Effects of injectable vitamin E on transit stress and receiving performance and investigating the relationship between acidosis risk and feeding behavior during finishing in beef steers

Dornbach, Colten W.

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https://hdl.handle.net/2142/115419 Copy

Description

Title

Effects of injectable vitamin E on transit stress and receiving performance and investigating the relationship between acidosis risk and feeding behavior during finishing in beef steers

Author(s)

Dornbach, Colten W.

Issue Date

2022-04-26

Director of Research (if dissertation) or Advisor (if thesis)

McCann, Joshua C

Committee Member(s)

• Shike, Daniel W
• Berger, Larry L

Department of Study

Animal Sciences

Discipline

Animal Sciences

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

• α-tocopherol
• feedlot
• receiving phase
• transit stress
• predictive modeling
• acidosis
• feeding behavior
• forage inclusion

Abstract

In study 1, the objective was to determine the effects of injectable vitamin E (VE) before or after transit on feedlot cattle receiving performance, health, and blood parameters. Angus × Simmental steers (n = 196; body weight [BW] = 163 ± 29 kg) were utilized in a randomized complete block design. Steers were blocked by BW and randomly assigned to 1 of 3 treatments: intramuscular injections of saline pre- and post-transit (CON), intramuscular injections of VE (2000 mg d-α-tocopherol) pre-transit and saline post-transit (PRE), or intramuscular injections of saline pre-transit and VE (2000 mg d-α-tocopherol) post-transit (POST). Pre-transit injections were administered on d 0, and steers were transported on d 7 for ~4 h (348 km). After arrival, steers were fed a common corn silage-based diet in GrowSafe bunks. Final BW tended to be greater (P = 0.08) for CON steers compared with POST steers and PRE steers being intermediate. From d 7 to 63, there was a treatment effect of VE on average daily gain (ADG) with PRE and CON steers exhibiting (P = 0.04) greater ADG compared with POST steers. Dry matter intake (DMI) and gain to feed (G:F) from d 7 to 63 were not affected (P ≥ 0.29) by treatment. Day 0 serum α-tocopherol concentrations were considered marginal (2.3 ± 0.2 mg/L). A treatment × day interaction (P < 0.01) was observed for serum α-tocopherol concentrations. Serum α-tocopherol concentrations were greatest for PRE steers on d 7 (prior to and post-transit), but greater for POST steers on d 10 and 14. A treatment effect increased (P = 0.04) plasma ferric-reducing antioxidant potential (FRAP) concentrations for POST steers when compared with CON steers and PRE steers being intermediate. Non-esterified fatty acids (NEFA) concentrations exhibited a treatment × day interaction (P = 0.04) with CON and POST steers being greater than PRE steers on d 14. On d 21, NEFA concentrations were greatest for POST steers compared with PRE steers and CON steers being intermediate. Plasma glucose exhibited a treatment × day interaction (P = 0.03) with PRE steers tending to be greater than POST steers on d 14 and CON steers being intermediate. There was no main effect (P ≥ 0.14) of treatment on the number of bovine respiratory disease (BRD) morbidity treatments. Hair cortisol concentrations were lower (P < 0.01) for PRE and POST steers when compared with CON steers. Overall, injectable VE administered before or after transit increased serum tocopherol concentrations while mitigating stress, but did not improve growth performance of beef steers during the receiving phase. In study 2, the experiments were to (1) assess acidosis risk during the end of the finishing phase and (2) build a predictive model utilizing initial feed intake behavior to identify steers at risk for acidosis. For experiment 1, DMI data from beef steers (n = 733) fed a corn-based diet were collected from the final 56 days of the finishing phase using a GrowSafe system. Acidosis risk was based on the frequency and severity of DMI fluctuations. Steers (n = 80) from 4 contemporary groups were selected for divergent acidosis risk. High-risk steers with greater DMI fluctuation had decreased (P ≤ 0.02) ruminal pH and ADG (1.72 kg) compared with low-risk steers (1.94 kg). These findings suggest steers with greater DMI fluctuation have an increased risk for acidosis. For experiment 2, DMI and feed intake behavior data from 5 contemporary groups of beef steers (n = 623) fed a corn-based diet were collected over the initial 45 d of the finishing phase using a GrowSafe system. Behaviors collected during the initial 45 d of finishing were utilized to construct a stepwise regression model using the GLMSELECT procedure of SAS 9.4 to predict acidosis risk during the final 56 days of the finishing phase. Acidosis risk was best predicted (r2 = 0.43; RMSE = 0.159) by 21 feed intake behavior traits. A majority of model variation was based around four terms: head-down duration, DMI fluctuation during the initial 45 d on a finishing ration, meal duration, and non-feeding interval frequency. The model predicted 72% of steers at greatest risk for acidosis. Overall, greater DMI fluctuation was indicative of acidosis risk based on decreased ruminal pH and ADG. A stepwise regression model was able to predict acidosis risk based on initial DMI and feed intake behaviors. Early identification of steers at risk for acidosis may facilitate mitigation strategies during the finishing phase to improve cattle health and growth performance. In study 3, the objective was to evaluate the effects of forage inclusion during finishing on growth performance, feeding behavior, and ruminal fermentation in steers at risk for acidosis. Angus × Simmental steers (n = 240; 350 ± 58 kg) were blocked by BW and allotted into 18 pens (n = 13 to 14 steers/pen). Steers were fed a high-moisture corn (HMC)-based finishing ration in GrowSafe bunks. Feeding behavior and DMI traits were collected from the initial 45 d of finishing. To predict acidosis risk, feeding behavior data was utilized in a predictive stepwise linear regression model, with 20% (n = 24) of steers within each block deemed to be at the greatest risk for developing acidosis being selected. These steers (n = 48; 483 ± 44 kg) were utilized in a randomized complete block design. Steers within each block were stratified by initial BW and assigned to 4 pens of 6 steers. Pens were randomly assigned to 1 of 2 dietary treatments (4 pens/treatment): (1) 15% (15CS) or (2) 30% corn silage (30CS) on a DM basis where corn silage replaced HMC in the diet. Overall BW, ADG, DMI, and G:F were not affected (P ≥ 0.19) by treatment. There tended to be a treatment effect (P = 0.09) for DMI from d 0 to 56 with 15CS steers having greater DMI. From d 56 to 112 there was a treatment tendency (P = 0.09) for 30CS steers to have a greater G:F. Steers consuming 30CS had greater (P ≤ 0.05) meal frequency and eating rate, as well as decreased meal length, from d 0 to 112. Fluctuations in DMI during the final 56 d on feed were not affected by treatment (P ≥ 0.22). No treatment × day effect was observed for molar proportions of acetate, propionate, and butyrate (P ≥ 0.11). Isobuyrate, valerate, and isovalerate tended to exhibit a treatment × day effect (P > 0.05), with molar proportions of isobutyrate tending to be greater on d 56 for cattle consuming 30CS. Ruminal pH tended to have a treatment × day effect (P = 0.05), with 30CS steers having increased ruminal pH on d 56 and 112. Carcass characteristics were not affected by treatment (P ≥ 0.39). Overall, increasing forage in a finishing ration altered feeding behaviors and ruminal fermentation in steers at risk for acidosis, but did not improve growth performance.

Graduation Semester

2022-05

Type of Resource

Thesis

Handle URL

https://hdl.handle.net/2142/115419

Copyright and License Information

Copyright 2022 Colten Dornbach

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