日粮维生素A水平对肉牛牛肉品质的影响

为了研究日粮维生素A(VA)水平与肉牛牛肉品质的关系,选用16头12月龄利木赞×鲁西黄牛阉牛,以添加0,1 100,2 200,4 400 IU/kg VA的日粮育肥6个月后屠宰,分析不同日粮VA添加水平对牛肉品质的影响。结果表明:(1)在肉牛屠宰特性方面,VA水平对肉牛屠宰率、肋部皮下脂肪厚度、肠系膜脂肪质量/活体质量、眼肌面积和肉品大理石花纹评分均无显著(P>0.05)影响,但大理石花纹随VA水平的降低而改善;VA水平显著(P<0.05)影响肉牛日增质量、背部皮下脂肪厚度和肉品剪切力,其中日增质量以2 200 IU/kg VA添加水平时最高,低于此水平则有随VA水平升高而增加的趋势,而背部皮下脂肪厚度和剪切力均以1 100 IU/kg VA水平时最低;(2)在肉品常规成分(以鲜样为基础)方面,VA水平显著(P<0.05)影响臀中肌干物质含量和背最长肌粗蛋白含量,而对臀中肌粗脂肪、粗蛋白和粗灰分含量及背最长肌干物质、粗脂肪和粗灰分含量无显著(P>0.05)影响;(3)在肉品氧化稳定性方面,VA水平对吊挂成熟的臀中肌和背最长肌的总色素含量、硫代巴比妥酸反应物值(TBARS)和滴水损失有显著(P<0.05)影响。其中,总色素含量在臀中肌和背最长肌均以1 100 IU/kg VA水平时最高,TBARS值在臀中肌以1 100 IU/kg VA水平时最低,而在背最长肌以2 200 IU/kg VA水平时最低。综合考虑,在该试验条件下,以1 100IU/kg VA水平日粮饲喂肉牛的效果最好。     

反刍动物瘤胃氮代谢研究进展

瘤胃内氮代谢过程主要包括蛋白质降解和微生物蛋白质合成。蛋白质在瘤胃内的降解由瘤胃微生物来完成,蛋白质的物理和化学特性、瘤胃及其内容物的特性均影响蛋白质降解。碳水化合物和蛋白质是限制瘤胃微生物生长的主要因素。瘤胃微生物蛋白质合成效率能准确地表示微生物对可利用能量的利用率,而瘤胃氮利用率能准确地表示微生物捕获可利用氮的效率,两者互补,可全面显示微生物对养分的利用效率。细菌细胞对氮的分配随发酵速度而变化,故以微生物氨基酸氮的质量作为瘤胃微生物蛋白质合成效率或氮利用率的衡量标准可能较微生物氮更准确。     

柑橘渣的综合利用

柑橘渣用途广泛,可以制作饲料,提取兽药、防霉剂、抗氧化剂、色素等等。我国柑橘渣资源丰富,对其综合利用可创造一定的经济和社会效益。文章阐述了我国柑橘渣资源在以上几个领域的开发利用现状,并强调了在畜牧业上的应用。     

产前驱虫对母羊产奶量和乳品质的影响

本试验旨在研究产前驱虫对母羊产奶量和乳品质的影响。采用2×2因子试验设计,选择自然感染胃肠道线虫(GIN)的小尾寒羊(STH)和乌珠穆沁羊(UJU)母羊各20只,随机分为驱虫组和非驱虫组,驱虫组母羊于产前30 d驱虫。从产羔后开始收集羊奶样品28 d,测定产奶量和乳品质。结果显示:产前驱虫能够显著提高STH和UJU母羊的产奶量(P0.001),但2个品种的提高程度不同,STH母羊的提高程度大于UJU母羊。此外,产前驱虫还能够显著提高羊乳的乳脂(P=0.008)、乳蛋白含量(P0.001)及冰点(P=0.010),显著降低羊乳的体细胞数(P0.001)、乳灰分含量(P=0.041)、pH(P0.001)和电导率(P=0.007)。综上,产前驱虫可提高母羊的产奶量和乳品质,且产前驱虫对STH母羊的影响程度大于UJU母羊。     

论动物科学专业创新型人才的培养

进入新世纪以来,知识经济初见端倪,"要迎接知识经济迅速兴起的挑战,最重要的是坚持创新"[1];但是一切创新归根结底无不源于人才创新,而创新型人才的造就又源于教育,可以说教育是培养创新型人才的摇篮,21世纪教育的使命就是培养具有创新精神和创新能力的创新型人才。动物科学专     

Effects of Compound Bacteria Preparation on Fermentation Quality and Rumen Fermentation Characteristics of Phragmites australis Silage北大核心CSCD

The purpose of this study was to investigate the effects of compound bacteria preparation (including homogeneous Lactobacillus/heterogeneous Lactobacillus, Bacillus subtilis and Aspergillus niger as well as their compatibility) on nutrient composition, fermentation quality and rumen fermentation characteristics of Phragmites australis silage. Taking growing Phragmites australis from Dongting lake as silage material, five groups were set up, which were blank group (CK group), lactic acid bacteria group (LA group, supplemented with Lactobacillus plantarum, Pediococcus pentosaceus and Lactobacillus buchneri), lactic acid bacteria+Bacillus subtilis group (LA+BS group), lactic acid bacteria+Aspergillus niger group (LA+AN group) and lactic acid bacteria+Bacillus subtilis+Aspergillus niger group (LA+BS+AN group), and each group had 3 replicates. The supplemental level of lactic acid bacteria was 1.5×108 CFU/kg silage raw materials, and the supplemental levels of Aspergillus niger and Bacillus subtilis were 1.0×108 CFU/kg silage raw materials (all were based on fresh weight of silage raw materials). After 60 days of silage, the nutrient composition and fermentation quality of Phragmites australis silage were determined, and the rumen fermentation characteristics were evaluated by in vitro fermentation and in vivo degradation. The results showed as follows: 1) the contents of dry matter and ash in LA, LA+BS and LA+AN groups were significantly lower than those in CK group (P<0.05), and the crude protein content in LA+BS, LA+AN and LA+BS+AN groups was significantly higher than that in CK and LA groups (P<0.05). 2) The silage sensory evaluation scores of all groups were 60 to 70 points, and the ratings were good. The comprehensive scores of fermentation quality in LA+BS and LA+AN groups were higher, among which, the ammonia nitrogen to total nitrogen ratio, acetic acid content and acetic acid to total acid ratio in LA+AN group were significantly decreased compared with CK group (P<0.05), while the lactic acid content and lactic acid to total acid ratio were significantly increased compared with CK group (P<0.05). 3) The dry matter disappearance rate and total gas production of in vitro fermentation in LA+AN group were significantly higher than those in the other groups (P<0.05), and in vitro fermentation parameters such as volatile fatty acid contents in fermentation liquid were improved. 4) The rumen fermentation dry matter degradation rate in LA+AN and LA+BS+AN groups at 8, 24 and 48 h was significantly higher than that in the other three groups (P<0.05). In conclusion, the combined application of lactic acid bacteria and Aspergillus niger with supplemental levels in this experiment has the best effect on the quality of Phragmites australis silage and rumen fermentation characteristics. © The Author(s) 2023.     

中药复方对山羊的影响:Ⅲ·瘤胃纤维降解酶及血清酶活性

试验旨在研究中药复方对山羊瘤胃纤维降解酶及血清酶活性的影响。选择6头健康的体重相近的安装有永久性瘤胃瘘管的周岁大足黑山羊羯羊,按3×3重复拉丁方试验设计,随机分为3组,1个对照组和2个处理组。对照组饲喂基础日粮,2个处理组分别在基础日粮上给每头羊日喂15 g复方Ⅰ和复方Ⅱ(由藿香、苍术、黄柏和生石膏等中药按不同比例组成)。结果表明:2种复方均能提高山羊瘤胃内pH及微晶纤维素酶、羧甲基纤维素酶、纤维二糖酶和木聚糖酶等纤维降解酶活性;2种复方均能降低山羊血清谷丙与谷草转氨酶、乳酸脱氢酶、肌酸激酶及碱性磷酸酶活性,仅提高血清α-淀粉酶活性。研究结果提示,中药复方可提高瘤胃纤维降解酶活性,改善机体组织器官的健康状况。     

舍饲大足黑山羊羔羊肉品理化性状及食用品质的研究

对6月龄舍饲大足黑山羊背最长肌的常规营养成分与矿物质、氨基酸、脂肪酸等含量的测定,同时对背最长肌的理化特性、重金属和农药残留等进行分析,结果表明,大足黑山羊肉品营养丰富,肉质优良,鲜嫩多汁,风味独特,食用安全,是一种集营养与保健于一体的优质保健性食品,具有较好的开发利用价值。     

不同日粮对奶牛瘤胃发酵模式及泌乳性能的影响

选用4头安装永久瘤胃瘘管和十二指肠瘘管的泌乳奶牛(体重为483 kg±21 kg,泌乳日龄为175 d±6 d),研究4种日粮,分别为30∶70CW(粗料由羊草组成)、30∶70CCA(粗料为玉米青贮+苜蓿+羊草混合型)、50∶50CCA、65∶35CCA日粮对泌乳奶牛瘤胃内pH、NH3 N浓度、VFA的动态变化及奶牛生产性能的影响。试验采用4×4拉丁方设计,每期23 d。结果表明,精粗比为65∶35CCA日粮条件下奶牛瘤胃内pH显著低于其它组(P<0 01), 65∶35CCA及50∶50CCA日粮组瘤胃内NH3 N浓度显著高于精粗比30∶70 日粮组(P<0 01),瘤胃内乙酸浓度随精料比例的提高而降低(P= 0 10),丙酸浓度、丁酸浓度及乙酸/丙酸比例差异均为极显著(P<0 01);在不同精粗比日粮条件下,乳脂率差异显著(P<0 01),以30∶70CCA组为最高;产奶量、乳蛋白率及非乳脂固形物含量均呈极显著差异(P<0 01),均以高精料组65∶35CCA组为最高。     

乳酸菌和烷基多糖苷对玉米秸秆黄贮品质及其体外发酵特性影响研究

研究玉米秸秆中添加乳酸菌和烷基多糖苷时对其黄贮品质与体外发酵特性的影响。采用3×3双因素试验设计,即乳酸菌设3个水平(0、1×10¹⁰、2×10¹⁰ CFU·kg^-1),烷基多糖苷设3个水平(0、0.10、0.20 g·kg^-1),每个处理3个重复。玉米秸秆黄贮完成后,采用体外发酵技术评定其瘤胃发酵特性。结果表明:随乳酸菌添加水平的上升,黄贮玉米秸乳酸含量、比表面积、外观总评分、酸性洗涤纤维和干物质含量显著(P<0.05)提高,氨氮/总氮显著(P<0.05)降低,体外发酵潜在最大产气量显著(P<0.05)增加、总挥发性脂肪酸浓度极显著(P<0.01)增加、产气速率显著(P<0.05)降低;随烷基多糖苷添加水平的升高,黄贮玉米秸外观总评分、酸性洗涤纤维和干物质含量、以及体外发酵后Zeta电位、电子迁移率及干物质消失率显著(P<0.05)升高;黄贮玉米秸粗蛋白质、pH值、乙酸和异丁酸含量以及体外发酵后丁酸、异丁酸、戊酸和异戊酸的摩尔百分比受乳酸菌与烷基多糖苷交互作用(P<0.05)的影响。结果表明:乳酸菌添加量为2×10¹⁰ CFU·kg^-1,烷基多糖苷添加量为0.2 g·kg^-1时,既能够保证玉米秸秆较好的黄贮品质,同时又能提高其降解特性。