The objective of this study was to evaluate the inclusion of different levels of 0.0%; 0.7%; 1.4% and 2.1% of Noni (Morinda citrifolia) in the feeding of lambs regarding ingestive behavior and physiological variables. The experiment was carried out in a double Latin (4x4) experimental design with eight animals, consisting of four periods and four experimental rations. Eight lambs with no defined racial pattern were used, with mean initial body weight (BW) of 23.74 ± 1.00 kg. The ingestive behavior was performed during 24 hours, always on the last day of each experimental period. The physiological variables and the environmental variables were measured during three days of each period. Data were submitted for analysis of variance and, when significant, regression equation was applied at 5% of probability. Statistical analysis was performed considering the subdivision of the plot, which consisted of the diurnal and nocturnal evaluation times for the ingestive behavior and the morning and afternoon periods for the physiological variables. The inclusion of Noni in fed lambs did not change (p > 0.05) the time spent with ingestive behaviors for dry matter intake (DMI), rumination (RUM), idleness (IDL), water intake (WIN) and other activity (OAC). However, the daytime During the period there was gr eater (p < 0.05) time use for DMI, WIN and OAC. Inclusion of Noni to diets provided higher (p > 0.05) time use during the night time for RUM and IDL. The physiological variables were not influenced (p > 0.05) by the inclusion of Noni in the diets of lambs. However, higher mean (p < 0.05) body temperature of the front and rear, rectal temperature and respiratory rate of the lambs were observed during the afternoon. The inclusion of up to 2.1% of Noni in lamb feed does not alter ingestive behavior and physiological variables. However, the consumption of dry matter and water is higher during the diurnal period, while rumination and idleness are more active during the night period.

The effect of inclusion of Morinda citrifolia L. (Noni) in standardized diets of sheep on in vitro digestibility and parameters fermentation was examined using two different inoculums (ruminal liquid and sheep feces). To determine the nutrients’ in vitro digestibility coefficient (IVDC), two sheep were used as inoculum donors. The experimental design was factorial (4 × 2), with four diets containing different proportions of Noni and two types of inoculum. The different dietary proportions of Noni (0%, 8%, 16%, and 24%) did not affect the IVDC of dry matter (DM), organic matter (OM) and crude protein (CP) for both inoculums. The IVDC of neutral detergent fiber (NDF) differed significantly between the inoculums. After in vitro incubation for 24 h, the pH value of the fermented material differed between the different diets and between the inoculums. Moreover, the concentration of ammoniacal nitrogen was affected by the proportion of Noni and differed between the inoculums after incubation for 24 h. The inclusion of up to 24% of Noni in standardized rations for ruminants did not affect the IVDC of DM, OM, CP, and NDF. The use of feces as inoculum for in vitro fermentation produced lower IVDC values than those by ruminal liquid. The diet containing 8% of Noni and fermented with ruminal liquid produced higher pH values after 24 h of incubation. Taken together, the different dietary Noni proportions and the different inoculums can alter the concentration of ammoniacal nitrogen of sheep diets after 24 h in vitro fermentation; however, they seem not to affect the IVDC of the nutrients.