Pre-weaning growth response of lambs fed creep mixtures with varying levels of energy and protein.

The pre-weaning nutrient requirements for growth of lambs were assessed by feeding them on ad libitum creep mixtures with free suckling and free choice of Pala (Z. nummularia) leaves. Thirty six lambs (15 days old) were divided into three equal groups and fed creep mixtures containing high (HEHP), medium (MEMP) and low (LELP) levels of digestible energy and protein. A cafeteria system of feeding management was used. The ratio of creep mixture, pala leaf and milk in the total DMI of HEHP lambs was 74.9:11.4:13.7. The corresponding ratios in DMI were 73.8:14.3:11.8 and 90.3:2.1:7.6 in MEMP and LELP regimens. Digestibility of DM, OM and CP was higher (P<0.01) in HEHP than MEMP and LELP. Digestibility of NDF and ADF was also significantly (P<0.01) higher in HEHP than MEMP and LELP. However, digestibility of cellulose and hemicellulose were higher (P<0.01) in LELP than other two groups. The lambs in all the three groups were in positive N balance while per cent N retention was lower (P<0.01) in LELP (52.6%) compared to MEMP (61.5%) and HEHP (70.4%). The lambs in HEHP, MEMP and LELP consumed 58.2, 51.6 and 83.5g DM, 10.4, 7.4 and 8.0g DCP and 250.4, 163.2 and 228.9kcal DE/kgW(0.75)/day amounting to an average of 43g DCP/Mcal DE consumed/day and had 124, 108 and 124g ADG, respectively. It is concluded from the study that ad libitum LELP creep mixture with free suckling and free choice pala (Z. nummularia) leaves was adequate to meet the growth requirement for 124g pre-weaning average daily gain.