Browsing by Author "Thompson, Alexander"
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Item The ground plan of the English parish church(Cambridge [Eng.] University Press, 1913) Thompson, AlexanderItem 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(2014-08) Thompson, Alexander; Johnson, Bradley J.; Rathmann, Ryan J.; Trojan, Sara J.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.Item Ionophore and Antimicrobial strategies alter live performance, carcass characteristics, and in vitro rumen fermentation parameters in beef cattle(2017-05) Thompson, Alexander; Johnson, Bradley J.; Rathmann, Ryan J.; Sarturi, Jhones O.; Corbin, Marilyn J.; Stevens, Richard D.One hundred ninety-two steers (BW = 354 ± 23.5 kg) were used in a randomized block design to evaluate the effects of ionophore and ractopamine hydrochloride (RH) supplementation strategies on performance and carcass characteristics. Twelve pens of 4 steers were assigned to each of the following treatments: unsupplemented control (CON), laidlomycin propionate (12.1 mg/kg DM) with or without RH (LPRH and LP, respectively), and monensin sodium (36.4 mg/kg DM) with RH (MSRH). Steers were fed for 151 d, of which, respective treatments received RH (Actogain; Zoetis, Florham Park, NJ) at a rate of 300 mg/(head • d) for the final 32 d. Laidlomycin was removed from the LPRH treatment during this period, as no combination feeding has been approved. Upon harvest, carcass data was collected by trained personnel, and subsequent analysis of the LM was conducted in order to estimate tenderness using Warner-Bratzler shear force (WBSF). Prior to RH supplementation, both LP and LPRH had greater ADG (P ≤ 0.02) and G:F (P < 0.01) than CON, while MSRH was intermediate. During the final 32 d, MSRH improved G:F (P ≤ 0.02) compared to all other treatments and tended to increase ADG over unsupplemented controls (P = 0.05). Cattle receiving LP without RH had significantly greater BW at d 151 than CON (P = 0.02), while both RH treatments tended to improve final BW (P ≤ 0.09). Ionophores improved ADG (P ≤ 0.03) and G:F (P < 0.01) for the entire feeding period, and although LP supplemented cattle had greater DMI for the final 32 d than both RH treatments (P ≤ 0.01), intakes for the 151 d trial were similar among treatments. Carcass weights were greater (P = 0.04) in cattle fed LP with no RH than CON, where cattle yielded an average of 12 kg more HCW. Ractopamine increased LM area in MSRH supplemented cattle (P = 0.03) and tended to increase LM area for steers receiving LPRH (P = 0.07). Longissimus steaks of MSRH supplemented cattle had greater WBSF values than CON (P = 0.04) after 7 d of postmortem aging, and greater WBSF values than LPRH steaks after 28 d (P = 0.03). All other carcass and WBSF measurements were similar among treatments. The results of this study indicate that LP supplementation without RH may yield similar performance and carcass responses associated with the administration of a beta-agonist. These results also suggest that performance and carcass characteristics for cattle fed LP are similar to those of cattle fed monensin throughout the feeding period.