Interaction of various inclusion levels of dietary vitamin D2 enriched yeast cell wall with zilpaterol hydrochloride on performance and post-mortem tenderness in feedlot steers
| dc.contributor.committeeChair | Johnson, Bradley J. | |
| dc.contributor.committeeMember | Rathmann, Ryan J. | |
| dc.contributor.committeeMember | Trojan, Sara J. | |
| dc.creator | Thompson, Alexander | |
| dc.date.available | 2014-08-27T13:54:51Z | |
| dc.date.issued | 2014-08 | |
| dc.description.abstract | The objectives of this study were to examine the impact of various inclusion rates of vitamin D2 enriched yeast cell wall (YCW) on feedlot performance, carcass characteristics, and post-mortem tenderness of cattle finished with zilpaterol hydrochloride (ZH). Crossbred steers (n = 192; BW = 546 ± 11 kg) were blocked by BW in a randomized block design and randomly assigned to pen (6 pens/block; 4 hd/pen). Pens within a block were assigned to one of six treatments (8 pens/treatment): 1) negative control (-CON; no YCW, no ZH), 2) positive control (+CON; no YCW, ZH), 3) 250,000 IU D2 YCW/hd/d (2.5 YCW), 4) 500,000 IU D2 YCW/hd/d (5.0 YCW), 5) 1,000,000 IU D2 YCW/hd/d (10.0 YCW), 6) 250,000 IU C-WALL/hd/d (YCW-C). All YCW treatments were supplemented with ZH. Steers were supplemented with respective treatments for the 51 d duration of the trial, of which ZH was supplemented d 28 to 47. Daily DMI was recorded, and BW was collected at d 0, 28, and 51. Carcass data was collected upon harvest and ten choice strip loins were randomly selected from each treatment for further analysis. Loins were cut into 2.54-cm thick steaks and assigned to one of four aging periods (7, 14, 21, 28 d). Tenderness was estimated using Warner-Bratzler shear force (WBSF). Data were analyzed using the GLIMMIX PROC of SAS with the fixed effect of treatment and the random effect of block. Warner-Bratzler shear force values were analyzed using the same model, including aging period as an additional factor. Dry matter intake showed a significant quadratic response (P = 0.01) for increasing levels of D2 YCW for the entire feeding period, with the greatest intake in the 10.0 YCW treatment (10.30, 10.27, and 10.66 kg/d respectively). Although non-significant, all ZH fed treatments had numerically greater WBSF values than negative control, but values among ZH treatments were not different across all aging periods. There was a tendency for lower WBSF values in the 10.0 g D2 YCW treatment when compared to positive control (P = 0.10, 0.06, 0.10, and 0.09), and WBSF values of steaks from the 10.0 g YCW treatment ranged from 0.44 (d 21) to 0.69 (d 7) kg lower than positive control for all aging periods. Results indicate that yeast cell wall supplementation could increase performance of finishing steers during ZH supplementation, while vitamin D2 supplementation may have positive effects on tenderness. | |
| dc.format.mimetype | application/pdf | |
| dc.identifier.uri | http://hdl.handle.net/2346/58842 | |
| dc.language.iso | eng | |
| dc.subject | Cattle | |
| dc.subject | Dry matter intake | |
| dc.subject | Yeast | |
| dc.subject | Zilpaterol hydrochloride | |
| dc.title | Interaction of various inclusion levels of dietary vitamin D2 enriched yeast cell wall with zilpaterol hydrochloride on performance and post-mortem tenderness in feedlot steers | |
| dc.type | Thesis | |
| thesis.degree.department | Animal and Food Science | |
| thesis.degree.discipline | Animal Science | |
| thesis.degree.grantor | Texas Tech University | |
| thesis.degree.level | Masters | |
| thesis.degree.name | Master of Science |