Intake and feeding behaviour of Morada Nova lambs fed different energy levels

The effects of metabolizable energy levels were evaluated on nutrient intake and ingestive behaviour in Morada Nova lambs. Forty Morada Nova lambs were used with an initial weight of 12.2 +/- 2.05 kg. Five treatments were defined according to the metabolizable energy levels (0.96, 1.28, 1.72, 2.18 and 2.62 Mcal/kg DM). The experimental model was a randomized block design. Linear effect (P<0.0001) of ME levels was determined for dry matter intake (DMI), organic matter (OM), crude protein (CP), total carbohydrates (TC), non-fibrous carbohydrates (NFC) and total digestible nutrients (TDN) in g/day. Quadratic effect was determined for NDF (P<0.017) and carbohydrate intake (P<0.003). Linear effect was determined for digestibility of DM, OM, NDF, TC and NFC. Eating, ruminating and total chewing times, expressed in hours/day, decreased linearly (P<0.0001) with the energy levels of experimental diets. Idle time increased linearly (P<0.0001) with the increase of energy levels of the rations. Feeding and rumination efficiencies were influenced by the energy levels (P<0.0001) when expressed in g DM/h. The number of ruminal boluses, number of chews and chews per ruminal bolus were not affected by the levels of ME. However, time spent chewing per ruminal bolus was influenced (P<0.0014). Increase in ME levels of diets influences nutrient intake and feeding behaviour of Morada Nova lambs during the growing period.