Effects of the addition of detoxified castor bean meal to sugarcane silage: blood parameters and histopathological findings in confined sheep.

The objective was to evaluate the blood parameters and histopathological findings of sheep fed sugarcane silage supplemented with increasing levels of detoxified castor bean meal (DCM) during a 60-days period. A total of 24 uncastrated male sheep, without a defined breed pattern, with an initial body weight of 25.0 ± 1.5 kg, were used. They were distributed in a completely randomized design with four treatments [0, 10, 20, and 40% DCM in sugarcane silage, based on natural matter (NM)] and six replicates. A quadratic effect was observed for ruminal epithelial thickness (P = 0.03) and ruminal papilla width (P = 0.03). A linear increasing effect (P = 0.02) was verified for the keratinized portion, with average values ranging between 32.3 and 50.4 μm as the DCM level increased. A time effect (P < 0.05) was also observed for hemoglobin, hematocrit, mean corpuscular volume, and lymphocytes, with the highest averages at 48 days (10.8 g/dL, 33.1%, 30.5, and 49.4 µL, respectively). For monocytes, a treatment × time interaction effect (P = 0.02) was found, with the highest means observed on day 1 for the 0%, 20%, and 40% levels (4.3, 6.7, and 5.8 µL, respectively). A slight histopathological alteration was observed for hyaline casts, regardless of the inclusion level of DCM. Thus, sugarcane silage supplemented with detoxified castor bean meal up to a level of 40% did not cause deleterious changes in the blood parameters and histological structure of the rumen, liver, and kidneys of confined sheep.