Effect of sugarcane genotype and maturity stage at harvest on feed intake and ruminal parameters of growing steers

Comparisons of Corn Stover Silages after Fresh- or Ripe-Corn Harvested: Effects on Digestibility and Rumen Fermentation in Growing Beef Cattle

Both waxy corn stover after fresh- (CF) and ripe-corn (CR) harvested are important byproducts of corn cropping system and have 20 d difference in harvest time. The study aimed to investigate the effects of prolonging harvest time on the nutritive value of corn stover silage by comparing CF with CR silages. In vitro ruminal experiment was firstly performed to investigate substrate degradation and fermentation of CF and CR silages. The CR diet was formulated by replacing 50% forage of CF silage with CR silage on a dry matter (DM) basis. Fourteen crossbred steers (Simmental × Limousin × local Chinese) aged 13 months with an average weight of 318.1 ± 37.1 kg were selected and randomly allocated into two dietary treatment groups. Although the CR silage had greater DM and fiber contents than CF silage, it did not alter in vitro degradation (p > 0.05), but with lower molar percentage of propionate and acetate to propionate ratio (p < 0.05). The cattle fed CR diet had a higher DM intake and lower fiber digestibility with reduction in 18S rRNA gene copies of protozoa and fungi and 16S rRNA gene copies of Fibrobacter succinogenes (p < 0.05). Further 16S rRNA gene amplicon analysis indicated a similar diversity of bacteria community between CR and CF treatments (p > 0.05). Few differences were observed in the abundance of genera larger than 1% (p > 0.05), except for the reduction in abundance of genera Ruminococcaceae_NK4A214_group in CR treatment (p < 0.05). In summary, prolonging 20 d harvest time of corn stover silage increases the forage fiber and DM content, which promotes feed intake with decreased fiber degradation, although rumen fermentation and growth performance are not changed in growing beef cattle.

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

The aim of this study was to evaluate the performance and meat quality of lambs fed sugarcane silage containing increasing levels of detoxified castor bean meal (DCBM). Twenty-four Santa Inês male sheep were used, with initial body weight of 25.34 ± 2.57 kg, distributed in a completely randomized design with four treatments (0, 70, 140, and 210 g/kg of DCBM in the sugarcane silage). Intake and digestibility of dry matter (DM) and crude protein (CP) were positively influenced (P < 0.05) by the levels of DCBM. There was a linear increase (P < 0.05) on the intake and digestibility of neutral detergent fiber with the inclusion of DCBM. The daily and total gains showed a quadratic effect (P < 0.05) with the inclusion of DCBM, with a maximum point of 241.64 g/d and 18.12 kg at the level of 161.9 g/kg of DCBM. There was a linear increase (P < 0.01) on the hot carcass with the inclusion of DCBM. The inclusion of DCBM did not influence (P > 0.05) the levels of total lipids (2.1%) in lamb meat, but the levels of oleic acid (C18:1 n-6c) and total monounsaturated fatty acids presented a quadratic effect (P < 0.05). It is recommended to include 160 g/kg of detoxified castor bean meal in sugarcane silage.