Optimization of feed efficiency and gut microbiota modulation in high-producing dairy goats under variable forage quality.

Project Abstract

This study investigates the interplay between feed efficiency and gut microbiota modulation in high-producing dairy goats subjected to variable forage quality, with the aim of identifying strategies that sustain production while reducing feed costs and environmental footprint. A multi-factorial design was employed involving 180 lactating goats randomly assigned to three forage quality regimes (high, medium, and low crude fiber and metabolizable energy) across two milking periods to capture seasonal variation. A comprehensive feeding trial spanned 12 weeks, during which individual feed intake, milk yield and composition, body condition, and nitrogen utilization were measured. Parallel analyses of hindgut and rumen microbiota were conducted using 16S rRNA gene sequencing, shotgun metagenomics, and targeted qPCR to quantify key microbial taxa and functional pathways related to fiber degradation, short-chain fatty acid production, and nitrogen metabolism. Digestibility trials were performed using total fecal collection and near-infrared spectroscopy to assess nutrient utilization efficiency. Metabolic status was evaluated through blood metabolites (NEFA, BHB, glucose, urea), oxidative stress markers, and hormonal indicators of energy balance. The study also incorporated feeding strategies designed to modulate the microbiota, including optimized forage-to-concentrate ratios, inclusion of prebiotic fibers, and select probiotic candidates with demonstrated murine and caprine efficacy. Advanced statistical models, including mixed-effects models and structural equation modeling, were used to disentangle direct effects of forage quality on production from indirect effects mediated by microbial community structure and function. Bioinformatic pipelines integrated taxonomic and functional profiles to identify microbial genes and pathways significantly associated with improved feed efficiency and milk production under varied forage scenarios. Preliminary results indicate that goats receiving higher-quality forage exhibit superior feed conversion ratios and milk fat globule stability, with distinct rumen and hindgut microbial signatures characterized by enriched fibrolytic bacteria and increased genes for acetogenesis and butyrate synthesis. In medium-quality forage, specific microbiota shifts correlated with compensatory increases in protein-sparing pathways and nitrogen recycling, mitigating declines in milk yield. In low-quality forage, probiotic and prebiotic interventions show promise in maintaining ruminal pH, stabilizing microbial diversity, and preserving milk yield, albeit with modest gains in feed efficiency. The research identifies critical microbial biomarkers predictive of resilient production under forage variability and demonstrates that targeted microbiota modulation can partially decouple production losses from deteriorating forage quality. Economic analysis suggests that integrating microbiota-informed feeding strategies can reduce feed costs per unit of milk while maintaining animal health and welfare. The study contributes to a mechanistic understanding of diet–microbiome–production interactions in dairy goats and provides practical guidelines for producers to optimize feed efficiency across fluctuating forage availabilities.

Project Overview

What This Project Is About

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A plain-language overview of how feeding strategies and gut microbes interact in dairy goats that produce a lot of milk, and how different forage quality affects both feed use and animal health.

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The Problem It Addresses

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Farmers often face fluctuating forage quality, which can lower how efficiently goats convert feed into milk and may disrupt gut microbes that aid digestion. Understanding this link helps improve productivity and animal welfare without increasing costs or synthetic additives.

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Objectives of the Project

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1. Assess how forage quality affects milk production and feed intake.
2. Analyze changes in the gut microbial community in response to different forages.
3. Identify sensible feeding strategies that optimize efficiency and gut health.
4. Provide practical guidelines for farmers to manage forage variation.

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What You Will Do Step by Step

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Review literature on forage quality, feed efficiency, and gut microbes.

Design a small-scale study with goats fed varying forages.

Collect data on feed intake, milk yield, and body condition.

Sample gut microbes (stool/ fecal) and analyze for key microbial groups.

Analyze relationships between forage, intake, milk, and microbes using simple stats.

Form practical feeding recommendations based on findings.

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Expected Outcome

A clear set of guidelines showing how to adjust forage quality or feeding practices to maintain high efficiency and healthy gut microbiota, with potential benefits for productivity and animal well-being.