ABSTRACT The objective of this study was to assess the effects of two levels of soybean hulls (0 and 400.1 g/kg) and whole or ground corn in the diet of newborn crossbred dairy male calves on intake, performance, blood indicators, and feeding cost. Twenty-eight calves with an average weight of 33.0±6.2 kg and four days of age were distributed into four treatment groups in a completely randomized design (n = 7) for 56 days. Weekly samples of feed, diets, and leftovers were collected to determine dry matter and nutrient intakes. To evaluate apparent digestibility, samples were taken using titanium dioxide as a maker. Blood samples were also collected to evaluate blood indicators. The inclusion of soybean hulls resulted in greater neutral detergent fiber intake by the calves, but reduced their non-fibrous carbohydrates intake, which was also reduced by the use of whole corn in the diet. Although the total digestible nutrients content of diets decreased with the use of whole corn and inclusion of soybean hulls, its intake did not vary (0.75 kg/d), regardless of the factors analyzed. The apparent digestibilities of dry matter (0.87 kg/kg) and crude protein (0.89 kg/kg) were similar, resulting in similar performance between the animals, regardless of the factors analyzed. In the quantities evaluated, the use of soybean hulls or whole corn did not affect blood indicators and was insufficient to reduce feed costs; the cost of daily feed was $2.06, while the cost per kilogram of gain was $3.74. The inclusion of up to 400.1 g/kg of soybean hulls or the replacement of ground corn with whole corn does not affect the performance of crossbred dairy calves during the preweaning period, demonstrating that both can be used in animal feed during this phase of production.

The objective of the present study was to evaluate the effects of corn milling and the inclusion of babassu mesocarp bran (BMB) on productive performance, digestibility of dietary nutrients, and blood parameters of dairy crossbred (Holstein-Gyr) bulls finished in confinement. Twenty-four bulls were fed four different experimental diets, containing two levels of inclusion of BMB (0 and 41.24%) and corn supplied in two different forms (ground and whole), for 98 days (77 days of data collection and 21 days of adaptation). The intakes and digestibility coefficients of the dry matter (DM) and nutrients were determined. There were no significant interaction effects of the BMB inclusion level and the form of corn used on the performance and digestibility variables. The intakes of DM, crude protein (CP), and neutral detergent fibre (NDF) increased with the inclusion of BMB in the diets. However, the inclusion of BMB in the diets decreased the ether extract intake, the NDF apparent digestibility, and the feed efficiency of DM and CP. Dry matter and NDF intakes also increased with the use of ground corn in the diet, which promoted an increase in the intake of total digestible nutrients (TDN), digestibility of non-fibrous carbohydrates, and average daily gain. However, the supply of ground corn reduced the feed efficiency of TDN. The remaining measured variables did not vary with the tested diets. The levels of plasma protein and albumin remained normal, but glucose concentrations were always high, irrespective of the tested diet. The form of corn supplied and the level of BMB inclusion had a significant interaction effect on the levels of triglycerides, urea, aspartate aminotransferase, and alkaline phosphatase. Babassu mesocarp bran can be included up to 41.24% in the diet of confined bulls without a negative effect on the animal weight gain. Corn should be supplied ground because this form improves the performance of crossbred bulls

The objective of this study was to evaluate the effect of grinding corn and inclusion of babassu mesocarp bran (BMB) in the diet of crossbred dairy young bulls finished in feedlot on their carcass and meat characteristics. Twenty-four young bulls were fed four experimental diets containing two BMB inclusion levels (0 and 41.24%) and corn in two forms of processing (ground and whole grains) for 98 days, and then slaughtered in a commercial packing plant. Among the quantitative carcass characteristics, there was interaction only in fat trimmings/whole hot carcass weight and cold carcass yield. The whole hot carcass and hot carcass weights showed reduced means with the use of whole corn. The other quantitative variables were not separately affected by BMB inclusion levels or by the form corn was processed. There was interaction between the factors for pistol cut weight, edible portion and weight of the cuts of the pistol cut, in which the use of whole corn and BMB promoted reduction in the mean values. The use of the whole corn grain reduced the participation of flank cut and elevated the participation of the bone fraction in the carcass. Inclusion of 41.24% of BMB did not change the qualitative meat characteristics, but the use of corn grain resulted in darker meat. The use of whole corn resulted in alteration in the weight of cuts like eye of rump and striploin, which have a high commercial value. There was interaction between factors for the percentages of moisture and minerals of the meat, whereas the crude protein content was affected by the two factors. The use of diets with whole corn or with babassu mesocarp bran may modify the carcass and meat characteristics of finishing crossbred young bulls.

The objective of the present study was to evaluate the effect of the use of babassu mesocarp meal (BMM) and corn in different physical forms on the feeding behavior of crossbred young bulls of a dairy breed. Twenty-four crossbred (Nellore vs. Holstein) steers (307.35 kg) were fed four experimental diets containing two levels of inclusion of the babassu mesocarp meal (0 and 412.4 g/kg) and corn in two physical forms (kernels or ground) for 98 days. Data was collected on three days during the finishing phase, with observations every five minutes, for 24 hours. When the activities performed by the animals were evaluated as a function of the period of the day, the physical form of the corn showed interaction with the BMM inclusion level on the time spent feeding and on other activities. When the activities were evaluated over the day, the defecation frequency was affected and decreased as BMM was included. The feeding time was longer at the moments that followed feed supply, whereas the time used for other activities increased during the morning period, regardless of the diet utilized. Rumination and idle times were affected by the period of the day and remained high during the night and morning periods. There was increase in feeding time and dry matter rumination efficiencies and neutral detergent fiber as BMM was added to the diet. The number of rumination chews per bolus, however, decreased as BMB was included. Inclusion of babassu mesocarp meal increases the animal feeding time but the physical form of corn does not change its feeding behavior.