# Digestibility, rumen fermentation, and blood metabolites of Barki rams fed Panicum maximum cv. Mombasa hay as a substitute for alfalfa hay, with or without spirulina

## TL;DR

This study shows that replacing some alfalfa hay with Panicum hay and adding Spirulina improves digestion and health in Barki rams.

## Contribution

The study introduces a novel combination of Panicum hay and Spirulina supplementation to enhance sheep productivity in forage-limited environments.

## Key findings

- Replacing 25% of alfalfa with Panicum hay improved rumen fermentation and nutrient digestibility.
- Spirulina supplementation significantly enhanced rumen parameters and blood metabolites.
- Combining 25% Panicum hay with Spirulina boosted productivity in Barki rams under forage-limited conditions.

## Abstract

There is a growing interest in alternative feed sources for sheep, especially under desert conditions. This study evaluated the effects of replacing 25% of alfalfa hay with Panicum maximum hay in three isocaloric and isonitrogenous diets, with or without Spirulina supplementation (2 mg/g), on nutrient digestibility and rumen fermentation in Barki rams. Forty-eight adult rams (2 years old; 45 ± 0.60 kg) were randomly assigned to six groups (n = 8). Forage represented 40% of the diet, and its composition varied as follows: 0% Panicum (all alfalfa with no replacement; T1, T2), 25% of the forage as Panicum (partial replacement; T3, T4), and 100% of the forage as Panicum (complete replacement; T5, T6). Spirulina was added to T2, T4, and T6. Results showed that all alfalfa hay diets significantly (P < 0.0001) enhanced rumen total volatile fatty acids (TVFA), ammonia (NH3) concentration, nutrient digestibility, nitrogen balance, and overall nutrient composition compared to diets with 10% Panicum and 30% alfalfa or 40% Panicum. Moreover, Spirulina supplementation significantly (P < 0.0001) improved all measured rumen parameters and digestibility indices relative to non-supplemented groups. Regarding blood metabolites, rams fed by 40% alfalfa hay exhibited the highest (P < 0.0001) levels of total protein, albumin, globulin, and urea, followed by those receiving 10% Panicum and 30% alfalfa. Spirulina supplementation also significantly increased these blood parameters compared with the unsupplemented groups. In conclusion, partial replacement of alfalfa hay with Panicum maximum hay (25%), combined with Spirulina supplementation, can enhance rumen fermentation, nutrient utilization, and metabolic profiles in Barki rams, suggesting a promising strategy for improving productivity under forage-limited conditions.