Farelo de mamona destoxificado como aditivo para ensilagem de cana-de-açúcar em dieta de ovinos confinados

Abstract

The aim was to evaluate the consumption, digestibility, performance, blood and histopathological parameters of confined sheep fed diets containing sugar cane supplemented with levels of detoxified castor bean meal (DBM). A total of 24 non castrated male sheep with an average body weight of 16 ± 0.75 kg were used in a completely randomized design with four treatments and six replicates. The treatments consisted of four levels of inclusion of castor bean bran in sugar cane silage (0, 10, 20 and 40% in natural matter). A linear effect was observed for crude protein (P = 0.038) and ether extract (P = 0.001) intakes, with averages ranging from 0.151 to 0.128 kg/day and from 0.068 to 0.044 kg/day, respectively. There was a linear trend for the digestibility of crude protein (P = 0.001) and ether extract (P = 0.018), with average values ranging from 754.174 to 472.875 g/day and from 813.017 to 725.080 g/day, respectively. However, there was no effect (P > 0.05) of the levels of DBM on the final weight, total gain, average daily gain, feed conversion and feed efficiency of the sheep, with averages of 23.785, 6.637, 0.138, 8.418 and 0.1212 kg/day, respectively. The second experiment aimed to evaluate the blood and histopathological parameters of confined sheep fed sugarcane silage supplemented with levels of FMD, following the same experimental protocol as in experiment 1. Blood samples were taken on the first and forty-eighth experimental days. Liver, kidney and rumen samples were collected after slaughter for histopathological analysis. A quadratic effect (P < 0.05) was observed for the epithelium thickness and papilla width variables as a function of DBM levels, with minimum values estimated by the regression model at 0.69% and 1.22% DBM levels, respectively. As for the keratinized portion variable, there was a linear effect (P < 0.05), with values ranging from 32.28 to 50.44 mm. There was an isolated effect (P < 0.05) of time for the variables hemoglobin (P = 0.0043), hematocrit (P = 0.0067), and mean corpuscular volume (P = 0.0068). When comparing the first day with the forty-eighth, there was an increase in most of the erythrogram variables, except for the following: erythrocytes at the 0% level and MCHC at the 10, 20 and 40% levels. There was an interaction (P = 0.0149) between DBM levels and time for monocytes. There was no effect (P > 0.05) on DBM levels at 1 and 48 days, with averages of 5.174 and 3.166, respectively. To the time factor within each level of DBM, there was a difference (P < 0.05) in the levels of 0, 20 and 40% DBM, with the highest values for monocytes being observed on the 1st day of collection, which did not differ from each other. However, there was no difference in time at the 10% DBM level. It is therefore recommended that up to 40% of detoxified castor bean meal be included in sugar cane silage for use in sheep diets without causing negative impacts on animal health.