PSI-34 Factors influencing bull selection and management in extensive rangeland production systems of California

Abstract

Abstract California’s 660,000 head of beef cattle are highly dependent on bulls used to produce offspring that can perform across the state’s diverse ecological regions. Bulls need to be functional on rugged coastal landscapes, rolling foothills, deserts and in high-elevation terrain. Few data exist that indicate factors related to selection, maintenance and longevity of bulls used in rangeland landscapes. Objectives herein, were to assess factors influencing bull purchasing, management, and culling decisions of California beef producers. Surveys were mailed to the California Cattlemen’s Association membership (n = 1,410) with ~ 12% response rate (n = 171). Data were analyzed for 56% of respondents (n = 95). Mean age and years of bull selection experience of respondents was 61 ± 1 years and 27 ± 2 years, respectively. Respondents managed cattle on a total of 694,949 ha of owned, private leased, and leased public rangelands in California and surrounding states. Cow-calf herd size was 378 ± 92 head and bull battery averaged 18 ± 3 head with average bull longevity of 5 ± 0.8 years. The average price paid for bulls in the last 2 years was $5166 ± 298, while the highest price paid in the last 5 years was $6958 ± 445. Survey responses were used to define current factors driving management after purchase and for subsequent breeding seasons. Methodology for bull turnout management (i.e. high-energy diet, pasture, supplemental hay) had no impact (P = 0.13) on average age of bulls when culled. After bull purchase, 46% of producers turned bulls out directly with females, while 49% held bulls until the following breeding season. Additionally, most producers (75%) did not manage bulls to reduce condition after purchase. Average bull longevity was moderately correlated (P = 0.01; r2 = 0.30) with average bull price a producer was willing to pay. The average age of bulls when culled was not influenced (P = 0.42) by the frequency of semen quality evaluation. Semen quality was evaluated annually by 45% of respondents, while 20% of respondents never evaluated semen quality. Respondents indicated bull age (35%) and structural soundness (29%) as the most common factors for culling bulls. This research suggests the need for additional research focused on bull selection and management to maximize producer investment in reproduction.