Ingestive behavior and thermoregulation in sheep fed forage cactus silage undergoing intermittent water supply

Abstract

This study aimed to assess the effect of using forage cactus silage in the diet of sheep under intermittent water supply on its ingestive behavior and thermoregulation. We used in the experiment thirty-six intact male sheep of undefned genotype with an initial average weight of 19.8 ± 2.1 kg and age of approximately six months. The experimental design was a randomized block design in a 3 × 3 factorial scheme composed of three levels of forage cactus silage in the diet (0, 21, and 42%), three water supply periods (0, 24, and 48 hours), and four replications. For the ingestive behavior, observations were carried out every 5 minutes for 2 periods of 24 hours. Thermoregulatory responses were taken at 7:00 and 15:00 h on days other than those intended for ingestive behavior tests. Intermittent water supply did not affect any of the studied variables (P > 0.05). The use of forage cactus silage signifcantly influenced the ingestive behavior of animals (P ° 0.05). Sheep fed forage cactus silage in the diet presented an average feeding effciency of 255.77 g DM h-1 and an average rumination effciency of 102.16 g DM h-1, while animals fed control diet showed values of 198.63 and 78.45 g DM h-1, respectively. Urinary frequency increased according to the levels of forage cactus silage in the diet, with 23.60 urination per day in animals fed diets with 42% of forage cactus silage and 10.83 urination per day in animals fed control diet. However, the search for water reduced, with averages of 2.73 and 0.54 per day for animals fed 0 and 42% forage cactus silage, respectively. The use of forage cactus silage also increased thermoregulatory responses of sheep, with an average respiratory rate of 103.35 mov. min-1 and heart rate of 140.08 mov. min-1 in the warmest period of the day (in the afternoon). Thus, sheep fed forage cactus silage increases its feeding and rumination effciencies, decreases its search for water, and increases its thermoregulatory responses. The intermittent water supply within 48 hours does not influence the ingestive behavior and thermoregulation of confned sheep.