云南引进帝国百脉根的研究

对引进帝国百脉根进行茎叶比、干鲜比、干草产量、营养成分和体外干物质消化率(IVDMD)的测定。结果表明，帝国百脉根含有丰富的营养，分枝期和盛花期粗蛋白含量分别高达28．0%和20．79%，粗纤维含量为13．0%和17．46%，Ca、P 丰富，比例恰当，体外干物质消化率较高而稳定，在分枝期和开花期分别为58．64%和57．25%。因此，帝国百脉根为饲用价值较高的优良豆科牧草，应予以进一步开发利用。     

Effect of Genotypes and Plant Maturity on Forage Quality of Certain Forage Legume Species Under Rainfed Conditions

Evaluation of plant species for animal feed requires the quantitative and qualitative comparison of different genotypes. Promising lines of annual legumes comprising seven genotypes of vetche ( Vicia spp.) and chicklings ( Lathyrus spp.) were compared for herbage quality. The content of crude protein (CP), neutral detergent fiber (NDF) and acid detergent fiber (ADF) in herbage and pods were measured at different stages of plant maturity. The proportion of the leaves to shoots (leafiness) and in vitro dry matter digestibility (IVDMD) were also determined. As plants matured IVDMD, CP and leafiness decreased and NDF and ADF increased. For all the genotypes maximum digestible dry matter (DDM) and CP yields were more or less attained at 50–100 % podding. Narbon vetch had the highest DDM. The possible uses of the different genotypes as animal feed are discussed based on the partitioning of the DDM and CP yield as plants matured.     

多花黑麦草抽穗期干物质体外消化率在品系间的差异

研究了不同熟期类型多花黑麦草品系的抽穗期干物质产量、干物质体外消化率 (IVDMD)以及细胞壁结构物质含量和消化率与IVDMD的相关性,结果表明:①不同熟期类型间IVDMD存在显著差异,其中极早熟类型和早熟类型极显著高于晚熟类型和中熟类型,晚熟类型又极显著高于中熟类型;相同熟期类型品系间,只有中熟类型的IVDMD差异显著。②极早熟类型和早熟类型的半纤维素含量以及中熟类型和晚熟类型的纤维素含量与IVD MD呈极显著负相关关系;所有熟期类型的半纤维素消化率以及晚熟类型纤维素消化率与IVDMD分别呈极显著和显著的正相关关系。     

Yield,quality and k/(Ca+Mg) ratio of tall fescue beeeding lines on amended and nonamended minesoil

Abstract

Surface mineable coal is abundant beneath many farmland areas in Missouri. Presently, 90% of the electricity generated in the state is by coal powered plants. Surface strip‐mining laws now require reclamation of these lands after drastic disturbance. Tall fescue (Festuca arundinancea Schreb) cultivars and breeding lines have been evaluated for yield, nutrient composition and quality on undisturbed lands, but not for these qualities and for adaptability to revegetate drastically disturbed lands.

Six breeding lines and 2 cultivars of tall fescue were evaluated for yield, nutrient composition, crude protein and IVDMD on limed and unlimed minesoils in west‐central Missouri. The experimental dersign was a randomized split‐block with lime treatment the split‐block, 3‐replications, with individual plots 1.21 x 3.05 m. Agriculture lime with ENM index of 291 at rate of 19 mt/ha was incorporated, fescue seeded and the experimental area mulched during August‐September, 1978. The 1979 harvest samples were composited for crude protein, nutrient and IVDMD analyses and the 1980 harvest samples were analyzed for individual plots.

The 1979 yield was not significantly different between genetic materials, but mean yield from limed minesoil was significantly higher than from unlimed minesoil. Yield data evaluation suggest Kenhy, WG3B, HMR to yield highest on unlimed minesoil and WG2B, LMR and HMR highest on limed minesoil, with MO‐96 lowest in yield limed or unlimed. The calculated K/(Ca+Mg) ratio of HMR and Kenhy was interpreted to be borderline for potential occurrence of grass tetany under limed environment. Differential divalent cation accumulation capacities of the breeding lines LMR and HMR was expressed on both the limed and unlimed minesoil. Potassium was not judged to reach a sufficiently high or Mg sufficiently low level to suggest potential problem of hypomagnesaema.

Lime increased IVDMD, but not crude protein. Crude protein varied by year, but IVDMD remained nearly constant. The genetic materials MO‐96 and H‐I accumulated higher quantities of Mg upon liming, but had lower IVDMD. Differences in yield were not significantly related to cation accumulation or forage quality on this minesoil, limed or unlimed.     

青刈黑麦抽穗期干物质体外消化率与细胞壁结构物质的关系

选用8个不同品系的青刈黑麦(Secal cerealeL.)为试验材料,研究其抽穗期干物质体外消化率与细胞壁结构物质的关系。结果表明:①抽穗期干物质(IVDMD)不同熟期类型间差异不显著;②早熟类型干物质纤维素含量与IVDMD呈显著负相关(r=0.670*),晚熟类型干物质纤维素含量与IVDMD呈极显著负相关(r=-0.936**),早熟、晚熟类型干物质纤维素消化率与IVDMD无显著相关;③IVDMD与半纤维素含量及消化率、木质素含量及其消化率无显著相关。     

玉米-豆粕型饲料非淀粉多糖酶谱及酶解条件优化研究

【目的】筛选玉米 豆粕型饲料非淀粉多糖（NSP）酶谱,并对其酶解条件进行优化,以增加饲料中低聚糖的含量,获得具有抑菌特性的酶解产物,同时提高饲料的体外干物质消化率（IVDMD）。【方法】以还原糖含量为评价指标,通过L₁₈(3⁷)正交试验,研究不同用量5种NSP酶（纤维素酶110,220和330 U/kg,木聚糖酶176,352和528 U/kg,果胶酶331,662和993 U/kg,β-葡聚糖酶124,248和372 U/kg,β-甘露聚糖酶83,166和249U/kg）组合对玉米-豆粕型饲料的酶解效果,筛选最佳酶谱。探讨酶解温度（35,45,55,65 ℃）对饲料还原糖含量的影响,以及酶解时间（0,3,6,9,12,15,18,21,24 h）对饲料糖组分、抑菌效果、IVDMD的影响,确定最佳酶解条件。根据上述优化条件制备酶解饲料,将其与普通饲料及添加质量分数0.05%和0.10%防霉剂的饲料加入一定比例水后于25 ℃条件下进行贮存试验,比较各类饲料的抑菌效果。【结果】5种NSP酶的最佳配比为纤维素酶110 U/kg,木聚糖酶528 U/kg,果胶酶993 U/kg,β-葡聚糖酶372 U/kg,β-甘露聚糖酶249 U/kg。最佳酶解温度为55 ℃,此条件下饲料中的还原糖得率最高,可达17.98 mg/g。最佳酶解时间为15 h,此时酶解产生的低聚糖含量为78.65 mg/g,酶解产物对大肠杆菌的抑菌能力最强,同时对蜡样芽孢杆菌、沙门氏菌、植物乳杆菌等食源性致病菌也有明显的抑制作用;饲料IVDMD随酶解时间的延长呈升高趋势,15 h后基本达到平衡,为54.25%～56.25%。饲料贮存试验结果显示,普通饲料及添加0.05%防霉剂饲料在特定条件下放置2 d开始出现表观腐败现象,添加0.10%防霉剂组饲料和酶解饲料未出现表观腐败现象;酶解饲料中的细菌总数和大肠杆菌数均明显低于普通饲料和添加防霉剂饲料,但其对青霉菌无抑制作用。【结论】获得了玉米-豆粕型饲料的NSP酶解的酶谱及优化条件,NSP酶解能够显著提高玉米-豆粕型饲料的IVDMD,增加低聚糖含量,提高饲料的细菌抑制能力。     

Effects of Cultivar and Maturity Stage on Chemical Composition and Ruminal Digestibility of Oat and Barley Hay Using Rumen Fluid or Faecal Liquor as the Inoculum

Smallgrains,suchasbarley,oat,wheatandryeplayasignificantroleasaforagesourceforlivestock.Smallgrainforageislushwithhighproteinandlowfiberwhenthevegetativepartsarestillgreen.OatandbarleyarewidelyusedinwesternCanadaforforageinadditiontograinproduction.Duetoagreatprogressinplantbreeding,manynewcultivarsareproducedannuallyandmanyhavebeenselectedasforagetypes.Itisimperativetomorefullycharacterizetheforage-producingpotentialofnewcultivarsinordertoproducetopqualityforageinfeedindustry.Manystudieshave…     

饲用灌木在不同生育期范式纤维与体外消化率动态变化

通过对几种饲用灌木在不同生育期的范式纤维和体外消化率的测定与分析,结果表明:各灌木范式纤维在各生育期变化规律不一,体外消化率随着生育期推移有所升高的为木豆、假木豆和火棘;树苜蓿和山蚂蝗呈营养期高、开花期低、结荚期高、种子成熟期低的倒N型变化。相关分析表明缩合单宁与ADF和ADL之间呈极显著正相关(P<0.01);IVDMD与NDF、ADF和ADL的含量呈极显著负相关(P<0.01)。     

Effect of dietary fiber on methane production in Chinese Lantang gilts

The objective of this study was to determine the effect of dietary fiber on methane (CH₄) production in pigs using the Chinese native Lantang gilts as study model. The study consisted of two experiments. In the first, 12 Lantang gilts (58.7±0.37 kg), individually housed in open-circuit respiration chambers were randomly divided into two groups (six replicates per dietary group) and fed either with low fiber diet [LFD; neutral detergent fiber (NDF)=201.5 g/kg] or high fiber diet (HFD; NDF=329.7 g/kg). Wheat bran was the main source of fiber for the LFD while ground rice hull (mixture of rice bran and rice hull) was used in the HFD. Results of the study showed that gilts fed LFD recorded higher (P<0.05) digestibility coefficients for dry matter (DM), total organic carbon (TOC), acid detergent fiber (ADF) and cellulose than those in the HFD. However, digestibility coefficient for NDF did not differ between treatments but that for hemicellulose was higher for HDF than for LDF. Because of the higher NDF and hemicellulose contents in the diet, pigs in the HFD recorded higher (P<0.05) amount of digested NDF (126.1 vs. 83.6 g/d) and hemicellulose (38.7 vs. 11.9 g/d) than those fed LFD. The higher amount of digested NDF and hemicellulose recorded for the HFD treatment was inconsistent with the lower (P<0.01) daily CH₄ production from gilts fed the HFD compared to that fed LFD (2.46 vs. 3.90 L/pig). To better explain for the unexpected higher CH₄ production from pigs fed LFD, an in vitro fermentation study was conducted using a factorial design comprised of two inocula (collected from low fiber and high fiber diets) and eight substrates (LFD, HFD, wheat bran, ground rice hull and their respective NDF residues). Results of the in vitro trial seems to suggest that the low CH₄ production from the HFD animals was primarily the results of low fermentation rates of HFD and the ground rice hull. However, the calculated CH₄ productions based on the molar percentage of volatile fatty acids (VFA) in both, in vivo and in vitro experiments reaffirmed the in vivo result, that is, CH₄ production from pigs fed HFD was lower than that fed LFD. Although there is a lack of scientific data from this study to fully explain for the unexpected lower CH₄ production from pigs fed the HFD, our results seems to suggest that quantity of digested fiber (including NDF) was not the sole factor affecting enteric CH₄ production in pigs.     

Yield,quality and K/(Ca+Mg) ratio of tall fescue breeding lines on amended and nonamended minesoil

Abstract

Surface mineable coal is abundant beneath many farmland areas in Missouri. Presently, 90% of the electricity generated in the state is by coal powered plants. Surface strip‐mining laws now require reclamation of these lands after drastic disturbance. Tall fescue (Festuca arundinancea Schreb) cultivars and breeding lines have been evaluated for yield, nutrient composition and quality on undisturbed lands, but not for these qualities and for adaptability to revegetate drastically disturbed lands.

Six breeding lines and 2 cultivars of tall fescue were evaluated for yield, nutrient composition, crude protein and IVDMD on limed and unlisted minesoils in west‐central Missouri. The experimental design was a randomized split‐block with lime treatment the split‐block, 3‐replications, with individual plots 1.21 × 3.05 m. Agriculture lime with ENM index of 291 at rate of 19 mt/ha was incorporated, fescue seeded and the experimental area mulched during August‐September, 1978. The 1979 harvest samples were composited for crude protein, nutrient and IVDMD analyses and the 1980 harvest samples were analyzed for individual plots.

The 1979 yield was not significantly different between genetic materials, but mean yield from limed minesoil was significantly higher than from unlimed minesoil. Yield data evaluation suggest Kenny, WG3B, HMR to yield highest on unlimed minesoil and WG2B, LMR and HMR highest on limed minesoil, with MO‐96 lowest in yield limed or unlimed. The calculated K/(Ca+Mg) ratio of HMR and Kenhy was interpreted to be borderline for potential occurrence of grass tetany under limed environment. Differential divalent cation accumulation capacities of the breeding lines LMR and HMR was expressed on both the limed and unlimed minesoil. Potassium was not judged to reach a sufficiently high or Mg sufficiently low level to suggest potential problem of hypomagnesaema.

Lime increased IVDMD, but not crude protein. Crude protein varied by year, but IVDMD remained nearly constant. The genetic materials MO‐96 and H‐I accumulated higher quantities of Mg upon liming, but had lower IVDMD. Differences in yield were not significantly related to cation accumulation or forage quality on this minesoil, limed or unlimed.