14 Mitigation Strategies for Heifer Development on ‘KY-31’ Tall Fescue

Abstract Tall fescue (Schedonorus arundinaceus) is the predominant cool-season perennial forage in Eastern U.S. However, a symbiotic endophyte reduces performance of animals grazing tall fescue. This results losses around $2 billion annually. Due to vasoconstriction caused by endophyte, decrease conception rates among cows and heifers consuming has been observed. With rising input costs, it necessary explore alternative mitigation strategies these production losses. The objective this study was mitigate toxic effects ‘KY 31’ limit-grazing annuals as an feed supplementation. In January 2022, 48 [14 months age; 365.9 ± 11.89 kg body weight (BW)] were randomly assigned only, with supplemental at 1% BW, limit for 24 h per week, only. Four grazed each three replicated paddocks treatment. Cool-season annual pasture mixture crimson clover (Trifolium incarnatum), ryegrass (Lolium multiflorum), oat (Avena sativa). Body condition scores (BCS), hair coat (HCS), BW recorded every 30 d. Forage samples taken biomass, nutritive value, ergovaline concentration On April 1, artificially inseminated (AI), determined 45 d after AI. Data analyzed using Glimmix procedure SAS 9.4 (SAS Inst, Cary, NC) α = 0.05. There no differences treatments HCS any weigh date (P > 0.05). BCS all less February than or March (5.6, 6.1, respectively; P < 0.0001), but there sampling Conception not different 0.10) averaged 75, 67, 42, 50% continuous-cool season, graze, feed, treatments, respectively. Crude protein (CP) concentrations control greater treatment, continuous treatment (13.5, 10.7, 10.4, 8.9%, respectively, 0.012). Neutral detergent fiber (NDF) acid (ADF) when compared fescue, annual, control, (48.2 vs 64.7% NDF 25.8 vs. 37.0% ADF; 0.0361). At time, indicate that forages may be advantageous option toxicosis replacement pastures spring.