Acta Agrestia Sinica ›› 2020, Vol. 28 ›› Issue (3): 703-711.DOI: 10.11733/j.issn.1007-0435.2020.03.014

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Fermentation Quality and Aerobic Stability of the Total Mixed Ration after Replacing Alfalfa with Different Rations of King Grass ‘Reyan No.4’

LIANG Long-fei, WANG Fei, DONG Xiang, HAO Jun   

  1. College of Animal Science, Guizhou University, Guiyang, Guizhou Province 550025, China
  • Received:2020-02-25 Revised:2020-03-24 Online:2020-06-15 Published:2020-05-30

‘热研4号’王草替代紫花苜蓿对TMR发酵品质及有氧稳定性的影响

梁龙飞, 王飞, 董祥, 郝俊   

  1. 贵州大学动物科学学院, 贵州 贵阳 550025
  • 通讯作者: 郝俊
  • 作者简介:梁龙飞(1994-),女,贵州湄潭人,硕士研究生,主要从事草地栽培及饲草加工利用研究,E-mail:1759815304@qq.com
  • 基金资助:
    贵州省科技支撑项目(黔科合支撑[2017]2504-2);贵州省科技重大专项计划(黔科合重大专项字[2016]3002号);贵州省草地生态畜牧业人才基地项目(RCJD2018-13)共同资助

Abstract: The objective of this study was to evaluate the effects of replacing alfalfa(Medicago sativa L.) with different proportions of king grass ‘Reyan No.4’(Pennisetum purpureum×P.americana ‘Reyan No.4’) on the fermentation quality,nutritional composition and aerobic stability of the total mixed ration(TMR) silage. The replacement ratios of king grass ‘Reyan No.4’ were set as 0% (H0,alfalfa control group),18%(H18),30%(H30) and 42%(H42),respectively. The silages were opened at 60 days ensiling and the fermentation quality and nutrient composition were analyzed,the aerobic stability was evaluated after 0,3,6,9,12 days of aerobic exposure. The results showed that with the increase of the replace ratio of king grass Reyan No.4,the lactic acid contents,the pH value and the ammonia nitrogen/total nitrogen in FTMR gradually decreased. The ammonia nitrogen/total nitrogen of all treatments were less than 100 g·kg-1TN while butyric acid were not detected. After 60 days fermentation,water soluble carbohydrates contents of H42 treatments were significantly higher than that of H0and H18(P<0.05). Compared with raw material,dray matter and crud protein decreased in all treatments. The decrease of dry matter content and crude protein content was the least in H42. During aerobic exposure,the amount of aerobic bacteria,yeast and molds gradually increased with the extension of aerobic exposure time,and the amount of lactic acid bacteria gradually decreased with the extension time. The pH value did not exceed 4.2 in the H42 group,which indicated the best aerobic stability. According to the economic benefit analysis,the feed cost of H42 is the lowest. It was most appropriate to select the H42 group as the suitable choice for TMR fermentation.

Key words: King grass ‘Reyan No.4’, Alfalfa, Fermented total mixed ration, Fermentation quality, Aerobic stability

摘要: 本试验旨在探讨不同比例‘热研4号’王草(Pennisetum purpureum×P.americana ‘Reyan No.4’)替代紫花苜蓿(Medicago sativa L.)对全混合日粮发酵品质及有氧稳定性的影响。试验设‘热研4号’王草替代比例为0%(H0,紫花苜蓿对照组),18%(H18),30%(H30),42%(H42)4个处理,青贮60 d后开袋取样,分析其发酵品质和营养成分,并分别在有氧暴露的第0,3,6,9,12 d取样评定其有氧稳定性。结果表明:随着热研4号王草替代比例的增加,发酵全混合日粮中乳酸含量、pH及氨态氮/总氮逐渐减小,各组氨态氮/总氮小于100 g·kg-1TN且均未检测到丁酸;发酵60d后,H42组水溶性碳水化合物含量显著高于H0,H18组(P<0.05),与发酵前相比,各组干物质和粗蛋白含量有所下降,H42组干物质和粗蛋白含量下降最小;有氧暴露期间,好氧细菌、酵母菌和霉菌的数量逐渐增加,乳酸菌的数量逐渐降低,H42组pH在12 d内未超过4.2,有氧稳定性最好。由经济效益分析可知,H42组饲料成本最低。综上所述,选用H42组进行全混合日粮发酵最为适宜。

关键词: 热研4号王草, 紫花苜蓿, 发酵全混合日粮, 发酵品质, 有氧稳定性

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