The objective of this study was to evaluate the effects of timing of injectable trace mineral (ITM) administration (28 days (d) prior to or at weaning) on performance and health in mixed-sex beef calves (n = 115; 224 ± 40 kg). Calves were randomly assigned to one of the following treatments: (1) no ITM (CON), (2) ITM administered 28 d before weaning (PW), or (3) ITM administration at weaning (WEAN). At weaning, calves were transported to a local auction barn, held overnight, and returned the following day; BW, blood, and hair samples were collected prior to and through the receiving period. Data were analyzed using SAS 9.4. Serum Se increased in PW calves following ITM administration (p < 0.01). Serum Mn increased in PW and WEAN groups (p < 0.01) and PW calves showed increased serum Cu at weaning (p < 0.01). Across treatments, calves experienced 6% shrink following weaning and transport, with recovery of BW and intake occurring within 21 d and 8 d, respectively. Despite improved mineral status, no performance benefits were observed during the receiving period, reflecting adequate baseline mineral status and low-stress management conditions, suggesting that ITMs may have limited benefits in well-managed herds.

The objective of this study was to evaluate the impacts of varying inclusion levels of soybean hull pellets (SHP) with annual ryegrass baleage (BAL) on animal performance and digestive kinetics in beef cattle. In Experiment 1 (Exp. 1), 60 weaned mixed-sex beef calves were randomly assigned to one of three treatments: 0.0%, 0.5%, or 1.0% body weight (BW) SHP with ad libitum access to BAL for 48 days (d). Animal performance, including BW, dry matter intake (DMI), and average daily gain (ADG), was evaluated for the duration of the study. In Experiment 2 (Exp. 2), six ruminally cannulated beef steers received the same treatments utilized in Exp. 1. Steers were dosed with ytterbium (Yb)-labeled BAL to evaluate ruminal passage rate across three 24 d periods. All data were analyzed using SAS 9.4. In Exp. 1, total BAL intake decreased in calves supplemented with SHP, while cumulative ADG increased from 0.30 (0.0% BW SHP) to 0.54 (0.5% BW SHP) and 0.74 kg/d (1.0% BW SHP), respectively. Final BW at D47 also increased as SHP inclusion increased. In Exp. 2, ruminal retention time decreased from 38.0 h (0.0% BW SHP) to 15.1 h (1.0% BW SHP), while cecum-to-proximal colon passage rate did not differ among treatments (p = 0.06). Baleage DMI did not differ between treatments. Results suggest that SHP supplementation improved calf performance despite reduced BAL intake in Exp. 1, with the greatest cumulative ADG observed in calves supplemented with 1.0% BW SHP. In Exp. 2, 1.0% BW SHP produced the greatest effects on passage rate kinetics, while BAL DMI was unaffected by SHP supplementation.

Climate shifts have significantly affected livestock systems due to their environmental interdependence. Among the strategies adopted by livestock systems to fill the gaps in forage biomass, preserved forages are the most commonly used. This research assessed the nutritional profile of African Stargrass (Cynodon nlemfuensis Vanderyst) preserved as silage and haylage at different feed-out periods (45, 60, 90, and 120 days). We found greater dry matter (DM) content in haylage (29.7%), with no important variations in silage over time. Stargrass silage had crude protein (CP) levels greater (13.0%) than haylage (11.9%); the former was not affected by the duration of the preservation period. Silage had lower levels of neutral detergent fiber (NDF) and higher levels of in vitro dry matter digestibility (IVDMD). The net energy for lactation (NEL) was similar for the two types of preservations evaluated. A principal component analysis (PCA) revealed that most of the variance in the dataset (69.6%) was explained by two principal components. PC1 showed that the most relevant variables were ADF, α-NDF, dNDF30, d NDF48, and NDICP, while Ash, Ca, and insoluble CP were the most relevant variables in PC2. Unlike haylage, the nutritional value of silage remained constant (p > 0.05) up to 120 days of preservation. It is important to note that haylage should not be stored beyond 90 days, regardless of the type of preservation.