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ARS Home » Plains Area » Clay Center, Nebraska » U.S. Meat Animal Research Center » Nutrition, Growth and Physiology » Research » Publications at this Location » Publication #427381
Research Project: Optimizing Nutrient Management and Efficiency of Beef Cattle and Swine

Location: Nutrition, Growth and Physiology

Title: Managing mature beef bulls on divergent planes of nutrition prior to the breeding season alters activity and eating behavior

Author
item DAHLEN, ROBERTA - North Dakota State University
item UNDERDAHL, SARAH - North Dakota State University
item Crouse, Matthew
item MCCARTHY, KACIE - University Of Nebraska
item CATON, JOEL - North Dakota State University
item SEDIVEC, KEVIN - North Dakota State University
item DAHLEN, CARL - North Dakota State University

Submitted to: State University Ag Report
Publication Type: Other
Publication Acceptance Date: 8/25/2025
Publication Date: 9/25/2025
Citation: Dahlen, R.B., Underdahl, S.R., Crouse, M.S., McCarthy, K.L., Caton, J.S., Sedivec, K.K., Dahlen, C.R. 2025. Managing mature beef bulls on divergent planes of nutrition prior to the breeding season alters activity and eating behavior. North Dakota Livestock Research Report. 5-8.

Interpretive Summary:

Technical Abstract: To evaluate eating and activity behaviors, fifteen mature Angus-based beef bulls (initial body weight [BW] = 1,764.2 ± 36.39 lb) were stratified by BW and randomly assigned to a positive (POS, n = 7) or negative (NEG, n = 8) plane of nutrition for 112 d. Bulls received a common total mixed ration delivered into Insentec feeders which were adjusted every two weeks to achieve targeted weight gain or loss of ~12.5% of BW. Behavior was monitored continuously using CowManager ear tags and classified as eating, ruminating, not active, active, or highly active. Data were averaged into four periods: 0 to 27, 28 to 55, 56 to 83, and 84 to 112 days, and analyzed using repeated measures in time within the MIXED procedure of SAS; bull was the experimental unit. Due to the targeted gain divergence, POS bulls had greater (P = 0.0003) dry matter intake (28.0 vs. 11.7 ± 2.36 lb/d) and increased (P < 0.001) weight gain (2.67 vs. - 2.65 ± 0.11 lb/d) than NEG bulls. There was a treatment × period interaction (P = 0.04) on eating behavior, with NEG bulls having more (P /= 0.44) in period 1. No treatment × period interactions (P = 0.14) were present for ruminating, active, and highly active behaviors. Ruminating also did not differ (P = 0.36) by treatment. Active and highly active behaviors were strongly impacted (P < 0.0001) by treatment, with POS bulls almost 2 h/d more active (283.8 vs. 176.8 ± 9.03 min/d) and half an h/d more highly active (117.6 vs. 84.3 ± 3.29 min/d) than NEG bulls. Thus, despite the lower feed intake, NEG bulls had greater time with eating behavior, perhaps indicating more time seeking food from pen floors and bedding after initial allotment was consumed. Moreover, the additional energy consumed by POS bulls allowed them to be more active and highly active.