秸秆纤维地膜覆盖栽培哈椒试验研究

为研究玉米和水稻秸秆纤维地膜覆盖栽培作物性能,并完善其制造工艺技术,采用随机区组试验方法,以裸地作为空白对照,实施玉米秸秆纤维地膜、水稻秸秆纤维地膜和传统塑料地膜4个处理覆盖栽培哈椒小区多重比较试验,研究秸秆纤维地膜的抑草、增温、保墒和降解性能及其对哈椒植株高度和产量影响。结果表明,玉米、水稻秸秆纤维地膜间的抑草、增温、保墒性能无显著差异,分别在68和110 d内完全降解;两种秸秆纤维地膜抑草性能显著优于传统塑料地膜的;秸秆纤维地膜与传统塑料地膜的保墒性能无显著差异,土壤含水量显著高于裸地的;秸秆纤维地膜覆盖处理的地表及地下10 cm土壤总积温与裸地对照无显著差异,极显著低于传统塑料地膜的;秸秆纤维地膜覆盖栽培哈椒的植株高度和产量显著高于裸地的,与传统塑料地膜无显著差异。     

不同方法调制的苜蓿主要营养成分奶牛瘤胃有效降解率

本文旨在研究不同方法调制的苜蓿对奶牛的营养价值.试验采用3×3拉丁方设计,用3头装有永久性瘤胃瘘管的中国荷斯坦奶牛,对加酸苜蓿青贮、半干苜蓿青贮和苜蓿干草的主要营养成分进行瘤胃有效降解率研究.结果显示:1)加酸苜蓿青贮的DM、CP、NDF和ADF的有效降解率均最高,但DM有效降解率三者之间差异不显著(P>O.05);2)加酸苜蓿青贮和半干苜蓿青贮的CP有效降解率显著高于苜蓿干草(P<0.05),但两者之间差异不显著(P>O.05);3)加酸苜蓿青贮的NDF有效降解率显著高于半干苜蓿青贮和苜蓿干草(PO.05);4)加酸苜蓿青贮ADF的有效降解率显著高于苜蓿干草(P<0.05),加酸苜蓿青贮与半干苜蓿青贮之间、半干苜蓿青贮与苜蓿干草之间差异不显著(P>O.05).     

氢氧化钙尿素复合处理芨芨草的效果研究

分别用4％尿素、4％尿素 4％氢氧化钙处理芨芨草，试验结果表明：氢氧化钙尿素复合处理剂可极显著(P＜O．01)提高芨芨草粗蛋白含量，比对照组提高142．61％，增加5．79个百分点。NDF舍量比对照组降低11．51％(P＜0．01)。钙含量比对照组提高1．92倍(P＜0．01)。4％尿素处理芨芨草后．芨芨草DM中CP含量比对照组增加145．81％(P＜0．01)。氢氧化钙尿素复合处理芨芨草后．可分别提高芨芨草DM、OM、NDF有效降解率55．08％、62．04％、28．89oA(P＜0．01)。4％尿素可分别提高芨芨草DM、0M、NDF有效降解率46．61％、50．87％、18．80％(P＜0．01)。     

The nutritive value of Prangos ferulacea

This study was conducted to determine the chemical composition and nutritive value of Prangos ferulacea, a plant found in the Mediterranean and Middle‐east regions, where it is used as animal fodder. Samples of mature plants were collected from S.E. Turkey. Metabolizable energy (ME) values were estimated from in vitro gas production measurements and from chemical composition. ME concentrations of the whole plant, leaves and stems were estimated to be 12·2, 11·9 and 12·7 MJ kg^?1 dry matter (DM) respectively, which compares favourably with high‐quality forages commonly used in ruminant feeding. The DM degradability of the whole plant, leaves and stems increased up until 48 h of in situ incubation, 866, 915 and 784 g kg^?1 DM respectively, but changed little between 48 and 72 h. In vitro DM and organic matter digestibility of the whole plant, leaves and stems were 0·769 and 0·806, 0·773 and 0·790, and 0·740 and 0·840 respectively. The results show that P. ferulacea may be regarded as a high‐energy forage, but further research is needed on its intake characteristics and the levels of animal performance that can be achieved from its inclusion in the diet.     

常规与非常规粗饲料在奶牛瘤胃中的降解特性研究

旨在探讨非常规粗饲料(玉米芯、毛豆荚壳)与奶牛常用粗饲料(苜蓿干草、玉米青贮)在奶牛瘤胃中的降解规律,试验选用3只装有永久性瘤胃瘘管的荷斯坦奶牛,采用尼龙袋法测定4种粗饲料的干物质(DM)、粗蛋白(CP)、中性洗涤纤维(NDF)和酸性洗涤纤维(ADF)的瘤胃降解规律。结果表明:1)苜蓿干草和毛豆荚壳的CP含量分别为17.55%和11.10%,且苜蓿干草显著高于毛豆荚壳(P<0.05);玉米芯和玉米青贮的CP含量分别为2.97%和8.41%,且玉米芯显著低于玉米青贮(P<0.05);玉米芯的NDF和ADF含量显著高于其他3种粗饲料(P<0.05),达到79.98%和43.35%。2)苜蓿干草的DM有效降解率最高(P<0.05),由高到低依次为苜蓿干草、毛豆荚壳、玉米青贮和玉米芯。毛豆荚壳的CP有效降解率显著高于其他3种粗饲料(P<0.05),由高到低依次为毛豆荚壳、苜蓿干草、玉米青贮和玉米芯。苜蓿干草的NDF有效降解率显著高于毛豆荚壳(P<0.05),玉米青贮和毛豆荚壳无显著差异(P>0.05);玉米芯的ADF有效降解率最高(P<0.05),苜蓿干草、玉米青贮和毛豆荚壳无显著差异(P>0.05)。综上所述,玉米芯和毛豆荚壳可作为非常规粗饲料资源加以开发利用。     

不同收获时间全株玉米青贮饲料在牛瘤胃内干物质降解率的研究

利用3头安装永久性瘤胃瘘管的西门塔尔杂种一代公牛，采用瘤胃尼龙袋技术，测定了不同收获期“四单19”全株玉米青贮饲料的干物质瘤胃降解率。结果表明：各期干物质瘤胃降解率依次为65．81％、67．59％、61．05％。根据测试结果分析，在吉林省中部地区，全株玉米青贮以8月31日至9月7日收获制作，其饲用价值较高。     

棕榈酸对营养物质瘤胃降解率及表观消化率的影响

选四头装有永久瘤胃瘘管的杂交黄牛,按4×4拉丁方设计,采用尼龙袋法研究棕榈酸对营养物质瘤胃降解率的影响。结果表明:添加1.5%～4.5%棕榈酸对干物质(DM)、有机物(OM)、中性洗涤纤维(NDF)、纤维素(CEL)及酸性洗涤木质素(ADL)的瘤胃降解率影响差异不显著(P>0.05)。第二个试验选用32头奶牛,分成4组,研究棕榈酸对营养物质全消化道表观消化率的影响。结果表明:添加1.5%棕榈酸,日粮有机物(OM)、粗蛋白(CP)、中性洗涤纤维(NDF)及粗脂肪(EE)的表观消化率与对照组差异均不显著(P>0.05);添加3.0%棕榈酸,日粮OM表观消化率较对照组下降2.16%(P<0.05),EE表观消化率较对照组提高3.44%(P<0.05),CP及NDF表观消化率与对照组差异不显著(P>0.05);添加4.5%棕榈酸,日粮OM、CP及NDF表观消化率较对照组分别下降2.74%(P<0.01)、2.01%(P<0.05)及8.50%(P<0.05),EE表观消化率较对照组提高3.55%(P<0.05)。     

Effects of rumen-degradable-protein to rumen-undegradable-protein ratio on nitrogen conversion of lactating dairy cows

Abstract

Fifteen multiparous dairy cows were used in a five replicated 3×3 Latin square design to study the effects of ratio of rumendegradable-protein (RDP) and rumen-undegradable-protein (RUP) on nitrogen (N) conversion in Chinese Holstein dairy cows. Three diets were formulated isonitrogenously with varying ratio of RDP/RUP. High ratio of RDP/RUP resulted in high urinary N excretion and total N excretion, but no significant dietary effects were observed on milk yield, milk composition, and nitrogen excretion in faeces. Different protein degradability changed the partitioning of the N excretion between urine and faeces. Results indicated that reduction in ratio of RDP/RUP could improve the efficiency of N utilization in lactating dairy cows by reduced N excretion in urine and faeces without impairing milk production.     

Flammable Australia: Fire Regimes,Biodiversity and Ecosystems in a Changing World

This study examined intraspecific variation in mineral composition and rumen degradability of Atriplex nummularia plants and the influence on selection preferences of sheep. Individual plants were categorised into high, medium and least preference groups by assessing the order in which they were selected by sheep. Nine plants were selected from each group and the regrowth of these plants was analysed for neutral detergent fibre (NDF), crude protein (CP), mineral composition and rumen degradability of dry matter. The data was subjected to one-way and multivariate analyses of variance. Highly preferred plants had a higher concentration of CP, phosphorous (P) and magnesium (Mg) in their edible forage compared to the medium or least preferred plants. Individual preferences of sheep were not, however, associated with the rumen degradability parameters. Principal component analysis revealed that highly preferred plants had lower NDF, manganese (Mn) and zinc (Zn), and higher CP, calcium, P, Mg and potassium values compared to the least preferred plants. In contrast, medium preferred plants exhibited inconsistent patterns, with a tendency to have higher sodium chloride and sodium, and lower Mn, Zn and copper, concentrations in the forage.     

Research note: The silage characteristics of two varieties of forage sorghum mixed in different proportions and at two stages of maturity

Abstract

Two varieties of forage sorghum, low grain Dekalb FS‐5 (FS) and higher grain Pioneer 947 (GS) were harvested at the milk and dough stages of maturity respectively. Each variety was ensiled separately and as mixtures under laboratory conditions. The mixtures comprised FS.GS at ratios of 3:1 and 1:1 respectively. At the milk stage the FS had a dry matter (DM) content of 338 g kg^?1 and water‐soluble carbohydrates (WSC) content of 120 g kg^?1, as compared with 389 g kg^?1 and 63 g kg^?1, respectively for the GS. At the dough stage, these contents were 374 g kg^?1 and 123 g kg^?1 for the FS, and 520 g kg^?1 and 29 g kg^?1 for the GS, respectively. At the dough stage the GS had higher neutral detergent fibre (NDF) and acid detergent fibre (ADF) contents than FS (592 g kg^?1 and 379 g kg^?1 vs. 533 g kg^?1 and 339 g kg^?1 DM, respectively). In the silage harvested at milk stage, the pH of FS alone decreased most slowly, whereas at the dough stage the pH of the GS remained highest. In mixtures the pH decline accelerated with an increasing proportion of FS. Following harvest at the milk stage the 3:1 (FS:GS) had the best ensiling characteristics, whereas following at the dough stage the 1:1 mixture provided the most stable silage. Rumen degradability of the silage of GS was higher than that of the FS silage, especially for material harvested at dough stage of maturity (59.2 g kg^?1 vs. 50.9 g kg^?1). Mixing FS with GS at the ensiling increased the digestibility of the resulting silage as compared with FS alone.