Evaluating the effects of lactic acid adaptation in beef cattle prior to an acidosis challenge and the effects of programmed compensatory gain feeding protocol on feedlot steer performance and behavior

Buessing, Zach T.

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https://hdl.handle.net/2142/120175 Copy

Description

Title

Evaluating the effects of lactic acid adaptation in beef cattle prior to an acidosis challenge and the effects of programmed compensatory gain feeding protocol on feedlot steer performance and behavior

Author(s)

Buessing, Zach T.

Issue Date

2023-05-04

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)

• Acidosis
• Limit-feeding
• Beef Cattle
• Feedlot

Abstract

In study 1,the objective was to determine if a seven-day lactic acid adaptation in cannulated steers affected ruminal fermentation during an acidosis challenge. In the in vivo experiment, 18 steers (790 ± 68 kg) were assigned to one of two treatments: control (CON) 500 mL of H2O or 1 mM DL-Lactic acid solution per kg steer BW (LAC). Steers were dosed with treatments via the cannula before feeding for 7 d during the adaptation period. The adaptation diet consisted of 30% grass hay, 25% corn silage, 25% dry rolled corn, 15% dry distillers grains, 10% supplement, and 5% molasses on a dry matter basis. To induce acidosis steers were fasted for 24 h and subsequently fed a high concentrate diet for 4 d, consisting of 55% high moisture corn, 15% corn silage, 15% dry distillers grains (DDG), 10% supplement, and 5% molasses on a dry matter basis. Rumen fluid was collected throughout the 4-d acidosis challenge to measure fermentation characteristics including rumen pH, redox, ammonia (NH3), volatile fatty acids (VFA), and lactic acid. Treatments did not affect (P ≥ 0.65) DMI before or after the acidosis challenge. A treatment × time interaction was not observed (P = 0.83) for ruminal pH, but pH was affected (P < 0.01) by time and remained between 5.6 and 5.0 for about 14 h during the challenge. A treatment × hour interaction tended (P = 0.08) to be observed for lactic acid; LAC had a greater concentration than CON at h 14 during the challenge. However, a treatment × hour interaction was not detected (P ≥ 0.38) for NH3, VFA, fecal pH, and redox potential. A companion experiment was conducted to determine if lactic acid adaptation in cannulated steers affected fermentation characteristics in an ex vivo model utilizing the previously described steers. Rumen fluid was collected prior to treatments being administered on d 7 of adaptation and added to 3 flasks containing corn, DDG, and corn silage. A treatment  hour effect (P < 0.01) was observed for pH; LAC had a greater pH at h 12. A treatment  hour interaction was not observed (P  0.15) for lactic acid and NH3. A treatment  hour interaction (P < 0.01) was observed for total VFA where CON had greater concentrations when compared with LAC at h 8. Overall, a 7-day lactic acid adaptation period impacted ex vivo fermentation but had minor effects in cannulated steers during an acidosis challenge. Further research is warranted to refine the lactic acid adaption period to help mitigate acidosis in feedlot cattle. In study 2, the objective was to determine the effects of programmed compensatory gain on feedlot steer growth performance and behavior. Simmental  Angus steers (n = 159; BW = 278 ± 49 kg) were blocked by weight, stratified by sire, and allotted to 10 pens. Each pen contained a 3.0 m-long bunk to allow 19 cm of linear bunk space per steer. Pens were randomly assigned to one of two treatments on d 0: control (CON) or programmed compensatory gain (PCG). To achieve programmed compensatory gain, the amount of feed offered to animals previously being fed ad libitum was reduced by 3.29% daily for 10 consecutive d. Thus, on d 54, PCG steers were consuming 72% of the original DMI and subsequently returned to ad libitum intake to facilitate a period of compensatory gain. Feed intake for CON pens was managed using a clean bunk strategy for the entire experiment. Steers were fed a common diet and fed twice daily at 0800 h and 1200 h. Programmed compensatory gain steers did have a greater (P = 0.03) ADG than CON steers from d 39-63. Control steers tended (P = 0.07) to have a greater ADG than PCG steers from d 63-92. From d 39-63, PCG steers had a greater (P < 0.01) G:F when compared with CON steers. However, from d 63-92, CON steers had greater (P = 0.05) G:F than PCG steers. The treatment did not affect (P  0.15) overall BW, ADG, DMI, and G:F. No treatment effect was observed (P  0.14) for any carcass characteristics. A treatment  day interaction was observed for the proportion of steers at the bunk in the morning (P = 0.02); more PCG steers were at the bunk on d 47, 49, 51, 54, and 58. No treatment  day interaction was observed (P  0.14) for the proportion of steers at the bunk in the afternoon, the proportion of steers waiting behind the bunk, the proportion of steers standing, or the occurrence of pushing. A greater (P  0.01) proportion of PCG steers waited behind the bunk during both feeding times. A greater (P < 0.01) proportion of PCG steers stood in the morning. During both feeding times, a greater (P = 0.01) occurrence of pushing occurred by PCG steers. Overall, the programmed compensatory gain feeding protocol had minimal effects on steer growth performance and behavior. Programmed compensatory gain feeding protocols should be further evaluated to determine the optimal length and severity of feed restriction.

Graduation Semester

2023-05

Type of Resource

Thesis

Copyright and License Information

Copyright 2023 Zach Buessing

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