012 Sand Mountain Elite Heifer Development Program I: Forage Growth and Utilization

Abstract The Sand Mountain Elite Heifer Development program was established to demonstrate to northeast Alabama commercial cattle producers recommended methods for replacement heifer development. In Autumn 2015, 3.2 ha of a novel endophyte tall fescue (Festuca arundinacae, Schreb) was clipped, 67.3 kg/ha N applied and allowed to stockpile. In October 2015, 3.2 ha of rye (Secale cereale L.) and 15.8 ha of ryegrass (Lolium perenne L.) were drilled into sod and 56 kg/ha N applied. In March, an additional 33.6 kg/ha N was applied to rye and ryegrass paddocks. Each forage type was divided into 0.81 ha paddocks (n = 17). Heifers (n = 48) were delivered in early January. Paddocks were rotationally stocked (n = 154 days) ensuring each heifer group grazed each forage type the same number of days. Heifers were allowed continuous access to water and mineral supplementation. Forage height was taken when heifers were turned into each paddock using a grazing stick and converted to kg DM by multiplying kg of forage per cm by cm of forage height for each forage type. Heifers were moved to a new paddock when 50% of the forage disappeared (range 1 to 10 days) as determined by height of the forage. Dependent variables of DM forage consumed per ha and DM forage consumed daily were analyzed using a general linear model with independent variables of forage type, heifer group and the interaction between forage type and heifer group. Ryegrass had significantly greater disappearance (722 ± 33 kg/ha) than fescue or rye (453 ± 58; 428 ± 41 kg/ha, respectively). Overall, it was shown that properly managed forages with favorable growing conditions (Jan: -2/8 C; Feb: 2/13 C; Mar: 8/19 C) can produce sufficient forage mass for developing replacement heifers. Table 012. Forage Produced and Consumed during Sand Mountain Elite Replacement Heifer Development Program in 2016 Forage Type No. Grazing Days No. Heifers Grazed Total Forage Mass, kg DM1 Forage Disappearance, kg DM1 Forage Disappearance Rate, kg DM/heifer/d2 Fescue 84 323 15,143 6,571 5.9 ± 0.9a Rye 71 462 14,014 7,926 6.5 ± 0.6a Ryegrass 143 735 34,694 19,331 8.6 ± 0.5b 1Actual forage values available and consumed. Heifers grazed 3.2 ha of Fescue, 3.2 ha of Rye and 9.7 ha of Ryegrass. 2Least Squares Means. Values with different superscripts within this column are significantly different from one another P