Effect of dietary peNDF levels on digestibility and rumen fermentation, and microbial community in growing goats

Jia Zhou; Benchu Xue; Anhai Hu; Shuangming Yue; Mei Wu; Qionghua Hong; Yuhan Wu; Zhisheng Wang; Lizhi Wang; Quanhui Peng; Bai Xue

doi:10.3389/fmicb.2022.950587

Effect of dietary peNDF levels on digestibility and rumen fermentation, and microbial community in growing goats

Front Microbiol. 2022 Aug 25:13:950587. doi: 10.3389/fmicb.2022.950587. eCollection 2022.

Authors

Jia Zhou¹, Benchu Xue¹, Anhai Hu¹, Shuangming Yue², Mei Wu¹, Qionghua Hong³, Yuhan Wu¹, Zhisheng Wang¹, Lizhi Wang¹, Quanhui Peng¹, Bai Xue¹

Affiliations

¹ Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, China.
² Department of Bioengineering, Sichuan Water Conservancy College, Chengdu, China.
³ Yunnan Animal Science and Veterinary Institute, Kunming, China.

Abstract

Physically effective neutral detergent fiber (peNDF) is a concept that accounts for the particle length of NDF in diets, sustaining the normal chewing behavior and rumen fermentation of ruminants. Specifically, peNDF_>1.18 is the commonest one that is calculated from NDF and the percentage of feed dry matter left on the 1.18, 8.00, and 19.00 mm sieves. This study aimed to investigate the effects of different levels of peNDF_>1.18 on the rumen microbiome and its correlation with nutrient digestibility and rumen fermentation in goats. A total of 30 Lezhi black goats were randomized and blocked to five dietary treatments (n = 6). All the diets were identical in composition but varied in hay lengths, leading to the different peNDF_>1.18 content of the diets: 32.97, 29.93, 28.14, 26.48, and 24.75%. The results revealed that the nutrient digestibility increased when dietary peNDF_>1.18 levels decreased from 32.97% to 28.14%, with the highest digestibility at 28.14% peNDF_>1.18 treatment, after which nutrient digestibility decreased with the decreasing of dietary peNDF levels. Ruminal NH₃-N concentrations in the 29.93% and 28.14% groups were higher than that in the 24.75% group (p < 0.05). Ruminal microbial protein concentration was the highest in the 32.97% group (p < 0.05). Daily CH₄ production in the 32.97% and 24.75% peNDF_>1.18 treatments was lower than that in the 26.48% group (p < 0.05) and no differences were observed among other groups. The relative abundance of rumen fungi at the phylum and genus levels and archaea at the species were affected by dietary peNDF_>1.18 content. In conclusion, decreasing dietary peNDF_>1.18 levels within a certain range can improve nutrient digestibility and change the rumen microbial community structure of goats. Dietary peNDF_>1.18 level should be 28.14% (roughage length around 1 cm) among the five levels for 4 months Lezhi black goats with the purpose of optimal nutrient digestibility.

Keywords: goat; microbial community; nutrient digestibility; peNDF; ruminal fermentation.