Effect of Supplementation during the Breeding Season on a May-calving Herd in the Nebraska Sandhills

Females in their first and second breeding season received either a 32% crude protein (DM) supplement or no supplement throughout the breeding season. Supplementation did not affect heifer BW, BCS, and pregnancy rate at pregnancy diagnosis. Supplementation impacted primiparous cow BW and BCS at pregnancy diagnosis, but did not affect pregnancy rates. Calf birth weight and dystocia rates were unaffected by supplementation for both heifers and primiparous cow. Calves nursing supplemented dams were heavier at weaning. Greater supplementation may be needed to affect pregnancy rate

Comparison of Two Alternate Prostaglandin Products in Yearling Beef Heifers

Yearling heifers were administered 1 of 2 alternate prostaglandin products (Lutalyse vs. Lutalyse HighCon), which differ in concentration of active ingredient and administration route. Timing of estrus, pregnancy rate to AI, and final pregnancy rate did not differ between treatments. Body weight and ADG were also not affected by prostaglandin treatment. These results indicate producers can utilize Lutalyse HighCon, administered subcutaneously (s.c.), to avoid injection site blemishes and reduce carcass discounts with no impact on estrus synchronization or pregnancy rates

Effects of Maternal Late Gestation Nutrition on May-Born Heifer Progeny

May-calving dams in late gestation grazed either sub-irrigated meadow with or without supplement or upland range with or without supplement. Supplementation was 1 lb/d of a 33% CP (DM) supplement. Heifer progeny from these dams were followed through their first and second breeding seasons. Both dam grazing and supplement treatment affected heifer progeny BW and BCS. Heifers born to dams who grazed meadow in late gestation attained a greater percentage of mature BW at the start of their first breeding season and increased pregnancy rates as primiparous cows. Grazing of meadow by May-calving dams in late gestation may increase stayability of heifer progeny. Although supplementing the dam during late gestation tended to increase heifer progeny BW at first breeding, the increased risk of dystocia at heifer’s first parturition may negate the benefit

Impacts of 40 Years of the Gudmundsen Sandhills Laboratory on Beef Cattle and Range Systems

The University of Nebraska (UNL) Gudmundsen Sandhills Laboratory (GSL) is a 12,800-acre research ranch in the Nebraska Sandhills. In 1978, Elmer “Pete” and Abbie Gudmundsen gifted the former Rafter C Ranch to the University of Nebraska Foundation. Thus, 2018 was the 40th year of UNL oversight of GSL. To the credit of UNL Administration, GSL development for range livestock research was delegated to a team of Research and Extension Specialists chaired by Dr. Don Clanton. Other members of that original team were Jim Nichols, Range Science; Gene Deutscher, Reproductive Physiologist; Dick Clark, Agricultural Economist; and Ivan Rush, Beef Extension Specialist. This team configured the ranch to investigate production and management questions pertinent to the region

Efficacy of a Second Injection of Prostaglandin F2α in Yearling Beef Heifers Following Previous Estrus Synchronization

Angus- based, yearling beef heifers were utilized to determine the effects of administering a second prostaglandin F2α (PGF; Lutalyse, Zoetis Animal Health, Parsippany, NJ) injection to heifers who did not previously respond to estrus synchronization. All heifers were exposed to a melengestrolacetate (MGA)- PGF protocol. Following PGF injection, heifers were observed for estrus (estrus detection patches rubbed) for 3 d and inseminated. Heifers who did not show signs of estrus were placed with fertile bulls. Aft er 3 d with bulls, heifers with greater than 50% of the rub- off coating removed from estrus detection aids were considered to have been bred. One- half of the heifers not showing estrus received a second PGF injection; the other half were the controls and received no further treatment. Heifers remained with bulls for 4 d. Percentage expressing estrus was greater for heifers receiving a second PGF injection. However, pregnancy rate was similar between treatments

Effects of Supplemental Energy and Protein Source on Performance of Steers Grazing Irrigated Corn Residue

Steer calves grazing corn residue (86 d) were assigned to 1 of 5 treatments to evaluate the effects of protein and energy supplements on steer performance. Th e 5 treatments consisted of 1) un-supplemented control (NS), 2) dry rolled corn only (CRN), 3) 89% dry rolled corn/6% molasses/5% urea (C + RDP), 4) 60/40 blend of soy- pass/soybean meal (SP), and 5) dried distillers grains plus solubles (DGS). Supplements were fed to provide equal TDN intake. Average daily gain among treatments was 1.48, 1.32, 0.53, 0.31, and −0.18 lbs. for SP, DGS, C + RDP, CRN, and NS, respectively. Only steers fed SP and DGS produced over- winter gains greater than 1 lb/d, suggesting metabolizable protein requirements must be met for growing calves to utilize residue efficiently

Effects of Backgrounding and Feedlot System Strategies on May-Born Steer Performance

May-born steers were backgrounded to achieve either a high or low rate of gain. The high rate of gain was achieved by offering steers meadow hay ad libitum and 4 lb/d of a 33% CP (DM) supplement, while the low rate of gain consisted of steers grazing meadow and offered 1 lb/d of the same supplement. After backgrounding, one-half of the steers from each group entered the feedlot in May as short-yearlings, while the remainder grazed upland range until entering the feedlot as long-yearlings in mid-September. Hot carcass weight was greater for steers backgrounded to achieve a high rate of gain, but they also consumed more during the feedlot phase and had fewer carcasses grade USDA average Choice or greater compared with steers backgrounded to achieve a low rate of gain. Long-yearling steers had increased marbling scores and percentage of carcasses grading USDA average Choice or greater compared with short-yearling steers. Furthermore, long-yearlings had increased carcass weight and risk for overweight carcasses

Effects of Prepartum Nutrition on May-Calving Cows and Progeny

May-calving dams grazed either sub-irrigated meadow or upland range from Jan. 5 to May 1 each year for 6 years. Within grazing system, dams received either no supplement or 1 lb/d of a 33% CP supplement from Jan. 5 to April 1. Dams grazing meadow in the prepartum period weighed more and had a greater body condition score prior to calving. They also tended to have greater pregnancy rates in the subsequent breeding season and tended to wean heavier calves than dams grazing upland range. Allowing May-calving dams to graze meadow in late gestation may increase herd profitability through increased dam pregnancy rates and weaned calf value. Furthermore, supplemented dams weaned heavier calves, independent of grazing system. Supplementation of May-calving dams in late gestation may be economical if the income from additional pounds of calf weaned is greater than the supplementation cost

Combined Analysis on the Effects of Late Gestation Supplementation in a Spring Calving Beef Herd

Data were compiled from 4 independent studies conducted over 13 years in the Nebraska Sandhills. Th is combined analysis evaluated the effects of late gestation supplementation on cow and calf productivity in a spring calving herd. Cows wintered on dormant range, sub- irrigated meadow or corn residue. Late gestation supplementation improved pregnancy rates regardless of supplement amount or over winter treatment. Supplement did not affect cow body weight and condition score. Calves born to cows fed supplement had greater weaning weights regardless of when they were weaned

Bioeconomic Factors of Beef Heifer Maturity to Consider when Establishing Criteria to Optimally Select and/or Retain Herd Replacements

Understanding the biology of heifer maturity and its relationship to calving difficulty and subsequent breeding success is a vital step in building abioeconomic model to identify optimal production and profitability. A limited dependent variable probit model is used to quantify the responses among heifer maturities, measured by a maturity index (MI), on dystocia and second pregnancy. The MI account for heifer age, birth BW, prebreeding BW, nutrition level, and dam size and age and is found to be inversely related to dystocia occurrence. On average there is a 2.2% increase in the probability of dystocia with every 1 point drop in the MI between the MI scores of 50 and 70. Statistically, MI does not directly alter second pregnancy rate; however, dystocia does. The presence of dystocia reduced second pregnancy rates by 10.67%. Using the probability of dystocia predicted from the MI in the sample, it is found that on average, every 1 point increase in MI added 0.62% to the probability of the occurrence of second pregnancy over the range represented by the data. Relationships among MI, dystocia, and second pregnancy are nonlinear and exhibit diminishing marginal effects. These relationships indicate optimal production and profitability occur at varying maturities, which are altered by animal type, economic environment, production system, and management regime. With these captured relationships, any single group of heifers may be ranked by profitability given their physical characteristics and the applicable production, management, and economic conditions