobiotic piglets

Tacrolimus (FK506), an inhibitor of calcineurin, is an immunosuppressive agent used in clinical trials of transplant patients. Although FK506 targets Ca(2+)-mediated T-cell signaling, phenotype(s) of the specific target cells and the corresponding cytokine pathways are not well known. In this study, the impact of FK506 on number and characteristic of T-cells in selected lymphoid tissues of gnotobiotic (GB) piglets was determined. FK506-treated GB piglets were compared with untreated GB and conventional piglets. The T-helper, cytotoxic, natural killer, double-positive, and activated T-cell populations were analyzed in suspensions of mononuclear cells isolated from thymus, mesenteric lymph nodes and peripheral blood. In vitro secretion of interleukin-8 and interferon-gamma in concanavalin A-stimulated lymphoid cell-cultures was measured by ELISA. Daily intramuscular treatment of GB piglets with 1mg/kg of FK506 from birth for 4 weeks resulted in lowered (P<0.05) in vitro secretion of interferon-gamma and interleukin-8. Moreover, depletions of MNC in systemic and mucosa-associated lymphoid tissues were observed in piglets treated with FK506. The depletions of mononuclear cells and low levels of interferon-gamma and interleukin-8 in piglets treated with FK506 were accompanied by lower proportion of CD3+, CD2+CD4+ and CD2+CD8+ T-cell phenotypes in peripheral blood but not in thymus and mesenteric lymph nodes. These results indicate that FK506-treatment causes immunosuppression in GB piglet, and this effect could be exploited further to study opportunistic pathogens in pig model.     

Immunoprophylactic effect of chicken egg yolk immunoglobulin (Ig Y) against porcine epidemic diarrhea virus (PEDV) in piglets

Porcine epidemic diarrhea virus (PEDV) is the causative agent of neonatal diarrhea in piglets, which causes high mortality rates. In this study, the immunoprophylactic effects of chicken egg yolk immunoglobulin (Ig Y) against PEDV were investigated in neonatal pigs. Ig Y was found to reduce the mortality in piglets after challenge exposures. The field application of Ig Y also revealed significant differences in survival rates of piglets given Ig Y, as compared with placebo or control. The results in this study indicated that Ig Y against PEDV could be an alternative way of supplementing prophylactic measures like colostral antibodies from sows.     

农八师农业专业合作社发展现状探析

本文使用访谈+问卷调查的方法对农八师进行了调查,包括农八师发展农业专业合作社所取得的成绩、存在的问题,并在此基础上提出了相关法律和政策建议,从而在理论和实践的层面上推动兵团农业专业合作社的进一步发展。     

无需光系统I（PS I）的放氧光合自养生长

与传统的光合作用Ｚ方案不同，本实验证明具有光系统Ⅱ（ＰＳⅡ）而无光系统Ｉ（ＰＳＩ）的衣藻（Ｃｈａｌｍｙｄｏｍｏｎａｓ）突变体，可以利用空气中的ＣＯ２作为碳源进行光合自养生长，同时释放氧气，ＰＳＩ缺失突变体在缺氧或有２１％Ｏ２的空气中，当光强为２００μＥ／ｍ＾２／ｓ时，它的光合自养作用都非常稳定，而且，野生型衣藻及较高等的植物中也存在的这种足以能维持细胞生长及代谢的ＰＳⅡ光合作用，这些突变体能借助空     

饲用抗生素和药物添加剂在养猪生产中的用途及用量

<正> 下面介绍一些猪饲料抗生素和药物类添加剂的用量和停药期,供参考。 1.对氨苯胂酸 50～100克/吨(以配合饲料为基础,下同):促进生长,提高饲料利用效率,可与其它药物和抗生素配伍使用,屠宰前需有5天停药期。 2.杆菌肽锌,杆菌肽甲撑水杨酸酯 10～50克/吨:促进生长,提高饲料利用效率,可与其他药物和抗生素配伍使用,屠宰前无停药期。 55～110克/吨:治疗肠炎,与某些药物和抗生素可以配伍使用,屠宰前无停药期。 3.盐酸金霉素 10～50克/吨:促进生长,提高饲料利用效率,与其他药物和抗生素配伍广泛,屠宰前无停药期。 55～110克/吨:治疗肠炎和痢疾,治疗鼻炎,     

虾青素和平衡时间对猪精子冷冻保存效果的影响

试验旨在研究虾青素和平衡不同时间对猪精子冷冻保存效果的影响。试验分为6组,空白对照组（冷冻保存I液）和试验组（冷冻保存I液中添加0.5 mmol/L虾青素,降温平衡时间分别为2、4、6、8、12 h）。结果表明：与空白对照组相比,平衡6 h的猪精子在解冻后各项运动参数均显著提高;平衡4、6、8 h组的精子活力、质膜完整性、顶体完整性、线粒体膜电位、DNA完整率显著提高,活性氧含量显著降低;平衡2、4、6 h组的超氧化物歧化酶、过氧化氢酶、谷胱甘肽过氧化物酶3种抗氧化酶活性显著提高,ATP含量显著提高;平衡6 h组的丙二醛水平降低4.74%(P<0.05)。综上,冷冻保存I液中添加0.5 mmol/L虾青素对猪精子冷冻保存具有一定的改善作用,其中以平衡6 h的效果最佳,能够显著提高猪精子冷冻保存效果。