Date of Graduation

Spring 2018


Master of Natural and Applied Science in Agriculture


College of Agriculture

Committee Chair

Phillip Lancaster


tall fescue, ergot alkaloids, arginine, beef cattle, energy supplement

Subject Categories

Agricultural Economics | Agricultural Science | Agronomy and Crop Sciences | Beef Science | Plant Biology


Two experiments were conducted to determine animal performance of alternative feeding strategies to heifers grazing endophyte-infected tall fescue during summer months. In Experiment 1, 40 Limousin heifers (261± 40kg initial BW) were stratified by weight and assigned to either a spring harvested tall fescue silage diet or grazing endophyte-infected tall fescue pasture with grain supplement having either natural or artificial shade for 80 days. In Experiment 2, 40 Limousin heifers (277 ± 44kg initial BW) were stratified by weight and assigned to either a traditional grain supplement or feather-meal supplement (rumen bypass arginine supplement) with natural or artificial shade while grazing endophyte-infected tall fescue pastures for 98 days. Heifers were weighed on two consecutive days at the start and end of each experiment. Cost of gain ($/kg) and returns ($/hd) were computed. In Experiment 1, weight gain of heifers was greater in grain supplement treatment than in silage treatment and was greater for natural than artificial shade. Cost of gain was higher for heifers fed silage and returns were higher for heifers fed grain supplement. In Experiment 2, there was no difference in weight gain between traditional and feather meal supplements. Cost of gain and returns were not different between supplement treatments. Heifers that were given natural shade had a greater weight gain than artificial shade in both experiments. In conclusion, feeding early-spring harvest tall fescue silage or a supplement with high rumen bypass arginine did not improve performance of growing cattle during summer.


© Kerri A. Johnson

Open Access