Effects of feeding sweet potato (Ipomoea batatas) vines as a supplement on feed intake, growth performance, digestibility and carcass characteristics of Sidama goats fed a basal diet of natural grass hay

Abstract

The objective of this study was to investigate the effects of substituting sweet potato [Ipomoea batatas (L) Lam] vines for concentrate on growth performance, digestibility, and carcass characteristics. Thirty yearling bucks (15.3 ± 1.64 kg) were assigned into six treatments in a randomized complete block design: natural grass hay alone (T1) or supplemented with 100 % sweet potato vines (SPV) (T2), 65 % SPV + 35 % concentrate (T3), 35 % SPV + 65 % concentrate (T4), and 100 % concentrate (T5) on dry matter (DM) basis. Supplemented goats (T2, T3, T4, and T5) consumed higher (p < 0.001) total DM (553, 567, 505, and 515 g/day), respectively, when compared to the nonsupplemented (T1) goats (349 g/day). The crude protein (CP) intake (32.0, 48.6, 54.7, and 69.2 g/day) increased with increasing levels of the concentrate in the diet for T2, T3, T4, and T5, respectively. The DM digestibility in T2, T3, T4, and T5, respectively, was higher (P < 0.01) (0.69, 0.72, 0.72, and 0.74) than in T1 (0.56). Apparent digestibility of CP was observed to be higher (P < 0.001) in T3, T4, T5 (0.78, 0.83, and 0.88) when compared to the bucks in T2 (0.60). Higher (P < 0.001) daily weight gain (31.2, 46.4, 48.6, and 47.6 g/day) were recorded for T2, T3, T4, and T5, respectively, whereas the nonsupplemented goats lost weight (-19.5 g/day). Slaughter weight, empty body weight, hot carcass weight, dressing percentage, rib-eye muscle area, and total edible offals were higher (P < 0.05) in supplemented goats compared with nonsupplemented ones. Therefore, it could be concluded that sweet potato vine can replace the conventional concentrate and could be fed with poor quality hay to prevent body weight loss of animal in the absence of other feed supplements.