高寒地区歪头菜营养品质动态变化及其评价

优质豆科牧草选育和栽培对于高寒地区畜牧业发展具有重要意义,歪头菜是高寒地区极具饲用价值的豆科牧草,对其进行产量和营养品质动态变化研究,有利于高品质饲草的生产和利用。在高山草原地区通过田间试验,研究了歪头菜在不同生长时期(分枝期、现蕾期、初花期、盛花期)刈割时,干草产量和粗蛋白(CP)、可溶性糖(WSC)、灰分(ASH)含量和矿物元素含量的动态变化。结果表明,歪头菜草产量随着生长逐渐增加,而CP、WSC含量在生长初期较高,生长后期(盛花期)CP含量降低,而WSC含量达到最高。ASH含量在整个生长过程中呈单峰曲线变化特征,但各矿物元素含量的变化规律不尽相同。从饲用角度看,各刈割期的CP含量均达到美国一等饲草标准,其中,盛花期干草产量和WSC含量最高,营养元素中,除Ca和Cu外,能够基本满足高寒地区家畜对P、K、Na、Mg、Mn和Zn元素的营养需求。进一步利用灰色关联度分析和权重赋值法对上述指标进行综合评价,发现盛花期综合评价值最高,因此建议歪头菜在高山草原地区的最佳利用时期为盛花期。

Nutrient variation and forage evaluation ofVicia unijuga in alpine grasslands

Breeding and cultivating high-quality legumes is an important way to develop livestock agriculture on alpine grasslands.Vicia unijuga is a perennial legume with high feeding value.Research on its hay yield and nutrient dynamics is needed to inform its production and utilization as forage.A field trial has been conducted on Gannan alpine grasslands with the aim of investigating the feeding value of V .unijuga at different growth stages.Samples were taken at branching,squaring,20% bloom and 80% bloom stages.Measurements were made to determine forage yield,crude protein (CP)and water soluble carbohydrate (WSC)contents,as well as the levels of ash and various other mineral elements.Results showed that hay yield increased with growth stage but that CP levels were higher at the early growth stage.While CP decreased at the late growth stage (80%bloom),WSC contents reached their highest level at this point.Ash levels showed a single-peak curve variation across the different growth stages.However,mineral element contents varied less consistently.P,Zn,Ca and Mn varied in half-peak or peak type curves,Na and Mg in linear type,K and Cu in wave type.In conclusion, CP contents reached the levels of first-class forage grasses in America.Hay yield and WSC levels were highest at the 80% bloom stage,at which point the levels of P,K,Na,Mg,Mn and Zn are sufficient to satisfy the basic needs of livestock.Grey relational analysis and weight assignment methods were used to evaluate the a-bove results.This analysis showed that the evaluation index was highest at the 80% bloom stage,which is thus the optimal cutting point ofV .unijuga for alpine grassland agriculture.