青贮剂对再生稻头季全株青贮品质和体外瘤胃发酵特性的影响

Effects of silage additives on quality and in vitro rumen fermentation characteristics of first season ratoon rice whole silage

旨在探究青贮剂对再生稻头季全株青贮品质和体外瘤胃发酵特性的影响。以再生稻头季全株为青贮原料,在青贮中分别添加植物乳杆菌(60%)+纤维素酶(30%)+木聚糖酶(10%)、植物乳杆菌(70%)+粪肠球菌(20%)+纤维素酶(5%)+半纤维素酶(5%)、植物乳杆菌(30%)+粪肠球菌(60%)+纤维素酶(5%)+半纤维素酶(5%)、等量水为对照(依次记为N_(1)、N_(2)、N_(3)和CK组,各组添加量为500 g·t^(-1)鲜重)。青贮45 d后开包取样,分析其青贮品质和体外瘤胃发酵特性。结果表明:1)青贮结束后,N_(1)、N_(2)和N_(3)组的总能显著高于CK组(P<0.05),中性洗涤纤维和酸性洗涤纤维含量显著低于CK组(P<0.05),且N_(2)组的中性洗涤纤维含量显著低于N_(1)和N_(3)组(P<0.05),N_(1)、N_(2)和N_(3)组的总可消化养分含量和乙酸含量均显著高于CK组(P<0.05),氨态氮/总氮显著低于CK组(P<0.05)。2)体外发酵24 h后,N_(2)组的24 h累积产气量和快速降解部分的产气量显著高于N_(1)、N_(3)和CK组(P<0.05),N_(2)组的潜在产气量显著高于N_(1)、N_(3)和CK组(P<0.05),且N_(1)组显著高于CK组(P<0.05),N_(1)和N_(2)组的pH显著低于N_(3)和CK组(P<0.05),N_(2)组的乙酸和氨态氮含量显著高于N_(1)、N_(3)和CK组(P<0.05),N_(1)和N_(2)组的丙酸含量显著高于N_(3)和CK组(P<0.05),N_(2)组乙酸/丙酸显著低于N_(3)和CK组(P<0.05),N_(2)和N_(3)组的干物质降解率和粗蛋白质降解率显著高于N_(1)和CK组(P<0.05),N_(2)组的有机物降解率、中性洗涤纤维降解率和酸性洗涤纤维降解率显著高于N_(1)、N_(3)和CK组(P<0.05)。综上所述,在实际生产中,建议青贮剂在以植物乳杆菌为主要添加剂的前提下,辅助添加粪肠球菌、纤维素酶和半纤维素酶,有利于获得营养价值较佳的再生稻头季全株青贮。

This experiment was conducted to investigate effects of silage additives on quality and in vitro rumen fermentation characteristics of first season ratoon rice whole-crop silage.The experiment compared three fermentation-enhancing preparations of bacterial and enzyme additives,added at 500 g·t^(-1) fresh weight when ensiling whole crop ratoon rice,and a control(CK,500 g·t^(-1) water).The additive treatments were:N_(1),Lactobacillus plantarum(60%)+cellulase(30%)+xylanase(10%);N_(2),L.plantarum(70%)+Enterococcus faecalis(20%)+cellulase(5%)+hemicellulase(5%);N_(3),L.plantarum(30%)+E.faecalis(60%)+cellulase(5%)+hemicellulase(5%).The silages were sampled after 45 d after ensiling,and the silage quality and in vitro rumen fermentation characteristics analyzed.The results were as follows:1)After ensiling,the gross energy,total digestible fiber,and acetate values of the N_(1),N_(2) and N_(3) silages were significantly higher than those of CK group(P<0.05),while the contents of neutral and acid detergent fiber and ammoniacal nitrogen∶total nitrogen of the N_(1),N_(2) and N_(3) groups were significantly lower than those of the CK group(P<0.05).Among treated silages,the neutral detergent fiber level of the N_(2) group was significantly lower than that of N_(1) and N_(3) groups(P<0.05).2)After 24 h in vitro fermentation,the 24 h cumulative gas production,the gas production of rapid degradation and the potential gas production of the N_(2) group were significantly higher than for the N_(1),N_(3) and CK groups(P<0.05),and the potential gas production of the N_(1) group was significantly higher than for the CK group(P<0.05).The N_(1) and N_(2) groups had lower pH than the N_(3) and CK groups(P<0.05),and the contents of acetate and ammonia of N_(2) group were significantly higher than those of the N_(1),N_(3) and CK groups(P<0.05).The propionate contents of the N_(1) and N_(2) groups were significantly higher than those of N_(3) and CK groups(P<0.05);the acetate∶propionate ratio of the N_(2) group was significantly lower than that of N_(3) and CK groups(P<0.05);the degradation rates of dry matter and crude protein of N_(2) and N_(3) groups were significantly higher than those of N_(1) and CK groups(P<0.05);the degradation rates of organic matter,neutral detergent fiber and acid detergent fiber values of the N_(2) group were significantly higher than for N_(1),N_(3) and CK groups(P<0.05).In conclusion,it is suggested that silage additives should be supplemented with E.faecalis,cellulase and hemicellulaseunder the premise that L.plantarum is the main agent required to produce first season ratoon rice whole silage with improved nutritional value in actual production.