Effects of starters with different processing methods of corn on rumen fermentation and microflora of pre-weaning and post-weaning lambs.
Effects of starters with different processing methods of corn on rumen fermentation and microflora of pre-weaning and post-weaning lambs.
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DOI：
10.3969/j.issn.1006-267x.2022.06.039
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发表时间：
2022-01-01
期刊：
影响因子：
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通讯作者：
Guo, Yan-li
中科院分区：
文献类型：
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作者：
Li, Yong;Cai, Xiao-fang;Guo, Yan-li
本试验旨在研究不同加工方法的玉米发酵剂对断奶前后羔羊瘤胃发酵及微生物区系的影响。选用8日龄平均体重（5.04 ± 0.75）kg、初生体重相近的湖羊公羔24只，随机分为两组，每组12只。将羔羊分配到两个日粮处理之一：（1）颗粒化发酵剂（PS组，玉米和其他饲料成分研磨后颗粒化）;（2）蒸汽压片玉米发酵剂（SFS组，玉米蒸汽压片后粉碎，其他饲料成分研磨后颗粒化，然后将粉碎的蒸汽压片玉米与颗粒化饲料混合）。对7日龄前的羔羊进行母乳喂养，并在8日龄时与其母畜分开，并移入单独的笼子中。从8日龄到35日龄，羔羊饲喂牛奶添加剂（MR）和它们各自的自由采食物。在35日龄时停止喂食MR。每组分别在21日龄（断奶前）和42日龄（断奶后）对6只羔羊实施安乐死，以进行采样。收集瘤胃内容物，测定瘤胃发酵参数和微生物区系。结果表明：断奶前和断奶后，SFS组羔羊的总挥发性脂肪酸、丙酸和丁酸含量均显著高于PS组（P < 0.05），断奶前分别提高了23.06%、35.58%、56.44%，断奶后分别提高了7.82%、28.87%、32.47%; SFS组羔羊拟杆菌相对丰度（61.96%）超过厚壁菌门（32.08%）和变形菌门（3.99%），成为断奶前羔羊的第一优势菌门，接近断奶后羔羊拟杆菌相对丰度（65.36%）。而PS组中拟杆菌的相对丰度（57.28%）高于厚壁菌门（31.21%）和变形菌门（1.15%），但仍低于断奶前（61.96%）和断奶后（65.36%）拟杆菌的相对丰度。与PS组相比，SFS组断奶前和断奶后的Sharpea和Oribacterium的相对丰度显著增加（P < 0.05）。在瘤胃功能方面，仅在KEGG 3水平，断奶前SFS组与氨基酸代谢相关酶的功能基因表达量显著高于PS组（P < 0.05），而与转运因子和脂肪酸降解代谢相关的功能基因表达量显著低于PS组（P < 0.05）。结果表明，与玉米粉发酵剂相比，玉米粉发酵剂更有利于断奶前后羔羊瘤胃发酵、优势菌群的建立以及断奶前瘤胃氨基酸和脂肪酸代谢功能的改善。
This study aimed to evaluate the effects of starters with different processing methods of corn on rumen fermentation and microflora of pre-weaning and post-weaning lambs. Twenty-four 8-day-old male Hu lambs[average body weight:(5.04 0.75) kg] with similar birth weight were randomly divided into two groups with 12 lambs in each group. Lambs were assigned to one of two dietary treatments: (1) pelleted starter (PS group, corn and other feed ingredients were pelleted after grinding); (2) steam-flaked corn starter (SFS group, the corn was crushed after steam-flaked processing, other feed ingredients were pelleted after grinding, and then the crushed steam-flaked corn was mixed with the pelleted feeds). Lambs before 7 days of age were breast feeding and separated from their dams at 8 days of age and moved into individual cages. From 8 to 35 days of age, the lambs were fed milk replacer (MR) and their respective ad lib starter. Feeding of MR was stopped at 35 days of age. Six lambs for each group were euthanized at 21 (pre-weaning) and 42 days of age (post-weaning) for sampling, respectively. The rumen contents were collected to measure rumen fermentation parameters and microflora. The results showed that the contents of total volatile fatty acids, propionate and butyrate of pre-weaning and post-weaning lambs in SFS were significantly higher than those in PS group (P < 0.05), and they were improved 23.06%, 35.58%, 56.44% (pre-weaning) and 7.82%, 28.87%, 32.47% (post-weaning), respectively. The relative abundances of Bacteroidetes (61.96%) of lambs in SFS group had exceeded Firmicutes (32.08%) and Proteobacteria (3.99%), and became the first predominant phylum during pre-weaning, and closed to the relative abundance of Bacteroidetes (65.36%) for post-weaning lambs. While in PS group, the relative abundances of Bacteroidetes (57.28%) exceeded Firmicutes (31.21%) and Proteobacteria (1.15%) post-weaning, and still lower than them of Bacteroidetes in SFS lambs pre-weaning (61.96%) and post-weaning (65.36%). Compared with PS group, the relative abundances of Sharpea and Oribacterium of pre-weaning and post-weaning lambs in SFS group were significantly increased (P < 0.05). In rumen function, only at KEGG level 3, the functional gene expression of enzyme related amino acid metabolism in SFS group was significantly higher than that in PS group pre-weaning (P < 0.05), while the expression of functional genes of transport factors and fatty acid degradation and metabolism in SFS group was significantly lower than that in PS group (P < 0.05). The results indicate that steam-flaked corn starter is benefit to the rumen fermentation, establishment of dominant microflora of lambs pre-weaning and post-weaning and the rumen amino acid and fatty acid metabolism functions pre-weaning compared with polleted starter.