Table 1.
Alfalfa and grass hay nutrient compositions (DM basis)1,2,3.
Fig 1.
Comparison of whole-blood Se concentrations (mean ± SEM) in weaned beef calves after 3, 6, and 9 weeks in the preconditioning period, and in the feedlot (week 12).
During the 9 week preconditioning period, calves consumed alfalfa hay harvested from a field not fertilized with Se (Control) or from a field fertilized with sodium-selenate (High Se; application rate of 90 g Se/ha; n = 15 calves per group for Control and High Se). Total dietary Se intake during weeks 7 to 9 was 1.09 and 27.45 mg Se/calf per day, respectively for calves in control and High-Se treatment groups. The normal reference interval for whole-blood Se concentrations in beef cattle is 120 to 300 ng/mL.
Fig 2.
Comparison of baseline-adjusted BW (kg; mean ± SEM) of weaned beef calves (primarily of Angus breeding and ranging in age from 6 to 9 months at baseline).
During the 9 week preconditioning period, calves consumed alfalfa hay harvested from a field not fertilized with Se (Control) or from a field fertilized with sodium-selenate (High Se; application rate of 90 g Se/ha; n = 15 calves per group for Control and High Se). Body weights at baseline ranged from 264 to 369 kg (328 ± 5 kg, mean ± SEM), and final body weights at the end of the preconditioning period ranged from 288 to 411 kg (366 ± 5 kg, mean ± SEM).
Fig 3.
Rarefaction analysis of 16S rRNA amplicon sequence variants (ASVs) obtained from nasal swabs after weaning (week 0), at the end of the Se-supplementation preconditioning period (week 9), and in the feedlot (week 12).
During the 9 week preconditioning period, calves consumed alfalfa hay harvested from a field not fertilized with Se (Control) or harvested from a field fertilized with sodium-selenate (High-Se; application rate of 90 g Se/ha; n = 15 calves per group for Control and High-Se).
Table 2.
Effect of feeding Se-biofortified hay in a 9-week preconditioning period on nasal microbiome diversity within calves.
Fig 4.
Principal coordinate analysis of unweighted UniFrac distances obtained from nasal swabs after weaning (week 0), at the end of the Se-supplementation preconditioning period (week 9), and in the feedlot (week 12).
During the 9 week preconditioning period, calves consumed alfalfa hay harvested from a field not fertilized with Se (Control) or harvested from a field fertilized with sodium-selenate (High Se; application rate of 90 g Se/ha; n = 15 calves per group for Control and High Se).
Table 3.
Effect of feeding Se-biofortified hay in a 9-week preconditioning period on nasal microbiome diversity within treatment groups.
Table 4.
Effect of feeding Se-biofortified hay in a 9-week preconditioning period on nasal microbiome diversity across time.
Fig 5.
Nasal microbiota profiles of healthy calves after weaning (week 0), at the end of the Se-supplementation preconditioning period (week 9), and in the feedlot (week 12).
During the 9 week preconditioning period, calves consumed alfalfa hay harvested from a field not fertilized with Se (Control) or harvested from a field fertilized with sodium-selenate (High Se; application rate of 90 g Se/ha; n = 15 calves per group for Control and High Se).
Table 5.
Effect of feeding Se-biofortified hay in a 9-week preconditioning period on number of nasal microbiota phyla.
Table 6.
Effect of feeding Se-biofortified hay in a 9-week preconditioning period on relative abundance, median % (interquartile range), of the major nasal microbiota phyla*.
Table 7.
Effect of feeding Se-biofortified hay in a 9-week preconditioning period on the presence, and number of calves harboring per Control (C) and High-Se (Se) treatment groups, of the minor nasal microbiota phyla*.
Table 8.
Effect of feeding Se-biofortified hay in a 9-week preconditioning period on number of nasal microbiota genera.
Fig 6.
Nasal Mycoplasmataceae profile of healthy calves after weaning (week 0), at the end of the Se-supplementation preconditioning period (week 9), and in the feedlot (week 12).
During the 9 week preconditioning period, calves consumed alfalfa hay harvested from a field not fertilized with Se (Control) or harvested from a field fertilized with sodium-selenate (High Se; application rate of 90 g Se/ha; n = 15 calves per group for Control and High Se).
Table 9.
Effect of feeding Se-biofortified hay in a 9-week preconditioning period on number of predicted metabolic pathways in nasal microbiota.
Fig 7.
Principal coordinate analysis of Bray-Curtis distances of predicted metabolic pathways for healthy calves after weaning (week 0), at the end of the Se-supplementation preconditioning period (week 9), and in the feedlot (week 12).
During the 9 week preconditioning period, calves consumed alfalfa hay harvested from a field not fertilized with Se (Control) or harvested from a field fertilized with sodium-selenate (High Se; application rate of 90 g Se/ha; n = 15 calves per group for Control and High Se).