CROP SCIENCE, VOL. 56, SEPTEMBER– OCTOBER 2016 WWW.CROPS.ORG 2841 RESEARCH C ool-season annual forages are an important component of livestock production systems in subtropical regions. Animal performance is often greater during the cool season (Vendramini et al., 2006) than the warm season (Stewart et al., 2007) in these regions. Reasons may include better forage nutritive value and reduced heat stress on grazing cattle during the cool season, which leads to greater forage intake. As a result, animal perfor- mance during the cool season has been a management option for increasing livestock productivity in subtropical regions. Mixing forage species with di ferent growth distributions can be an efcient strategy for increasing the length of the grazing season (McCormick et al., 2006). Early- to midmaturing cereal rye, oat, and triticale varieties usually produce forage earlier in the season than annual ryegrasses. Beck et al. (2007) tested oat, cereal rye, triticale, and wheat (Triticum aestivum L.) planted alone or in mixture with annual ryegrass in Arkansas. In general, cereal rye and wheat were superior to oat and triticale, leading to greater ADG and gain per area. Annual ryegrass was a necessary complement to small grains when overseeding cool-season annuals into bermudagrass [ Cynodon dactylon (L.) Pers.] sod. Mullenix et al. (2012) assessed pasture characteristics and animal performance Animal Performance and Pasture Characteristics on Cool-Season Annual Grass Mixtures in North Florida José C.B. Dubeux, Jr.,* Nicolas DiLorenzo, Ann Blount, Cheryl Mackowiak, Erick R.S. Santos, Hiran M.S. Silva, Martin Ruiz-Moreno, and Tessa Schulmeister ABSTRACT Cool-season forage mixtures are an option for extending the length of the grazing season. Small grains have a different growth distribution than annual ryegrass and may increase livestock gain per area. This 2-yr grazing study tested three small grain–annual ryegrass mixtures: (i) cereal rye (Secale cereale L. ‘FL401’)–annual ryegrass (Lolium multiflorum Lam. ‘Prine’); (ii) oat ( Avena sativa L. ‘Horizon 201’)–annual rye- grass Prine; (iii) triticale (× Triticosecale spp. ‘Tri- cal 342’)–annual ryegrass Prine. Stocking rate was adjusted, based on herbage allowance, using continuous stocking. Response variables included herbage mass, herbage allowance, herbage accumulation rate, herbage N, herb- age in vitro organic matter digestibility (IVOMD), botanical composition, average daily gain (ADG), grazing days, stocking rate (SR), gain per area, and blood urea N (BUN). Seasonal and annual variation occurred for most of the responses, but total season animal production was similar among mixtures. The ADG in 2014 was 0.90 and 0.85 kg head -1 d -1 in 2015. Stocking rate var- ied among mixtures within sampling dates and years, but season-long average SR was similar among mixtures. Total season animal gain was 367 kg body weight (BW) ha -1 in 2014 and 313 kg BW ha -1 in 2015. Small-grain species and vari- eties resulted in different growing curves, with FL401 cereal rye being the earliest variety in the present study. Oat and triticale demonstrated a more evenly distributed growth rate along the season, facilitating the adjustment of the stock- ing rate and grazing management. J.C.B. Dubeux, Jr., N. DiLorenzo, A. Blount, C. Mackowiak, E.R.S. Santos, H.M.S. Silva, M. Ruiz-Moreno, and T. Schulmeister, Univer- sity of Florida, North Florida Research and Education Center, 3925 Highway 71, Marianna, FL, 32446. Received 2 Mar. 2016. Accepted 30 Apr. 2016. *Corresponding author (dubeux@uf.edu). Assigned to Associate Editor Carlos Pedreira. Abbreviations: ADG, average daily gain; AU, animal unit; BUN, blood urea N; BW, body weight; DM, dry matter; HAR, herbage accumulation rate; IVDDM, in vitro digestible dry matter; IVOMD, in vitro organic matter digestibility; SR, stocking rate. Published in Crop Sci. 56:2841–2852 (2016). doi: 10.2135/cropsci2016.03.0141 © Crop Science Society of America | 5585 Guilford Rd., Madison, WI 53711 USA All rights reserved. Published June 24, 2016