The Effect of (Amla) Fruit Supplementation on the Rumen Microbiota and Its Correlation with Rumen Fermentation in Dairy Cows

Introduction: Medicinal plants, rich in phytochemicals like phenolic acids, flavonoids, and tannins, offer potential benefits in enhancing productivity, quality, and animal health. Amla fruit () is one such plant with promising attributes. This study aimed to investigate the impact of fresh Amla fruit (FAF) supplementation on ruminal microbial composition and its correlation with rumen fermentation in lactating dairy cows.

Methods: The study employed a repeated crossover design involving eight ruminally cannulated mid-lactation Holstein dairy cows. Animals received varying levels of fresh Amla fruit supplementation (0, 200, 400, and 600 g/d).

Results: When 400 g/d of FAF was added to the diet, there was a significant increase in the relative abundance of Firmicutes ( = 0.02). However, at 200 g/d, the relative abundance of ruminal Bacteroidota was higher than the 0 and 400 g/d FAF supplementation ( < 0.01). LEfSe analysis identified distinct taxa, such as in the 200 g/d group, in the 400 g/d group, and in the 600 g/d group. Notably, the random forest species abundance statistics identified as a biomarker related to milk yield. , and were positively correlated with ruminal total VFA and molar proportion of propionate, while gut group and were negatively correlated.

Discussion: FAF supplementation affects the abundance of beneficial microbes in a dose-dependent manner, which can improve milk yield, efficiency, rumen health, desirable fatty acids, and animal health.