The profitability of beef cow-calf operations relies on the reproductive ability of females to calve at 2 yr of age and provide a calf each subsequent year for her lifetime. The management of replacement heifers could affect her ability to conceive early, calve, and rebreed. Common management practices use heifer body weight (BW) (and body condition score (BCS) as indicators of puberty onset but do not indicate body composition and fat deposition. The objective of this study was to use ultrasound measurements of carcass traits to compare the effect of different diet management practices on muscle development and fat deposition of post-weaning heifers. The heifers placed on a higher energy diet are expected to have greater mean carcass trait measurements than the lower energy diet heifers. A total of 124 purebred Angus heifers from the Iowa State University McNay Memorial Research and Demonstration Farm were used for this study. Two diets were administered in this study. One group of heifers (G1; n = 61) was developed on a low-energy roughage diet to reach a target BW of 55% of mature BW at the time of breeding. The second group (G2; n = 63) was developed on a grain diet to reach the target BW of 65% mature BW at breeding. Body weight and ultrasound measurements for backfat (BFAT), ribeye area (REA), and intramuscular fat (IMF) were collected over three time points (0-d, 55-d, and 123-d) during the study to quantify the development of body composition characteristics. The initial measurements were collected 1 wk post-weaning. Significant mean differences between the two groups were observed for BW, BFAT, and REA at 55-d (P = 0.027, P = 0.008, and P < 0.0001, respectively), and 123-d (P < 0.001). The mean differences for BW, BFAT, and REA at 123-d between G1 and G2 were 30.98 kg, 0.10 cm, and 7.81 cm2, respectively No significant difference was found between the groups for IMF measurements at 55-d (P = 0.927) or 123-d (P = 0.169). This suggests IMF is not significantly influenced by diet during the early, post-weaning heifer developmental stage. Although further research is needed, the results from this study suggest the development of weight, BFAT, and REA in early post-weaning beef heifers is influenced by the energy concentration of the diet.

Extension personnel routinely conduct needs assessments to develop programs addressing challenges faced by cattle producers. The objective of this project was to identify and evaluate the needs of cattle producers in Iowa. Needs assessment listening sessions were conducted by the Iowa Beef Center across six regions of the state of Iowa. A total of 54 stakeholders across the six regions participated, representing cow-calf, feedlot, veterinary, and allied industries. During each session, participants were asked to write down a list of challenges or opportunities they observed in the beef industry. Each producer was asked to share an item on their list that they perceived or experienced as the most challenging and briefly expand on the topic. Once every attendee had an opportunity to engage, the process was repeated until topics had been exhausted. Each listening session lasted approximately 2 to 3 hours. Notes from all six meetings were compiled, and major themes were aggregated. Common themes were found across all six regions, while others were only addressed within specific regions. Producers statewide addressed challenges in cattle marketing (n = 31), land use and availability (n = 22), herd health (n = 20), and feed costs (n = 19). Farm transition (n = 14), consumer education (n = 14), and animal handling and welfare (n = 8) were discussed in five of the six regions. Production profitability (n = 8) and labor (n = 5) were only addressed in four regions. Topics discussed in fewer than four regions tended to be specific to either cow-calf or feedlot enterprises. For example, traceability (n = 4) was only discussed in the northwestern and northcentral regions with a large feedlot presence. In contrast, heifer development (n = 4) was discussed in three regions with more cow-calf operations. In conclusion, this project illustrates the diversity and commonality of challenges facing cattle producers in the state of Iowa and is indicative of issues facing cattle producers nationally. Although these listening sessions were specific to Iowa cattle producers, the methods used to gain insight into challenges facing cattle producers have applications beyond Iowa. The diversity of responses reinforces the need for routine needs assessments for extension program development to address the needs of the beef industry nationally and globally.

A 144-day study assessed the effects of dietary energy and implant potency to determine optimum strategies for managing feed conversion (F:G) and marbling. Fifty-four Angus steers (327 ± 8 kg) from Iowa State University’s herd genetically selected for enhanced marbling were stratified by initial bodyweight (BW), ultrasound intramuscular fat, and age to a 2 × 3 factorial. Dietary treatments included: low energy (1.30 Mcal NEg/kg DM, 18% roughage level; LE) or high energy finishing ration (1.39 Mcal NEg/kg DM, 8% roughage; HE). Implant treatments (IMP; Merck) included: no implant (NOIMP), Revalor-IS (RIS), or Revalor-200 (R200) on d 0 and 74. Steers were fed via bunks capturing daily individual feed disappearance (n = 9 steers/treatment). Steers were weighed on d 0, 74, and 144 and harvested on d 145. Data were analyzed in Proc Mixed of SAS with fixed effects of diet, IMP, and interaction. No interactions were observed for feedlot performance (P > 0.17). Steers fed HE had greater average daily gain (ADG) and final BW than LE steers (P < 0.01) while LE steers had greater F:G (P = 0.04). Final BW and ADG were greatest for R200, intermediate for RIS, and lowest for NOIMP (P < 0.01). F:G was greatest for NOIMP, intermediate for RIS, and lowest for R200 (P < 0.01). Steers fed HE had increased ribeye area (P < 0.01) and tended to have greater marbling score (P = 0.06; 809) than LE steers (769). While ribeye area increased in response to implant potency (P < 0.01), marbling score was not impacted (P = 0.21) by IMP (815, 771, 782, for NOIMP, RIS, R200, respectively). Overall, steers graded 100% Choice or higher and 55% Prime. These data suggest implants, when used appropriately, improve growth performance and efficiency in beef steers without compromising carcass quality.

Abstract A 187-day study utilizing Angus steers (283±4.4 kg) in a 2 x 2 factorial examined the effects of diet and implant strategy on growth and carcass performance of steers selected from Iowa State’s Angus herd genetically selected for enhanced marbling. Factors included diet: finishing (63 NEg; 12% roughage; FIN) or backgrounding (57 NEg, 30% roughage) fed for first 70 days before transitioning to finishing diet (BKG) and implant strategy (IMP): single, long duration implant administered on d0 (Synovex One Feedlot, Zoetis; ONE) or a multiple, regular duration implant strategy (Synovex S on d0, Synovex Choice on d70 and d155, Zoetis; SCC) designed to match trenbolone acetate delivery of 200 mg. Steers were stratified to treatment by marbling potential and initial body weight, and fed via bunks that captured individual steer feed disappearance (n = 15 steers/treatment). Carcass ultrasound, including percent intramuscular fat (IMF), was collected on d0, 70, 155, and 187. Data were analyzed in Proc Mixed of SAS with fixed effects of diet, IMP, and interaction. Initial weight was covariate for performance data, and initial IMF was covariate for IMF analysis. Steers fed BKG had greater DMI, lower ADG, and decreased G:F (P< 0.01) during first 70 days versus FIN. Implant strategy had no effect on growth at d0-d154. From d155-d187, IMP affected ADG (P=0.01) with ONE having lesser ADG, while BKG had greater ADG than FIN. ONE had greater marbling and IMF (P=0.01) on d187 than SCC, suggesting greater IMF deposition during the final re-implant period (d155-d187) and reinforcing the importance for timing of implant administration. Regardless of IMP or diet, steers selected for enhanced marbling graded 100% Choice and higher with 65% of carcasses grading Prime, suggesting potential for using implants to increase efficiency without sacrificing carcass quality.

The beef industry has made rapid genetic selection for improved marbling. Although the industry has experienced an increase in USDA Prime-grading carcasses, research using modern day technology on high quality genetic potential cattle has been lagging behind the trend. Therefore, the objective of this study was to determine growth and carcass characteristics of steers with known genetic potential for high marbling capabilities when fed differing nutritional strategies and administering different implant programs.

Genetic trends for milk expected progeny difference (EPD) across most breeds have continued an upward trend, although direct selection pressure on milk EPD has not been an over-arching goal of seedstock breeders in recent years. Creep feeding has become very popular in the seedstock industry to maximize animal performance and to condition animals destined for a production sale. However, the animal behavior aspects of creep feeding and the individual impact on the dam’s milk EPD have rarely been studied or quantified. This study used the Super SmartFeed™ (C-Lock Inc., Rapid City, SD) to monitor calf creep feeding behavior and individual intake of creep feed during mid-to late-lactation.

Annual forages can provide flexibility when managing forage supply by helping fill forage production gaps or serving as primary forage sources. The use of annual species for forage production can potentially help producers stretch feed supplies, extend grazing seasons, increase carrying capacity, and facilitate expansion. Annual forages can be incorporated into cropping systems as winter cover crops or as alternative crops planted during the growing season. Greater knowledge of potential yield and nutritional value of annual forage species will empower producers to make informed decisions about the use of annual forages. Additionally, demonstration of annual forage rotations may provide information regarding the overall sustainability of this alternative land use.

While the Iowa 4-H & FFA carcass contest cattle are not completely representative of all Iowa cattle, they can indicate trends for the Iowa cattle industry and represent the calves locally available for projects. With nearly 60% of these cattle receiving an $8/cwt premium, cattle feeders have the potential to improve net revenues by marketing cattle into a grid market.

During 2016, IBC staff made 183 presentations to more than 13,700 participants, conducted 564 personal consultations, and over 4,100 phone or email consultations. The webinars and videos IBC produced were viewed more than 20,000 times, and the online software tools had 375,000 downloads. There were 180,000 website visitors and 3,500 social media contacts. IBC funded 4 mini grant projects investigating current industry questions including: Management effects on ergovaline content of stockpiled tall fescue for winter grazing • Grazing cover crops • Calving management on Iowa beef cattle farms • Corn silage characteristics on Iowa farms Iowa Beef Center staff are also involved in current ISU Beef Research projects related to cover crop grazing by stocker cattle, bull reproduction and fescue tolerance. Beef team staff authored nine 2017 Animal Industry Research reports. They annually conduct a needs assessment such as listening sessions, formal surveys, or think tanks. The following are some examples of featured programs evaluated in 2016.

Effectively measuring short-term impact, particularly a change in knowledge resulting from extension programming can prove to be challenging. Clicker-based technology, when used properly, is one alternative that may allow educators to better evaluate this aspect of the logic model. While the potential interface between clicker technology and extension programming has been regularly hypothesized about, the success of use and stakeholder attitude towards such technology in an extension setting has not been well defined to date. Based on data collected during Iowa Beef Center winter extension programming, clicker-based technology yielded increased participant response rates when compared to hand-written program evaluations. Moreover, the technology effectively monitored change in knowledge and was viewed in an overwhelmingly positive manner by stakeholders. Thus, when used properly, clicker technology is well suited to extension as a program evaluation tool, and in particular an effective means by which to track short-term outcomes.