Feeding value of urea molasses-treated wheat straw ensiled with fresh cattle manure for growing crossbred cattle calves

The study was carried out to evaluate the influence of urea plus molasses-treated wheat straw (WS) ensiled with cattle manure (CM) on nutrients intake, their digestibilities, and growth performance of crossbred (Sahiwal × Holstein Friesian) cattle calves. The CM was mixed with ground WS in a ratio of 30:70 on dry matter (DM) basis. The WS–CM mixture treated with urea (4% DM) and molasses (4% DM) was allowed to ferment for 40 days in a cemented pit. Four iso-nitrogenous and iso-energetic fermented wheat straw (FWS)-based experimental diets were formulated. The FWS0, FWS20, FWS30, and FWS40 diets contained 0%, 20%, 30%, and 40% FWS, respectively. Twenty calves (9–10 months of age) were randomly allocated to four dietary treatments in a randomized complete block design, five in each group. Increasing trends for DM, organic matter, crude protein, and neutral detergent fiber intakes by calves were observed with increasing dietary FWS level. Weight gain was significantly different among calves fed different levels of FWS. The highest weight gain (491.8 g/day) was observed in calves fed FWS40 diet, while calves fed FWS0 and FWS20 diets gained 350.0 and 449.6 g/day, respectively. The results from this study imply that the FWS can be added up to 30% in the diet of growing crossbred calves without any detrimental effect on their performance.     

Use of additives to capture nitrogen in ammoniated wheat straw: Intake, ruminal parameters, digestibility and nitrogen utilization in buffaloes

This study examined the influence of urea treated wheat straw (UTWS) ensiled with additives on feed intake, digestibility, ruminal characteristics and N utilization in Nili-Ravi buffalo bulls (Babulus bubalis) fed ad libitum. Wheat straw was treated on large scale with 4% urea at a 50% moisture level. The UTWS was ensiled with 6% CSL, 6% acidified molasses, 2% acetic acid and 2% formic acid on DM basis in four different cemented trench silos for 15 days. Four diets each having 50% dry matter (DM) from UTWS ensiled with acetic acid (AD), formic acid (FD), acidified molasses (MD) or corn steep liquor (CD) and 50% DM from concentrate mixture were fed to ruminally cannulated bulls in a 4 × 4 Latin square design. Ruminal total VFA, acetate, cellulolytic ruminal bacterial count, DM and NDF degradability were significantly higher with MD and CD diets compared with AD and FD diets. Intake of different feed fractions was higher in bulls fed MD and CD diets. Total tract apparent digestibility of nutrients was similar across all treatments. Nitrogen retention was higher in bulls fed MD and CD diets than those fed AD and FD diets. Ensiling UTWS with fermentable carbohydrates sources having low pH compared to organic acids increased the N fixation in the matrix of cell wall fiber thus slowing its release at ruminal level that probably enhanced the N synchronization with carbon skeleton (fiber fermentation) and this consequently improved the N utilization.     

Effects of Fermented Green Juice and Cellulase on the Fermentation Quality of Rice Straw Silage and Rice Straw with Sugarcane Tip Mixed Silage

Rice straw and sugarcane tip were used as the silage materials in this research,and there were two groups:Rice straw silage and mixed silage of rice straw and sugarcane tip with the mixed ratio 6:4(m/m).Four treatment groups were set up in each silage:Control group (CON) and three treatment groups which added 2 mL/kg fermented green juice (FGJ),3 mL/kg cellulase (CEL) and 2 mL/kg FGJ+3 mL/kg CEL (MIX),and treatment was repeated 3 times. The materials were ensiled at room temperature for 60 days,and the fermentation quality and chemical compositions were tested. The result showed that for the two kinds of raw silage materials,the contents of WSC and CP in rice straw were lower than those in sugarcane tip,while the contents of NDF and ADF in rice straw were higher than those of sugarcane tip.Compared with the CON group,the NDF,ADF,pH and NH₃-N in FGJ group were extremely significantly decreased when rice straw was silaged alone (P<0.01),while WSC was extremely significantly increased (P<0.01),and DMR was increased. The NDF,ADF,pH,GLR and NH₃-N in MIX group were extremely significantly decreased (P<0.01),while lactic acid,WSC and DMR were increased. In CEL group, the ADF was significantly decreased (P<0.05), and other indicators also had improved in different degrees. Compared with rice straw silage,the NDF,HC,pH and NH₃-N of mixed silage were lower,while DMR and WSC were obviously increased. In conclusion,the fermented green juice and it compound with cellulase had the similar effects on improving the fermentation quality,and the effects were both better than that of cellulase. The fermentation quality of rice straw with sugarcane tip mixed silage was better than rice straw silage.     

不同稻秸平菇菌糠营养成分差异及其体外瘤胃发酵特性研究

本试验旨在研究不同收菇次数对稻秸平菇菌糠营养成分和体外瘤胃发酵特性的影响。选取1676(OM1)、江都71(OMJ)、六月灰(OML)3种平菇真菌接种稻秸,分别收取第0、1、2茬平菇菌糠,记为OM1-0、OM1-1、OM1-2、OMJ-0、OMJ-1、OMJ-2、OML-0、OML-1和OML-2,以其为底物测定常规营养成分,并采集瘘管羊的瘤胃液进行体外模拟瘤胃发酵72 h试验。结果表明:OM1-1组粗蛋白质(CP)、总挥发性脂肪酸(TVFA)、氨态氮(NH₃-N)、氢气及72 h总产气量显著高于OM1-0和OM1-2组;OMJ-1组CP、粗脂肪(EE)、氢气和NH₃-N浓度显著高于OMJ-0和OMJ-2组;OML-0组总能(GE)、EE、TVFA、NH₃-N和各产气量均高于OML-1和OML-2组;3种稻秸平菇菌糠中性洗涤纤维(NDF)和酸性洗涤纤维(ADF)含量均随收菇次数增加而显著降低;OML-0组CP、各产气量、NH₃-N及TVFA浓度显著高于OM1-0和OMJ-0组,且体外发酵液pH和乙丙比显著低于OM1-0和OMJ-0组。综合来看,OML-0组营养物质组成和体外发酵特性较优,具有较高饲用价值。     

绿汁发酵液和纤维素酶对稻草青贮及稻草、甘蔗梢混合青贮品质的影响

本研究以稻草和甘蔗梢为青贮原料,调制稻草青贮及稻草与甘蔗梢混合青贮（混合比例为6：4（m/m））。在稻草青贮及稻草、甘蔗梢混合青贮中均设计添加2 mL/kg的绿汁发酵液组（FGJ）、3 mL/kg的纤维素酶组（CEL）、2 mL/kg绿汁发酵液+3 mL/kg纤维素酶的复合组（MIX）和对照组（CON）,每个处理重复3次,室温条件下贮存60 d后开封,测定青贮的发酵品质和化学成分。结果显示,青贮原料稻草干物质中的可溶性碳水化合物（WSC）和粗蛋白质（CP）含量均低于甘蔗梢,而中性洗涤纤维（NDF）、酸性洗涤纤维（ADF）含量均高于甘蔗梢。稻草单独青贮后,与CON组相比,FGJ组的NDF、ADF、pH和氨态氮均极显著降低（P<0.01）,WSC极显著增加（P<0.01）,干物质回收率（DMR）升高;MIX组的NDF、ADF、pH、气体损失率（GLR）和氨态氮均极显著降低（P<0.01）,乳酸、WSC及DMR升高;CEL组中除ADF显著降低外,其他指标也有不同程度的改善。与稻草青贮相比,稻草、甘蔗梢混合青贮的pH、氨态氮、NDF和半纤维素（HC）均降低,而DMR和WSC均明显升高。综上所述,绿汁发酵液及其与纤维素酶的复合添加剂对改善稻草青贮及稻草、甘蔗梢混合青贮品质的效果相近,且优于纤维素酶;稻草、甘蔗梢混合青贮的品质优于稻草青贮。     

Fermentation characteristics and nutritional value of ruminal contents and blood ensiled with untreated or sodium hydroxide-treated wheat straw.

Bovine ruminal contents and blood were ensiled with wheat straw, either untreated or treated with 4% NaOH (DM basis), with and without addition of 5% dry molasses. Proportions of ruminal contents, blood, and straw were 45:15:40, wet basis, respectively. Wheat straw also was ensiled alone, and water was added to attain 43% DM. After 60 d, all silages had a desirable aroma. The pH of the ensiled mixtures of ruminal contents, blood, and untreated straw was 4.43 and 4.56, with and without molasses, respectively. Values for silages containing treated straw, with and without molasses, were 5.95 and 7.37, respectively. All silages had substantial levels of lactic acid (2.4 to 4.9%, DM basis). Addition of molasses increased (P less than .01) lactic acid concentrations. In a metabolism trial, 36 wethers were fed a 50% orchardgrass hay basal diet alone or supplemented with ensiled materials (1:1 ratio, DM basis) such that final diets had about 7 and 4% of their DM from ruminal contents and blood, respectively. Among the diets containing the ensiled mixtures, digestibilities of DM, OM, energy, NDF, ADF, cellulose, and hemicellulose were 6 to 20 percentage units higher (P less than .01) for silages containing treated vs untreated straw. Addition of molasses increased apparent digestibility only of CP and only in sheep fed ensiled mixtures with treated straw (interaction of straw treatment x molasses addition, P less than .05). Nitrogen balance was increased (P less than .05) from 1.6 g/d to 2.9 g/d by NaOH treatment of straw. Metabolizable energy was higher (P less than .05) for diets containing silages with NaOH-treated straw.(ABSTRACT TRUNCATED AT 250 WORDS)     

纤维素酶对常规水分和低水分稻草青贮品质的影响

为了研究不同水平纤维素酶对常规和低水分稻草青贮发酵品质的影响,为生产优质稻草青贮饲料提供理论依据。试验调制常规水分（70.00%）和低水分（37.50%）两种水分的稻草青贮,每种水分均设4组纤维素酶（cellulase,CEL）添加浓度,分别为0（CON）、20（CEL1）、40（CEL2）和80 mg·kg^-1（CEL3）,共计8个处理。每个处理重复3次。常温下青贮60 d开封,测定青贮饲料的发酵品质和化学成分。结果发现：两种水分青贮料中,低水分青贮料的pH和DMR显著（P<0.05）提高,NH₃-N含量显著（P<0.05）低于常规水分青贮料;常规青贮中,4组纤维素酶浓度组的WSC含量显著（P<0.05）增加、NDF和ADF含量显著（P<0.05）减少,其中CEL1组和CEL2组的pH显著（P<0.05）降低;低水分青贮中,4组纤维素酶浓度组的pH和NDF含量显著（P<0.05）降低、DM含量显著（P<0.05）增加,另外,CEL2组和CEL3组的DMR含量显著（P<0.05）提高,CEL2组的WSC含量显著（P<0.05）增加;2种水分青贮中,均以CEL2组的DM、DMR、WSC最高,pH、GLR、NDF含量、ADF含量、NH₃-N含量最低。研究结果表明,在常规水分和低水分稻草青贮中,3个纤维素酶水平都有显著的添加效果,且以40mg·kg^-1的添加效果最佳。     

糖蜜添加对西兰花茎叶稻秸苜蓿混合青贮发酵品质的影响

本试验目的是评价糖蜜添加对西兰花茎叶稻秸苜蓿混合青贮发酵品质的影响,试验设3个处理,即糖蜜添加为0(对照组),2.5%,5.0%,添加比例以鲜重为基础。在青贮后的第1,3,5,7,14和30天打开青贮罐,测定青贮饲料发酵品质。结果表明,对照组pH值在青贮发酵最初14 d缓慢下降,青贮第30天,对照组的pH值显著上升到4.96(P<0.05),糖蜜添加组pH值从第3天开始随青贮时间增加而显著降低(P<0.05),30 d后,pH值均低于4.0。在青贮的第14天,所有处理组乳酸含量均达到其最大值,分别为50.82,84.84,86.64 g/kg DM。所有处理组乙酸和挥发性脂肪酸含量均随着青贮时间的增加而逐渐增加。在青贮发酵过程中所有处理组丙酸和丁酸均未检出或少量检测到。与对照组相比,糖蜜添加显著(P<0.05)提高了乳酸/乙酸、乳酸含量,同时显著(P<0.05)降低了pH值、氨态氮/总氮和丁酸含量;但2.5%和5.0%糖蜜添加青贮在pH值、乳酸/乙酸、乳酸含量、氨态氮/总氮和丁酸含量上无显著差异。综上所述,添加2.5%糖蜜即可提高混合青贮发酵品质。     

添加不同水平糖蜜对全株“张杂谷”青贮体外瘤胃发酵特性和营养物质降解率的影响

本试验旨在研究添加不同水平糖蜜对全株"张杂谷"青贮发酵特性及其营养物质降解率的影响。选用3头安装有永久性瘤胃瘘管且体况相近的荷斯坦奶牛作为瘤胃液供体,在全株"张杂谷"青贮中分别添加0（对照组）、2%、4%和6%糖蜜,室温条件下贮存60 d,评定添加糖蜜对全株"张杂谷"青贮品质的影响。结果显示,①4%糖蜜组干物质（DM）含量显著高于2%、6%糖蜜组（P<0.05）,但与对照组间差异不显著（P>0.05）;各组间粗蛋白质（CP）含量无显著差异（P>0.05）;4%糖蜜组中性洗涤纤维（NDF）含量显著低于对照组及2%糖蜜组（P<0.05）,酸性洗涤纤维（ADF）含量显著低于其他组（P<0.05）。②添加4%糖蜜后干物质消失率（DMD）显著高于对照组及2%糖蜜组（P<0.05）;4%糖蜜组粗蛋白质消失率（CPD）、中性洗涤纤维消失率（NDFD）显著高于对照组及6%糖蜜组（P<0.05）,酸性洗涤纤维降解率（ADFD）含量显著高于对照组（P<0.05）。③与对照组相比,添加糖蜜组代谢能（ME）、泌乳净能（NE_L）和72 h总产气量（GP_{72 h}）升高（P>0.05）;添加4%糖蜜组产气量达到理论最大产气量的1/2时的时间（C）显著低于对照组（P<0.05）。④添加糖蜜组发酵液pH、氨态氮（NH₃-N）、微生物蛋白（MCP）、总挥发性脂肪酸（TVFA）、非生糖类挥发酸与生糖类挥发酸比例（NGR）、乙酸、丙酸、丁酸、戊酸及支链脂肪酸与对照组均无显著差异（P>0.05）,其中4%糖蜜组各项发酵指标均较好。综上所述,本研究条件下,糖蜜最适添加水平为4%。     

凋萎和添加剂对稻草裹包青贮发酵品质和营养价值的影响

本试验旨在研究凋萎和添加剂对稻草裹包青贮发酵品质和营养价值的影响。将10月底收割的鲜稻草和凋萎24 h稻草(干鲜比分别为36.5%、42.3%)均设4个组,即对照组、糖蜜组(单独添加糖蜜)、青贮宝组(单独添加青贮宝)和糖蜜+青贮宝组(糖蜜和青贮宝联合添加),每组制作3包。常温裹包青贮50 d后,开包采样进行感官品质、发酵参数和营养价值评定。结果显示:无论鲜稻草是否凋萎,稻草单独青贮难以成功,添加剂糖蜜、青贮宝的添加有利于稻草的裹包青贮;单独添加青贮宝显著降低凋萎稻草青贮的氨态氮(NH_3-N)含量(P0.05);单独添加糖蜜显著提高凋萎稻草青贮的乙酸含量(P0.05),显著降低凋萎稻草青贮的中性洗涤纤维(NDF)和酸性洗涤纤维(ADF)含量(P0.05);联合添加糖蜜和青贮宝可显著提高鲜稻草或凋萎稻草青贮的粗蛋白质(CP)和钙(Ca)含量(P0.05),显著降低鲜贮稻草青贮的NDF含量(P0.05),显著降低凋萎稻草青贮的NH_3-N含量(P0.05),显著增加凋萎稻草青贮的乙酸、丙酸和丁酸含量(P0.05)。凋萎显著降低稻草青贮的干物质回收率和丙酸含量(P0.05),提高稻草青贮的CP和NH_3-N含量(P0.05)。综上,稻草单独青贮难以成功,添加糖蜜和青贮宝有利于提高稻草青贮的发酵品质,稻草青贮前凋萎要适度。     

水分和添加剂对辣椒秸秆青贮品质的影响

本试验旨在探究不同水分和添加剂对辣椒秸秆青贮发酵品质的影响,为扩大饲料资源提供新的途径。试验选取末次收获辣椒后的辣椒鲜秸秆为原料,设3个水分(75%左右、65%左右和55%左右)梯度,分别添加甲酸(1.5% FW,FA)、丙酸(1.5% FW,PA)、玉米粉(100 g/kg DM,CF)和马铃薯渣(30% FW,PD),以不使用添加剂为对照组(CK),100 mL PE瓶常温青贮45 d,测定其发酵品质和营养成分。结果表明,水分、添加剂及其互作对辣椒秸秆青贮效果均有显著影响(P<0.05);随含水量的降低,pH和干物质升高,乳酸、酸性洗涤纤维和中性洗涤纤维降低,含水量75%青贮饲料的pH和中性洗涤纤维最低,乳酸生成最多,氨态氮/全氮较低;与CK相比,添加FA显著(P<0.05)降低青贮饲料pH和氨态氮/全氮,增加乳酸和可溶性糖;添加PD和CF有效补充了发酵底物的不足,干物质和可溶性糖显著(P<0.05)增加;各添加剂组青贮料中均较少或未检测到丁酸。结合灰色关联度对参试青贮调制方式的青贮效果进行综合评价表明,含水量75%+FA的综合表现最佳,其次是含水量65%+PD。综上可知,辣椒秸秆适宜青贮的含水量为75%左右;添加马铃薯渣青贮于各水分条件下效果皆较优,在生产实践中值得推荐。     

多花黑麦草与大豆秸秆混合青贮发酵品质的研究

本研究旨在将多花黑麦草与大豆秸秆以不同比例混合青贮,评价其发酵品质,筛选出适宜的混合比例。试验设多花黑麦草与大豆秸秆的混合比例为10∶0(对照组)、9∶1 (S₁)、8∶2 (S₂)、7∶3(S₃)和6∶4(S₄)5个处理。青贮42 d后打开青贮桶,测定青贮饲料的发酵品质。结果表明,多花黑麦草与大豆秸秆混合青贮显著提高了干物质含量,降低了挥发性脂肪酸含量和氨态氮/总氮的值,其中S₂和S₃处理的丁酸和氨态氮/总氮值最低。V-Score 评分显示各混贮组的V-Score 得分均高于对照组,其中S₂和S₃处理的发酵品质为优等,而对照组的发酵品质为不良。从发酵品质和秸秆利用最大化的角度出发,建议将多花黑麦草和大豆秸秆以7∶3的比例混合青贮较为适宜。     

Effect of fibrolytic enzyme inclusion in high concentrate fattening diets on nutrient digestibility and growth performance of Awassi lambs

The objective of this study was to study the effect of fibrolytic enzyme (FE) inclusion on nutrient digestibility and growth performance of Awassi lamb fed on a high concentrate diet. Thirty weaned Awassi lambs (initial body weight = 20.4 ± 3.0 kg) were fed a high concentrate diet (with or without the addition of FE (15 lambs/treatment)) for 60 d in a completely randomized design. The diet contained 17, 7, 58.5, 15, and 2.5% wheat straw, wheat bran, barley grain, soybean meal and minerals, respectively. Lambs were fed ad libitum twice daily at 08:00 and 15:00 h. Dry matter, OM, CP, and NDF intakes were all similar (P > 0.05) for lambs fed diet with or without the FE and averaged 1078, 941, 171, and 432 g/d, respectively. Metabolizable energy intake was also not affected (P > 0.05) by the enzyme supplementation and averaged 2.87 Mcal/d. Dry matter, OM, CP, and NDF digestibilities were all unaffected (P > 0.05) by the enzyme inclusion and averaged 64.8, 67, 65.7 and 60.4%. Final body weight, average daily gain, and feed to gain ratio were all unaffected (P > 0.05) by the FE inclusion and averaged 34.9 kg, 222 g/d, and 5.4, respectively. In summary, FE treatment of high concentrate diet for lambs had no effect on nutrient intake or any of the growth performance parameters. Therefore, supplementing such diets with FE for fatting Awassi lambs is not recommended.     

苎麻青贮及不同粗蛋白质水平精料补充料对西门塔尔牛生长性能和血清生化指标的影响

本试验旨在研究苎麻青贮饲料品质及以苎麻青贮饲料为唯一粗饲料使用时,不同粗蛋白质（CP）水平精料补充料对西门塔尔牛生长性能和血清生化指标的影响。试验将苎麻与玉米秸秆按照质量比为1：1的比例混合均匀后打捆制成苎麻青贮饲料。选择年龄相近,体重为（324.83±30.27） kg的健康西门塔尔肉牛18头,随机分为3组,每组6头,1头牛为1个重复,分别饲喂CP含量为18.0%（高CP水平,试验Ⅰ组）、16.0%（中CP水平,试验Ⅱ组）和14.0%（低CP水平,试验Ⅲ组）的精料补充料。预试期10 d,正试期60 d。结果表明,苎麻与玉米秸秆混合青贮后,感官等级评定为1级优良,pH为4.24,氨态氮（NH₃-N）含量显著增加（P<0.05）,干物质（DM）、有机物（OM）、CP、中性洗涤纤维（NDF）、酸性洗涤纤维（ADF）、钙（Ca）和总磷（TP）含量均无显著差异（P>0.05）。饲养试验结果表明,试验Ⅰ组肉牛平均日增重（ADG）最高,达到1.49 kg/d,试验Ⅱ、Ⅲ组ADG与试验Ⅰ组相比分别降低了14.09%和11.41%（P>0.05）。3个试验组的干物质采食量（DMI）和料重比（F/G）均无显著差异（P>0.05）。不同CP水平精料补充料对西门塔尔牛血清中碱性磷酸酶（ALP）、天门冬氨酸转移酶（AST）、ALT/AST、总蛋白（TP）、白蛋白（ALB）、球蛋白（GLB）、白球比（A/G）、总胆固醇（TCHO）、甘油三酯（TG）、高密度脂蛋白（HDL）和低密度脂蛋白（LDL）均无显著影响（P>0.05）,但是试验Ⅰ组血清丙氨酸转移酶（ALT）活性显著高于试验Ⅲ组（P<0.05）,但与试验Ⅱ组无显著差异（P>0.05）。综上,苎麻的营养水平较高,和玉米秸秆混合后青贮可得到品质较好的苎麻青贮饲料;将苎麻青贮饲料作为肉牛唯一粗饲料来源,高CP含量（18%）的精料补充料可提高肉牛的生长性能。     

Effects of exogenous fibrolytic enzymes on ruminal digestibility in steers fed high fiber rations

The effects of two exogenous fibrolytic enzyme products on ruminal disappearance and fermentation of oat straw-wheat middlings based diets were evaluated. Six steers (322 ± 34.4 kg body weight) fitted with ruminal cannulas were used in a 3 × 3 Latin square replicated. The treatments consisted of: 1) control, 2) Fibrozyme (2 g/kg dry matter), and 3) Promote (3 ml/kg dry matter). Both, Fibrozyme (Alltech Inc.) and Promote NET (Cargill Corp.) were sprayed as liquid onto diets and feeds 24 h before feeding. Samples of diets were ruminally incubated from 0 to 72 h. Enzymes did not change dry matter intake, average daily gain and feed conversion. Fibrozyme increased crude protein (CP) disappearance rate of diet, while Promote increased CP total disappearance. In diets, enzymes did not affect ruminal neutral detergent fiber (NDF) and acid detergent fiber (ADF) fractions. Fibrozyme and Promote did increase CP total disappearance, ADF potential disappearance and ADF disappearance rate of wheat middlings, as well as dry matter (DM) and CP total disappearance, NDF disappearance rate, ADF potential disappearance and ADF disappearance rate of oat straw. Ruminal pH values were higher with enzymes, as compared to control. Total volatile fatty acids concentration and molar proportion of acetate and butyrate were not affected by both enzymes, but molar proportion of propionate was lower and acetate:propionate ratio higher with Promote than control. Fibrozyme and Promote did increase DM and CP soluble fractions of diets, as well as, ADF potential disappearance of wheat middling and oat straw.     

玉米粉和乳酸菌对甘薯蔓、酒糟及稻草混合青贮品质的影响

为评价玉米粉和乳酸菌对甘薯蔓、酒糟及稻草(4∶4∶2)混合青贮品质的影响,试验设对照组(CK)、玉米粉添加组(CF)、乳酸菌添加组(LAB)、玉米粉和乳酸菌组合添加组(CF+LAB),每个处理6个重复,室温下贮藏60 d开封,取样分析青贮品质。结果表明,添加玉米粉和乳酸菌制剂均明显提高了青贮料的感官品质,与CK相比,CF处理、LAB处理及CF+LAB处理中 CP含量极显著提高(P<0.01), NH₃-N/TN、AA、PA、Ash含量极显著降低(P<0.01),CF处理极显著地提高了DM、CP、LA含量(P<0.01),而LAB处理则极显著地降低了NDF、ADF含量(P<0.01),CF+LAB中NH₃-N/TN、AA含量及pH值极显著低于LAB(P<0.01),显著低于CF(P<0.05)。综上所述,添加玉米粉和乳酸菌制剂均提高了青贮品质,单独添加乳酸菌制剂青贮品质要次于单独添加玉米粉,两者组合添加青贮品质更好。     

不同水平干苹果渣对育肥牛体外产气量、发酵参数、营养物质消化率和生长性能的影响

[目的] 研究不同水平干苹果渣替代精料补充料中部分能量饲料对西门塔尔育肥牛瘤胃体外产气量、发酵参数、营养物质消化率和生长性能的影响。[方法] 分别采用0、4%、8%、12%、16%干苹果渣替代肉牛精料补充料中部分玉米,应用体外产气法测定各组日粮体外发酵0~72 h的产气量;体外产气试验结束后,测定瘤胃液的发酵参数;体外发酵48 h测定人工瘤胃液营养成分体外消化率;利用4%、8%、12%干苹果渣替代精料补充料中部分玉米,测定饲喂不同替代比例日粮育肥牛的增重指标。[结果] 4%干苹果渣组总产气量显著（P<0.05）高于8%和16%干苹果渣组,各组样品产气主要集中在4~24 h,36~72 h产气量趋于平稳。产气后各组pH值均在正常范围;8%干苹果渣组氨态氮浓度显著（P<0.05）高于12%和16%干苹果渣组;4%和8%干苹果渣组的乙酸、异丁酸、丁酸、异戊酸和戊酸浓度显著（P<0.05）高于其他各组。对照组的干物质、粗蛋白和中性洗涤纤维消化率显著（P<0.05）高于其他各组,8%干苹果渣组酸性洗涤纤维消化率显著（P<0.05）高于其他各组。各组育肥牛的试验期间总增重和日增重差异均不显著（P>0.05）。[结论] 4%干苹果渣替代精料补充料中部分玉米可提高西门塔尔育肥牛瘤胃体外发酵产气量,4%和8%干苹果渣替代精料补充料中部分玉米可提高瘤胃液中氨态氮浓度及挥发性脂肪酸浓度,有利于瘤胃发酵和饲粮消化。     

不同温度条件下发酵时间对完全混合发酵日粮(TMF)发酵品质的影响

本试验旨在研究不同温度条件下，发酵时间对完全混合发酵日粮（total mixed fermentation ration，TMF）发酵品质的影响。将0.5% CT-10（同型发酵乳酸杆菌）、5%糖蜜和TMR装入发酵袋内并于5、15和25℃条件下密封发酵，在发酵5、10、15、20和30 d时开袋取样测定其发酵品质。结果显示：5℃时，随着发酵时间的延长，各组间中性洗涤纤维（NDF）和粗灰分（Ash）无显著差异（P > 0.05），而干物质（DM）、粗蛋白质（CP）、粗脂肪（EE）和酸性洗涤纤维（ADF）含量均随时间的增加而显著降低（P < 0.05）；15℃时，各组间NDF含量无显著差异（P > 0.05），而其他指标含量均呈现下降趋势；25℃时，各组间EE、Ash、NDF和ADF无显著差异（P > 0.05），而CP随着发酵时间的增加显著降低（P < 0.05）。不同的发酵时间对TMF有机酸含量影响显著（P < 0.05），在5和15℃时，发酵30 d天时pH分别降至4.23和4.36，达到发酵过程中的最低点；各个发酵温度条件下，氨态氮（NH₃-N）含量变化趋势一致，前15 d持续增加，之后又呈现先缓慢降低再增加的趋势；25℃时，发酵20 d，pH降至4.57，乳酸含量和TVFAs含量分别达到最高。综合以上结果和V-Score评分最终得出：5℃时，发酵20 d效果较好，15℃时，发酵15、20 d效果较好；25℃时，发酵5 d效果较好，饲料等级均为优。     

南疆干旱灌溉区青贮玉米农艺性状和发酵品质动态分析及评价

为研究荒漠灌溉地区青贮玉米农艺性状和发酵品质动态变化规律以及筛选第三师地区最佳青贮玉米栽培品种,选择4个青贮专用和11个粮饲兼用型玉米品种为试验材料,分别在灌浆期、1/4乳线期、1/2乳线期和3/4乳线期进行农艺性状测定并调制青贮饲料。发酵60 d进行青贮饲料发酵品质、营养成分和体外消化测定,以农艺性状、营养成分、发酵品质和消化特征为评价指标,利用相似优先比法对15个玉米品种进行综合评价。结果表明:随生育期推进各青贮玉米株高、穗位、鲜草产量、全株鲜重、茎秆鲜重、果穗鲜重、籽粒鲜重、干物质(DM)、粗蛋白(CP)、可溶性碳水化合物(WSC)、淀粉含量和代谢能(ME)不断递增,到3/4乳线期达到峰值;其中,3/4乳线期大丰30鲜草产量最高,金玉9号DM含量最高,新饲玉10号CP含量最高,先玉696 WSC含量最高,屯玉765淀粉含量最高,均与其他品种差异显著(P<0.05)。随生育期推进,中性洗涤纤维(NDF)、酸性洗涤纤维(ADF)含量、氨态氮∶总氮(NH₃-N/TN)、有机物消化率(OMD)和产气速率不断递减,ADF、NDF、NH₃-N...     

酵母多糖对哺乳犊牛瘤胃发酵的影响

试验旨在研究日粮中添加不同剂量的酵母多糖对哺乳犊牛瘤胃发酵参数的影响。选用56头新生荷斯坦犊牛随机分为4组,每组14头（其中母犊6头、公犊8头）。试验Ⅰ组（对照组）饲喂基础日粮,试验Ⅱ、Ⅲ、Ⅳ组在基础日粮中分别添加1、2、3 g/（头·d）的酵母多糖,试验期60 d,分别在20和60日龄时每组各屠宰4头犊牛,采集瘤胃液测定挥发性脂肪酸（VFA）、pH、氨态氮（NH₃-N）及微生物蛋白（MCP）产量。结果表明：①在整个生长期内,各处理组犊牛瘤胃液pH及丁酸浓度、乙酸/丙酸差异均不显著（P>0.05）;②20日龄时,试验Ⅲ组犊牛瘤胃乙酸浓度极显著高于试验Ⅰ组（P<0.01）,试验Ⅱ组丙酸浓度显著高于试验Ⅰ组（P<0.05）,总挥发性脂肪酸（TVFA）浓度在各组间差异不显著（P>0.05）,60日龄时,试验Ⅲ组犊牛瘤胃乙酸浓度极显著高于试验Ⅰ组（P<0.01）,各组之间丙酸浓度差异不显著（P>0.05）,试验Ⅱ、Ⅲ、Ⅳ组TVFA浓度显著高于试验Ⅰ组（P<0.05）,其中试验Ⅲ组最高;③ 20日龄时,试验Ⅲ组犊牛瘤胃NH₃-N浓度显著低于试验Ⅰ组（P<0.05）,试验Ⅱ组MCP产量显著高于其他各组（P<0.05）,60日龄时各组之间NH₃-N浓度差异不显著（P>0.05）,试验Ⅲ组MCP产量显著高于其他各组（P<0.05）。综合上述结果,在犊牛日粮中添加2 g/（头·d）的酵母多糖降低了瘤胃液NH₃-N浓度,提高了MCP产量及TVFA浓度,增强了瘤胃内氨和蛋白质的利用,有利于犊牛瘤胃发酵状态的稳定。本试验条件下酵母多糖在0~60日龄犊牛日粮中的适宜添加量为2 g/（头·d）。