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A retrospective analysis was conducted to evaluate the effect of number of estrous cycles exhibited before breeding on growth and reproductive performance of replacement beef heifers fed ad-libitum or restricted by 20% less than ad-libitum during postweaning development over a 9-yr period. Progesterone concentration in blood samples collected at 9- to 11-d intervals were used to assign heifers into groups by number of estrous cycles exhibited before the start of breeding: 0 (nonpubertal; n = 395), 1 (n = 205), 2 (n = 211), 3 (n = 116), or >3 (n = 249). Heifers (P < 0.01) in the 0 cycle group were born 6 d later than the 1, 2, or 3 cycle groups, which were born 4 d later (P < 0.01) than the >3 cycle group. Weight of heifers at birth decreased (P < 0.05) as the number of cycles increased. Weaning weight and ultrasound measures of loin area and fat thickness over the loin at 1 yr age increased as the number of cycles increased (P < 0.01). Postwean weight gain, hip height at 1 yr age, and weights from the start of breeding through precalving increased with cycle numbers in a quadratic fashion (P < 0.02) and were greater (P < 0.05) in ad-libitum than restricted-fed heifers. Pregnancy rate in the 0 cycle group was lower (84%; P < 0.05) than the 1 (90%) or >3 (94%) estrous cycles groups and tended to differ (P < 0.1) from the 2 (88%) and 3 (89%) estrous cycle groups. Interval from the start of breeding to calving was 3 to 5 d longer (P < 0.05) for the 0 cycle group (300 ± 1 d) than other groups. Proportion of heifers calving in the first 21 d was less (P < 0.05) in the 0 or 1 cycle groups than other groups. Pregnancy rates of 2-yr-old cows (n = 898) were lowest (P < 0.05) for the 0 (73%) and 2 (79%) estrous cycle groups than the 1 (85%), 3 (90%), or >3 (92%) estrous cycle groups. Restricted level of feeding during postweaning development resulted in greater (P < 0.05) proportion of heifers in 0 cycle group and lower (P < 0.05) proportion in >3 cycle group, but reproductive performance was not influenced (P > 0.1) by level of feeding or interaction of feeding and estrous cycle grouping. In summary, date of birth and rate of physical maturation (weight, height, and fat deposition) were associated with timing of puberty. Pregnancy rate was greater in heifers that exhibited estrus before the start of breeding, but did not improve from having more than one estrous cycle. Proportion conceiving early was greater for heifers having two or more cycles before breeding.

Extension is a vital component of the Land Grant mission, facilitating transfer of knowledge and technology to end users. However, traditional Extension publications, particularly print, reach an ever-shrinking audience. With each new generational transfer of farm management, decision-makers in animal agriculture are less familiar with Extension as an authoritative source of information. As a consequence, producers may be more likely to receive misinformation from less reliable yet more readily accessible sources online, such as forums, blogs, or social media posts. In an attempt to address this challenge, we have explored use of program-specific Extension communications through social media platforms (YouTube, Facebook, Instagram, and Twitter). We hypothesized that video content in particular would result in significant viewership due to organic sharing behavior. Accounts were created using Mizzou Repro as branding, with content specifically focused on University of Missouri Extension efforts related to reproductive management of beef cattle. Videos are approximately 2 min (range 1.8 to 2.7 min) and are designed to communicate a single concept thoroughly but concisely. Scripts are prepared in advance, but videos feature a rotating speaker, typically a faculty member, graduate student, or Extension field specialist. To retain viewer interest for the full duration, videos incorporate changing camera angles, live animals, and graphs or figures. Of the platforms evaluated, content published on Facebook generated the most engagement (views, comments, and other interaction). Specifically, videos published to Facebook generated the most engagements as compared to other types of content such as photos or written text. In addition, we observed willingness of viewers to subscribe to future account posts, as well as significant interest from allied industry in sharing content with their audiences. Together, these observations suggest that social media videos and program-specific branding are effective tools to communicate Extension messages and build a long-term audience in the digital age.

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