Chemical Ceratoides,Years Composition and Ruminal Digestibility of a Salt-tolerant Perennial Plant,at Different

It has been proposed that salt-tolerant plant could be used as a feed resource for ruminants whereby salt would be removed from salinized land (Asian-Aust. J. Anim. Sci. (2002) 15:998-1001). Ceratoides...     

皮瓤分离玉米秸不同部分的化学成分、能量价值和瘤胃降解特性

本试验采用化学分析、模型预测和尼龙袋技术分析了皮瓤分离玉米秸不同部分的化学成分、能量价值和瘤胃降解特性。采用单因子完全随机化试验设计,模拟玉米秸茎皮作为建筑业新材料的秸秆分离工艺,将玉米秸人工分离为茎叶、苞叶、芯轴、茎皮和茎髓5个部分,以整株玉米秸作为对照。结果表明:1)皮瓤分离玉米秸各部分中,茎叶占全株比例最高(31.02%),茎皮(29.39%)次之,随后为芯轴(18.93%)、苞叶(10.87%)和茎髓(9.69%)。2)玉米秸各部分间化学成分含量存在显著差异(P<0.05)。其中,可溶性糖和淀粉含量以茎髓(10.7%和0.67%)为最高;全株玉米秸的粗脂肪、粗蛋白质和粗灰分含量分别0.85%、5.2%和4.8%,这3种成分在茎皮中的含量很低,仅为0.62%、2.9%和2.8%;茎皮酸性洗涤不溶蛋白质占粗蛋白质的比例远高于苞叶、茎叶、茎髓和芯轴,说明茎皮中蛋白质被瘤胃微生物利用的程度很低;玉米秸分离后各部分的纤维组分含量分布很不均匀,其中茎皮和芯轴的酸性洗涤纤维和酸洗木质素含量高于苞叶、茎髓、茎叶,表明茎皮和芯轴的营养价值低于茎髓、茎叶和苞叶。3)虽然玉米秸各部分中茎皮和芯轴的总能高于茎髓、苞叶和茎叶,但茎皮中消化能、代谢能、维持净能、泌乳净能和育肥净能几项可利用能量最低,苞叶最高,茎叶、茎髓和芯轴居中。4)玉米秸各部分干物质、有机物的瘤胃降解参数均有显著差异(P<0.05),其中茎皮和芯轴的干物质、有机物潜在降解部分及有效降解率显著低于茎叶、苞叶和茎髓(P<0.05),茎皮的NDF有效降解率显著低于茎叶、苞叶、茎髓和芯轴(P<0.05),表明苞叶、茎髓和茎叶的营养价值较高,而茎皮和芯轴的营养价值较低。结论:皮瓤分离玉米秸各部分的营养价值存在显著差异,其中茎皮营养价值最低,其余部分营养价值从高到低的顺序为苞叶>茎髓>茎叶>芯轴。     

可降解蛋白及非蛋白氮对模拟瘤胃体外发酵、营养物质降解率的影响

以11.85%和8.38%两个水平的可降解蛋白(RDP)及非蛋白氮(NRN)作为试验因子,进行2×2试验设计。应用体外短期发酵技术,研究了RDP及RDP与非蛋白氮组合对模拟瘤胃发酵及营养物质降解率的影响。结果表明:添加NPN处理组的pH、NH3-N浓度显著(P<0.05)高于未添加NPN处理组。高RDP水平pH值、NH3-N浓度、细菌N与低RDP水平的相比,高RDP处理组显著(P<0.05)高于低RDP处理组,说明日粮中RDP水平显著提高瘤胃内pH值、NH3-N浓度和细菌N的产量。同时发现,RDP与NPN互作对瘤胃发酵影响不显著。对瘤胃发酵营养物质降解率的研究发现,反刍动物日粮中添加适量的NPN,有利于优化瘤胃内环境,提高物质成分在瘤胃中的降解率。RDP水平对模拟瘤胃发酵时干物质(DM)、酸性洗涤纤维(ADF)降解没有显著影响,但显著提高了中性洗涤纤维(NDF)的降解率。     

Chemical Composition and Ruminal Degradability of Spineless Cactus Grown in Northeastern Brazil

A study was conducted to determine chemical composition and ruminal nutrient degradability of eight spineless cactus cultivars grown in northeastern Brazil. Results showed that neutral detergent fiber was similar for all cultivars and averaged 249 g · kg^-1 ± 7.3 SEM. Acid detergent fiber ranged between 148 g · kg^-1 and 207 g · kg^-1 with some significant differences between cultivars. Starch and water-soluble carbohydrates were similar for all cultivars and averaged 198 g · kg^-1 ± 6.3 SEM and 155 g · kg^-1 ± 9.0 SEM, respectively. Protein content was less than 50 g · kg^-1 with some significant differences between cultivars. Calcium was the mineral with the highest concentration followed by potassium and magnesium with no differences between cultivars. Effective ruminal degradability of dry matter and neutral detergent fiber were unaffected by cultivar and averaged 701 g · kg^-1 ± 8.4 SEM and 503 g · kg^-1 ± 5.8 SEM, respectively. It was concluded that cultivars had little impact on chemical composition and ruminal degradability of spineless cactus. Based on chemical composition and in situ ruminal degradability, spineless cactus can be considered an excellent source of fermentable carbohydrates for grazing and nongrazing ruminants. Because of its high carbohydrate quality, spineless cactus can be used an emergency feed or as part of a complete diet providing that the diet contains an adequate amount of degradable protein.     

过硫酸盐处理对小麦秸主要化学成分及瘤胃降解率的影响

分别用不同比例的过硫酸铵、过硫酸钾处理麦秸,水分调至45%,密封保存20d,然后分析测定相关营养指标。结果表明:0.5%、1%、2%的过硫酸铵可分别提高麦秸DM中CP含量12.88%、25.15%、40.80%(P<0.01);分别降低NDF含量2.14%、8.01%、11.75%(P<0.05);可极显著(P<0.01)提高麦秸DM、OM、NDF有效降解率。以2%过硫酸铵处理麦秸效果最好,可分别提高麦秸DM、OM、NDF有效降解率31.80%、32.54%、33.66%。0.5%、1%、2%的过硫酸钾可分别降低(P<0.05)NDF含量3.20%、6.90%、10.79%;可极显著(P<0.01)提高小麦秸DM、OM、NDF有效降解率。以2%过硫酸钾处理麦秸效果最好,可分别提高麦秸DM、OM、NDF有效降解率29.59%、30.76%、30.57%;2%过硫酸盐优于4%尿素处理小麦秸的效果。     

不同蛋白和中性洗涤纤维水平对瘤胃发酵、消化和微生物蛋白合成的影响

以3头装有瘤胃瘘管的干奶牛作为瘤胃液供体,用体外培养法研究不同日粮蛋白和中性洗涤纤维(NDF)水平对瘤胃发酵、消化和微生物蛋白合成的影响。采用2×3双因子完全随机设计,粗蛋白水平14%、16%和18%,NDF水平为32%和36%。体外发酵后2、4、6、12、24 h取瘤胃液测定pH、NH3-N浓度和微生物蛋白含量,发酵结束后测定饲料中干物质(DM)、NDF和酸性洗涤纤维(ADF)消化率。结果表明:随着蛋白水平升高,瘤胃发酵pH有增加趋势(P=0.079),显著提高NDF和ADF消化率和细菌蛋白合成量(P<0.05),但不影响DM消化率和原虫蛋白的合成量(P>0.05);日粮中NDF水平显著影响瘤胃pH、NH3-N浓度和ADF消化率(P<0.05),但不影响DM和NDF消化率以及微生物蛋白的合成量(P>0.05)。本试验条件下,日粮中16%CP和32%NDF组可在一定程度上促进瘤胃发酵,提高纤维消化率以及微生物蛋白的合成量。     

Kenaf Dry Matter Production,Chemical Composition,and In Situ Disappearance When Harvested at Different Intervals

Kenaf (Hibiscus cannabinus L.) is a tropical plant that has potential as a forage crop. However, data on the amount and quality of forage produced by kenaf is scarce. The objectives of this research were to determine 1) the DM yield, proportions of leaf and stalk, and chemical composition and 2) the in situ OM and N disappearance of kenaf harvested throughout the growing season. Kenaf (‘Everglades 41’) was planted in June of 1990, 1991, and 1993. The seeding rate was 5.6 kg/ha and 100 kg of N /ha was applied shortly before or after planting. Harvesting began 40 d after planting (DAP) with additional harvests at 10-d (1991 and 1993) or 20-d (1990) intervals. Daily whole plant DM accumulation ranged from 12.6 to 17.2 g/m². At 101 DAP, 726 to 974 g of DM were harvested/m². As kenaf matured, the proportion of the total plant DM represented in leaves decreased (P<0.01) from 68% at 40 DAP to 44% at 101 DAP. Leaf DM contained more (P<0.01) than twice the CP as stalk DM at all harvests. Delaying harvest decreased (P<0.01) whole plant CP concentration from 22% at 40 DP to 15% at 101 DAP, because the stalks made up a larger proportion of the total biomass. The OM in the leaves was twice as digestible (P<0.01) as the OM in the stalks (89.3 vs 44.8%). The N in the leaves was more (P<0.01) digestible than the N in the stalks (93.2 vs 61.5%). Kenaf can be grown during the summer season and harvested as high quality forage as early as 40 DAP. Whole plants harvested at 80 DAP produced from 426 to 729 g/m² of DM and had a CP content of 14 to 19%. Harvesting later than 80 DAP will increase DM yield, but CP content and in situ OM and N disappearance will decrease.     

不同水平的蛋氨酸铜对奶牛瘤胃内环境及日粮表观消化率的影响

[目的]为探讨日粮中添加不同水平的蛋氨酸铜对奶牛瘤胃内环境及日粮表观消化率的影响。[方法]在日粮中分别添加0 mg/kg、18 mg/kg、27 mg/kg DM的蛋氨酸铜,采用3×3拉丁方试验设计,试验动物为3头装有永久性瘤胃瘘管的中国荷斯坦奶牛,平均体重500 kg,均处于干奶期,试验基础日粮由混合精料、羊草和玉米全株青贮组成,精粗比为30∶70。[结果]表明,日粮添加蛋氨酸铜有提高瘤胃pH值、NH3-N的趋势;但对各时间点的瘤胃液pH值、NH3-N没有显著影响（P〉0.05）;添加27 mg/kg DM的蛋氨酸铜显著提高了日粮各个营养物质的表观消化率。[结论]添加蛋氨酸铜不影响奶牛瘤胃的内环境,添加27 mg/kgDM的蛋氨酸铜可以提高日粮的表观消化率。     

不同种植年限桑树根际土壤真菌群落多样性研究

为探究林木根际土壤真菌群落的演变规律,按照空间换时间法,基于Illumina高通量测序分析研究大时间跨度下不同栽植年限(10 a、80 a和200 a)桑树根际土壤真菌群落的组成变化情况。结果表明,10 a、80 a和200 a树龄桑树根际土壤真菌共有的门为9个,各树龄桑树根际土壤中优势菌门相同,但相对丰度存在差异,第1优势菌门为子囊菌门(Ascomycota),其次是担子菌门(Basidiomycota)和被孢霉门(Mortierellomycota);前5优势菌属均为杯盘菌属(Ciboria)、被孢霉属(Mortierella)、土球酵母属(Solicoccozyma)、镰刀菌属(Fusarium)、假裸囊菌属(Pseudogymnoascus),随着树龄的升高,土球酵母属的相对丰度增加,镰刀菌属和杯盘菌属的相对丰度先升高后降低,被孢霉属的相对丰度降低。对优势菌属影响最大的是土壤氯离子含量,其次是速效磷含量、有机质含量、速效钾含量、碱解氮含量、全盐量和钠离子含量。栽植年限的增长提高了桑树根际土壤真菌的相对丰度和均匀度,改变了桑树根际土壤真菌的群落组成,减少了子囊菌门真菌的积累。     

饲粮氮水平对牦牛瘤胃发酵及营养物质消化代谢特征的影响

本试验旨在探讨饲粮不同氮水平对牦牛瘤胃发酵及营养物质消化代谢特征的影响.试验选择4头体重相近[(148.5±9.2)kg]的3岁去势天祝白牦牛,采用4×4拉丁方设计,试验共分4期,每期21 d,4个饲粮氮水平[干物质(DM)基础]分别为低氮[粗蛋白质(CP)8.98%]、中低氮(CP 12.36%)、中高氮(CP 15...     

体外法研究FNDF、NFC浓度相同的不同粗饲料来源日粮对瘤胃发酵、纤维消化和微生物蛋白合成的影响

假设在以玉米青贮为基础的日粮中,粗饲料来源中性洗涤纤维(FNDF)和非纤维性碳水化合物(NFC)浓度相同的日粮对瘤胃发酵、纤维消化和微生物蛋白合成无显著影响.为证明该假设,本试验通过体外培养法探究不同粗饲料来源(分别为苜蓿、燕麦草、羊草和稻草)对瘤胃发酵、纤维消化和微生物蛋白合成的影响.试验采用单因素设计,4组日粮中FNDF和NFC含量相同,各组日粮中FNDF含量为24.9g/100g DM,其中由玉米青贮提供20.25g/100g DM,其余4.75g/100g DM分别由苜蓿、燕麦草、羊草和稻草提供.结果表明:①在以玉米青贮为基础的日粮中,不同粗饲料来源日粮对瘤胃发酵和微生物蛋白合成无显著影响(P＞0).05);②在以玉米青贮为基础的日粮中,不同粗饲料来源日粮对日粮中纤维消化无显著影响(P＞0.05).综上可知,对于泌乳后期奶牛而言,当日粮中FNDF和NFC含量相同时,可实现用低质牧草替代优质牧草.     

不同断奶日龄羔羊瘤胃组织显微及超微结构比较

试验通过比较不同断奶日龄的湖羊羔羊瘤胃组织结构的差异,特别是瘤胃乳头超微结构变化,旨在为羔羊适宜断奶日龄的确定提供瘤胃生长发育的依据。选择新生湖羊羔羊24只（初生重：2.80 kg±0.08 kg）,随机分为3组,每组8只,分别为30日龄早期断奶组（EEW-30）、45日龄早期断奶组（EW-45）和60日龄常规断奶组（NW-60）。在各断奶日龄及75日龄时每组分别屠宰4只羔羊,测定体重及瘤胃空重,计算瘤胃相对重量;采集瘤胃组织进行显微及超微形态学测定。结果显示：①EEW-30组羔羊断奶体重极显著低于NW-60组（P<0.01）,而EW-45组与NW-60组断奶体重无显著差异（P>0.05）;75日龄时3组羔羊的体重无显著差异（P>0.05）。各组羔羊瘤胃相对重量与其体重变化规律相同。②光镜下可见：断奶时,EEW-30组瘤胃壁厚度极显著低于NW-60组（P<0.01）,EW-45组与NW-60组无显著差异（P>0.05）;75日龄时,EW-45组羔羊瘤胃壁厚度显著高于NW-60组（P<0.05）。断奶时EEW-30组瘤胃乳头较短小,极显著短于NW-60组（P<0.01）,EW-45组也显著短于NW-60组（P<0.05）。断奶时瘤胃乳头宽度和面积在3组间差异均不显著,在75日龄时也无显著组间差异（P>0.05）。③扫描电镜观测结果显示：EEW-30组断奶时单位面积瘤胃微乳头（ruminal micro-papillae）数量极显著低于NW-60组（P<0.01）,而EW-45与NW-60组间无显著差异（P>0.05）;75日龄时,3组羔羊单位面积瘤胃微乳头数量无显著差异（P>0.05）。上述试验结果显示,断奶时羔羊瘤胃形态结构在EEW-30与NW-60组间差异明显,而EW-45与NW-60组较为接近,瘤胃微乳头状结构也呈相同变化趋势。提示45日龄时断奶较为适宜。     

多年生黑麦草愈伤组织诱导和植株再生

对多年生黑麦草Lolium perenne品种"德比"成熟种子的愈伤组织诱导和植株再生进行了探索研究.结果表明:在附加10 mg/L 2,4-D,500 mg/L CH(水解酪蛋白),0.5 mg/L 6-BA和0.5 mg/L NAA的N6培养基中愈伤诱导率最高,达85%.分化培养基以附加1 mg/L、6-BA、0.5 mg/L KT的N6培养基为最优,分化率为77. 73%.在大量元素减半的N6培养基中附加30 g/L蔗糖及0.2 mg/L NAA进行生根培养,生根率达100%.     

添加剂对华北驼绒藜青贮发酵品质和体外消化率的影响

以华北驼绒藜(Ceratoides arborescens(Losinsk.)Tsien et C.G.Ma)为研究材料,探讨添加剂处理对其青贮品质和体外消化率的影响。试验设置了对照、乳酸菌和纤维素酶共10个处理组,调制青贮饲料,45 d后开封并取样分析。结果表明:0.01%Lalsil Dry可以明显提高ADF体外消化率(P<0.05)。纤维素酶处理的乳酸含量明显高于对照(P<0.05),其中0.03%的添加量还明显降低了pH值、氨态氮和NDF含量(P<0.05)。混合添加处理的乳酸含量均明显高于对照,NPN明显低于对照(P<0.05),且LM3+CF3显著降低了华北驼绒藜青贮饲料的pH值和NDF的含量(P<0.05),明显提高了ADF的体外消化率。     

6种饲料原料瘤胃降解特性和瘤胃非降解蛋白质的小肠消化率

本试验旨在研究新疆地区玉米青贮、棉籽壳、苜蓿草粉、苜蓿干草、葡萄籽粕、蕃茄酱渣6种奶牛饲料原料的瘤胃降解特性和瘤胃非降解蛋白质(RUP)的小肠消化率(Idg)。选用3头装有永久性瘤胃瘘管的泌乳荷斯坦奶牛,采用尼龙袋法和改进三步体外法测定饲料原料的干物质(DM)、粗蛋白质(CP)、中性洗涤纤维(NDF)和酸性洗涤纤维(ADF)的瘤胃降解特性以及RUP的Idg和小肠可消化粗蛋白质(IDCP)含量。结果表明:1)苜蓿草粉和玉米青贮的DM有效降解率最高,显著高于次之的苜蓿干草、番茄酱渣(P0.05),葡萄籽粕、棉籽壳最低,显著低于其他原料(P0.05);CP有效降解率为番茄酱渣苜蓿草粉玉米青贮苜蓿干草棉籽壳葡萄籽粕,各原料间差异显著(P0.05);NDF有效降解率为玉米青贮苜蓿草粉棉籽壳苜蓿干草番茄酱渣葡萄籽粕,各组饲料原料间差异显著(P0.05);ADF有效降解率为玉米青贮棉籽壳苜蓿干草番茄酱渣苜蓿草粉葡萄籽粕,各组饲料原料间差异显著(P0.05)。2)苜蓿草粉RUP的Idg和IDCP含量最高,Idg显著高于依次降低的苜蓿干草、玉米青贮、番茄酱渣、葡萄籽粕、棉籽壳(P0.05),IDCP含量与苜蓿干草差异不显著(P0.05),显著高于依次降低的玉米青贮、番茄酱渣、葡萄籽粕、棉籽壳(P0.05)。综上所述,不同饲料原料具有不同的瘤胃降解特性,进入小肠IDCP的含量也不同。玉米青贮的DM、NDF和ADF在瘤胃的有效降解率较高,苜蓿草粉RUP的Idg较高,苜蓿草粉和苜蓿干草的IDCP含量较高。     

日粮中添加不同植物油对奶牛瘤胃液挥发性脂肪酸及乳脂肪酸组成的影响

以3头年龄相同、平均体重650kg左右、泌乳期相同的装有永久性瘤胃瘘管的荷斯坦奶牛为试验动物,采用3×3拉丁方设计,探讨日粮中添加脂肪酸组成不同的植物油(葵花油、胡麻油、菜籽油,日粮脂肪含量均为6.5%)对奶牛瘤胃液总挥发性脂肪酸含量动态变化的影响,以及对乳脂肪酸组成的影响。结果表明,3个试验组奶牛瘤胃液总挥发性脂肪酸(TVFA)浓度差异不显著(P0.05);葵花油组反-C18:1含量和C18:2含量显著高于胡麻油组和菜籽油组(P0.05),后两组反-C18:1含量、C18:2含量差异不显著(P0.05);葵花油组和胡麻油组的多不饱和脂肪酸(PUFA)含量差异不显著(P0.05),但均显著高于菜籽油组(P0.05);胡麻油组的饱和脂肪酸(SFA)含量显著低于其他两组(P0.05),而其他两组SFA含量差异不显著(P0.05);葵花油组的CLA含量显著高于菜籽油组(P0.05),但与胡麻油组差异不显著(P0.05),菜籽油组和胡麻油组CLA含量差异显著(P0.05)。     

高寒地区人工草地土壤微生物群落对不同种植方式和年限的响应

为了探讨高寒地区多年生人工草地土壤微生物对不同种植方式和年限的响应,本试验采用Illumina MiSeq高通量测序技术,研究了高寒地区不同生长年限的单播和混播人工草地土壤细菌和真菌群落多样性变化.结果表明:研究共识别出63个细菌门类和17个真菌门类,约有50％ 的真菌门未识别出来.已识别类群中细菌以变形菌门(Prot...     

Chemical Composition and Energy Value of Different Fat Sources for Growing Pigs

The chemical composition, digestibility and energy value of eight animal and vegetable fat batches was determined (animal fat, soya oil, palm oil, palm oil, palm oil mix and vegetable oil byproduct). To a basal diet, 5, 10, 15, 20, 25 or 30% dietary fat was added, and digestibility and balance experiments with each fat batch were carried out with three litters of six female pigs, weighing 50-75 kg. The digestibility was determined by multiple regression analysis. The content of HCl-extracted fat and the amount of gross energy was nearly equal for all the fat sources and as such not related to the variation in fatty acid composition or digestibility. Inclusion of soya oil, which is high in polyunsaturated fatty acids, enhanced protein digestibility, whereas inclusion of the other fat sources did not influence protein digestibility. A curvilinear function of fat digestibility (% of intake) to dietary fat concentration was found, thus reflecting the significance of the endogenous fat losses on the determined digestibility value. In contrast, the relationship of digested fat (g day     

Effects of 34 Years of Experimentally Manipulated Burn Seasons and Frequencies on Prairie Plant Composition

Historically, tallgrass prairie burns occurred at many seasons and frequencies. Currently, tallgrass prescribed burns often occur annually in the spring, usually for cattle forage production. Altering burning season and frequency is known to affect plant composition and biomass production, but researchers are still uncertain how burning season and frequency interact. We present the long-term effects of a factorial combination of different burn seasons (spring, summer, autumn, or variable [rotated through seasons]) and frequencies (annual or quadrennial) on the plant composition and biomass production of an ungrazed, restored tallgrass prairie in eastern Nebraska, United States. The experimental plots were established in 1978 and visually surveyed for baseline data in 1979 and 1981. Experimental burn treatments were begun in 1982. Plots were visually surveyed until 2011 with the following results: 1) annual spring and summer burns increased C₄ graminoid abundance; 2) annual autumn burns increased forb abundance; 3) burn season had little effect on plant composition for quadrennial burns; and 4) variable season burns generally led to plant composition that was intermediate between annual spring/summer and annual autumn burns. We also clipped biomass to estimate aboveground annual net primary production (ANPP) in 2015, a year in which both annual and quadrennial burns occurred. Total ANPP did not differ significantly between burn frequencies nor between spring and autumn burns (772 g m^? 2 average) but was lower in summer burns (541 g m^? 2). ANPP results were similar to visual surveys, with significantly higher C₄ graminoid ANPP in spring than autumn burns and significantly lower forb and C₃ graminoid ANPP in spring than autumn burns. Overall, these results suggest autumn burns can increase forb and C₃ graminoid abundance, without strongly affecting total ANPP relative to spring burns. Future studies should compare plant and livestock production between spring and autumn burns in grazed fields.     

植物生长调节剂和盐度对驼绒藜属植物——绵毛优若藜种子发芽功能的影响

绵毛优若藜[Ceratoides lanata (Pursh)J.T.Howell]是一种灌木,具有一年生小枝,属于藜科,广泛分布于美国犹他州北部盐碱沙地.其种子没有休眠性,大约90％的种子在非盐碱土条件下发芽.其种子发芽率随盐度的增高而下降,超过10％的种子在900 mmol/L氯化钠中可以发芽,且几乎所有的种子在不到24 h内发芽,超出这个时间段后不再有种子发芽.赤霉酸不能缓解盐度对绵毛优若藜种子发芽产生的影响,而激动素和壳梭孢(菌)素可以大大减轻盐分对其发芽的影响,乙烯利能够完全缓解盐胁迫对绵毛优若藜种子发芽的影响.