Effect of oat decortication on chemical composition,in vitro digestibility and in situ degradability

The effect of decortication on chemical composition and degradability characteristics of four Danish oat varieties was investigated. Effective degradability (ED) and post-ruminal disappearance (PRD) were measured by in situ and mobile bag techniques respectively. Decorticated oat showed higher (p = .01) concentrations of crude protein (CP; 134 vs. 108 g/kg DM) and crude fat (71.6 vs. 53.1 g/kg DM) and a higher (p = .001) organic matter digestibility (OMD; 888 vs. 703 g/kg OM) than oat. The content of total fatty acids (FA) in DM was higher in decorticated oat. The proportion of linoleic acid (C18:2 n6) increased (p < .05) due to decortication, while the linolenic acid (C18:3 n3) proportion of total FA decreased in decorticated oat. Decortication increased (p = .01) the concentration of amino acids (AA), but the proportion of lysine in total AA decreased (p < .002). Effective degradability (ED) of both DM and CP was (p < .001) higher in decorticated oat. Decortication increased the total tract disappearance (TTD) and PRD of CP (p < .001). In conclusion, decortication can be used as a practical approach to increase the nutritional value of oat.     

拉伸膜裹包苜蓿青贮饲料体外消化率的研究

为探讨长期贮藏拉伸膜裹包苜蓿Medicago sativa青贮饲料养分的体外消化率,采用两步法测定体外干物质消化率（IVDMD）和体外粗蛋白消化率（IVCPD）,采用一步法测定体外中性洗涤纤维消化率（IVNDFD）和体外酸性洗涤纤维消化率（IVADFD）。结果表明,除IVCPD外,鲜割苜蓿拉伸膜裹包青贮饲料的IVDMD、IVNDFD、IVADFD低于苜蓿原料;绿汁发酵液和甲酸处理拉伸膜裹包苜蓿青贮饲料的IVDMD、IVCDP、IVNDFD、IVADFD没有差异;晾晒处理拉伸膜裹包苜蓿青贮饲料的养分消化率低于苜蓿原料;晾晒处理拉伸膜裹包苜蓿青贮饲料的IVDMD和IVCPD显著低于鲜割苜蓿青贮饲料（P<0.05）。总体来说,苜蓿青贮后,养分的消化率下降,晾晒降低了苜蓿青贮饲料的IVDMD和IVCPD。     

燕麦与苜蓿不同比例组合对驴盲肠体外发酵的影响

研究燕麦干草与苜蓿不同比例组合对驴盲肠液体外发酵的影响,旨在为肉驴养殖中粗饲料的科学利用提供理论依据。将燕麦干草和苜蓿按干物质比为80∶20、60∶40、40∶60和20∶80分为Ⅰ、Ⅱ、Ⅲ、Ⅳ组,通过体外产气法与人工瘤胃持续发酵法培养2、4、8、12和24 h,各时间点3个重复,发酵终止后测定发酵参数和饲草养分降解率,通过24 h时发酵参数的加权估算值计算饲草组合效应值。结果表明:1)燕麦与苜蓿不同比例组合影响了其养分降解率,随着苜蓿比例的增加,干物质(DM)和酸性洗涤纤维(ADF)降解率增大,Ⅳ组显著高于Ⅰ组(P<0.05),各组中性洗涤纤维(NDF)降解率差异不显著(P>0.05)。2)随着苜蓿含量的增加,pH逐渐升高,Ⅳ组显著高于Ⅰ组(P<0.05);各时间点产气量(GP)均为Ⅱ组显著高于其余3组(P<0.05),且24 h时Ⅳ组显著高于Ⅰ和Ⅲ组(P<0.05);从发酵12 h开始Ⅲ、Ⅳ组氨态氮(NH_3-N)浓度显著高于Ⅰ、Ⅱ组(P<0.05);24 h时Ⅱ组微生物蛋白(MCP)浓度显著高于Ⅲ组(P<0.05),与Ⅰ、Ⅳ组无显著差异(P>0.05);燕麦与苜蓿不同比例组合对挥发性脂肪酸(VFA)有显著影响,24 h时Ⅰ和Ⅳ组丙酸浓度显著高于Ⅱ和Ⅲ组(P<0.05),而Ⅰ、Ⅱ组总VFA(TVFA)含量显著高于Ⅲ、Ⅳ组(P<0.05)。3)发酵24 h后Ⅰ、Ⅱ和Ⅳ组均产生正组合效应,且Ⅳ组效应值最大,而Ⅲ组产生负组合效应。综上所述:燕麦与苜蓿按20∶80组合时能提高DM、NDF和ADF降解率,且多项组合效应值更高;燕麦与苜蓿饲喂驴以20∶80组合效果较好。     

白腐真菌对稻草秸秆生物降解的研究

试验对白腐菌TK-X-03在固态培养条件下稻草秸秆的生物降解进行了研究。通过正交试验,确定葡萄糖、(NH4)2SO4和MnSO4的最适添加量分别为3%、0.015%、0.05%。稻草降解过程中赖锰过氧化物酶(MnP)、木质素过氧化物酶(LiP)、漆酶(Laccase)、纤维素酶和木聚糖酶的酶活在培养的第6、7、9、10和15d达到最高值,分别为1.06U/g、8.71U/g、0.054U/g、400U/g和0.26U/g。培养25d后,稻草秸秆中纤维素、半纤维素和木质素的降解率依次为25.1%、29.8%和55.1%。     

Relationships between chemical composition and in vitro gas production parameters of maize leaves and stems

This study investigated the chemical composition (proximate and Van Soest analysis) and in vitro gas production parameters of maize leaves and stems separately, and related the in vitro gas production parameters with the chemical composition, of thirteen maize cultivars. After harvest in September 2016, all plants were separated into two morphological fractions: leaves and stems. The crude protein (CP) content was greater, and the ratio of acid detergent lignin (ADL) to potentially rumen degradable fibre (calculated as the difference between neutral detergent fibre and ADL; ADL:pRDF) was lower in the leaves than in the stems in all 13 cultivars. For the leaves, the cumulative gas production between 3 and 20 hr (A2), representing cell wall fermentation in the rumen fluid, and the cumulative 72-hr gas production (GP72), representing total organic matter (OM) degradation, were moderately to weakly correlated with the chemical composition, including hemicellulose, cellulose, ADL and CP content (R² < 0.40), whilst the best relationship between the half-time value (B2), representing the rate of cell wall degradation, and chemical composition had an R² of 0.63. For the stems, the best relationship between A2, B2 and GP72 with chemical composition was greater (R² ≥ 0.74) and the best relationship included hemicellulose (A2 only), cellulose and ADL (GP72 and A2 only) contents. In conclusion, maize leaves and stems differed in chemical composition, in particular CP content and ADL:pRDF. The A2 and GP72 of the stems, but not of the leaves, were highly correlated with the chemical composition, indicating that the cell wall and OM degradation of maize stems can be better predicted by its chemical composition.     

Changes in chemical composition and digestibility of three maize stover components digested by white‐rot fungi

Maize stover (total stem and leaves) is not considered a ruminant feed of high nutritive value. Therefore, an improvement in its digestibility may increase the viability of total forage maize production systems in marginal growth regions. The objective of this study was to describe the changes in chemical composition during the storage of contrasting components of maize stover (leaf, upper stem and lower stem) treated with either of two lignin degrading white‐rot fungi (WRF; Pleurotus ostreatus, Trametes versicolor). Three components of maize stover (leaf, upper stem and lower stem), harvested at a conventional maturity for silage production, were digested with either of two WRF for one of four digestion durations (1–4 months). Samples taken prior to fungal inoculation were used to benchmark the changes that occurred. The degradation of acid detergent lignin was observed in all sample types digested with P. ostreatus; however, the loss of digestible substrate in all samples inoculated with P. ostreatus was high, and therefore, P. ostreatus‐digested samples had a lower dry matter digestibility than samples prior to inoculation. Similarly, T. veriscolor‐digested leaf underwent a non‐selective degradation of the rumen‐digestible components of fibre. The changes in chemical composition of leaf, upper stem and lower stem digested with either P. ostreatus or T. veriscolor were not beneficial to the feed value of the forage, and incurred high DM losses.     

Comparison of in vitro digestibility and chemical composition among sugarcane bagasses treated by four white-rot fungi

The capabilities of four white‐rot fungi to improve the digestibility of sugarcane bagasse for ruminants were determined. Bagasse was cultured with Lentinula edodes, Pleurotus eryngii, Pleurotus salmoneostramineus, Ceriporiopsis subvermispora (ATCC 90467) or C. subvermispora (CZ‐3) at 26°C for 8, 12 or 16 weeks. The in vitro organic matter digestibility (IVOMD) and in vitro neutral detergent fiber digestibility (IVNDFD) in untreated bagasse were 45.6 and 40.3%, respectively. Meanwhile, the bagasse cultured with L. edodes and two strains of C. subvermispora, respectively, for 12 weeks, were elevated to 68.6 and 59.1%, 60.6 and 49.9% and 59.9 and 49.0%, respectively. In contrast, the IVOMD and the IVNDFD in bagasse cultured with P. eryngii and P. salmoneostramineus were the same or lower than those in untreated bagasse. In vitro gas production (IVGP) in bagasse cultured with L. edodes and two strains of C. subvermispora for 12 weeks was also higher than that of untreated bagasse. These changes in IVOMD, IVNDFD and IVGP demonstrate that L. edodes has a higher capability of improving the digestibility for ruminants than C. subvermispora, P. eryngii or P. salmoneostramineus.     

Effects of ammonium hydroxide treatment on the in vitro dry matter digestibility and gas production of wheat straw, sugarcane bagasse medium and konara oak rotted by edible basidiomycetes

Wheat straw, sugarcane bagasse medium and konara oak logs used to cultivate edible basidiomycetes were treated with ammonium hydroxide to investigate the relationship between the degree of rotting and the effect of ammonium hydroxide treatment on digestibility. Wheat straw was sampled before inoculation and on days 67 and 97 after inoculation with Pleurotus salmoneostramineus. Similarly, bagasse media were sampled before inoculation and on days 47 and 96 after inoculation with Pleurotus abalonus. Konara oak logs were sampled before inoculation and at 2 and 4 years after inoculation with Lentinula edodes. Aliquots of the samples were treated with ammonium hydroxide (NH₄‐N, 3% dry matter) at 45°C for 10 days. Ammonium hydroxide treatment increased the in vitro dry matter digestibility (IVDMD) and gas production (IVGP) of all the samples, except the konara oak samples collected before inoculation. The degree of increased digestibility was largest for the samples collected after short cultivation periods, followed by those collected after long cultivation periods and those collected before inoculation. However, the IVDMD and IVGP values after short cultivation periods were lower than those after long cultivation periods. Ammonium hydroxide treatment is effective at improving the digestibility of white‐rotted materials, although the effect is lessened as rotting proceeds.     

收割时期和收割高度对小麦秸秆营养成分和消化率的影响

文章旨在明确收割时期和收割高度对小麦秸秆营养成分和体外消化率的影响。试验选取山农22号小麦品种作为研究对象,分别在3个成熟期进行不同收割高度的取样。收割时期分别为蜡熟期的倒数2周、1周和0周;收割高度分别为距离地面5cm、10cm和15cm。结果表明,收割时期和收割高度均影响小麦秸秆营养成分和体外消化率。小麦秸秆中可溶性糖、淀粉和粗蛋白质含量随收割时期的推迟显著下降(P<0.05)。随着收割时期的推迟,小麦秸秆中中性洗涤纤维含量和酸性洗涤纤维含量逐渐升高(P<0.05),钙和磷含量逐渐降低(P<0.05)。小麦秸秆中粗蛋白质、钙和磷含量随着收割高度的增加显著升高(P<0.05),可溶性糖、中性洗涤纤维和酸性洗涤纤维含量显著下降(P<0.05)。因此,为了获得质量较高的小麦青贮,需要在小麦蜡熟期倒数第2周,在距离地面15cm的高度收获小麦秸秆。     

Chemical composition and in vitro ruminal digestibility of Ludwigia grandiflora

Ludwigia grandiflora is an amphibious plant that has been designated as a specific alien plant in Japan. Due to the risk of regeneration on land, plants are burned after eradication. Since L. grandiflora is fertile and rich in biomass, this study investigated the use of L. grandiflora as a feed for ruminants. We measured general components, detergent fiber components, and in vitro dry matter digestibility (IVDMD) using rumen microbes for three forms (terrestrial form, emergent form, and floating-leaved form) of L. grandiflora. In addition, concentrations of hazardous metallic elements were also measured from the viewpoint of feed safety. Crude protein, neutral detergent fiber, acid detergent fiber, and acid detergent lignin were contained 10.31–14.62, 27.83–42.28, 20.54–36.05, and 6.94–18.90 (%DM), respectively. IVDMD was 50.75%–68.24%. Toxic elements such as Pb, Cd, and Hg were not detected in all forms. These results suggest that L. grandiflora could be partially used as alternative roughage for ruminants.     

苜蓿干草和秸秆组合体外发酵营养特性及其利用研究

应用体外发酵产气技术,评价了苜蓿Medicago sativa干草和玉米Zea mays、小麦Triticum aestivum秸秆分别以0:100、25:75、50:50、75:25 和100:0进行两两组合时的发酵特性.结果表明:不同比例组合产气量(GP)、理论最大产气量(A)、产气速率(b)及产气延滞时间(LAG)变化趋势不同;苜蓿干草与玉米秸秆按50:50的比例或苜蓿干草与小麦秸秆按75:25的比例组合时的效应明显好于其他组合.48 h产气量与粗蛋白(CP)(P<0.05)及中性洗涤可溶物(NDS)含量呈正相关关系,而与中性洗涤纤维(NDF)、酸性洗涤纤维(ADF)、半纤维(HC)含量及NDS/CP(P<0.01)呈负相关关系;理论最大产气量与CP、NDS的含量呈正相关关系,与NDF、ADF、HC和NDS/CP(P<0.01)呈负相关关系;产气速率与CP(P<0.01)、HC(P<0.01)、NDS(P<0.01)呈极显著正相关关系,分别与NDF(P<0.01)、ADF(P<0.01)、NDS/CP(P<0.05)呈负相关关系;产气延滞时间与饲草料的主要营养成分的相关关系不明显,只与NDS/CP(P<0.05)呈显著正相关关系.结论认为, 饲草中非结构性碳水化合物与蛋白质比例决定了体外发酵产气的特性.生产实践中应针对低质粗饲料营养特性,适当添补易发酵或高蛋白牧草,提高粗饲料利用效率.     

Morphological fractions,chemical composition and in vitro digestibility of stover of four common vetch varieties grown on the Tibetan plateau

This study evaluated the varietal variability and interrelationship of the grain and stover yields, and stover quality characteristics of four common vetch varieties (three improved varieties and one local variety) used on the Tibetan Plateau. Stover quality attributes determined included chemical composition, in vitro true digestibility of dry matter (IVTD) and neutral detergent fibre (dNDF). The improved varieties were superior to the local variety in grain yield, harvest index and potential utility index (PUI). The wide ranges in the proportions of leaf (24.3%–34.6%), pod (22.0%–45.6%) and stem (29.5%–44.7%) fractions were observed. Significant varietal differences (p < .001) were observed for the whole‐stover content of crude protein [CP; 78.1–101 g/kg dry matter (DM)], neutral detergent fibre (aNDF; 520–564 g/kg DM), acid detergent fibre (ADF; 520–564 g/kg DM), IVTD (597–658 g/kg DM) and dNDF (305–384 g/kg aNDF). The leaf fraction had the highest levels of CP, IVTD and dNDF, while the highest contents of aNDF and ADF were observed in the stem fraction. Canonical correlation analysis showed that significant (p < .001) correlations between the quality attributes of whole stover and proportions and quality attributes of stover morphological fractions. Pearson correlation between the grain and stover yield was negative and significant (r = ?.295; p = .001), while the correlations between the grain/stover yield and stover quality traits were positive or non‐significant. Ranking of the varieties differed when grain yield, PUI and stover quality scores were investigated. Of the varieties tested, Lanjian No.2 has the best potential for use as a ruminant feed, as indicated by PUI and stover quality.     

Diversity of chemical composition, dry matter intake, in vivo digestibility and in situ dry matter degradability of oat hay (Avena sativa)

Diversity of chemical composition, in vivo digestibility and in situ dry matter degradability of oat hay (Avena sativa) were studied. Oat hay samples obtained from 22 batches imported were analyzed for chemical composition. The result showed a wide range of variations in crude protein (3.9–8.8%, on a dry matter basis), crude fiber (22.1–35.2%), nitrogen free extract (50.0–66.0%), organic cellular contents (23.4–40.0%), organic cell wall (53.1–70.8%), organic a (4.1–9.8%), organic b (49.0–63.8%) fractions and the estimated total digestible nutrients (50.3–63.8%) from the organic components. Of these, four oat hay samples were used for the measurement of dry matter intake, in vivo digestibility and in situ dry matter degradability in sheep. Significant differences were observed for the dry matter intake, in vivo digestibility of dry matter, crude protein, crude fiber and nitrogen free extract, dry matter disappearance at 48 h and effective degradability at k = 0.05 h^?1 of the samples (P < 0.05). The results revealed a wide range of diversity of nutritional quality of the imported oat hay that could have an affect on production potential in animals.     

体外法评价张杂谷秸秆、全株青贮张杂谷和燕麦草的营养价值

试验旨在通过体外产气法评价张杂谷秸秆、全株青贮张杂谷和燕麦草的营养价值。采用单因素试验设计,将1 g张杂谷秸秆、全株青贮张杂谷和燕麦草分别进行体外发酵,每组设4个重复,测定和分析三种粗饲料对体外产气量、挥发性脂肪酸、营养物质降解率、pH值、微生物蛋白、氨态氮的影响。结果表明,张杂谷秸秆、全株青贮张杂谷4、8、16、24、36、48、72 h的产气量及理论最大产气量(B)均极显著小于燕麦草的(P<0.01),全株青贮张杂谷8、16、24、36、72 h的产气量极显著大于张杂谷秸秆(P<0.01);产气速率(c)和延搁时间(Lag)张杂谷秸秆和燕麦草的差异均不显著(P>0.05),极显著低于全株青贮张杂谷(P<0.01)。体外发酵72 h后,乙酸、丁酸、总挥发性脂肪酸浓度均是张杂谷秸秆产生的极显著低于全株青贮张杂谷、燕麦草的(P<0.01);丙酸、乙酸/丙酸浓度张杂谷秸秆极显著低于全株青贮张杂谷(P<0.01),全株青贮张杂谷极显著低于燕麦草(P<0.01)。干物质、粗蛋白质、中性洗涤纤维和酸性洗涤纤维降解率均表现出张杂谷秸秆极显著低于全株青贮张杂谷(P<0.01),全株青贮张杂谷极显著低于燕麦草(P<0.01);pH值变化为张杂谷秸秆、全株青贮张杂谷极显著高于燕麦草(P<0.01);微生物蛋白质产量三者差异均不显著(P>0.05),NH3-N浓度为张杂谷秸秆显著低于全株青贮张杂谷(P<0.05),两者与燕麦草差异不显著(P>0.05)。因此,该试验条件下,张杂谷秸秆、全株青贮张杂谷体外发酵在产气量、营养物质降解率方面相对次于燕麦草,全株青贮张杂谷相对优于张杂谷秸秆,具体原因及实际饲喂应用效果有待研究。     

刈割茬次与制粒对紫花苜蓿维生素和化学成分的影响

为探究不同刈割茬次与制粒对紫花苜蓿(Medicago sativa)草颗粒的营养品质、维生素含量与大肠杆菌数量间差异,本研究以内蒙古自治区农牧业科学院试验基地紫花苜蓿为研究材料,选择3个刈割茬次(第1茬、第2茬、第3茬)紫花苜蓿现蕾期刈割,制作草颗粒,取样测定其维生素含量、化学成分及大肠杆菌数量.结果表明:刈割茬次对紫花苜蓿维生素B2、B3、B5、B6和Vc含量影响显著(P<0.05),其中,第2茬紫花苜蓿维生素B2、B3、B5含量显著高于第1茬和3茬(P<0.05),第1茬和第2茬维生素B6、Vc显著高于第3茬(P<0.05).刈割茬次对紫花苜蓿干物质(dry matter,DM)、有机质(organic matter,OM)、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)含量影响显著,第2茬紫花苜蓿品质优于第1茬和第3茬.制粒对紫花苜蓿维生素B3、B5含量无显著影响(P>0.05),而制粒显著降低了维生素B2、B6、Vc、VK1含量(P<0.05).两个因素的互作效应对紫花苜蓿B1、B6、OM、DM含量影响显著(P<0.05).大肠杆菌数量由低到高的顺序为第1茬<第3茬<第2茬,制粒显著抑制了大肠杆菌的活性(P<0.05).第1茬紫花苜蓿草颗粒大肠杆菌数量最低.     

稻草与不同饲料混合在体外消化率上的组合效应研究

以体外干物质消化率(IVDMD)对鲁梅克斯K-1(Rumex patientia,RP)、紫云英(Astragalus sinicus,AS)、高丹草(Sorghum hybrid Sudangrass,SHS)、苏丹草(Sorghumsudanense,SS)、矮象草(Pennisetumpurputeumcv.mott,PPM)、苜蓿(Medicagosativa,MS)、木薯干草(CH)、稻草(RS)、氨化稻草(ARS)与木薯渣(CR)的品质进行了评定。IVDMD(%)自高到低的排序为:CR(77.63)、RP(61.32)、MS(55.26)、AS(54.91)、CH(52.97)、SHS(40.24)、PPM(38.70)、ARS(36.88)、SS(34.15)、RS(26.63)。除AS与MS外,各种饲料间的IVDMD差异显著(P0.05)。本研究将组合效应值(AE)定义为混合饲料实测IVDMD与各单个饲料IVDMD加权和值之差。分别以RS、ARS作为低、中等品质基础秸秆饲料,再分别添补RP、AS、SHS、SS、PPM、MS与CH(RS还补饲ARS),共6个组合。结果表明,任一组合均观察到正组合效应,以添补MS的最大;CH作为添补料其效果要好于禾本科牧草,与豆科牧草相似;对低质秸秆基础饲料的补饲较对中等品质的组合效应明显。     

刈割茬次与制粒对紫花苜蓿维生素和化学成分的影响

为探究不同刈割茬次与制粒对紫花苜蓿(Medicago sativa)草颗粒的营养品质、维生素含量与大肠杆菌数量间差异,本研究以内蒙古自治区农牧业科学院试验基地紫花苜蓿为研究材料,选择3个刈割茬次(第1茬、第2茬、第3茬)紫花苜蓿现蕾期刈割,制作草颗粒,取样测定其维生素含量、化学成分及大肠杆菌数量。结果表明：刈割茬次对紫...     

Urea utilization in growing lambs. 3. Effect of urea and straw on carcass composition

Subsequent to a growth experiment with intensively fattened lambs the value of the carcasses of 4 animals each from 7 groups was determined. The control groups with mixed fattening feed for lambs and the groups with wheat and barley mixtures containing urea showed higher carcass yields, net gains, fat percentage and padding, dry matter and fat content of the carcass and lower quotas of important cuts as well as a lower crude protein content in the carcass than groups with grain without urea and groups with straw. This is due to the higher weight gains of the first-mentioned groups. There were no significant differences in the carcass characteristics between the animals of the control group and the grain-urea groups. The carcass quality of the male lambs was better than that of the female ones.     

高山美利奴育成公羊在返青期与盛草期牧场的营养监测

本研究以祁连山放牧地的高山美利奴育成公羊为研究对象,于返青期和盛草期,采用粪袋全收粪和酸不溶灰分(AIA)结合法测定其采食量,并探究其放牧地牧草营养物质的供给规律和其营养的盈缺。结果显示,盛草期放牧草地植物群落优势度指数、地上生物量、多样性指数、物种丰富度指数、均匀度指数均显著高于返青期(P<0.05)。在牧草养分化学指标上,粗蛋白和粗灰分含量在盛草期显著高于返青期(P<0.05),盛草期牧草粗饲料分级指数(GI)也显著高于返青期(P<0.05)。返青期和盛草期高山美利奴育成公羊干物质、粗蛋白采食量差异不显著(P>0.05),代谢能采食量在盛草期显著高于返青期(P<0.05)。牧草有机物和干物质消化率返青期和盛草期差异不显著(P>0.05),牧草粗蛋白、中性洗涤纤维和酸性洗涤纤维消化率在返青期显著高于盛草期(P<0.05)。盛草期高山美利奴育成公羊瘤胃氨态氮(NH3-N)含量、丁酸、支链脂肪酸比例显著高于返青期(P<0.05),高山美利奴育成公羊瘤胃内总挥发性脂肪酸含量返青期显著高于盛草期(P<0.05)。参照中国美利奴育成公羊(体重70 kg,日增重100 g)营养需要推荐量,高山美利奴育成公羊每只日代谢能和粗蛋白采食量在返青期分别比推荐量低9.32 MJ和45.23 g·d^?1;而在盛草期二者则分别低7.32 MJ和32.64 g·d^?1。综上所述,盛草期牧草GI值、牧草生产力显著高于返青期;体重为70 kg的高山美利奴育成公羊在返青期和盛草期牧场,日增重达到100 g时,代谢能和粗蛋白摄入量均不足,需补饲一定量的能量和蛋白饲料。