The Effect of Substitution of Groundnut Cake by Water Melon Seed Cake (Citrullus Lanatus) in Ration for Lamb Fattening in Sudan

The present study was conducted t o eva luate water mel on ( Citrullus lanatus) seed cake as a possible pr otein s upplement for growing I amb i n compar ison to gr oundnut cake. Graded proportion of water melon seed cake (W MSC) ( 0, 25, 50, 75, 100%) w hich replace groundnut cake (G NC) w ere incorporated in five diets iso-caloric, iso-nitrogenous diet for lamb. Diet A c ontained 0% proportion of WMSC, d iet B , C , D and E contained 25%, 5 0%, 7 5% and 100% WMSC proportions re spectively. F orty five ye arling m ale l ambs of Sudan desert sheep ecotype Kabashi with ave rage body weight of 31.5 kg were used. Carcass composition parameters did not differ significantly among the treatment groups. Muscle and fat percentages were s lightly hi gher in t he cont rol group. But bone percentage was higher in gr oup E w hich ha d gi ven higher percentage of WMSC. The slaughter by-products sho wed no significant differences a mong dietary treatments. Chemical co mposition of m eat r evealed that t he protein content i n the muscles of all treatment groups except group E had similar values. Group A had t he highest (P < 0.01) f at an d lowest moisture content, while g roup E had the lowest fat content and highest moisture content. Fat co ntent was decrease w ith increasing level of WMSC inclusion in the d iet, while m oisture content increases with i t increasing l evel. There i s a s ignificant effect (P < 0.01 and P < 0.05) among treatment groups for sacroplasmic pr oteins and non-protein ni trogen respectively, but there was no significant effect was observed for myofibrillar proteins. The values of these proteins were decreased with increasing di etary l evel of WMSC. Meat quality at tributes showed s ignificant effect for water holding capacity ( P <0. 001), cooking l oss (P < 0.01) and shear force (P < 0.001) indicated t hat meat of group A was of superior water holding ca pacity and lower cooking l osses, so i t was more t ender than the ot her groups. T he m eat colour r evealed significant (P < 0.05), (P < 0.01) an d (P <0.001) eff ect among dietary treatments for lightness, redness and yellowness respectively, indicated that group C, D and E were darker in col our than group A and B. Dietary t reatments showed no significant effect among the t ested gr oups for taste pa nel scores of tenderness, juiciness, flavour, colour and overall acceptability. However, meat from animals in gr oup A was desired mor e t han the meat from other groups. There i s a s ignificant effect (P < 0.01 and P < 0.05) among treatment groups f or sacroplasmic pr oteins and non-protein ni trogen respectively, but there was no significant effect was observed for myofibrillar proteins. The values of these proteins were de creased with incr easing di etary l evel of WMSC. It could be concluded that WMSC when incorporated i n l amb di ets produces carcasses which w ere s ignificantly not different from that produced by G NC diet. Meat muscle composition and quality was also had a tendency to be similar to that of the GNC diet.