Utilization of sunflower heads in sheep

The nutritive value of sunflower heads (SH) in rams and the effect of total mixed rations (roughage: concentrate, 60:40) containing SH at 0 (R₀), 20 (R₂₀), 40 (R₄₀) or 60% (R₆₀) replacing groundnut haulms on growth performance of lambs was studied in a 90 d growth trial. The SH contained 8.4% CP and the effective degradability of DM and CP was 54.8 and 37.0%o, respectively. The DCP and TDN contents were 2.8 and 53.8%, respectively and the rams were in negative balance for N, Ca and P retention when fed exclusively on SH.

The effective DM degradability of TMR was increased (P<0.01) up to 40% of SH in rations while the effective CP degradability was decreased (P<0.01) beyond 20% of SH in the total mixed rations. The digestibility of OM, CP, EE, NFE and hemicellulose (P<0.05) increased while CF (P<0.05), ADF and cellulose (P<0.01) digestibility decreased with the increase in level of SH in the TMR. The ram lambs were in positive nitrogen, calcium and phosphorus balance with no significant effect of the dietary treatments. The ADG and feed efficiency were not significantly influenced by the dietaiy treatments. The results indicated that exclusive feeding of sunflower heads could not sustain even maintenance requirments of sheep where as it could be effectively utilized in total mixed rations up to 60% without any adverse effect on the growth performance of ram lambs.