Feeding behaviour of lactating ewes fed diets containing different neutral detergent fiber levels

The aim of this study was to evaluate the effects of different neutral detergent fiber (NDF) levels in the diet on ingestive behavior of lactating ewes. Eighteen 5/8 Ile de France 3/8 Texel ewes, housed in individual cage 24 hours postpartum, were used. Animals were assigned to one of three treatments: 34, 43 and 52% NDF in the diet, in dry matter (DM) basis. The total mixed rations, composed by corn silage (Zea mays L.), ground corn, soybean meal (Glycine max L.), limestone, salt and dicalcium phosphate, were given twice a day, at 0830 AM and 0430 PM. Ingestive behavior was determined by visual appreciation. The increase of the NDF level in the diet significantly influenced (P<.05) DM and NDF intakes, milk yield, and the feeding, rumination, idleness resting and total chewing times, that varied quadratically (P<.05). The NDF feeding and rumination efficiency increased, whereas DM feeding and rumination efficiency linearly decreased (P<.05) as effect of the NDF increased, being necessary more time to feed the same amount of total mixed ration. Highest NDF levels in the diet can cause depression in DM intake.

concentrate; forage; idleness; intake; sheep; rumination