Ingestive Behaviour of Grazing Ewes Given Two Levels of Concentrate

Abstract

This study aimed to evaluate the influence of concentrate supplementation on the ingestive behaviour of grazing ewes. Twelve pregnant pluriparous sheep were used, six of the Santa Inês breed and six of the Morada Nova breed. The supplement was formulated to supply the animals with two feed levels (0.5% and 1.5% of body weight) of nutrition. The experimental design was a randomized 2 x 2 x 2 factorial arrangement (two breeds, two supplementation levels and two feeding shifts, morning and afternoon) with six replicates per treatment, totalling 24 experimental units. Focal sampling was used to record the time spent on the adopted behaviour at 10-minute intervals for 10 continuous hours, with three replications, totalling 180 records per animal. Sampling started at 07:00. Time spent grazing, ruminating and resting did not correlate with the level of concentrate supplementation. It was expected that concentrate supplementation would reflect directly on forage intake owing to the substitution effect, which causes sheep where the supplement supplied a small proportion of net energy requirement, to have a greater grazing intensity. The two breeds differed in the time spent ruminating or lying, with the Santa Inês sheep spending more time in these activities. Greater intensity of grazing and ruminating occurred in the morning, which is directly related to the climatic conditions of the region. Time of day is a factor that imposes limitations on the feeding behaviour patterns of ewes that are supplemented on pasture.

Keywords: Breed, Grazing, Morada Nova, Santa Inês, Season