Finishing of grazing crossbred steers supplemented with detoxified castor bean meal (Ricinus communis L.) in the rainy-dry transition period.

This study evaluated levels of replacement of soybean meal by castor bean meal in the finishing crossbred steers on Brachiaria brizantha cv. Marandu pasture during the rainy-dry transition period. Forty Holstein-Zebu crossbred steers with an average initial weight of 395.93 ± 10 kg were randomly allocated to four treatment groups that were supplemented with concentrate levels of replacing (0, 290, 613, and 903 g/kg DM of the supplement; at 0.4% body weight [BW]). The experimental period was 120 days. A completely randomized experimental design was adopted; with regression analysis using the computational software package (SAS 9.2, USA). Intake and digestibility of dry matter (DM) and nutrients and animal performance were evaluated. The replacement levels did not influence (P > 0.05) the intakes of DM (kg/day), organic matter (OM, kg/day), neutral detergent fiber (NDF, kg/day and %BW), non-fibrous carbohydrates (NFC, kg/day), or total digestible nutrients (kg/day). However, the intake of crude protein (CP) and ether extract (EE, kg/day) decreased as the replacement levels were increased (P < 0.05). The digestibility of DM, OM, NDF, and EE did not change, whereas CP digestibility decreased linearly and NFC digestibility increased linearly (P < 0.05). The replacement levels did not affect (P > 0.05) final body weight, average daily gain, feed conversion, and carcass yield. Castor bean meal can replace up to 903 g/kg DM of soybean meal in the composition of the supplement without compromising the performance of steers on Marandu pasture during the rainy-dry transition period.

Nutrient intake and ingestive behavior of feedlot steers fed with licuri cake.

The objective of this study was to evaluate the effects of the inclusion of different levels of licuri cake on the consumption of dry matter and nutrients and ingestive behavior of feedlot crossbred steers. Forty-four crossbred steers with an average age of 24 months and a mean live weight of 358.19 ± 41.57 kg were used in the study. The animals were aleatorically distributed in a completely randomized design made up of four treatments, with 11 animals used per treatment: the control treatment (without the inclusion of licuri cake in the diet) and treatment with the inclusion levels of 8.5, 17, and 25.5% of licuri cake, respectively, in the total dry matter of the diet. The inclusion of licuri cake influenced the intake of dry matter, crude protein, ether extract, neutral detergent fiber corrected for ash and protein, and non-fibrous carbohydrates corrected for ash and protein, each of them showing quadratic behavior. There was an effect of the tested diets on the time spent on food intake and number of idle periods, which presented a quadratic effect, with maximum and minimum values obtained for the inclusion levels of the licuri cake of 16.92% and 11.00%, respectively. There was no effect of the tested diets on the time spent on rumination and idleness. The feed efficiency of the dry matter, the duration of the feeding period, and the duration of the idleness period were influenced by the inclusion of the licuri tart in the diet, presenting a linear decreasing effect. There was an increasing linear effect for the number of feeding periods and the duration of rumination periods. Given the results obtained, it can be concluded that the licuri cake changes the consumption and behavioral parameters of feedlot steers, being recommended its use in up to 8.5% of inclusion in the total dry matter of the diet.