Influence of various concentrate-to-roughage ratios on dietary intake and nutrient digestibilities of weanling horses.
Authors: Turcott-White Susan K, Nielsen Brian D, Robison Cara I, Skelly Christine D, Rosenstein Diane S, Pritchard Abby, Herdt Thomas
Journal: Journal of animal physiology and animal nutrition
Summary
# Editorial Summary Concentrate-to-roughage ratios significantly influence nutrient utilisation in weanling horses, with implications for growth and metabolic efficiency during this critical developmental period. Researchers fed 24 weanlings one of three dietary treatments (70:30, 50:50, and 30:70 concentrate-to-roughage ratios) and measured feed intake and nutrient digestibility at both 5 and 8 months of age using standardised collection protocols. Whilst total feed intake remained consistent across all treatment groups, crude protein digestibility was substantially higher in the high-concentrate diet at both time points (most notably at 8 months, p <0.01), whereas weanlings receiving forage-heavy diets showed a tendency towards superior neutral detergent fibre digestion and numerically higher energy digestibility. For practitioners formulating weanling rations, these findings suggest that concentrate-based feeding optimises protein utilisation—particularly important for supporting skeletal development and muscle accretion—whilst higher forage inclusion may offer modest advantages in fibre metabolism without compromising overall nutrient intake. The results indicate no single "best" ratio exists across all metrics, but rather practitioners should balance protein digestibility gains from concentrate feeding against the physiological benefits of adequate forage provision, tailoring ratios to individual growth targets and underlying metabolic demands.
Read the full abstract on PubMed
Practical Takeaways
- •For weanling horses, higher concentrate diets improve protein digestibility, which may support growth and development during this critical period.
- •Higher roughage diets increase fecal output without affecting total feed intake, suggesting different digestive kinetics that may influence gut health and feeding management.
- •Diet formulation should balance protein digestibility gains from concentrates against potential fiber digestion benefits of higher roughage inclusion, depending on production goals.
Key Findings
- •No differences in body weight or daily feed intake among the three concentrate-to-roughage ratios (70:30, 50:50, 30:70) at either 5 or 8 months of age.
- •High concentrate diet (70:30) resulted in significantly higher crude protein digestibility at both 5 months (p<0.05) and 8 months (p<0.01) compared to lower concentrate ratios.
- •Low concentrate diet (30:70) produced greater fecal output than high concentrate diet at both 5 and 8 months (p<0.01).
- •Weanlings tended to digest neutral detergent fiber more efficiently on high-roughage diets while digesting energy more efficiently on high-concentrate diets (p=0.09 and p=0.06 respectively).