Replacement of groundnut cake with sunflower and karanj seed cakes on performance, nutrient utilisation, immune response and carcass characteristics in Nellore lambs

An experiment was conducted with 21 Nellore male lambs (9–10 months age) of uniform body weight (27.6±1.03 kg) to assess the effect of replacing groundnut cake (GNC) totally with sunflower seed cake (SFC) and karanj seed cake (KSC) in sorghum stover-based complete diets on growth performance, nutrient utilisation,immuneresponse and carcass traits. Lambs were randomly assigned to a control diet (13.0% GNC) and two test diets containing SFC (14.5%) and KSC (12.0%), as sole protein supplements and fed respective diets according to requirements recommended by the Indian Council of Agricultural Research, 1998 for a period of 155 days. Daily feed intake and fortnightly body weight of each lamb were recorded throughout the feeding trial. After 120 days, a metabolic trial of 6 days was conducted to determine nutrient digestibilities and balances. After the 75th day, all lambs were sensitised intramuscularly with heat-killed Brucella abortus S99 and 20% chicken red blood cell (RBC) suspension and a booster was given after 15 days to assess the humoral immune response. Antibody titres were estimated in serum collected from sensitised lambs on 7, 14, 21, 28 and 35th day post sensitisation. The cell-mediated immune response was assessed by delayed type hypersensitive (DTH) reaction against phytohemagglutinin-P and in vitro lymphocyte proliferative assay (LPA) on the 150th day of the experiment. On the 155th day, four representative lambs from each group were slaughtered for carcass studies. The karanjin content in KSC estimated by high-performance liquid chromatography (HPLC) was 0.325%, hence constituted 390mg karanjin per kg diet. Dry matter (DM), nutrient intake and digestibilities of proximate constituents, energy and fibre fractions by SFC- and GNCfed lambs did not differ, but DM and nutrient intake by lambs which were fed KSC was lowered (P < 0.05) compared to other diets. This resulted in lower (P < 0.05) growth rates, nutrient efficiency and relatively higher digestibility co-efficients for DM, organic matter, crude fat, nitrogen-free extract, energy and neutral detergent fibre in KSC-fed lambs. Balance of phosphorus (P) was comparable among the groups, but calcium (Ca) and nitrogen (N) balance was lower (P < 0.05) in KSC-fed lambs. Antibody titres against B. abortus and chicken RBC was depressed (P < 0.05) in lambs which were fed KSC diet on the 7th day post sensitisation, while such depression was not observed with SFC feeding. The DTH response and in vitro LPA response were not affected by SFC, but the response was lower on KSC diet. No effect of variation in protein supplements was observed on carcass characteristics.The study indicated that the incorporation of SFC as the sole protein source in the diets of lambs had no effect on body weight, nutrient intake, nutrient digestibilities, immune response and carcass traits. But with 12% KSC inclusion in complete diets (390mg karanjin per kg), there was depressed performance and immunocompetence in lambs.