Nutrient Utilization, Ruminal Fermentation, and Health Responses of Maintenance Goats to Cowpea (Vigna unguiculata var. sesquipedalis) Silage as a Sustainable Alternative to Commercial Feed.

Abstract

In this study, we evaluated the substitution effect of cowpea silage as a replacement for commercial feed on the nutrition and health of goats being fed for maintenance. First, the nutrient loss and ruminal fermentation characteristics of wilted cowpea forage ensiled (EC) or not ensiled (NEC) were tested in vitro. The dry matter (DM) and organic matter (OM) degradability, ammonia nitrogen concentration, and 48 h total gas production were significantly greater, whereas pH was lower in EC (Experiment 1). Three diets composed of commercial feed and EC at ratios (%) of 100:0 (T1), 50:50 (T2), and 25:75 (T3) were subsequently tested using six Japanese Saanen × Shiba goats in a replicated 3 × 3 Latin square design (Experiment 2). Nutrient intake, same as DM, ether extract (EE) and nonfiber carbohydrate (NFC) digestibility decreased from T1 to T3. However, acid detergent fiber (ADFom) and crude protein (CP) intakes were greater at T2. Nitrogen intake and balance were also greater in T2 goats, whereas blood urea nitrogen (BUN), alanine transaminase (ALT), and creatinine (CRE) were greater at T1. Alternatively, substituting commercial feed with 50% EC in the diets of goats fed for maintenance is feasible for optimizing protein efficiency without hindering animal health.