Nutritional parameters of beef heifers fed diets with different roughages

Abstract

The purpose of this study was to evaluate intake, digestibility and efficiency of microbial protein synthesis of beef heifers fed with sugarcane silage with different calcium oxide (CaO) levels (0, 7.5; 15 g/kg), fresh sugarcane and corn silage. The same concentrate was offered at 5 g/kg bodyweight (BW) for every diet. Five ruminally and abomasally fistulated beef heifers (373.8 ± 33.12 kg BW) were used in a 5 × 5 Latin square design. Heifers fed sugarcane silage diets presented lower dry matter (DM) intake than those fed fresh sugarcane. Corn silage provides greatest DM intake compared with other roughages. CaO levels had a quadratic positive effect (P < 0.05) on DM and total digestible nutrients (TDN). For TDN intake (3.43 + 4.39 CaO – 2.56 CaO2) the maximum TDN intake of 5.31 kg/day was obtained at 8.6 g/kg CaO. The total apparent digestibility for neutral detergent fibre increased with CaO levels. An increase in nitrogen balance was observed with the inclusion of CaO in the sugarcane silage. Corn silages-based diets provide greater DM intake and digestibility and nitrogen balance compared with the diets based on sugarcane. Adding CaO to sugarcane as it is ensiled improves DM intake and TDN than diet sugarcane silage without CaO. However, the use of high levels of CaO (15 g/kg) in sugarcane at ensiling decreases the diet intake. Based on the maximum energy intake, the use of 8.6 g/kg CaO in sugarcane at ensiling is recommended.

The inclusion of detoxified castor bean meal in sugarcane silage increases the carcass weight and the content of unsaturated fatty acids in lamb meat

“…It is possible that the observed increase in the intake of NFC—with the increases in the intake of NDF—has provided a linear increase in the intake of TDN in sheep. Moraes et al (2018) also observed increases in the intake of TDN for cattle when the sugarcane silage was added.…”

“…It is possible that the observed increase in the intake of NFC-with the increases in the intake of NDF-has provided a linear increase in the intake of TDN in sheep. Moraes et al (2018) et al, 2015) favoring the access and adherence of microruminal organisms to the potentially digestible fraction of NDF (Donnelly et al, 2018). In addition, the improvement in the silage fermentation pattern provided by the inclusion of DCBM may have increased the levels of soluble NDF (pectic substances) in the residual NDF of the silage (Wang et al, 2020), which may also contribute to the increase in digestibility of NDF in the diet.…”