Distiller’s dried grain with solubles (Zea mays L) in the diet of sheep reared in the tropical region of Brazil: ingestive behavior and physiological parameters

Abstract

This study aimed to evaluate the effects of inclusion of different levels of distiller’s dried grain with solubles (DDGS) in the diet of sheep raised in the tropical region of Brazil on ingestive behavior and physiological parameters. We used four sheep with mean body weight (BW) of 25 ± 2 kg, distributed in a Latin square design, with four periods, and four DDGS inclusion levels (0, 8, 16, and 24%). The sheep were placed in metabolism cages, and received two meals per day. The data on ingestive behavior and physiological parameters of the sheep were analyzed with analysis of variance (ANOVA), and the observed differences were tested using regression equations at 5% probability. The inclusion of DDGS levels in sheep diets did not change the time spent on ingestive behavior, such as dry matter intake (DMI), rumination (RUM), resting (RES), water intake (WAI), and other activities (OAC) expressed in minutes. However, during the night period, there was an increase (p < 0.05) in the time spent ruminating in relation to the daytime period. However, there was a reduction (p < 0.05) in the time spent on the activities of RES and WAI of the sheep. The inclusion of DDGS in sheep rations did not change (p > 0.05) the physiological parameters measured. However, we found that the afternoon period influenced (p < 0.05) the physiological parameters evaluated, such as body temperature of the front (BTF), body temperature of the rear (BTR), rectal temperature (RET), and respiratory frequency (REF), which were higher in relation to the values observed in the morning. Thus, we conclude that the inclusion of up to 24% of dried distillery grains with solubles in the feeding of sheep in the tropical region of Brazil does not alter the ingestive behavior and physiological parameters of sheep. However, sheep raised in confinement in the tropical region of Brazil spent more time ruminating at night. During the day, sheep spent more time on resting activities and water intake. In addition, sheep raised in a tropical environment need to be monitored for thermal stress during the afternoon, due to the increase in rectal temperature and respiratory frequency. In addition, sheep raised in a tropical environment require greater monitoring of thermal stress during the afternoon, due to the elevation of physiological parameters such as rectal temperature and respiratory frequency in this period.