Journal of King Saud University: Science (May 2023)
Deciphering the influence of soil and feed on the nutritional status of ruminants in rainfed areas using metagenomic analysis
Abstract
The soil–plant-animal continuum is an emerging domain in biological research and hence, to ascertain this aspect, the present study was conducted in three agro-ecologically different areas in Andhra Pradesh and Telangana, India. The goal of this work was to explore the impact of feed type and geographical conditions on the growth dynamics of sheep feed with three different diets – sorghum stover (Vizag district), groundnut halums (Krishna district) and red gram chunni (Ranga Reddy district). Animals were fed these diets at night daily for 90 days after their routine daytime grazing. The study regions varied in altitude, annual rainfall and mean temperature. Soil analysis was performed in these regions to check for pH, mineral content, organic carbon and bacterial composition. Growth dynamics (average daily gain of 41.56–77.11 g per day) and feed conversion ratios (6.26–10.93) differed markedly (p < 0.05) among animals in the three regions. Metagenomics sampling of sheep ruminal fluid from sheep reared in the three distinct regions (and separate feed types) was carried out by sequencing 16S rRNA V3-V4 regions. Comparison of alpha diversity and operational taxonomic unit (OTU) richness showed remarkable variations in the Chao1, ACE, Shannon and Simpson indices. The results of this work reveal the relationship between feed type, geographical location and ruminal microflora composition. The presence of numerous genera and species differences were discovered in the three samples, and the presence of several methanogens was confirmed. In conclusion methane emissions from cattle and sheep may be mitigated by altering the feed type, which directly influences the ruminal and gut microflora composition. Further research is recommended in order to determine the optimal relationship between soil and feed and their impact on the nutritional status of ruminants in rainfed areas, taking into account various farming and agroclimatic conditions.
