<p>This research examined the effects of different probiotic dosages on three-month-old Guiqian semi-fine wool ram lambs (initial weight: 18.57 ± 0.96 kg). The lambs were randomly assigned to four dietary treatments: a control group (CON) received a standard basal diet, while three experimental groups, PRB1, PRB2, and PRB3, were supplemented with 1,000 mg/kg DMI, 2,000 mg/kg DMI, and 3,000 mg/kg DMI, respectively, of a probiotics blend (containing <i>Bacillus subtilis</i> and <i>Bacillus licheniformis</i>, each ≥ 1 × 10<sup>8</sup> CFU/g) over a 60-day period. The findings revealed that probiotics supplementation markedly improved final body weight and average daily gain (ADG), with the PRB2 group showing the most pronounced increase (<i>P</i> &lt; 0.01). Compared with control lambs, probiotic-fed lambs presented significantly elevated serum Ig G and Ig A levels and reduced levels of the proinflammatory markers IL-6 and TNF-α (<i>P</i> &lt; 0.05). The PRB2 group also presented increased Ig M, IL-10, and IL-1β concentrations (<i>P</i> &lt; 0.05). Antioxidant profiling revealed that PRB1 lambs presented increased serum GSH-Px, T-AOC, and CAT activity, whereas PRB2 lambs presented further improvements in these markers plus elevated T-SOD and reduced MDA content (<i>P</i> &lt; 0.05). Probiotics also modulated rumen ecology, lowering the NH<sub>3</sub>-N concentration (<i>P</i> &lt; 0.05) while increasing the total volatile fatty acid (TVFA) content. The PRB2 group notably altered the microbial composition, decreasing <i>Bacteroidota</i> and <i>Verrucomicrobiota</i> while increasing <i>Firmicutes</i> at the phylum level (<i>P</i> &lt; 0.05). At the genus level, <i>Christensenellaceae_R-7_group</i> and <i>Lachnospiraceae_NK3A20_group</i> increased, whereas <i>Prevotella</i>, <i>Succiniclasticum</i>, <i>Selenomonas</i>, and <i>Eubacterium_coprostanoligenes_group</i> decreased (<i>P</i> &lt; 0.05). The experimental results revealed that the addition of different doses of probiotics to the basal diet improved the growth performance, antioxidant capacity, and immunity of Guiqian semi-fine wool sheep and had a positive effect on the rumen microorganisms of Guiqian semi-fine wool sheep, and the best effect was achieved at the addition level of 2000 mg/kg.</p>

错误:搜索内容不能为空,请输入英文关键词
错误:关键词超出字数限制,请精简
高级检索

Supplementation of a Dietary Probiotics Blend can Enhance Growth Performance in Guiqian Semi-Fine Wool Sheep by Modulating Rumen Microbiota and Immune Function

  • Yandi Peng,
  • Xiaoyun Shen

摘要

This research examined the effects of different probiotic dosages on three-month-old Guiqian semi-fine wool ram lambs (initial weight: 18.57 ± 0.96 kg). The lambs were randomly assigned to four dietary treatments: a control group (CON) received a standard basal diet, while three experimental groups, PRB1, PRB2, and PRB3, were supplemented with 1,000 mg/kg DMI, 2,000 mg/kg DMI, and 3,000 mg/kg DMI, respectively, of a probiotics blend (containing Bacillus subtilis and Bacillus licheniformis, each ≥ 1 × 108 CFU/g) over a 60-day period. The findings revealed that probiotics supplementation markedly improved final body weight and average daily gain (ADG), with the PRB2 group showing the most pronounced increase (P < 0.01). Compared with control lambs, probiotic-fed lambs presented significantly elevated serum Ig G and Ig A levels and reduced levels of the proinflammatory markers IL-6 and TNF-α (P < 0.05). The PRB2 group also presented increased Ig M, IL-10, and IL-1β concentrations (P < 0.05). Antioxidant profiling revealed that PRB1 lambs presented increased serum GSH-Px, T-AOC, and CAT activity, whereas PRB2 lambs presented further improvements in these markers plus elevated T-SOD and reduced MDA content (P < 0.05). Probiotics also modulated rumen ecology, lowering the NH3-N concentration (P < 0.05) while increasing the total volatile fatty acid (TVFA) content. The PRB2 group notably altered the microbial composition, decreasing Bacteroidota and Verrucomicrobiota while increasing Firmicutes at the phylum level (P < 0.05). At the genus level, Christensenellaceae_R-7_group and Lachnospiraceae_NK3A20_group increased, whereas Prevotella, Succiniclasticum, Selenomonas, and Eubacterium_coprostanoligenes_group decreased (P < 0.05). The experimental results revealed that the addition of different doses of probiotics to the basal diet improved the growth performance, antioxidant capacity, and immunity of Guiqian semi-fine wool sheep and had a positive effect on the rumen microorganisms of Guiqian semi-fine wool sheep, and the best effect was achieved at the addition level of 2000 mg/kg.