全株玉米青贮饲料、苜蓿及谷草间组合效应的研究

Study on the associative effects of whole corn silage,alfalfa hay an millet straw

本试验旨在研究全株玉米青贮(WCS)、苜蓿干草(AH)及谷草(MS)间的组合效应。将WCS与AH以100∶0,80∶20,60∶40,50∶50,40∶60,20∶80,0∶100 7种比例组合,筛选出WCS与AH间的最优组合,将此组合再与MS按照上述7种比例组合。通过体外发酵技术测定72 h产气量(GP),检测体外培养液72 h的干物质消失率(DML)、NH3-N、微生物蛋白(MCP)及挥发性脂肪酸(VFA)产量,并计算各个指标的单项组合效应指数(SFAEI)和多项组合效应指数(MFAEI)。结果表明:在不同比例WCS与AH的组合中,72 h累积GP及DML均以80∶20组合最高(P<0.01),且随着AH比例的增加而降低;MCP产量、NH3-N浓度及VFA随着AH比例的增加呈现先上升后下降的趋势,在60∶40组合时MCP产量最大(P<0.05);GP与DML的SFAEI在80∶20组合最大,其他指标的SFAEI均在60∶40组合最大,MFAEI以60∶40组合最大。在WCS-AH最优组合(60∶40)与MS的组合中,72 h GP与DML以100∶0组合最高(P<0.01),并且随着MS比例的增加而降低;其余三个指标均为80∶20组合最大;GP及DML的SFAEI均以60∶40组合最大,其余三个指标的SFAEI及MFAEI均以80∶20组合最大。综上,在本试验设计条件下,WCS、AH和MS的最适组合比例为48∶32∶20。

The objective of this experiment was to study the associative effects of whole corn silage （WCS） ,alfalfa hay （AH） and millet straw （MS） by gas production technique in vitro.First,WCS was mixed with AH in the proportion of 100： O, 80：20,60：40,50：50,40：60,20：80 and 0：100.Selected out the best combination of WCS and AH （WCS-AH）,the WCS-AH was grouped with MS according to the 7 kinds of proportion above.The cultural medium gas production （GP）,the dry matter loss （DML） ,ammonia nitrogen （NH3-N） ,microbial crude protein （MCP）and volatile fatty acids （VFA）fermented of 72 h were measured,and the single factor associative effects index （SFAEI） and multiply factors associative effects index （MFAEI） were calculated.The results showed as follows：In different proportion combinations of WCS and AH,cumulative GP and DML were the highest in 80：20 combination（P 〈 0.01 ）, and gradually decreased with the increase of AH ratio;MCP, NH3-N and VFA concentration presented a trend that increased first and then decreased with the increase of AH ratio,and the production MCP in combination（60：40） was the largest（P 〈 0.05） ;SFAEI of GP and DMI were the largest in the 80：20 combination,the largest SFAEI of other indicators were in the 60：40 combination,and MFAEI was the largest in the 60：40 combination.In the optimal combination of WCS-AH （60：40） and MS,the GP and DML of 72 h were the highest at the ratio of 100：0 （P 〈 0.01 ）,and gradually decreased with the increase of MS ratio;the other indicators were the largest in the ratio of 80：20.SFAEI and MFAEI of GP and DML were the largest at the ratio of 60：40,SFAEI of other there indicators were the largest at the ratio of 80：20.In summary,the WCS and AH combination at ratio of 60：40,WCS-AH and MS combination at the ratio of 80：20 were found to give the largest associative effects.So,the appropriate proportion of WCS,AH and MS combination was 48：32：20.