Skip to main content
ARS Home » Plains Area » Clay Center, Nebraska » U.S. Meat Animal Research Center » Nutrition, Growth and Physiology » Research » Publications at this Location » Publication #387879
Research Project: Improve Nutrient Management and Efficiency of Beef Cattle and Swine

Location: Nutrition, Growth and Physiology

Title: Managing mature beef bulls on divergent planes of nutrition alters scrotal circumference and concentrations of hormones and metabolites

Author
item DAHLEN, CARL - North Dakota State University
item UNDERDAHL, SARAH - North Dakota State University
item Crouse, Matthew
item MCCARTHY, KACIE - University Of Nebraska
item KASSETAS, CIERRAH - North Dakota State University
item BAUMGAERTNER, FRIEDERIKE - North Dakota State University
item KIRSCH, JAMES - North Dakota State University
item DORSAM, SHERI - North Dakota State University
item SEDIVEC, KEVIN - North Dakota State University
item WARD, ALISON - North Dakota State University
item CATON, JOEL - North Dakota State University

Submitted to: State University Ag Report
Publication Type: Other
Publication Acceptance Date: 9/30/2021
Publication Date: 10/8/2021
Citation: Dahlen, C.R., Underdahl, S.R., Crouse, M.S., McCarthy, K.L., Kassetas, C.J., Baumgaertner, F., Kirsch, J.D., Dorsam, S.T., Sedivec, K.K., Ward, A.K., Caton, J.S. 2021. Managing mature beef bulls on divergent planes of nutrition alters scrotal circumference and concentrations of hormones and metabolites. 2021 North Dakota State Livestock Research Report. p. 50-53. Available: https://www.ag.ndsu.edu/publications/livestock/north-dakota-livestock-research-report

Interpretive Summary:

Technical Abstract: Fifteen mature beef bulls (4 and 5 years old; BW = 1,816 ± 38.3 lb) were used in each of two years to evaluate effects of divergent planes of nutrition on concentrations of hormones and metabolites. In Year 1, bulls were ranked by BW and randomly assigned to one of two treatments for a 112-d evaluation period; 1) managed on a positive plane of nutrition (POS), or 2) managed on a negative plane of nutrition (NEG). In Year 2 bulls were assigned to the opposite treatment they received in Year 1 (i.e. POS in Year 1 were assigned to NEG in Year 2, and vice versa). Bulls were fed a common diet with deliveries into Insentec feeders adjusted biweekly to achieve targeted weight loss or gain (~12.5% of original BW). Blood samples were collected on d 0, 56, and 112 and analyzed for concentrations of amino acids (AA) in Year 1 and for glucose, non-esterified fatty acids (NEFA), testosterone (T), triiodothyronine (T3), thyroxine (T4), and insulin-like growth factor-1 (IGF-1) in Year 1 and Year 2. By design, bull BW was influenced by a treatment × day interaction (P < 0.0001), with POS bulls being heavier (P < 0.01) than NEG bulls by d 28. Over the course of the experiment POS bulls gained 2.74 ± 0.10 lb/d while NEG lost 2.35 ± 0.10 lb/d. Body condition score and scrotal circumference were also impacted by treatment × day interactions (P < 0.0001), both starting similar among treatments, then greater for POS than NEG thereafter. To achieve targeted weight divergence POS bulls (30.4 ± 0.99 lb/d) ate more (P < 0.0001) than NEG bulls (11.2 ± 0.99 lb/d). Concentrations of glucose, NEFA, T3, T4, and IGF-1 were influenced by treatment × day interactions (P < 0.0001). Concentrations of glucose, T3, T4, and IGF-1 were greater (P < 0.01) for POS bulls on d 112 compared with NEG bulls on the same days. Concentrations of NEFA, however, were greater (P < 0.001) for NEG than POS on d 56 and 112. Total amino acids present in serum were impacted by a treatment × day interaction (P < 0.001), with POS bulls having more (P