NUTRITIONAL STUDIES ON COMPENSATORY GROWTH PHENOMENON IN FATTENING BUFFALO CALVES

This study was conducted to investigated the effects of feed restriction at early age and re-alimentation (compensatory growth phenomenon) on growth and fattening buffalo calves performance. Twenty four buffalo calves with an average 123±1.05 Kg live body weight (LBW) and aged six months old were used in a feeding trial lasted for (150 – days) as restricted feeding period followed by (90- days) as re-alimentation period using randomized complete block design. Animals were divided into four similar groups (six calves per group) according to their LBW. During the feed restriction period, all animals’ groups were fed the roughage portion (50% corn silage, 40% ammoniated – treated rice straw and 10% berseem hay) at the ad libitum level with supplementation of concentrate feed mixture (CFM) at the levels of 1.5%  (T1) as control, 1% (T2), 0.5 (T3) and 0.00% (T4) as tested rations, based on their (LBW). Following, the restriction period, all calves were fed on 2.5% CFM of their LBW plus 1% ammoniated treated rice straw (TRS) over re-alimentation period. In the restricted feed period, results indicated that most of nutrient digestibilities were significantly (P<0.05) lower with the restricted rations (T2, T3 and T4) than those of control group (T1). Vice versa trend was associated with CF digestibility among the dietary treatments. The feeding values as TDN, DCP and DE were followed comparable trends to those of nutrient digestibilities among treatments. Also, the DMI of calves fed restricted (T3 and T4) rations were significantly (P<0.05) lower than those calves fed restricted rations (T2) and unrestricted ration (T1). Daily gain was decreased significantly (P< 0.05) with calves restricted feed rations (T3 and T4) than those of the restricted ration (T2) and control groups (T1), but no significantly difference was found between T1 and T2 in this item. Likewise, feed conversion (as Kg DM or TDN /kg gain) was decreased significantly (P<0.05) with all calves fed restricted (T2, T3 and T4) rations compared with non-restricted (T1). Blood serum total protein and albumin concentrations were significant lower (P<0.05) for all restricted rations than that of control one. During re-alimentation period, results indicated that calves fed restricted rations (T2, T3 and T4) consumed significant lower DMI and achieved significant higher daily gain in comparison with those of unrestricted group (T1). Also, feed conversion ratio was significantly better with restricted groups vs. the unrestricted one (control). Over the whole experimental period (240 - days), DM intake of calves fed restricted rations (T2, T3 and T4) were significantly (P<0.05) lower than that of non-restricted (T1). Average daily gain of calves fed unrestricted rations (T1) and restricted ration (T2) were significantly (P<0.05) higher than those of restricted rations (T3 and T4). Calves fed restricted ration (T2) was significantly (P<0.05) better in feed conversion than those of the restricted rations (T3 and T4) and control one (T1). The improvement of economic efficiency based on control ration (100%) were 108.19, 113.31 and 125.26% % for the tested rations (T2, T3 and T4), respectively. Based on this study, results indicated that all calves fed restricted rations (T2, T3 and T4) in re-alimented period gave significant better growth performance, daily gain and feed conversion ratio over the re-alimented period, being incidencing the compensatory phenomenon which led to potential positive effect on economical efficiency over the whole period of fattening calves.