Pittaluga Alejandro M, Miccoli Florencia E, Guerrero Leandro D, Relling Alejandro E
Department of Animal Sciences, The Ohio State University, Wooster, OH, USA.
Facultad de Ciencias Agrarias, Universidad Nacional de Lomas de Zamora, Lomas de Zamora, Argentina.
J Anim Sci. 2025 Jan 4;103. doi: 10.1093/jas/skae387.
Our objective was to evaluate the effect of a multispecies fungal extract (MFE) on growth performance, apparent total tract digestibility (ATTD), fermentation characteristics, and rumen microbiome composition of beef cattle fed forage-based diets. For experiment 1, ruminally cannulated Angus × SimAngus cows (n = 4; body weight [BW] = 569 ± 21 kg) were used in a randomized crossover design with two 21-d study periods and a 23-d washout period to evaluate the effect of dietary inclusion of an MFE on in situ digestion, ruminal fermentation, and the composition of the rumen microbiome. Treatments consisted of a forage-based diet with or without the inclusion of a MFE. Rumen samples were collected on days 5, 10, and 20. Experiment 2 evaluated different inclusion rates of the MFE in a randomized complete block design using Angus × SimAngus-crossbred steers (n = 80; BW = 370 ± 44 kg). Steers were blocked by BW and randomly assigned to one of four treatments (2 pens/treatment): diet with no MFE, 0.02%, 0.04%, and 0.08% of the MFE (dry matter [DM] basis). Steers were fed a forage-based diet for 122 d. Subsets of 10 steers/treatment were randomly selected for the determination of ATTD on d 20, 40, and 60. All data were analyzed using the MIXED procedure of SAS. In exp 1, adding the MFE to the diet tended to increase the ruminal disappearance rate of the DM on day 10 (P = 0.06). No interactions or treatment effects were observed for the short-chain fatty acid profile of the rumen fluid (P ≥ 0.13). Metagenomic analysis of the rumen microbiome showed an MFE × d interaction for the Fibrobacter genus (P = 0.01), which on day 20 was less abundant in the rumen of cows fed the MFE. In exp 2, steers supplemented with 0.04% of MFE had a lower average daily gain and were lighter at the end of the experiment (cubic, P ≤ 0.04) compared to steers supplemented with 0.02% MFE. Steers fed the diet with 0.02% of MFE had the greatest gain-to-feed ratio among the MFE-supplemented groups (cubic, P < 0.01). Dietary inclusion of the MFE increased neutral detergent fiber digestibility (linear, P = 0.05). Steers supplemented with 0.04% of MFE had the greatest acid detergent fiber digestibility among treatments (quadratic, P = 0.03). Collectively, results showed that ruminal disappearance rate and digestibility of forage-based diets increased due to MFE supplementation, but did not translate into growth performance improvements or beneficially alter rumen fermentation.
我们的目标是评估一种多物种真菌提取物（MFE）对以草料为基础日粮的肉牛生长性能、表观全肠道消化率（ATTD）、发酵特性和瘤胃微生物群组成的影响。在实验1中，使用瘤胃插管的安格斯×西姆安格斯母牛（n = 4；体重[BW]=569±21千克）进行随机交叉设计，有两个21天的研究期和一个23天的洗脱期，以评估日粮中添加MFE对原位消化、瘤胃发酵和瘤胃微生物群组成的影响。处理包括含或不含MFE的以草料为基础的日粮。在第5、10和20天采集瘤胃样本。实验2采用随机完全区组设计，使用安格斯×西姆安格斯杂交阉牛（n = 80；BW = 370±44千克）评估MFE的不同添加率。阉牛按体重进行分组，并随机分配到四种处理之一（每个处理2个栏）：不含MFE的日粮、0.02%、0.04%和0.08%的MFE（基于干物质[DM]）。阉牛饲喂以草料为基础的日粮122天。每个处理随机选择10头阉牛的子集，用于在第20、40和60天测定ATTD。所有数据均使用SAS的MIXED程序进行分析。在实验1中，在日粮中添加MFE在第10天倾向于提高DM的瘤胃消失率（P = 0.06）。瘤胃液的短链脂肪酸谱未观察到相互作用或处理效应（P≥0.13）。瘤胃微生物群的宏基因组分析显示，纤维杆菌属存在MFE×天数的相互作用（P = 0.01），在第20天，饲喂MFE的母牛瘤胃中该菌的丰度较低。在实验2中，与添加0.02%MFE的阉牛相比，添加0.04%MFE的阉牛平均日增重较低，且在实验结束时体重较轻（三次方，P≤0.04）。在添加MFE的组中，饲喂含0.02%MFE日粮的阉牛的料重比最高（三次方，P<0.01）。日粮中添加MFE可提高中性洗涤纤维消化率（线性，P = 0.05）。添加0.04%MFE的阉牛在各处理中酸性洗涤纤维消化率最高（二次方，P = 0.03）。总体而言，结果表明，添加MFE可提高以草料为基础日粮的瘤胃消失率和消化率，但并未转化为生长性能的改善，也未对瘤胃发酵产生有益改变。
