Feeding behavior of lambs on feedlot finishing fed with concentrate containing maize replacement levels by mesquite pod meal

This study aimed to evaluate the ingestive behavior of feedlot finished lambs fed concentrate containing maize replacement levels by mesquite pod meal (MP) (10, 35, 60 and 85% based on natural matter, by containing the same dry matter content). We used 25 lambs, initial body weight (BW) 31.53 ? 4.05 kg and 180 days of age were placed in individual pens with 0.8 m², fitted with troughs and watering the outside. The diets were composed of 60% concentrate containing the substitution of maize by MP and 40% dehydrated Opuntia, formulated to daily gain of 0.150 kg body weight, constituted of 12.6% CP. We used a completely randomized design with five treatments and five replications, each animal being a repetition. The experiment lasted 45 days, divided into three experimental sub-periods of 15 days each and five days of data collection, with a period of adaptation to confinement of 10 days. The number of chewing had a linear increase (P < 0.05), however, the concentration of NDFap decreased while increased the MP levels in the diets. The increase in chewing may possibly be due to the larger particle size of MP compared to maize. The average time spent with rumination was 3.53 (h/day), because of the relatively low NDF intake, resulted of the composition of the experimental diets associated with reduced particle size, resulting in high idle time (12.36 h/day). It is concluded that MP levels in the diets affect the number of chewing without interfering with time spent with rumination.