Effect of supplemental palm oil on nutrient utilization, feeding economics and carcass characteristics in post-weaned Muzafarnagari lambs under feedlot condition

Thirty male post-weaned Muzafarnagari lambs, of about 3 months of age and similar body weight (18.47 ± 1.31 kg), were divided into 5 similar groups in order to observe the effect of graded levels of palm oil supplementation on growth, nutrient utilization, cost of feeding, carcass characteristics and meat quality under feedlot regimen. Lambs in different treatment groups were fed with concentrate mash supplemented with 0% (T1), 2.5% (T2), 5.0% (T3), 7.5% (T4) and 10% (T5) palm oil and gram straw (Cicer arietinum) ad libitum. The growth trial was continued for 12 weeks. A metabolism trial of 6 days collection was conducted after 60 days of experimental feeding. After 90 days of feeding, randomly selected three animals from each group were slaughtered according to standard procedure for assessment of carcass traits and meat quality. Separated thoracic portion of Longissimus thoracis muscle from each carcass was collected for analysis of moisture, protein and fat. Accelerated growth in lambs under T3 (P < 0.05) was observed as compared to other treatments with similar DM intake. Similarly, DM intake (kg)/kg gain was found most efficient (P < 0.01) in T3 and least efficient in 10% palm oil supplemented T5. Due to this, feed cost (rupees)/kg weight gain was calculated less (44.23) in T3 than other palm oil supplemented treatments. DM, CP, Ca and P intakes were similar in all treatment groups during metabolism trial. Intake ratio of Ca and P was recorded 3.68:1.00, 3.42:1.00, 3.37:1.00, 3.69:1.00 and 3.44:1.00 in T1 to T5 treatments, respectively. Water intake and water intake/kg DM intake was also similar in different treatment groups. OM digestibility was significantly higher (P < 0.01) in 2.5% palm oil supplemented T2 ration as compared to other treatments. DM, CP, EE, CF, NFE and P digestibilities were found similar among different treatment groups. TDN percentage in the feed increased from 60.16 (T1) to 66.17 (T5), which was mainly due gradual increase of palm oil in the diet, although the difference was non-significant. Whereas, DCP percentage in feed gradually depressed (P < 0.05) due to higher level of palm oil supplementation. Nitrogen retention (%) as percentage of N-absorbed was significantly higher (P < 0.05) in palm oil supplemented groups than control T1, being highest in T3 and T4. This could be the reason for higher body weight gain in T3 and T4. Dressing and meat percentages (empty weight basis) ranged from 52.00 (T4) to 55.06 (T2) and 58.10 (T2) to 62.27 (T5), respectively, however, the differences were similar. Muscle fat% (DM basis) increased (P < 0.01) from 19.84 (T1) to 28.94 (T5) due to palm oil addition. Meat protein% (DM basis) remained unaffected due to these treatments, which ranged from 59.95 (T1) to 70.47 (T2). Result indicates that addition of 5% palm oil in concentrate mixture improved growth performance and feed conversion efficiency of weaned Muzafarnagari lambs keeping the quality of meat unaffected.