断母乳日龄对犊牛营养物质消化和血清生化指标的影响

本试验旨在研究不同断母乳日龄对犊牛营养物质消化和血清生化指标影响。试验选用新生红安格斯与西门塔尔杂交肉犊牛60头,根据日龄和体重随机分成5个处理,每个处理12头犊牛,公母各占1/2,试验组分别在28、42、56和70日龄进行断母乳(分别为28A、42B、56C、70D组),随后人工哺乳代乳品至90日龄;对照组( CK组)随母哺乳至150日龄。试验时间为出生至150日龄,期间测定体重(0、70、90、150日龄)和血清生化指标(70、90、150日龄)的变化。每个处理选取6头犊牛分别在断奶前(85~90日龄)和断奶后(145~150日龄)进行2期消化代谢试验。每期6 d,其中2 d预试期,4 d正试期。结果显示：1)试验全期体重各组间无显著差异(P>0.05)。2)断奶前各组犊牛营养物质消化率差异不显著(P>0.05),断奶后28A、42B组犊牛干物质消化率显著高于56C、70D组( P<0.05),有机物消化率显著高于70D组( P<0.05),其中42B组消化率略高。3)150日龄试验结束时,28A和42B组血清葡萄糖、总蛋白、甘油三酯、尿素氮、胆固醇、结合珠蛋白、白细胞介素-2、胰岛素样生长因子-1、免疫球蛋白M含量与CK组相比差异不显著( P>0.05),血清免疫球蛋白G、免疫球蛋白A含量分别显著低于、高于CK组( P<0.05),其中42B组略高。由此可见,红安格斯与西门塔尔杂交肉犊牛的断母乳时间以42日龄较为适宜。     

Effects of Different Substrates on Fermentation Parameters

Fermenting different raw materials (corn, soybean meal and cottonseed meal) with three kinds of strains (Lactobacillus, yeast and Bacillus subtilis) were employed to optimize the fermentation parameter with sensory evaluation, pH and amount of probiotics retention.The results showed that the time to reach stable pH of materials with different substrates was different.Cottonseed meal had the longest time to reach stable pH followed by soybean meal, while corn had the shortest time under the condition of same water content.Different substrates had no effect on initial pH of corn, soybean meal and cottonseed meal.The count of the probiotics was also influenced by different substrates.When pH reached steady state, corn had the largest number of the probiotics followed by soybean meal and cottonseed meal.The color and smell of three materials after fermented had distinctive features.But cottonseed meal had the highest viscosity followed by soybean meal and corn.Because of shorter time and more microorganisms, corn was better than soybean meal and cottonseed meal to be fermenting medium.     

凝结芽孢杆菌对感染产气荚膜梭菌肉鸡生长性能、肠道病变及免疫器官指数的影响

本试验旨在研究日粮中添加凝结芽孢杆菌对感染产气荚膜梭菌肉鸡生长性能、肠道病变及免疫器官指数的影响。选用312只1日龄科宝500肉鸡公雏,随机分成4个处理,每个处理6个重复,每个重复13只鸡。采用2×2双因子完全随机设计,产气荚膜梭菌分为无感染产气荚膜梭菌组和感染产气荚膜梭菌组,日粮中凝结芽孢杆菌水平分别为0和400mg/kg。试验期35d。结果表明,感染产气荚膜梭菌后15~35日龄肉鸡平均日增重显著降低(P0.05),28日龄肠道病变严重(P0.01),35日龄法氏囊指数极显著降低(P0.01);日粮中添加凝结芽孢杆菌可显著提高15~35日龄肉鸡平均日增重(P0.05),显著降低料重比(P0.05),能缓解感染导致的肠道损伤(P0.05),28日龄肉鸡胸腺指数极显著提高(P0.01),35日龄法氏囊指数极显著提高(P0.01)。肠道病变结果分析表明,日粮中添加凝结芽孢杆菌与感染产气荚膜梭菌有显著交互作用(P0.05)。综上所述,日粮中添加凝结芽孢杆菌能够提高感染产气荚膜梭菌肉鸡生长性能及免疫器官指数,增强动物免疫能力,并能缓解由于产气荚膜梭菌感染而导致的不利影响。     

养殖模式对冬季商品肉鸭舍温湿指数的影响

选择1日龄健康樱桃谷SM3系商品代肉鸭18 490羽,随机分为网上(N组)和发酵床上(B组)2组进行饲养,监测冬季一个完全生长周期内(42d)鸭舍温度(T)、相对湿度(RH)及温湿指数(THI)变化,探讨不同养殖模式对商品肉鸭舍温湿指数的影响。结果表明:N组和B组舍内平均温度均明显高于平均气温;N组舍内温度全部高于B组,N组平均温度比B组高8.32℃,差异显著(P0.05)。N组和B组舍内相对湿度均明显高于室外;N组舍内平均相对湿度比B组高2.47%,无显著性差异(P0.05)。试验期N组有16d处于热应激状态,B组有6d处于冷应激状态。结果提示,在北方寒冷气候下网上供暖养殖模式能为商品肉鸭提供更舒适的温湿度条件。     

An overview of animal science research 1945–2011 through science mapping analysis

The conceptual structure of the field of Animal Science (AS) research is examined by means of a longitudinal science mapping analysis. The whole of the AS research field is analysed, revealing its conceptual evolution. To this end, an automatic approach to detecting and visualizing hidden themes or topics and their evolution across a consecutive span of years was applied to AS publications of the JCR category ‘Agriculture, Dairy & Animal Science’ during the period 1945–2011. This automatic approach was based on a coword analysis and combines performance analysis and science mapping. To observe the conceptual evolution of AS, six consecutive periods were defined: 1945–1969, 1970–1979, 1980–1989, 1990–1999, 2000–2005 and 2006–2011. Research in AS was identified as having focused on ten main thematic areas: ANIMAL‐FEEDING, SMALL‐RUMINANTS, ANIMAL‐REPRODUCTION, DAIRY‐PRODUCTION, MEAT‐QUALITY, SWINE‐PRODUCTION, GENETICS‐AND‐ANIMAL‐BREEDING, POULTRY, ANIMAL‐WELFARE and GROWTH‐FACTORS‐AND‐FATTY‐ACIDS. The results show how genomic studies gain in weight and integrate with other thematic areas. The whole of AS research has become oriented towards an overall framework in which animal welfare, sustainable management and human health play a major role. All this would affect the future structure and management of livestock farming.     

遮阴对成坪期草地早熟禾和紫羊茅生长特性的影响

以冷季型草坪草草地早熟禾(Poa pratensis)的优异(Merit)、新哥来德(Nu Glade)、肯塔基(K.B.G)3个品种和紫羊茅(Festuca rubra)的两个品种宝瑞(Boreal)、梦神(rubra),共5个品种草坪草为研究对象,在人工遮阴控制下,对其成坪期耐阴性进行了比较。试验设置的遮阴处理分别是遮阴度22%、45%、66%、83%,以不遮阴的全光照为对照(CK)。结果表明,成坪期,随着遮阴度的提高,株高先增加后降低,各品种株高值达到最高时的遮阴度有差异,草地早熟禾在遮阴度为83%时均显著低于其他处理(P0.05);宝瑞在遮阴度为22%时根长极显著高于对照(P0.01),其他品种随着遮阴度的提高根长变短;遮阴使各品种的比叶重降低;遮阴度45%以上时,叶宽都显著小于对照(P0.05);随着遮阴度提高草地早熟禾枝条干重下降,紫羊茅先增加后降低。     

饲粮不同水平蚕沙对绵羊生长性能、屠宰性能、器官发育和血清生化指标的影响

本试验旨在研究饲粮中添加不同水平蚕沙对绵羊生长性能、屠宰性能、器官发育和血清生化指标的影响。试验选用32只90日龄绵羊,随机分成4组,每组8只。各组饲粮中蚕沙水平分别为0(对照)、20%(T20)、30%(T30)、40%(T40)。预试期15 d,正试期60 d。试验结束后每组随机选取3只羊屠宰。结果表明:1)T20和T30组的平均日增重(ADG)高于对照组(P0.05),显著高于T40组(P0.05),日均采食量(ADFI)显著低于对照组(P0.05),料重比(F/G)低于对照组(P0.05),ADFI和F/G显著低于T40组(P0.05)。2)T20和T30组屠宰率与对照组无显著差异(P0.05),而显著大于T40组(P0.05);对照组与T20、T30组胴体重差异不显著(P0.05);T20、T30、T40组的眼肌面积和胴体脂肪含量值均显著大于对照组(P0.05)。3)T20组的心脏重量显著大于对照组(P0.05),T30和T40组的脾脏重量显著大于对照组(P0.05)。4)对照组血清球蛋白(GLO)含量显著小于T40组(P0.05)。试验组血清碱性磷酸酶(ALP)活性显著低于对照组(P0.05)。综合以上,饲粮中添加蚕沙能够增大绵羊ADG,提高屠宰率,降低料重比,蚕沙在饲粮中的适宜比例为20%~30%,最佳比例为20%。     

基于 DEA 和 Malmquist 指数的广东省渔业效率研究

【目的】分析掌握广东渔业的产出效率,为发展可持续的低耗高产渔业提供数据参考。【方法】基于数据包络分析（DEA）及 Malmquist 指数,对 2011—2022 年期间广东渔业综合技术效率和全要素生产率指数及其分解进行测算和分析,并与全国平均值进行对比。【结果】广东渔业综合技术效率每年均高于全国平均水平,但2011—2014 年、2018—2019 年和 2021 年广东渔业规模报酬呈现递减。通过对广东水产养殖和水产品捕捞的综合技术效率分别进行测算,发现 2011—2022 年期间广东水产养殖的综合技术效率较高,除 2013 年和 2014 年外,均为DEA 有效。将 DEA 无效年份的广东水产养殖和水产品捕捞在生产前沿面上的投影调整为 DEA 有效,结果显示,2013 年和 2014 年广东水产养殖投入的冗余率分别为 5.98% 和 10.46%,而 2011—2014 年、2018—2019 年和 2021年广东水产品捕捞投入的冗余率在 39.73%~74.27% 之间,说明水产品捕捞的过度投入以及由此引发的捕捞综合技术效率低下是造成 2011—2014 年、2018—2019 年和 2021 年广东渔业规模报酬递减的主要原因。广东渔业的技术进步和全要素生产率上升幅度与全国平均水平相差较远,全要素生产率和技术进步指数均比全国平均增幅低 4.7%,说明广东省在渔业技术进步方面有较大提升空间。【结论】建议广东加大渔业科技的投入力度,加强渔业技术创新,以促进渔业技术进步和提高全要素生产率;加快渔业产业结构调整,合理布局养殖和捕捞规模,以解决广东渔业规模报酬递减的问题;加强渔业资源保护和增殖放流,利用自然生产力增加可捕捞渔业资源;加强水产良种创制及养殖新模式和新技术的开发,进一步拓展水产养殖空间和提高水产养殖的产出效率。     

小麦饲料中添加木聚糖酶对高原型藏羊胃肠道发育的影响

旨在分析小麦粉中添加木聚糖酶(xylanase, Xyl)对藏羊羔羊胃肠道发育的影响。选择同质性良好的2～3月龄高原型藏羊公羔60只,随机分为两组,每组30只,各组内设置5个重复。对照组(Control group)饲喂不含木聚糖酶的日粮,试验组(Test group)饲喂含0.2%木聚糖酶的日粮,试验分为预饲期10 d和正试期90 d。饲养试验结束时,两组各随机选取5只羔羊进行屠宰,采集消化道组织置于多聚甲醛固定,并收集血液、瘤胃和空肠内容物。结果显示：1)与对照组相比,试验组瘤胃的角质层厚度、颗粒层厚度,瓣胃的乳头长度、乳头宽度、角质层厚度、颗粒层厚度,皱胃的黏膜厚度以及十二指肠的肌层厚度,空肠的绒毛高度、黏膜厚度,回肠的肌层厚度显著提高(P<0.05);2)对照组瘤胃和血清的LPS含量显著高于试验组(P<0.05);3)相较于对照组,试验组瘤胃的糜蛋白酶、胰蛋白酶、脂肪酶活性以及空肠的糜蛋白酶、α-淀粉酶活性显著提高(P<0.05);4)试验组瘤胃的总抗氧化能力水平、谷胱甘肽过氧化物酶及过氧化氢酶活性以及空肠的总抗氧化能力水平、谷胱甘肽过氧化物酶、超氧化物歧化酶...     

The effect of remifentanil infusion on sevoflurane minimum alveolar concentration–no movement (MACNM) and bispectral index in dogs

ObjectiveTo determine the effect of remifentanil infusion on the minimum alveolar concentration of sevoflurane preventing movement (SEVOMAC_NM) and bispectral index (BIS) in dogs.Study designProspective, unmasked study.AnimalsA total of 10 adult Beagle dogs weighing 9.0 ± 1.1 kg.MethodsDogs were anesthetized with sevoflurane and baseline SEVOMAC_NM was determined. Remifentanil was infused at 5, 10 and 20 μg kg^–1 hour^–1, in sequence, with 20 minutes washout between infusions. Variables monitored throughout anesthesia included heart rate (HR), oscillometric blood pressure, end-tidal partial pressure of carbon dioxide, end-tidal sevoflurane concentration (Fe′Sevo) and BIS. SEVOMAC_NM after remifentanil infusion (SEVOMAC_NM-REMI) determination started 20 minutes after the start of each infusion. Venous blood samples were collected for plasma remifentanil concentration determination at baseline, SEVOMAC_NM-REMI determination time points, and 20 minutes after each infusion was stopped. A mixed model analysis was used to determine the effect of remifentanil infusion on response variables. The relationships between BIS and Fe′Sevo, plasma remifentanil concentrations and the percentage decrease in baseline SEVOMAC_NM were evaluated (p < 0.05).ResultsThe overall SEVOMAC_NM at baseline was 2.47 ± 0.11%. Addition of remifentanil at all infusion rates significantly decreased SEVOMAC_NM, but the medium and high doses resulted in significantly greater decreases in SEVOMAC_NM than the lower dose. There was no difference in SEVOMAC_NM percentage change between infusions 10 and 20 μg kg^–1 hour^–1. Plasma remifentanil concentrations were significantly different in all infusion rates. Baseline BIS value was 70 ± 1 and was lower than the BIS values recorded during all remifentanil infusions. BIS values were not significantly different among infusion rates. HR was lower and mean arterial pressure was higher during remifentanil infusions than at baseline.Conclusions and clinical relevanceAll remifentanil infusions decreased SEVOMAC_NM in dogs. Remifentanil infusion at any rate studied did not reduce BIS values.