Effects of dietary forage to concentrate ratio and wildrye length on nutrient intake, digestibility, plasma metabolites, ruminal fermentation and fecal microflora of male Chinese Holstein calves

Twenty-eight male, weaned Chinese Holstein calves（（156.8±33.4） kg） were used to investigate the effects of dietary forage to concentrate ratio（F：C） and forage length on nutrient digestibility, plasma metabolites, ruminal fermentation, and fecal microflora. Animals were randomly allocated to four treatments in a 2×2 factorial arrangement： whole-length forage（WL） with low F：C（50：50）; WL with high F：C（65：35）; short-length forage（SL） with high F：C（65：35）; and SL with low F：C（50：50）. Chinese wildrye was used as the only forage source in this trial. The grass in the SL treatments was chopped using a chaff cutter to achieve small particle size（-50% particles 〉19 mm）. Dry matter intake（DMI） and organic matter（OM） intake was increased by increasing both F：C（P〈0.01） and forage length（FL）（P〈0.05）, while acid detergent fiber（ADF） and neutral detergent fiber（NDF） intakes were only increased by increasing the F：C（P〈0.01）. The digestibility of NDF was increased as the FL increased（P〈0.01）, and it was also affected by interaction between F：C and FL（P〈0.05）. Cholesterol（CHO）（P〈0.01）, leptin（LP）（P〈0.05）, and growth hormone（GH）（P〈0.01） concentrations in plasma were increased as dietary F：C increased. A significant increase in plasma triglyceride（TG）（P〈0.01）, insulin（INS）（P〈0.05）, and GH（P〈0.01） levels was observed with decreasing dietary FL. Ruminal p H values of calves fed with low F：C diets were significantly lower than those in high F：C treatment（P〈0.05）. Increasing the F：C enhanced ruminal acetic acid（P〈0.05） and acetic acid/propionic acid（P〈0.01）. Fecal Lactobacillus content was significantly higher, while Escherichia coli and Salmonella contents were significantly lower in WL and high F：C groups（P〈0.05）. Lower fecal scores（higher diarrhea rate） were observed in calves fed with SL hay compared to WL hay（P〈0.05）. Denatured gradient gel electrophoresis（DGGE） bands and richness index（S） were significantly affected by the interaction between F：C and FL（P〈0.05）, under high F：C, band numbers and richness index from WL group were higher than that from SL group（P〈0.05）, whereas there were no differences between WL andSL groups under low F：C（P〉0.05）. Microflora similarity was 50–73% among the different treatments. It is concluded that the WL with high F：C（65：35） diet is suitable for weaned calves.

Effects of Different Sowing Times on Plant Height, Leaf Stem Ratio and DW/FW Ratio of Forage Sorghum in Autumn Idle Land

The aim was to explore the linear regression prediction models between sowing time and plant height, leaf stem ratio and DW/FW ratio of forage sorghum in autumn idle land. [Method] The relationships between sowing time and plant height, leaf stem ratio and DW/FW ratio of forage sorghum were simulated and compared by employing field plot experiment and linear regression analysis. [Result] The sowing time had a great impact on plant height, leaf stem ratio and DW/FW ratio of forage sorghum in autumn idle land. With the delay of sowing time, the plant height and DW/FW ratio of forage sorghum decreased, while the leaf stem ratio increased. The regression models between sowing time and plant height, leaf stem ratio and DW/FW ratio of forage sorghum were established： plant height and sowing time, yheight = 234.725- 5.005X; leaf stem ratio and sowing time,ylcaf= 0.096 ＋ 0,019x; DW/FW ratio and sowing time, ydry= 0.305-0.002X. From July 23rd to August 30th, the plant height of forage sorghum was reduced by 5.005 cm, the leaf stem ratio was increased by 0.019 and the DW/FW ratio was reduced by 0.002 in average when hhe sowing time was delayed by one day. [Conclusion] This study provides a theoretical support for the production of forage sorghum in autumn idle land.

Effects of Dietary Concentrate to Forage Ratios on Production Performance and Serum Biochemical Indicators in Post-fattening Hainan Yellow Cattle

[Objective]The paper was to investigate the effects of dietary concentrate to forage ratios on production performance and serum bio-chemical indicators of post-fattening Hainan Yellow Cattle.[Method]Sixteen Hainan Yellow Cattles with the same genetic backgrounds and similar initial weight of(242.22 ±0.71 kg) were randomly divided into four treatments.Cattles were fed with diets of different concentrate to forage ratios(20:80, group Ⅰ;30:70, Group Ⅱ;40:60, group Ⅲ;50:50, group Ⅳ).The trial lasted 62 d.[Result]The daily gain in experimental group Ⅳ was significantly higher than that in experimental group Ⅱ(P<0.05), but the feed gain ratio in experimental group Ⅳ was lower than those in other ex-perimental groups(P>0.05).The feed intake in experimental group Ⅳ was also markedly higher than those in experimental groups Ⅰ and Ⅱ(P<0.05).Compared with the experimental group Ⅱ, the gross profit of experimental group Ⅳ was significantly promoted(P<0.05).The alanine aminotransferase and aspartate aminotransferase activities in experimental group Ⅱ were markedly higher than those in experimental groups Ⅰ, Ⅲ and Ⅳ.[Conclusion]When the dietary concentrate to forage ratios was 50∶50, the production performance of post-fattening Hainan Yellow Cattle was better.

Effect of Saccharomyces cerevisiae on alfalfa nutrient degradation characteristics and rumen microbial populations of steers fed diets with different concentrate-to-forage ratios

Live yeast（Saccharomyces cerevisiae） constitutes an effective additive for animal production;its probiotic effect may be related to the concentrate-to-forage ratio（CTFR）.The objective of this study was to assess the effects of S.cerevisiae（SC） on fiber degradation and rumen microbial populations in steers fed diets with different levels of dietary concentrate.Ten Simmental × Local crossbred steers（450 ± 50 kg BW） were assigned to a control group or an SC group.Both groups were fed the same basal diet but the SC group received SC supplementation（8 × 10^9 cfu/h/d through the ruminal fistula）following a two-period crossover design.Each period consisted of four phases,each of which lasted 17 d：10 d for dietary adaptation,6 d for degradation study,and 1 d for rumen sample collection.From the 1^（st） to the 4^（th） phase,steers were fed in a stepwise fashion with increasing CTFRs,i.e.,30：70,50：50,70：30,and 90：10.The kinetics of dry matter and fiber degradation of alfalfa pellets were evaluated;the rumen microbial populations were detected using real-time PCR.The results revealed no significant（P〉 0.05） interactions between dietary CTFR and SC for most parameters.Dietary CTFR had a significant effect（P〈 0.01） on degradation characteristics of alfalfa pellets and the copies of rumen microorganism;the increasing concentrate level resulted in linear,quadratic or cubic variation trend for these parameters.SC supplementation significantly（P〈 0.05） affected dry matter（DM） and neutral detergent fiber（NDF）degradation rates（c_（DM）,c_（NDF）） and NDF effective degradability（ED_（NDF））.Compared with the control group,there was an increasing trend of rumen fungi and protozoa in SC group（P 〈 0.1）;copies of total bacteria in SC group were significantly higher（P〈 0.05）.Additionally,percentage of Ruminobacter amylophilus was significantly lower（P〈 0.05）but percentage of Selenomonas ruminantium was significantly higher（P〈 0.05） in the SC group.In a word,dietary CTFR had a significant effect on degradation characteristics of forage and rumen microbial population.S.cerevisiae had positive effects on DM and NDF degradation rate or effective degradability of forage;S.cerevisiae increased rumen total bacteria,fungi,protozoa,and lactate-utilizing bacteria but reduced starch-degrading and lactate-producing bacteria.

Study on the Relationship of Seedling Density and Line Spacing to Leaf-stem Ratio, DW/FW Ratio and Grass Yield of Forage Sweet Sorghum

[ Objectives ] The aim was to optimize the configuration of seedling density and line spacing of forage sweet sorghum （ Sorghum blcolor （ L. ） Moench） and explore its high-yield cultivation techniques. [ Methods] Effects of such two influencing factors as line spacing and seedling density on the leaf-stem ratio, DW/FW ratio and grass yield of forage sweet sorghum were analyzed by using split-plot experiment design experiment method and LSD method of IBM. SPSS. Statis- tics. v22 stati, stics software. [ Results ~ Seedling density and line spacing had no obvious effect on the leaf-stem ratio and DW/FW ratio of forage sweet sorghum but had obvious influences on the grass yield. Moreover, the optimal combination of seedling density and line spacing for high yield of forage sweet sorghum was A2 B4, that is, seedling density was 225 000 plants/hm2, and line spacing was 40 cm. [ Conclusions] The results provided a theoretical basis and technical support for high-yield cultivation techniques of forage sweet sorghum.

The Influence of Forage/Concentrate Ratio and Full Fat Soya By-Pass Supplementation on the Fatty Acids Profile from the Carcase of Fatting Lambs

There was organized a 2×2 factorial type experience in which it has been aimed the influence of forage/concentrates ratio and the effect of supplementing the ratio with full fat soya by-pass （FFS） on the production performance and carcass fatty acid profile of fattening lambs. 32 Tsigai lambs were divided into 4 groups and were fed with 2 different diets regarding the forage/concentrates ratio （35/65 and 65/35, on a DM basis）, containing or not 5% FFS （full fat soya treated with formaldehyde 12.5%）. Including FFS in diet and the ratios rich in concentrates determined a significant improvement in weight gain （P〈0.01）, in the degree of food recovery and in fatty acid profile from the carcass. It has been significantly increased （P〈0.01） the weight of polyunsaturated fatty acids （PUFA） from intramuscular fat （longissimus dorsi-LD and femoral biceps-FB） and the deposit fat （subcutaneous-SC and perirenal-PR） and decreased the proportion of saturated （SFA） and monounsaturated fatty acids （MUFA）. Most significant differences were recorded about PUFA from Omega-3 series （C18：3 n-3, EPA C22：3 n-3, DPA and DHA） and CLA isomers （conjugated linolenic acid： C 18：2 C9, tl I＋C 18：2 t10, C 12）. The best profile of fatty acids, considered in light of the influence on human health （high concentration of Omega 3 fatty acids and CLA and low in SFA） was established in LD, for lambs fed with diets high in concentrates and which contained FFS （HC/S）.

不同精粗比饲粮中添加凝结芽孢杆菌对绵羊羔羊生长性能和消化代谢的影响

本试验旨在研究不同精粗比条件下饲粮添加凝结芽孢杆菌(BC)对绵羊羔羊生长性能和消化代谢的影响。试验采用2×2因子完全随机设计,2个因素分别为精粗比[40∶60(低精料)、70∶30(高精料)]和BC[不添加和添加1.0×1010CFU/kg BC]。选取48只4月龄的杜泊×小尾寒羊F1代公羔,按体重随机分为4个组,分别饲喂低精料饲粮(LD组)、添加BC低精料饲粮(LD+BC组)、高精料饲粮(HD组)、添加BC高精料饲粮(HD+BC组),每组12只。生长性能试验共计70 d,其中预试期10 d,正试期60 d;消化代谢试验共计7 d,其中适应期4 d,取样期3 d。结果显示:1)24只饲喂高精料饲粮羔羊的末重(FBW)和平均日增重(ADG)显著或极显著高于24只饲喂低精料饲粮羔羊(P<0.05或P<0.01),并且料重比(F/G)极显著低于24只饲喂低精料饲粮羔羊(P<0.01);24只饲喂添加BC饲粮羔羊的ADG显著高于24只饲喂不添加BC饲粮羔羊(P<0.05)。2)24只饲喂高精料饲粮羔羊对干物质(DM)、有机物(OM)、中性洗涤纤维(NDF)的表观消化率极显著高于24只饲喂低精料饲粮羔羊(P<0.05),而对酸性洗涤纤维(ADF)的表观消化率则极显著低于24只饲喂低精料饲粮羔羊(P<0.01);24只饲喂添加BC饲粮羔羊对DM、OM、NDF的表观消化率显著高于24只饲喂不添加BC饲粮羔羊(P<0.05)。同时,饲粮精粗比和BC在羔羊对OM和NDF的表观消化率上有显著的交互作用(P<0.05)。HD+BC组的OM和NDF的表观消化率显著高于其他3组(P<0.05)。3)24只饲喂高精料饲粮羔羊的粪能、总能表观消化率、总能代谢率极显著低于24只饲喂低精料饲粮羔羊(P<0.01);24只饲喂添加BC饲粮羔羊的总能表观消化率显著高于24只饲喂不添加BC饲粮羔羊(P<0.05)。饲粮精粗比和BC在粪能和总能表观消化率上有显著的交互作用(P<0.05)。4)24只饲喂高精料饲粮羔羊在氮表观消化率、微生物蛋白(MCP)合成量上显著或极显著高于24只饲喂低精料饲粮羔羊(P<0.05或P<0.01);饲粮精粗比和BC在摄入氮、粪氮、可消化氮、沉积氮、氮沉积率以及血清中尿素氮含量上有显著的交互作用(P<0.05)。综上所述,饲粮中添加BC较不添加BC可提高绵羊羔羊对饲粮中OM、DM、NDF的消化吸收,有效提高总能表观消化率,进而促进羔羊生长。相较饲喂精粗比为60∶40的饲粮,饲喂精粗比为70∶30的饲粮可提高绵羊羔羊对饲粮中OM、DM、NDF的消化吸收,有效提高总能表观消化率、氮表观消化率和MCP合成量,提高羔羊的生长性能。因此,BC可以作为一种新型的益生菌制剂应用于羔羊生产中,且在精粗比为70∶30的高精料饲粮中添加效果更优。

反刍动物日粮精粗比和非纤维性碳水化合物/中性洗涤纤维的研究进展

反刍动物的生长发育受日粮精料水平的影响。日粮精粗比和非纤维性碳水化合物/中性洗涤纤维(NFC/NDF)是反映日粮精料水平的2个常用指标。适宜的精粗比和NFC/NDF可以提高反刍动物的生产性能,维持瘤胃健康,提高经济效益。本文主要综述日粮精粗比和NFC/NDF对反刍动物生产性能、消化代谢和产品品质的影响,以期为反刍动物的日粮配制及健康生产提供参考。

不同精粗比饲粮中添加凝结芽孢杆菌对绵羊羔羊瘤胃发酵和免疫功能的影响

本试验旨在研究不同精粗比饲粮中添加凝结芽孢杆菌(BC)对绵羊羔羊生长性能、瘤胃发酵和免疫功能的影响。试验采用2×2双因子完全随机设计,2个因素分别为精粗比[40∶60(低精料)、70∶30(高精料)]和BC[不添加和添加1.0×10^(10)CFU/kg BC]。选取48只体重相近的4月龄杜泊×小尾寒羊F1代公羔,随机分为4个组,分别饲喂低精料饲粮(LD组)、添加BC的低精料饲粮(LD+BC组)、高精料饲粮(HD组)、添加BC的高精料饲粮(HD+BC组),每组12只。预试期10 d,正试期60 d。结果显示:1)24只饲喂高精料饲粮的羔羊瘤胃内pH,氨态氮、乙酸、异丁酸浓度以及乙丙比值显著低于24只饲喂低精料饲粮的羔羊(P<0.05),丙酸、戊酸和总挥发性脂肪酸浓度显著高于24只饲喂低精料饲粮的羔羊(P<0.05);24只饲喂添加BC饲粮的羔羊瘤胃内丙酸浓度显著高于24只饲喂未添加BC饲粮的羔羊(P<0.05)。饲粮精粗比和BC之间在瘤胃发酵参数上不存在显著的交互作用(P>0.05)。2)24只饲喂高精料饲粮的羔羊瘤胃内淀粉酶和蛋白酶活性显著高于24只饲喂低精料饲粮的羔羊(P<0.05),木聚糖酶活性显著低于24只饲喂低精料饲粮的羔羊(P<0.05);24只饲喂高精料饲粮的羔羊瘤胃内的总菌、栖瘤胃普雷沃氏菌、嗜淀粉瘤胃杆菌数量显著高于24只饲喂低精料饲粮的羔羊(P<0.05),黄色瘤胃球菌、产琥珀酸丝状杆菌、溶纤维丁酸弧菌和原虫数量显著低于24只饲喂低精料饲粮的羔羊(P<0.05)。24只饲喂添加BC饲粮的羔羊瘤胃内淀粉酶活性显著高于24只饲喂未添加BC饲粮的羔羊(P<0.05)。24只饲喂添加BC饲粮的羔羊瘤胃内嗜淀粉瘤胃杆菌、栖瘤胃普雷沃氏菌和溶纤维丁酸弧菌数量显著高于24只饲喂未添加BC饲粮的羔羊(P<0.05)。饲粮精粗比和BC之间在瘤胃微生物酶活性和功能微生物数量上不存在显著的交互作用(P>0.05)。3)24只饲喂高精料饲粮的羔羊血清中免疫球蛋白G(IgG)含量显著低于24只饲喂低精料饲粮的羔羊(P<0.05)。24只饲喂添加BC饲粮的羔羊血清中白细胞介素-4(IL⁃4)含量显著高于24只饲喂未添加BC饲粮的羔羊(P<0.05)。饲粮精粗比和BC在血清中IL⁃4含量上存在显著的交互作用(P<0.05)。综上所述,在不同精粗比饲粮中添加BC均可以促进瘤胃发酵,有效提高羔羊对饲粮的消化吸收,同时还可以提高机体炎症应答水平,进而促进羔羊健康生长,且在高精料饲喂条件下添加BC效果更好。因此,BC可以作为一种新型的益生菌制剂应用于羔羊生产中,且在精粗比为70∶30的高精料饲粮中添加效果更优。

三江源区适宜的小黑麦和饲用豌豆混播比例及施肥方法

【目的】三江源区地处青藏高原,是中国母亲河的发源地,也是牦牛等典型牲畜的重要草场。探索适宜的施肥方法和牧草作物混播比例,旨在提高牧草产量,减轻生态重要地区天然草场的放牧压力。【方法】于2022年在三江源地区进行了小黑麦和饲用豌豆的田间试验,试验材料为小黑麦品种‘青饲麦1号’和饲用豌豆品种‘青建1号’。设置3个施肥处理:不施肥(A_(1))、单施氮肥(尿素75 kg/hm^(2),A_(2))、氮磷配合施用(尿素75 kg/hm^(2)和过磷酸钙300 kg/hm^(2),A3);每个施肥处理下,分别设小黑麦和豌豆混合播种比例70∶30(B1)、50∶50(B_(2))和30∶70(B_3)。在豌豆盛花期刈割前,调查小黑麦和饲用豌豆株高、叶片形态指标(面积、周长、长度、宽度),及生物量和营养品质。【结果】与不施肥处理A_(1)相比,施肥处理(A_(2)和A_3)显著提高了牧草的鲜重和干重、蛋白质产量以及两种作物的株高和叶面积。A_(2)和A_3处理在上述指标上没有显著差异,但A_3处理叶宽的增幅显著高于A_(2)。A_(2)和A_3处理对两种牧草粗蛋白、可溶性糖、中性和酸性洗涤纤维含量均无显著影响,但A_(2)处理增加了粗脂肪含量。小黑麦和饲用豌豆的播种比例对两种作物的鲜重、干重、蛋白质产量和株高没有显著影响,但降低小黑麦播种比例增加了饲草粗脂肪和可溶性糖含量,显著降低了中性与酸性洗涤纤维含量。播种比例与施肥有显著的交互作用,A_3B_(1)的牧草鲜重和干重最高,分别比其他处理高36.09%~180.08%和62.27%~281.59%,叶面积和蛋白质、可溶性糖含量也最高。A_3B_(1)处理的小黑麦叶片周长比A_(1)B_(1)、A_(1)B_(2)和A1B3处理分别高15.76%、40.29%和54.51%,饲用豌豆叶面积比A1B1、A1B2和A1B3处理分别提高20.31%、14.06%和64.65%,饲草中性洗涤纤维含量分别比A1B1、A1B2和A1B3处理增加了7.15%、27.14%和17.89%。【结论】氮磷配施可显著提高牧草生产性能、叶片形态和牧草质量。小黑麦和饲用豌豆按70∶30的比例混合播种,牧草生产性能、叶片形态和质量均优于其他处理。因此,在高寒地区,建议推广小黑麦和饲用豌豆按70∶30的比例混合播种,并配施氮、磷肥。

高寒区燕麦、豌豆农艺性状对氮添加和间作模式的响应

间作种植与氮添加对高寒区燕麦(Avena sativa)和豌豆(Pisum sativum)农艺性状影响的研究报道较少。基于此,本研究以燕麦新品系‘青永久872’和饲用豌豆‘青建1号’为试验对象,比较间作种植模式和氮添加对间作燕麦、豌豆关键农艺性状的调控作用及产量的影响。结果表明:1)种植方式和氮添加均影响燕麦和豌豆农艺性状表现;2)低氮添加和隔行间作种植的燕麦、豌豆间作体系总土地当量比最高,且在N_(2)(50 kg·hm^(−2))和N_(3)(200 kg·hm^(−2))处理下燕麦种间竞争力强于豌豆;3)冗余分析(RDA)表明,种植方式和氮添加水平与燕麦株高、分蘖等与草产量相关的农艺性状正相关,氮添加水平与豌豆草产量相关农艺性状正相关,种植方式与豌豆种子产量相关农艺性状正相关;4)灰色关联分析表明,在未添加氮N1(0 kg·hm^(−2))时,单播燕麦分蘖和豌豆始荚节数、隔行间作燕麦单株籽粒数和豌豆荚数以及同行混合间作燕麦分蘖和豌豆荚数与草产量关联系数最大;在低氮添加N_(2)(50 kg·hm^(−2))时,单播燕麦分蘖和豌豆单株籽粒数、隔行间作燕麦粒长和豌豆荚数以及同行混合间作燕麦单株小穗数和豌豆单株籽粒数与草产量关联系数最大;在高氮添加N_(3)(200 kg·hm^(−2))时,单播燕麦茎粗和豌豆荚数、隔行间作燕麦单株籽粒重和豌豆单株籽粒数以及同行混合间作燕麦单株籽粒数和豌豆荚数与草产量关联系数最大。由此可见,合理安排种植方式和精准施氮是高寒区高品质栽培草地建植的关键。

不同灌草组合与行数比对多花木蓝灌草地牧草产量的影响

[目的]探明灌草组合和行数比对灌草地牧草产量的影响,为贵州中低海拔喀斯特地区多花木蓝灌草地建植与饲草生产提供依据。[方法]以黔南多花木蓝(I)、钻石T多花黑麦草(L)、宽叶雀稗(P)和WL525HQ紫花苜蓿(M)为试验材料,采用随机区组试验设计,研究7种灌草组合(A1,I 13.50kg/hm^(2)+L 24.00 kg/hm^(2);A2,113.50 kg/hm^(2)+P 9.00 kg/hm^(2);A3,113.50 kg/hm^(2)+P 9.00 kg/hm^(2)+M 7.50 kg/hm^(2);A4,I 13.50 kg/hm^(2)+P 11.70 kg/hm^(2)+M 3.00 kg/hm^(2);A5,I 13.50 kg/hm^(2)+L 8.40 kg/hm^(2)+P 8.10 kg/hm^(2)+M 3.75 kg/hm^(2);A6,I 13.50 kg/hm^(2)+L 12.00 kg/hm^(2)+P 4.50 kg/hm^(2)+M 7.50 kg/hm^(2);A7,I 13.50 kg/hm^(2)+L 14.40 kg/hm^(2)+P 4.95kg/hm^(2)+M5.25 kg/hm^(2))和5种行数比(B_(1),1:3;B_(2),1:2;B_(3),1:1;B_(4),2:1;B_(5),3:1)处理,多花木蓝混播灌草地牧草产量的变化。[结果]灌草组合和行数比对灌草地的灌草产量构成和总产量均有显著影响。多花木蓝与3种草本混播灌草地的总产量较高,其中,以A6生产表现最好,为15.25 t/hm^(2)。多花木蓝与草本牧草以行数比B_(1)(1:3)或B_(2)(1:2)混播效果较好,牧草产量为13.33 t/hm^(2)和14.13 t/hm^(2)。不同建植模式以A6B_(1)的总产量最高,为16.66 t/hm^(2);A6B_(2)(15.94 t/hm^(2))和A6B_(3)(15.77 t/hm^(2))其次。[结论]牧草产量以灌草组合13.50 kg/hm^(2)多花木蓝+12.00 kg/hm^(2)多花黑麦草+4.50 kg/hm^(2)宽叶雀稗+7.50 kg/hm^(2)紫花苜蓿按灌草行数比1:3混播的最高,可作为贵州中低海拔喀斯特地区多花木蓝灌草地建植的适宜模式推广应用。

紫花苜蓿与饲用燕麦混合青贮研究

为了解紫花苜蓿与饲草燕麦不同混合比例对青贮品质的影响,试验按紫花苜蓿与腊熟初期的饲草燕麦的鲜草质量比1∶0(M1)、0∶1(M2)、1∶2(M3)、2∶1(M4)混合青贮。青贮60 d后进行发酵品质和营养价值分析。结果表明,M2的pH值最低(3.84),最高的是M1。乳酸含量最高的是M3,最低的是M1。M2、M3的干物质含量较高约为30.0%。M1的粗蛋白含量最高,随着苜蓿混合比例的降低,混合青贮料的粗蛋白含量逐渐降低。M2的淀粉含量最高,随着燕麦混合比例的降低,混合青贮料的淀粉含量逐渐降低。综上,腊熟初期的饲用燕麦单贮青贮质量优秀,但营养价值低于与紫花苜蓿混合青贮。综合青贮料的发酵品质、营养价值,当紫花苜蓿与饲用燕麦混合比例为1∶2时,青贮品质较优。

不同精粗比饲粮添加2种复合植物精油对断奶羔羊生长性能、养分表观消化率、血清指标和瘤胃发酵参数的影响

本试验旨在研究不同精粗比饲粮中添加2种复合植物精油(EOB)对断奶羔羊生长性能、养分表观消化率、血清指标和瘤胃发酵参数的影响。采用2×2因子试验设计,以精粗比(50∶50、70∶30)和EOB种类(EOB_(1)、EOB_(2))作为2个因素,选择48只(24只公,24只母)2月龄体况良好、平均体重为(19.55±2.16)kg的断奶黑山羊(乐至型),按体重随机分为4个处理,每个处理4个重复,其中2个重复全为公羊,2个重复全为母羊,每个重复3只羊。4个处理分别为低精饲粮(LD)+EOB_(1)(LD-EOB_(1))、LD-EOB_(2)、高精饲粮(HD)+EOB_(1)(HD-EOB_(1))、HD-EOB_(2),EOB添加量均为100 g/t。试验包括70 d的饲养试验和8 d的消化代谢试验;饲养试验预试期10 d,正试期60 d;饲养试验结束后,各处理选取4只体重相近的试验羊转入代谢笼,单笼饲喂,消化代谢试验预试期3 d,正试期5 d。结果表明:1)2种EOB组间平均日增重、平均干物质采食量和料重比均无显著差异(P>0.05);HD组山羊1~60日龄料重比显著低于LD组(P<0.05)。2)EOB_(2)组山羊粗蛋白质表观消化率有高于EOB_(1)组的趋势(P=0.065);HD组干物质表观消化率显著高于LD组(P<0.05),粗蛋白质表观消化率有高于LD组的趋势(P=0.056);EOB种类和精粗比对中性洗涤纤维和酸性洗涤纤维表观消化率无显著影响(P>0.05)。3)EOB_(2)组山羊血清甘油三酯含量显著高于EOB_(1)组(P<0.05),血清乳酸脱氢酶活性和尿素氮含量显著低于EOB_(1)组(P<0.05);HD组血清谷丙转氨酶活性显著高于LD组(P<0.05)。4)EOB_(2)组血清总超氧化物歧化酶活性显著高于EOB_(1)组(P<0.05);HD组血清总超氧化物歧化酶活性有高于LD组的趋势(P=0.054)。5)EOB_(2)组山羊瘤胃氨态氮浓度较EOB_(1)组显著降低(P<0.05),而瘤胃pH显著升高(P<0.05),瘤胃微生物蛋白含量有升高的趋势(P=0.056);HD组瘤胃pH和氨态氮浓度显著低于LD组(P<0.05),而微生物蛋白含量与LD组无显著差异(P>0.05)。综上所述,饲粮中添加EOB_(2)较EOB_(1)可提高山羊对饲粮蛋白质的消化吸收,提高抗氧化性能,降低高精饲粮引起的瘤胃低酸度环境,改善瘤胃内环境;HD组(70∶30)较LD组(50∶50)可提高山羊对饲粮中营养物质的消化率,促进机体对蛋白质的代谢,有效提高饲料利用率,增强机体的抗氧化性能。因此,断奶羔羊育肥前期饲粮精粗比可提高至70∶30,但不宜用于育肥全期,且在HD中添加EOB_(2)效果优于EOB_(1)。

牦牛日粮精粗比转换对瘤胃微生物菌群的影响

试验旨在比较牦牛日粮精粗比转换对牦牛瘤胃微生物菌群及代谢的影响。选取6头体重相近、体况良好、健康的3周岁公牦牛。前2个月牦牛饲喂精粗比为35∶65的日粮(C35组),后2个月牦牛饲喂精粗比为65∶35的日粮(C65组)。预试期15 d,正式试验期120 d。结果显示,C35组牦牛的谱系多样性(PD whole tree)值、Chao1指数显著高于C65组(P<0.05)。C35组牦牛瘤胃脱硫菌门相对丰度极显著高于C65组(P<0.01),C35组瘤胃疣微生物门相对丰度显著高于C65组(P<0.05)。C35组牦牛瘤胃UCG-005和未培养属丰度极显著高于C65组(P<0.01),C65组瘤胃普氏菌科UCG-003属丰度显著高于C35组(P<0.05),C35组牦牛瘤胃未培养细菌属丰度显著高于C65组(P<0.05)。C35组牦牛信号分子和相互作用、耐药性:抗菌的基因家族KEGG2水平显著高于C65组(P<0.05)。C35组和C65组牦牛瘤胃菌群的厚壁菌门和拟杆菌门的相对丰度最高。研究表明,牦牛饲喂后期转化为高精料后,会影响牦牛瘤胃微生物生长繁殖,使瘤胃微生物菌群的丰度和多样性呈现出不同程度的降低,日粮中精料比例的改变可促使牦牛瘤胃微生物菌群的代谢通路发生改变,最终影响牦牛瘤胃的发酵模式。

日粮不同精粗比对肉牛生长性能和血液生化指标的影响

为探究日粮不同精粗比对肉牛生长性能和血液生化指标的影响,试验采用完全随机区组设计,选择24头10月龄左右体重相近的健康西门塔尔杂交牛随机分为3组,预饲期10 d,正试期72 d。结果表明:随日粮精粗比的增加,西门塔尔杂交牛的平均日增重呈现先增加后降低的趋势,但3组间差异不显著(P>0.05),各组日均采食量逐渐降低且差异显著(P<0.05)。试验2组的平均日利润比试验1组和3组分别高8.26%、28.11%,3组比1组降低15.49%。随着精料水平提高,血浆白蛋白、谷丙转氨酶、谷草转氨酶、尿素氮、血糖和总蛋白含量均有升高的趋势,但差异均不显著(P>0.05)。综合各项指标分析,日粮精粗比为6∶4时西门塔尔杂交牛血液生化指标维持正常、可获得较高生长性能和经济效益。

日粮精粗比对育肥湖羊生产性能和经济效益的影响

为研究日粮精粗比对湖羊羔羊早期育肥生产性能和经济效益的影响,采用完全随机区组设计,选择日龄相近(80±2 d)、体重相近(21.91±0.64 kg)、健康状况良好的湖羊公羔80只,随机分为试验Ⅰ、Ⅱ、Ⅲ和Ⅳ4个组,每组20只,分别饲喂精粗比为40∶60、50∶50、60∶40、70∶30的日粮,试验期为40 d,分析短期育肥阶段各组羔羊的生产性能和经济效益.结果表明,采用不同精粗比日粮对湖羊羔羊进行短期育肥,育肥效果存在极显著差异(P<0.01);精粗比为50∶50(试验Ⅱ组)日粮的饲喂效果最佳,可有效提高湖羊的生产性能和经济效益.

不同饲草配比对威宁黄牛育肥、胴体和肉质性状的影响

试验旨在评估不同饲草配比日粮对威宁黄牛育肥、胴体和肉质的影响。选取健康体重相近的(24±1)月龄威宁黄牛84头(公、母牛各半),均分为7组,饲喂不同饲草调配的日粮,T1组(17%巨菌草+18%黑麦草+12%金荞麦+18%青贮玉米)、T2组(25%巨菌草+18%黑麦草+12%金荞麦+10%青贮玉米)、T3组(45%巨菌草+20%黑麦草+12%玉米)、T4组(25%黑麦草+40%金荞麦)、T5组(20%玉米秸秆+45%黑麦草)、T6组(20%干稻草+45%黑麦草)、T7组(30%黑麦草+35%青贮玉米)。预试期15 d,正试期60 d。结果表明:不同饲草配比对威宁黄牛的采食量、平均日增重、净肉率、肌肉氨基酸和脂肪酸组成有显著影响(P<0.05),而对肌肉化学组成和常规肉品质的影响未达显著水平(P>0.05)。T7组育肥性能和胴体性状效果最优,T4组次之,T5组最差。T1组肌肉中鲜味氨基酸含量最高;日粮中含金荞麦的T1、T2、T4组肌肉中抗氧化氨基酸含量均高于其他组,含黑麦草最高的T5组和T6组肌肉中必需氨基酸和支链氨基酸含量均高于其他组;T4组肌肉中芳香族氨基酸含量最高;T7组肌肉中总氨基酸和甜味氨基酸含量最高。T4组肌肉中必需脂肪酸含量最高,T2组次之,T5组最低。说明不同的饲草配比能影响肉牛的育肥和胴体性状,也能影响肌肉中氨基酸和脂肪酸的组成,肉牛养殖者可通过调整饲草配比改善肉牛育肥、胴体和肉质性状。

巨大芽孢杆菌BM1259对不同精粗比体外瘤胃发酵特性的影响

为利用体外发酵法研究巨大芽孢杆菌对不同精粗比底物发酵特性的影响,以3头装有永久性瘤胃瘘管的荷斯坦干奶期奶牛作为瘤胃液供体动物,将豆粕和稻秸以4∶6、5∶5、6∶4的比例混合作为对照组(分别为C1、C2、C3处理),在此基础上添加0.1 g巨大芽孢杆菌(1×10^(10)cfu·g^(-1))作为4∶6 (T1处理)、5∶5 (T2处理)、6∶4 (T3处理)试验组,测定48 h的发酵参数。结果表明:① T1、T2和T3处理48 h产气量显著高于对照组。②与对照组相比,T2和T3处理发酵液pH值显著降低。③ T1和T2处理发酵液氨态氮(NH3-N)浓度显著高于对照组,T3处理NH3-N浓度有升高趋势(P=0.058)。④ T3处理总挥发性脂肪酸(TVFA)和微生物蛋白(MCP)显著高于对照组(C3处理),日粮精粗比与巨大芽孢杆菌对TVFA存在互作效应(P<0.05)。综上,在以豆粕和稻草为底物的发酵条件下,基础日粮中添加1×10^(10)cfu·g^(-1)巨大芽孢杆菌能提高底物的发酵程度,其中以底物精粗比6∶4的效果最为明显。

甘肃中部干旱半干旱区小黑麦饲用价值评价

为研究甘肃中部干旱半干旱地区小黑麦的饲用价值,筛选最适种植品种,对从中国农业科学院作物科学研究所引进的11个小黑麦新品系进行了连续2 a的品比试验,鉴定其田间农艺性状、鲜草产量、干草产量、茎叶比等差异。结果表明,3297、5全50鲜草产量分别为68.25、67.05 t/hm^(2),较对照品种中饲3241分别增产7.70%、4.81%;干草产量分别为23.55、22.80 t/hm^(2),较对照品种中饲3241分别增产5.64%、2.25%;茎叶比分别为1.78、1.87,饲草可利用价值高。综合评价认为,3297、5全50以开花盛期获取鲜干草为佳。