Growth, Carcass, Offal, Meat Yield and Quality of Broiler Chickens Offered Roselle (Hibiscus sabdariffa L.) Calyx Extracts

Abstract

Four concentrations of roselle calyx extract-RCE excluding water only-T1 were prepared by hot-water extraction at 100°C for 10minutes using 5 (T2), 10 (T3), 15 (T4) and 20 (T5) grams roselle calyx-RC per Liter of water (g RC/L). These with T1 were offered as drinking water to 28-day-old Arbor Acres chickens (n=210, r=6) for 21 days. Weight gain-WG, feed intake-FI, feed conversion ratio-FCR and final weight-FW were assessed. At 49 days old, 2-birds/replicate were sacrificed. Percent-% in carcass yield-(breast weight-BRW, thigh weight-TWG, drumstick weight-DWG), external offal-(head, neck, shank), internal offal-(gizzard, liver, heart, abdominal fat) and meat yield-(breast meat-BM, thigh meat-TM and drumstick meat-DM) were assessed. Selected BM were boiled and assessed for colour-(redness-a*, yellowness-b*, lightness-L*) and sensory qualities-(flavour and juiciness). Data were analyzed using ANOVA at α0.05. FW-(1571.90±32.64g) and WG-(40.86±40.45g) in T5 were significantly-(p<0.05) higher than treatments-(T1, T2 and T3), while FI across treatments were not significantly different. The BRW of 23.05±0.2%-(T5) was significantly higher than 18.43±0.3%-(T2) and 17.87±0.2%-(T1) while TWG-(12.47±0.2%) and DWG-(13.13±0.4%) in T5 were significantly higher than treatments-(T1-T4). Head-(3.18±0.2%), shank-(5.38±0.2%), gizzard-(2.99±0.2%) and liver-(2.39±0.2%) in T5 were higher (p<0.05) than treatments-(T1-T4). The percent-% BM of 18.12±2.4 (T5) was significantly higher (p>0.05) than 12.75±0.13% (T1), 13.29±0.44 (T2), 15.71±0.39 (T3) and 16.10±0.39 (T4). The percent-% TM of 8.91 (T5) and DM of 10.33 (T5) were significantly-(p<0.05) higher than treatments-(T1-T4). Redness-a* of 11.67±0.06 and lightness-L* of 46.89±0.25 in T5 were significantly-better than treatments-(T1-T4). The flavour (6.08±0.15) and juiciness (6.31±0.05) in T5, were higher (p<0.05) than other treatments-(T1-T4). It demonstrates that aqueous roselle calyx extract can serve as a non-toxic growth promoter, significantly improving final body weight, feed efficiency and meat quality. Thus, meat from chickens offered 5 to 20g roselle calyx/L extract had better carcass yield, meat yield, desirable colour and sensory qualities.