Use of Watermelon (Citrullus lanatus) Seeds in Diets for Fattening Lambs

Abstract

This study was conducted to evaluate the effect of feeding diets with different levels of whole watermelon seeds on growth performance, carcass characteristics and meat quality of lambs. Thirty 6-month old lambs of Sudan desert sheep with an average weight of 33.8 Kg were used in this study. They were randomly divided into three groups (n=10) and assigned into three treatment diets with different levels of watermelon seeds (WS) for 52 days. The diets were WS0, WS10, or WS20, which contained 0% (control), 10% and 20% watermelon seeds, respectively. The results showed that final live weight, daily weight gain and total weight gain, hot carcass weight, cold carcass weight and chiller shrinkage were higher (P < 0.05) in WS0 and WS20 groups compared to WS10 group. Feed conversion ratio was higher (P < 0.05) in sheep fed WS10 compared to sheep fed WS0. Treatment diets did not affect carcass composition (muscle, fat and bone) and meat chemical composition. However, water-holding capacity and cooking loss were significantly different among the treatment groups, where lambs fed on WS10 had inferior water-holding capacity and higher cooking loss. Treatment diets had no significant effect on meat lightness (L*); but redness (a*) and yellowness (b*) values were significantly higher in WS0 group compared to WS10 and WS20 groups. Shear force value was lower (P < 0.05) in WS10 compared to WS0 and WS20. It was concluded that inclusion of whole watermelon seeds up to 20% in lamb diets supported sufficient feedlot performance, carcass characteristics and meat quality.