氧气对低地鸡蛋胚胎死亡和孵化率的影响

通过模拟常压低氧和高海拔增氧孵化试验，研究了氧气浓度对低地良种鸡蛋胚胎死亡率和孵化率的影响。死亡胚胎的分布用2阶段增长模型分析。模拟2900m海拔常压低氧孵化增加了胚胎后期死亡率，使孵化率降低到接近2900m海拔实际孵化率水平；2900m海拔全期增氧孵化可以有效降低前期和后期胚胎死亡率，大大提高孵化率；阶段增氧孵化也能不同程度提高孵化率，改变胚胎死亡分布，其中效果最好的为前期增氧组。结果说明低氧是影响2900m海拔鸡蛋孵化的最主要因素。     

灌注果寡糖对生长绵羊瘤胃发酵功能的影响

采用营养灌注技术研究了果寡糖对生长绵羊瘤胃发酵功能的影响。试验选取6只安装有永久性瘤胃瘘管的内蒙古半细毛羯羊，随机分为两组，试验组一灌注1．00％果寡糖，试验组二灌注2．00％果寡糖。结果表明：灌注果寡糖可以显著（P〈0．05）降低试羊的瘤胃液相pH和瘤胃内的NH3-N浓度，显著提高（P〈0．05）瘤胃内的VFA含量和MCP含量。两个灌注水平都可以提高生长绵羊的瘤胃发酵功能。但2．00％的灌注水平仅在瘤胃NH3-N浓度的降幅方面比1．00％的灌注水平显著增大（P〈0．05），在对瘤胃液相pH值、VFA含量和MCP含量的影响方面两个灌注水平没有显著差异（P〉0．05）。     

以豁眼鹅为母本的杂交试验研究初探——品种选择与杂交配套系建设

测定豁眼鹅、莱茵鹅、朗德鹅的品种优势、杂交组合的产蛋及仔鹅生长速度等生产性能,筛选出最佳组合,建立配套系。结果:莱豁鹅杂交组合的产蛋量低于豁眼鹅对照组,但比父系莱茵鹅有了明显提高;仔鹅的生长速度明显快于母系。朗豁鹅杂交组仔鹅生长速度较豁眼鹅对照组略有提高,但母鹅产蛋量则明显不如莱豁杂交组。     

Research Progress of Epigenetics Modification in the Process of Skeletal Muscle Cell Proliferation and Differentiation

Skeletal muscle is the most abundant tissue and the main component of muscle in animals.The process of skeletal muscle cell's proliferation and differentiation is the basis of muscle development and it's directly affects the meat production performance of domestic animals.It has been found that epigenetic modification plays an important role in regulating the proliferation and differentiation of skeletal muscle cells.In this study,the effects of epigenetics on skeletal muscle in terms of the effects of DNA methylation on the proliferation and differentiation of skeletal muscle cells,the selection and expression of factors regulated by histone acetylation,the regulation of non-coding RNA,and the effects of chromosome remodeling.Research progress in the process of muscle cell proliferation and differentiation,briefly describes the effects of different modification methods and factors on the two processes of skeletal muscle proliferation and differentiation.At the same time,the methods and means used by predecessor in the study of skeletal muscle proliferation and differentiation were reviewed,and then the role of apparent regulatory factors in skeletal muscle growth was analyzed.The purpose was to further explain the important role of epigenetic modification in the proliferation and differentiation of skeletal muscle,enhanced the understanding of the regulation of skeletal muscle proliferation and differentiation,provided a reference path for integration with animal production,and also provided skeletal muscle.Molecular regulation of such as growth and development provided more reference materials.     

猪肉风味的影响因素

风味是评价猪肉品质的重要指标之一,它受很多因素影响。本文论述了饲养管理方式、日粮来源与营养素、贮藏条件、季节等因素对猪肉风味的影响,讨论了建立客观的风味评定体系的迫切性。     

环境因素对丹顶鹤越冬行为的影响

丹顶鹤在盐城越冬期间各种环境因素对其行为都将产生一定的影响,对此我们进行了观察记录。该项工作主要用8×40、10×50双筒和20倍单筒望远镜实地观察、照相机摄影等直接记录丹顶鹤的各种行为；种群数量计算为直接计数法；气候因子则根据各级气象部门的预报结果,结合观察点温度计等手段测算。结果表明丹顶鹤越冬期间,气候因子的变化是对其行为产生直接影响的主要因素,温度、雨、雾、雪、风等发生大幅度变化时,都将导致越冬期丹顶鹤的行为发生相应的适应性变化,对迁徙行为的影响则更为明显。而食物和水源则通过气候因子的变化和安全度的影响再次反应到丹顶鹤的越冬行为中来。本文最后提出了减轻灾害性天气对丹顶鹤越冬行为的影响建议。     

Effect of diet with high fats and cholesterol on PPARα gene expression and body cholesterol level in mice

AIM:To investigate the effects of dietary fats and cholesterol on liver PPARα gene expression and body cholesterol (Chol) level in C57BL/6J mice. METHODS:The animals (n=75) were randomly divided into five groups and respectively received formula mash for 6 weeks. RESULTS:As compared to Chol diet, Chol+PUFA diet produced significantly higher liver cholesterol (P<0.01), serum total cholesterol (TC), focusing on HDL-C. While Chol+MUFA diet resulted in unchanged serum TC and lower liver cholesterol (P<0.01). Chol+SFA diet rsulted in higher liver cholesterol (P<0.01) and serum TC, focusing on LDL-C. Furthermore, Chol+PUFA diet increased the mRNA and protein content of PPARα (P<0.01) in liver, while Chol+MUFA and Chol+SFA diets decreased the mRNA content of PPARα significantly (P<0.01). CONCLUSIONS:These results indicated that addition of fats containing PUFA to diet high in cholesterol increased PPARα mRNA and protein expression, addition of fats containing MUFA or SFA to diet high in cholesterol decreased PPARα mRNA expression. The change of PPARα gene expression may further affect body cholesterol level.     

Effect of endogenous H2S on pulmonary hypertension during acute lung injury induced by LPS and its interaction with NO

AIM: To investigate the effect of H2S on pulmonary artery hypertension during acute lung injury induced by LPS and the interaction between the systems of hydrogen sulfide (H2S)/cystathionine-β-lyase (CSE) and nitric oxide (NO)/nitric oxide synthase (NOS) in this process. METHODS: Seventy-two adult male rats were randomly divided into four groups: control group, LPS group, LPS+L-NAME group and LPS+propargylglycine (PPG) group. Mean pulmonary artery pressure (mPAP) of each rat was examined at 2 h, 4 h, 6 h and 8 h after treatment. H2S and NO contents in plasma, NO content, iNOS, cNOS and CSE activity in lung were measured at 4 h or 8 h after treatment, respectively. Expression of iNOS in lung tissue was also detected by immunohistochemistry technique, and the injury of lung was evaluated with morphological changes under microscope. RESULTS: LPS could induce severe lung injury, and mPAP, NO content, iNOS activity and its protein expression in LPS group significantly increased, but cNOS activity, H2S content and CSE activity decreased compared with those of control group. Administration of L-NAME before LPS could attenuate the changes induced by LPS. Pre-administration of PPG, a CSE inhibitor, exacerbated the injury by LPS, but there was no prominent variation in cNOS activity. CONCLUSION: Reduced endogenous H2S could increase pulmonary artery hypertension during acute lung injury induced by LPS. There is a negative effect between H2S/CSE system and NO/NOS system in this process.     

Exogenous carbon monoxide protects against the lung injury induced by ischemia-reperfusion of hind limbs in rats

AIM: To study the mechanism of protective effect of exogenous carbon monoxide (CO) in the lung injury induced by ischemia-reperfusion (IR) of hind limbs in rats. METHODS: Thirty-two SD rats were randomly divided into 4 groups: control, control+CO, IR and IR+CO. A rat model of ischemia in hind limbs and the reperfusion lung injury was made. The rats in IR+CO and control+CO groups were exposed to air containing 2.5×10-8 CO for 1 h before reperfusion or the corresponding control time point, while the other two groups were exposed to the routine air. The lung tissue structure, polymorphonuclear leukocyte (PMN) count, wet-to-dry weight ratio (W/D), malondialdehyde (MDA) content and the animal survival rate were observed. The carboxyhemoglobin (COHb) levels in artery blood were detected with CO-oximeter and the expression of intercellular adhesion molecule-1 (ICAM-1) in the lung was detected by Western blotting. RESULTS: Compared to control, the animal mortality, lung PMNs number, W/D, MDA content and ICAM-1 expression were all significantly increased in IR group. Compared with the IR group, the blood COHb level was significantly increased and the animal mortality, lung PMNs number, W/D, MDA content and ICAM-1 expression were all significantly decreased in IR+CO group. CONCLUSION: These data suggest that exogenous CO attenuate limb IR-induced lung injury by down-regulatiny ICAM-1 expression and suppressing PMN sequestration in the lung following limb IR in rats.