青贮处理对两品种甜高粱营养成分及瘤胃降解率的影响

试验旨在研究青贮处理对两种甜高粱营养成分及瘤胃降解率的影响.选取3头装有永久性瘤胃瘘管的荷斯坦阉牛,采用尼龙袋法对甜高粱青贮前和青贮后的营养成分及瘤胃降解特率进行评定.结果 表明,青贮前,巨能甜高粱的粗蛋白(CP)含量显著高于大龙甜高粱(P＜0.05),非蛋白氮(NPN)、中性洗涤纤维(NDF)、酸性洗涤纤维(ADF)...     

Research note: Maize and forage sorghum as silage crops under drought conditions

Abstract

Maize (Senkuil) and a forage sorghum hybrid (DeKalb FS2) were compared as silage crops under drought conditions. Sorghum yielded more digestible organic matter per hectare than maize. Maize and forage sorghum silage were well preserved and stable under aerobic conditions.     

不同收获期玉米青贮DM和CP奶牛瘤胃降解率研究

结果表明：蜡熟期玉米青贮DM的有效降解率（60.07%）分别比乳熟期（52.91%）和乳熟前期（45.13%）高7.16个百分点（P＜0.05）和14.94个百分点（P＜0.01）;乳熟期玉米青贮DM的有效降解率比乳熟前期高7.78个百分点（P＜0.05）.蜡熟期玉米青贮CP的有效降解率（81.93%）分别比乳熟期（76.43%）和乳熟前期（73.36%）高5.50个百分点（P＜0.05）和8.57个百分点（P＜0.05）;乳熟期玉米青贮CP的有效降解率比乳熟前期高3.07个百分点，但差异不显著.     

Degradation characteristics and tannin bioassay of some browse forage from Kenya harvested during the dry season

The potential nutritional value of six species of browse forage from Kenya harvested during the dry season were evaluated by chemical composition, in sacco dry matter (DM) degradation and in vitro gas production technique. The effect of tannins on the rumen fermentation of the forage was evaluated using polyethylene glycol (PEG) in an in vitro study. The chemical composition of the species of browse forage differed significantly (P < 0.05). The content of organic matter ranged from 846.7 to 946.5 g/kg DM. The forage had a high crude protein content (155.5–280.9 g/kg DM) and variable content of neutral detergent fiber (NDF, 236.2–682.8 g/kg DM). The content of total extractable tannins was generally low (0.6–38.5 g/kg DM). At 24 h of incubation, the in sacco DM disappearance ranged from 31.2% to 84.2%. The effective DM degradability also ranged from 29.7 to 73.5%. The gas production after 96 h incubation ranged from 17.5 to 44.2 mL/200 mg DM. Use of PEG indicated that tannins had an inhibitory effect on rumen microbial fermentation and this is dependant upon the amount and activity of the tannins present. The estimated in vitro organic matter digestibility and metabolizable energy also increased numerically with the PEG addition. The result of this study indicates that such species of browse forage have the potential to be used as feed supplements for ruminants, especially during the dry season.     

饲用油菜的营养成分分析及其在山羊瘤胃降解特性研究

本研究旨在通过化学分析和瘤胃瘘管山羊动物模型研究饲用油菜的营养成分、瘤胃降解特性,为饲用油菜饲喂反刍动物提供营养参数。试验测定华油杂62油菜盛花期及结荚初期植株营养成分含量,并用3只装有永久瘤胃瘘管的波尔山羊测定饲用油菜的瘤胃降解率。结果表明:1)盛花期饲用油菜的粗蛋白质和总氨基酸含量分别达到17.30%、11.48%,显著高于结荚初期(P<0.05);两个生长期饲用油菜的粗脂肪、粗灰分、钙、磷、中性洗涤纤维和酸性洗涤纤维含量差异不显著(P>0.05)。盛花期植株中硫甙含量为10.17 μmol·g^-1、单宁含量为0.94%,均高于结荚初期。2)盛花期、结荚初期饲用油菜中干物质、粗蛋白质、有机物、中性洗涤纤维、酸性洗涤纤维的瘤胃降解率随消化时间的延长均逐渐升高;盛花期饲用油菜粗蛋白质的瘤胃降解率在72 h时达到84.70%;干物质的瘤胃降解率在0~24 h快速升高,48 h后稳定在67%左右;中性洗涤纤维和酸性洗涤纤维的瘤胃降解率上升速度较慢,72 h时分别为48.22%和45.78%。结荚初期饲用油菜中干物质和有机物的瘤胃降解率在0~72 h均低于同时间点的盛花期。3)盛花期、结荚初期饲用油菜植株中各营养成分之间快速降解部分差异显著(P<0.05),粗蛋白质快速降解部分均为最高,分别达到64.06%和68.81%;粗蛋白质有效降解率显著高于其他营养成分(P<0.05),分别达到76.50%和75.13%。结论盛花期和结荚初期饲用油菜的主要营养成分含量和瘤胃降解率均较高,盛花期饲用油菜更易被山羊瘤胃消化。     

不同比例青贮甘蔗尾与青贮玉米秸秆组合对奶水牛体外产气的影响

试验旨在研究不同比例青贮甘蔗尾(SS)与青贮玉米秸秆(CS)组合对奶水牛体外产气的影响。以不同添加剂处理的青贮甘蔗尾(SS1、SS2、SS3)和CS为原料,发酵底物的精粗比为46(DM),每种SS分别以0%(对照组)、25%、50%、75%和100%代替底物中的CS。结果表明:(1)SS组合CS,96 h累积产气量随着SS比例增加而升高,其中含SS3组96 h累积产气量显著高于对照组(P<0.05);(2)含SS1、SS2组可消化有机物与对照组比差异不显著(P>0.05),但随着SS1或SS2添加有升高趋势。SS3组合CS,可消化有机物和代谢能均高于SS3组,且显著高于对照组(P<0.05)。因此,SS组合CS对奶水牛瘤胃发酵具有促进作用,适宜比例组合能提高瘤胃消化代谢率。     

整株玉米不同成熟阶段对其青贮品质及有氧稳定性的影响

随着整株玉米不断成熟,其干物质(DM)、淀粉、中性洗涤纤维(NDF)和酸性洗涤纤维(ADF)含量不断增加,而可溶性碳水化合物(WSC)、水分含量不断降低。成熟早期高含量的WSC为乳酸菌提供了大量的发酵底物,可促进青贮发酵,但高水分会降低青贮料的有氧稳定性;成熟后期,低水分和低含量的WSC使青贮达不到理想的发酵效果,此外,高木质化也导致青贮料消化率降低。综合各方面因素,在1/3乳腺期到2/3乳腺期阶段青贮的整株玉米无论是发酵效果还是有氧稳定性方面均可达到较好效果。     

品种及成熟期对玉米秸秆不同形态部位干物质及粗蛋白降解特性的影响

玉米秸秆是反刍家畜主要粗饲料来源之一,其营养降解特性不仅受玉米品种及成熟时期的影响,而且与玉米秸秆形态部位组成相关。本试验通过分析不同类型玉米品种秸秆不同形态部位在2个成熟期干物质（DM）及粗蛋白（CP）的瘤胃降解特性,为玉米秸秆在反刍家畜中的利用提供数据支持。试验选用科湘玉11号（常规玉米）、高油115（高油玉米）、科湘糯玉1号（糯玉米）、沪青1号（饲用玉米）和科湘甜玉1号（甜玉米）5个品种玉米,分别在抽穗后的第17天（乳熟期）和第31天（蜡熟期）采集其叶片、叶鞘、茎秆及苞叶4个形态部位的样品,利用瘤胃尼龙袋技术分析所有样品的DM及CP的瘤胃降解动力学参数变化规律,结果表明：蜡熟期叶片、叶鞘、茎秆部位DM,以及叶片和苞叶部位CP的快速降解部分（a值）显著（P<0.001）高于乳熟期,但其叶片、叶鞘和茎秆部位DM,叶片、叶鞘和苞叶部位粗蛋白的慢速降解部分（b值）,以及苞叶干物质有效降解率（ED）极显著（P<0.001）低于乳熟期。新培育品种玉米不同形态部位干物质及粗蛋白的a、b及ED值与普通品种玉米相近或更高。不同形态部位间DM及CP降解动力学参数也存在显著差异,ED值都按...     

Effects of replacing grass silage harvested at two maturity stages with maize silage in the ration upon the intake, digestibility and N retention in wether sheep

The objective of this experiment was to study the effects of interactions between medium quality grass silage (GS1) and maize silage (MS) as well as between low-quality grass silage (GS2) and MS on ad libitum intake, digestibility and N retention in wether sheep. Two grass silages (GS1 and GS2) were ensiled in round bales, without additives, from the primary growth of orchard grass (Dactylis glomerata L.) harvested at two different maturity stages. The study consisted of seven feeding treatments incorporating GS1, GS2 and MS fed alone and forage mixtures of GS1 and MS as well as GS2 and MS (67:33% and 33:67%, respectively, DM (dry matter) basis).Delayed harvesting lowered (P < 0.05) the crude protein (CP) concentration in GS2 compared to GS1. The DM content (g kg^− 1 fresh sample) and starch concentration (g kg^− 1 DM) of MS were 264 and 211, respectively.Inclusion of MS in the GS1-based ration had positive linear effects on CP and starch digestibility (P < 0.05 and P < 0.01, respectively) and N intake (P < 0.01) while a negative effect on neutral detergent fibre (NDF) and acid detergent fibre (ADF) digestibility (P < 0.05 and P < 0.01, respectively). A positive associative response of GS1 and MS was observed for DM ad libitum intake (g kg^− 1 M^0.75 day^− 1) (quadratic, P < 0.05), CP digestibility (quadratic, P < 0.01), N intake (quadratic, P < 0.01) and N balance (quadratic, P < 0.05). Inclusion of MS into the GS2-based ration had a positive linear effect on the ration fresh matter ad libitum intake (kg day^− 1 and g kg^− 1 M^0.75 day^− 1) (P < 0.01 and P < 0.001, respectively), NDF ad libitum intake (kg day^− 1 and g kg^− 1 M^0.75 day^− 1) (P < 0.01), digestibility of DM (P < 0.01), organic matter (OM) (P < 0.01), ADF (P < 0.05), starch (P < 0.001), digestibility of OM in DM (D-value) (P < 0.001), and N intake (P < 0.01). Positive associative effects of GS2 and MS were observed on all the intake and digestibility parameters measured, N intake (quadratic, P < 0.001) and N balance (quadratic, P < 0.05). It was concluded that, as expected, a positive associative response of GS2 and MS was recorded for all the measured parameters while that of GS1 and MS for a limited number of parameters, probably due to lower quality of MS (lower starch concentration) than required for improved utilization of the GS1-based ration.     

甲醛处理对豆饼干物质和蛋白质瘤胃降解率及胃蛋白酶消化率的影响

豆饼用２ｇ／ｋｇＤＭ甲醛处理后,１０ｈ瘤胃干物质（ＤＭ）降解率从８７．１９％下降到豆饼含水量为１４％和６０．９３％和含水量１８％时的５６．２９％,粗蛋白降解率从８７．６９％分别下降到４８．３６％和４３．４３％,随着甲醛用量的增加,干物质的粗蛋白的降解率进一步下降,但下降幅度减少。在甲醛用量低于２ｇ／ｋｇＤＭ的情况下,甲醛用量对ＰＨ为４．５时的胃蛋白酶４ｈ和８ｈ干物质和粗蛋白消化率没有明显影响,但     

不同苜蓿品种混播和播种量对牧草产量及品质的影响

以紫花苜蓿品种‘巨能7’、‘三得利’为供试材料,采用混播方式（‘巨能7’单播,‘巨能7’与‘三得利’同行混播,‘巨能7’与‘三得利’间行混播）和播种量（13.5、18.0、22.5 kg·hm^-2）二因素随机区组设计,探究了干旱地区滴灌条件下混播方式和播种量对2017-2019年紫花苜蓿产量及品质的影响,并利用主成分分析方法（principal component analysis, PCA）进行综合评价,以期得到紫花苜蓿适宜混播方式和播种量。结果表明,混播方式和播种量对2017-2019年苜蓿平均株高、一级分枝数、干草产量、粗灰分、中性洗涤纤维含量和相对饲喂价值影响显著（P<0.05）,而对鲜干比、叶茎比、酸性洗涤纤维和粗蛋白含量影响不显著。其中,‘巨能7’与‘三得利’同行混播、播种量为18.0 kg·hm^-2时苜蓿干草产量显著高于间行混播、播种量为22.5 kg·hm^-2组合,高达16.79 t·hm^-2;‘巨能7’与‘三得利’同行混播、播种量为18.0 kg·hm^-2时苜蓿相对饲喂价值为156.87,仅次于同行混播、播种量为13.5 kg·hm^-2组合。经PCA综合分析,‘巨能7’与‘三得利’同行混播、播种量为18.0 kg·hm^-2时苜蓿综合表现最好,可在宁夏引黄灌区推广应用。     

不同生育期虎尾草的体外发酵产气特性

试验选用3只装有瘤胃瘘管的浏阳黑山羊,采用体外发酵产气技术研究不同生育期虎尾草(Chloris virgata)体外模拟瘤胃发酵的72 h累积总产气量以及0、2、4、6、8、10、12、24、36、48、72 h甲烷产量,发酵液中72 h的挥发性脂肪酸(Volatile Fatty Acid,VFA)和氨氮(NH3-N),以及72 h干物质消失率。结果表明,不同生育期虎尾草的灰分(Ash)、粗蛋白(Crude protein,CP)、中性洗涤纤维(Neutral Detergent Fiber,NDF)、酸性洗涤纤维(Acid Detergent Fiber,ADF)含量差异显著(P0.05)或极显著(P0.01),Ash、CP含量随着生育期的延长而逐渐降低,NDF、ADF含量则呈逐渐增加趋势;随着生育期的延长,总产气量、甲烷的理论最大产气量(VF)以及72 h干物质消失率均呈逐渐降低的趋势,其中各生育期间总产气量的VF差异不显著(P0.05),幼苗期、拔节期、抽穗期、开花期、成熟期间甲烷产气量的VF也差异不显著,但均极显著高于干枯期样品(P0.01),成熟期、干枯期间的72 h干物质消失率极显著低于其余几个生育期(P0.01);发酵液中NH3-N、总VFA以及乙酸浓度的变化趋势为“降低-增高-降低”趋势。综合考虑虎尾草各生育期所含营养成分以及体外发酵的产气特性,建议虎尾草在抽穗至开花期间进行刈割利用。     

Effects of diets containing alfalfa hay or barley flour mixed alfalfa silage on feeding behavior, productivity, rumen fermentation and blood metabolites in lactating cows

The effects of barley flour on the fermentation parameters of alfalfa silage and on the productivity of dairy cows were investigated. Alfalfa forage was ensiled either with or without barley flour. Barley flour was soaked in water for 24 h before being mixed with alfalfa (12 kg: 100 kg dry matter bases) at ensiling. Eighteen multi-parous cows were assigned to three equal treatment groups using a completely randomized design. Three isocaloric and isonitrogenous total mixed rations containing alfalfa hay, ordinary alfalfa silage or barley flour mixed alfalfa silage were then prepared. The concentrations of ammonia nitrogen, acetic acid and butyric acid were lower in barley flour mixed alfalfa silage compared to that in ordinary alfalfa silage but the concentration of lactic acid was lower in the ordinary alfalfa silage. Feeding behavior, milk yield and composition, ruminal fermentation and blood metabolites were measured. Although dry matter intake and milk production were not affected, the effect of preparation of alfalfa influenced feeding behavior and rumen fermentation parameters. Cows on alfalfa silage diets spent longer ruminating compared to those fed alfalfa hay. The ruminal ammonia nitrogen and blood urea were affected by ensiling (alfalfa hay versus alfalfa silages) while both parameters were lower in cows fed on barley flour mixed alfalfa silage than those fed on ordinary silage. Although similar blood glucose was recorded for cows fed on alfalfa silages, it was higher in cows fed on alfalfa hay. It is concluded that the addition of barely flour when making alfalfa silage may improve both the fermentation process during ensilage and the ruminal ammonia nitrogen utilization with no significant effects on productivity.     

Chemical composition, in vitro digestibility and gas production of straws from different varieties and accessions of chickpea

Chemical composition, in vitro digestibility and gas production of straw from four different varieties of Kabuli chickpea (Cicer arietinum) were studied. Kinetics of fermentation of straws from 19 different accessions of chickpea was also evaluated using gas production technique. Significant difference (p < 0.05) was observed in the yield of straw [from 1041 to 1174 kg dry matter (DM)/ha] from different varieties. The proportion of seed/straw from different varieties varied from 0.61 to 0.93. Crude protein, neutral detergent fibre and acid detergent fibre content of straw ranged from 28.1 to 35.8, 598.6 to 645.4 and 459.2 to 473.4 g/kg DM respectively. Organic matter digestibility was different (p < 0.05) among varieties and varied from 471.4 to 535.5 g/kg DM. Potential gas production (A), the rate constants (c and d) and lag times of straws from different chickpea varieties were not different (p > 0.05). However, the rate constants (c and d) and lag times were different (p < 0.05) among accessions. Potential gas production (A) differed (p < 0.05) approximately twofold among different accessions. The results emphasized that in any evaluation of chickpea varieties or accessions, where straw of this legume seed is used as an animal feed, not only seed yield but also yield and quality of straw should be taken into consideration.     

冬闲田种植大麦不同生育期的营养价值和青贮品质

利用冬闲田种植一年生饲草或饲料作物,是解决南方粗饲料不足的有效途径。本研究利用冬闲田种植大麦(Hordeum vulgare),分析其不同刈割期的产量、营养价值和青贮发酵品质。主要研究结果如下,1)大麦的干物质产量随生育期的推进逐渐提高,但乳熟期相对饲用价值和干物质消化率显著高于其它生育期(P0.05),分别为107.19和63.84%。2)随着生育期的推进,全株大麦青贮发酵品质显著提高(P0.05)。3)添加乳酸菌Lactobacillus plantarum CCZZ1可以显著增加各生育期大麦青贮饲料的乳酸含量,降低pH、丁酸和氨态氮含量(P0.05),显著提高青贮发酵品质(P0.05),但开窖后容易引起有氧变质;添加乳酸菌L.parafarraqinis ZH1能有效改善各生育期大麦青贮饲料的有氧稳定性。因此,冬闲田种植大麦宜在乳熟期至蜡熟早期收割青贮,并有益南方畜牧业发展。     

A note on the effect of dietary proportions of kale (Brassica oleracea) and grass silage on rumen pH and volatile fatty acid concentrations in dry dairy cows

The objective of this study was to evaluate the effect of varying proportions of dietary kale on rumen pH and volatile fatty acid production. Four pregnant dry dairy cows permanently fitted with ruminal cannulae were randomly assigned to four kale: grass silage dietary proportions (0:100, K0; 60:40, K60; 85:15, K85 and 100:0, K100) on a dry matter basis in a 4 × 4 Latin Square design with four 20 day periods. Cows were acclimatised for 15 days, followed by a five-day period of experimental sampling and measurement. Internal pH meters were installed to continuously monitor rumen pH while rumen liquor collection tubes were used to sample rumen liquor for volatile fatty acid analysis at 0, 4, 8 and 12 h after feeding on each sampling day. Cows on treatment K85 had a lower (P < 0.001) ruminal pH compared to cows on treatments K100, K60 or K0 (6.26, 6.32, and 6.32 vs. 5.91, respectively). While a gradual decrease in rumen pH was observed over an eight-hour period for K85 before recovery, offering K100 did not reduce rumen pH below 6.0 or induce acidosis. Increasing the dietary proportion of kale did not affect (P > 0.05) acetate:propionate ratio production (3.71, 3.65, 3.86, 3.78 mmol L^− 1 for K0, K60, K85 and K100, respectively). Offering cows K60 had increased (P < 0.05) rumen VFA concentration (71.67 mmol L^− 1) relative to K0 (53.45 mmol L^− 1), while offering K85 and K100 had no affect on rumen VFA concentration (61.74 and 59.35 mmol L^− 1) (Table 2). Offering dry cows K100 relative to K0 reduced dry matter intake by 17.5% (7.32 vs. 8.87 kg DM day^− 1, respectively) which may be associated with the presence of S-methyl-L-cysteine sulphoxide which can cause haemolytic anaemia and depressed DM intake. The results suggest that increasing the dietary proportion of kale was associated with a progressive decrease in dry matter intake but with minimal effects on rumen pH, total volatile fatty acid concentration and individual volatile fatty acid proportions.     

不同酶、菌及复合酶菌制剂对水稻秸秆青贮品质与瘤胃降解率的影响

为研究不同组合酶菌制剂处理对水稻秸秆青贮饲料的营养成分、发酵品质及瘤胃降解特性的影响,试验共设9个处理组:对照组(CK)、复合酶制剂处理组(C)、果胶酶+漆酶处理组(PL)、复合酶制剂+果胶酶+漆酶处理组(CL)、植物乳酸杆菌处理组(LP)、布氏乳酸杆菌处理组(LB)、植物乳酸杆菌+布氏乳酸杆菌处理组(LPB)、复合酶制剂+果胶酶+漆酶+植物乳酸杆菌(CLP)、复合酶制剂+果胶酶+漆酶+植物乳酸杆菌+布氏乳酸杆菌处理组(CLPB),以水稻秸秆为研究对象,采用真空聚乙烯袋袋装发酵,贮藏45d后取样,利用实验室化学分析和半体内法(insitu)对水稻秸秆青贮饲料的营养成分含量、发酵品质及瘤胃降解率进行测定分析。结果表明:(1)与对照组相比,酶制剂处理组(C、PL和CL)pH、乙酸含量、氨态氮/总氮、DM、ADF级纤维素含量显著降低(P<0.05),其DM、NDF、ADF和纤维素瘤胃有效降解率显著升高(P<0.05)。(2)与对照组相比,菌制剂处理组(LP、LB和LPB)pH、氨态氮/总氮、NDF、ADF及纤维素含量显著降低(P<0.05),乙酸及DM、纤维素、CP瘤胃有效降解率显著提高(P<0.05)。(3)与酶制剂、菌制剂及对照组组相比,复合酶菌制剂处理组(CLP和CLPB)pH和纤维素含量最低,乳酸含量及DM保存量最高,NDF、纤维素及CP的瘤胃有效降解率最高。综上所述,复合酶菌制剂组合添加能更好的改善水稻秸秆青贮饲料的发酵品质,提高其主要营养物质的瘤胃降解率。     

瘤胃微生物体外发酵不同配比大豆荚与稻草混合粉产气量研究

为农村广泛开展稻草、玉米秸、麦秸、豆秸、谷草、荚壳等低粗饲料的有效利用,尤其是资源丰富的玉米秸秆和稻草,利用瘤胃微生物体外生物合成蛋白质饲料。试验设置7个处理组3重复,研究瘤胃微生物体外发酵大豆荚和稻草混合粉的产气量和气体种类。结果发现:大豆荚和稻草粉配比为7:3组合和6:4组合都能够促进羊瘤胃微生物体外繁殖与生长而提高饲料粗纤维的降解率。大豆荚和稻草混合粉配比7:3组合作为羊的瘤胃微生物体外发酵底物比较适宜。     

Effects of graded levels of liquid brewer's yeast on chemical composition and fermentation quality in cassava pulp and rice straw‐based total mixed ration silage

This study aimed to evaluate the effect of liquid brewer's yeast (LBY) addition on chemical composition and fermentation quality of mixture of LBY and cassava pulp (CVP) with rice straw (RS) in different ratios during preservation periods. Four mixtures of LBY, CVP and RS were made, that is mixture ratio of LBY : CVP : RS of 0% LBY, 20% LBY, 35% LBY and 50% LBY were 0:70:30, 20:50:30, 35:35:30 and 50:20:30 as fresh matter, respectively. The bags were opened at weeks 0, 1, 2, 4 and 8 after storage. The contents of dry matter, organic matter, crude protein (CP), ether extract (EE), neutral detergent fiber and acid detergent fiber ranged 36.4‐40.0, 88.9‐90.8, 4.0‐12.0, 1.1‐1.3, 58.8‐61.6 and 37.6‐40.0, respectively, and the contents of CP and EE increased and the other components decreased in proportion to LBY inclusion (P < 0.01). 50% LBY had the highest (P < 0.05) pH (4.81) and ammonia nitrogen per total nitrogen (NH₃‐N/TN) (7.40%) and the lowest V‐score (90.3). Propionic and butyric acid contents were 0.01% or lower in each mixture and storage period. There were rapid pH decrease and NH₃‐N/TN increase during the first week of the storage period. The increases of NH₃‐N/TN and acetic acid content and decreases of pH, lactic acid content and V‐score during the preservation were more drastic as LBY inclusion increased. Although higher proportion of LBY produced higher CP and lower fiber contents in the mixture, attention should be paid for the reduction of fermentation quality during longer storage periods.