谷草与苜蓿的不同配比对绵羊日粮组合效应的影响

摘要

为了探讨不同精粗比下谷草与苜蓿配比对绵羊日粮组合效应的影响,本试验以谷草与苜蓿为粗饲料,采用体外产气法测定精粗比为40∶60时,谷草∶苜蓿为60∶0、50∶10、40∶20、30∶30、20∶40、10∶50及0∶60,精粗比为30∶70时,谷草∶苜蓿为70∶0、60∶10、50∶20、40∶30、30∶40、20∶50、10∶60及0∶70的15组日粮及谷草、苜蓿和精料补充料分别培养2、4、6、9、12、24、36、48、72、96 h的产气量(GP),并通过24 h产气量(GP24h)及其加权估算值计算出各日粮的组合效应值(AE).结果表明:①精粗比为40∶60时,比较各组GP24h,50∶10组极显著大于10∶50组(P＜0.01);40∶20、60∶10组显著大于10∶50组(P＜0.05);各组AE值均为正值,但组间无显著差异(P＞0.05);50∶10的GP24h、b、a+b均为最大,其AE最优.②精粗比为30∶70时,比较各组GP24h,50∶20、60∶10、70∶0组显著大于0∶70组(P＜0.05),40∶30、20∶50组有大于0∶ 70组的趋势(P=0.063,P=0.064);各组AE值无显著差异(P＞0.05);40∶30组的GP24h、b、a+b均较大,其AE最优,其次是20∶50、10∶60组.综合以上结果,谷草与苜蓿配比为50∶10(精粗比为40∶60)和40∶30、20∶ 50、10∶60(精粗比为30∶70)时,可以获得较高的AE.%This experiment was conducted to investigate the effects of the proportion of alfalfa and rice straw on associative effects (AE) of diets in vitro.Rice straw ∶ alfalfa were 60 ∶ 0,50 ∶ 10,40 ∶ 20,30 ∶ 30,20 ∶ 40,10 ∶ 50,0 ∶ 60 when concentrate-roughage ratio (C ∶ R) was 40 ∶ 60,and rice straw ∶ alfalfa were 70 ∶ 0,60 ∶ 10,50 ∶ 20,40 ∶ 30,30 ∶ 40,20 ∶ 50,10 ∶ 60,0 ∶ 70 when C ∶ R was 30 ∶ 70.Gas production (GP) was recorded at 2,4,6,9,12,24,36,48,72 and 96 h.The AE was defined as the difference between the observed in vitro GP24 h and the predicted value from individual feed fermented alone.The results showed as follows∶① GP24 h of the group50 ∶ 10 was extremely significantly greater than the group 10 ∶ 50 (P＜0.01),and GP24 h of the groups 40 ∶ 20 and 60 ∶ 0 were significantly greater than the groups 10 ∶ 50 (P＜0.05) when C ∶ R was 40 ∶ 60.The AE of all groups were positive and there were no significant difference among them (P＞0.05).WhenC∶ Rwas40 ∶ 60,the GP24h,b,a+b of group 50 ∶ 10 were the greatest and it's AE was the best.(②GP24h of the groups 60 ∶ 10,70 ∶ 0 and 50 ∶ 20 were significantly greater than the group of 0 ∶ 70 (P＜0.05) and groups 40 ∶ 30 and 20 ∶ 50 were greater than the group0 ∶ 70 (P=0.063,P=0.064) whenC∶ R was 30 ∶ 70.The AE of all groups had no significant difference (P＞0.05).When C ∶ R was 30 ∶ 70,the GP24 h,b,a+b of group 40 ∶ 30 was the greatest and it's AE was the best,followed by the groups 20 ∶ 50 and 10 ∶ 60.It is concluded that the AE of the groups of 50 ∶ 10 (C ∶ R was 40 ∶ 60),40 ∶ 30,20 ∶ 50 and 10 ∶ 60 (C ∶ R was 30 ∶ 70) were greater.