Abstract
Background:
Feed availability in tropical regions fluctuates between rainy and dry seasons and is a major constraint on goat productivity. While forage is abundant during the rainy season, dry-season shortages often result in inadequate nutrient intake, reduced growth, and increased mortality. Complete silage technology offers a practical solution due to its balanced nutrient composition, long storage life, and ability to ensure year-round feed availability. However, exclusive feeding of complete silage has not consistently produced optimal performance, likely due to nutrient degradation during fermentation. Supplementation with protein sources and readily soluble carbohydrates is therefore necessary to improve nutrient availability and animal performance.

Aim:
This study evaluated the effects of protein and readily soluble carbohydrate supplementation on the productivity of Kacang goats fed complete silage.

Methods:
A randomized complete block design was used with 15 Kacang goats allocated to three dietary treatments and five replications. The treatments consisted of T1 (70% complete silage + 30% supplementation of protein sources and readily soluble carbohydrates), T2 (50% complete silage + 50% supplementation), and T3 (30% complete silage + 70% supplementation).

Results:
Results of ANOVA showed that dietary treatments did not significantly affect (P>0.05) intake of dry matter, organic matter, crude protein, crude fat, carbohydrates, nitrogen-free extract, gross energy, or metabolizable energy. However, ash intake (P<0.05) and crude fiber intake (P<0.01) were significantly influenced by treatment. Digestibility of dry matter, organic matter, ash, crude protein, crude fat, crude fiber, carbohydrates, gross energy, and metabolizable energy differed significantly among treatments (P<0.05), with higher values observed in diets containing 50–70% complete silage (T1–T2) than in T3. Growth performance parameters did not differ significantly among treatments (P>0.05), although T1 and T2 tended to show higher values than T3.

Conclusion:
Diets containing 50–70% complete silage with 30–50% supplementation of protein sources and readily soluble carbohydrates improved nutrient and energy digestibility and tended to enhance growth, despite no significant effects on intake or overall growth performance.

Key words: Complete silage; Fattening; Kacang goats; Performance; Protein–carbohydrate supplementation.