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Suitability of T riticale, either as a M ono crop or in a B lend with A nnual R yegrass as P asture F orage for G razing by G rowing B eef C attle during the C ool S eason Bob Myer, Ann Blount, Cheryl Mackowiak, and Ron Barnett 1 Summary A two y r, 2 x 2 factorial study was conducted to evaluate the suitability of triticale forage, either as a mono crop or in a blend with annual ryegrass, for grazing by growing beef cattle during the cool season. These two triticale treatments were compared to rye forage, either as a mono crop or in a blend with ryegrass. The and their respective blends with annual tilled past ures during early November (Yr 1) or late Oct. (Yr 2). In all, 8, 1.6 acre pastures were planted each year (two replicates). For each year, 16 tester growing beef heifers (Yr 1; 537 59 lb avg. body wt.) or steers (Yr 2; 559 147lb) divided among two blo cks were used. Grazing started in late January and lasted until April or May of each year. Overall, estimated forage dry matter yield, animal grazing days and cattle body weight gain per acre were not affected (P > 0.05) by pasture forage species; however, average daily weight gain of tester cattle tended to be greater (P = 0.04) for triticale vs. rye treatments. Blending ryegrass with the forage cereals resulted in longer grazing periods (P < 0.001), and increases in forage yield (P < 0.001), grazing days (P < 0.001), and gain per acre (P < 0.001) with no species by mono crop vs. blend interaction; however, a species by year interaction (P = 0.04) was obtained for forage dry matter yield in that the triticale was better than rye in Yr 1 and rye better than triticale in Yr 2. The triticale pastures were more even in forage availability during the cool season whereas rye tended to have a large the early spring. The results suggest that forage triticale is suitable for cool sea son pastures, especially if blended with annual ryegrass, for grazing by growing beef cattle. Introduction In the Coastal Plain region of the S outheastern United States, the planting of cool season annuals such as annual ryegrass ( Lolium multiforum L.), oat ( Avena sativa L.), and (or) rye ( Secale cereale L.) is common to provide grazing or harvested as green chop and (or) silage for cattle during the winter spring season (typically from December to May). New forage varieties of triticale ( X Triticosecale Wittmack) have gained popularity in this region by dairy producers for silage and green chop. We are not aware of any trials on the evaluation of these newer triticale varieties as pasture forage for grazing by growing beef cattle during the cool season. Additionally, there is some evidence from research conducted elsewhere that triticale may be a more suitable crop in a blend with annual ryegrass than rye (Myer and Lozano del Rio, 2004). We hypothesize that a new variety of forage triticale will be suita ble forage, especially if blended with annual ryegrass, for grazing by growing beef cattle. The objective of this study was to evaluate the suitability of triticale forage, either as a mono crop or in a blend with annual ryegrass, for grazing by growing beef cattle during the cool season. Materials and Methods This study was conducted at the University of orida Research and Education Forage triticale is suitable for cool season pastures for grazing by growing beef cattle. 1 Department of Animal Sciences, North Florida Research and Education Center, University of Florida Marianna, FL
Center (NFREC) located near Marianna in northwest Florida. The study evaluated two forage types rye or triticale, and two different planting methods planted as mono crops (rye or triticale alone) or planted in a blend with annual ryegrass. The study was conducted over two consecutive yr fall 2008 to spring 2009, and fall 2009 to spring 2010. For each yr, eight 1.6 acre fenced pastures were used. The pastures were prepared by deep plowing followed by disc harrowing, and t he forages were planted using a grain drill. Recommended (UF/IFAS) seeding rates were used and initial fertilization and rates were based on soil analysis. The recommended wheat (for forage) seeding rates were used for triticale. The pastures were planted during the second wk of November for Yr 1 and during the last wk of October for Yr 2. Grazing was started when the forage was about 8 to 12 in in height within a pasture. Grazing was continued until there was a lack of adequate forage for grazing within a 342, rye All pastures over both yr were grown under dry land conditions. All pastures were top dressed twice with nitrogen fertilizer, each time with 60 lb of N/acre; sulfur was also top dressed during the first application (12 lb/ac re ). For each yr, 16 growing Brangus, Brangus x Angus, Brahman, Romosinuano or Romosinuano x Angus heifers (Yr 1) and steers (Yr 2) were used (average initial weight of 537 59 and 559 147 lb for Yr 1 and 2 ; respectively). The animals were allotted equally within each of the two replicates into groups of two based on initial weight and genetic background. Pasture treatment was assigned at random to the groups within replica te. Cattle were weighted at start and end of grazing as well as every 28 d while grazing. All weights were taken after an overnight fast. The two cattle allotted to each pasture each yr were known as fr utilized when available forage in the pastures used for each pasture were recorded. Water and complete high magnesi um cattle mineral were available free choice at all times while the cattle were grazing. Forage samples were collected from small enclosed un grazed areas in each pasture to estimate forage dry matter yield (DMY), and to determine crude protein (CP) and i n vitro dry matter digestibility (IVOMD). Data collected cattle), and estimated pasture forage DMY and pasture forage quality (CP, IVOMD). Data were analyzed as a 2 x 2 factorial design combined over yr. The model included the four pasture treatments and the two main effects. The main effects evaluated included main pasture forage species (rye vs. triticale) and pasture planting method (mono crop vs. blend with an nual ryegrass). Results and Discussion For each yr grazing began late January later than typical. We have started as early as late November in previous research utilizing prepared seed bed (clean tilled) pastures (Myer and Blount, 2007). The late start may have due to late planting for Yr 1, due to dry conditions, and because of unusually cold conditions that occurred during December and January for Yr 2, even though the pastures for Yr 2 were planted near the optimum time of mid to late October. The average length of grazing was greater ( P > 0.001) for the blend pastures compared to the mono crop pastures (Table 1). The average length of grazing of the triticale containing pastures was greater ( P = 0.007) than the rye containing pastures mainly due to the triticale/ryegrass pastures lasting l onger than the rye/ryegrass pastures (forage species by mono crop vs. blend interaction, P = 0.09; Table 1).
Overall, estimated pasture forage DMY, animal grazing d / acre and cattle body weight gain per acre were not affected ( P > 0.05) by pasture forag e species H owever, average daily weight gain of tester cattle tended to be greater ( P = 0.04) for the triticale treatments vs rye (Table 1). Blending ryegrass with the forage cereals resulted in overall increases in forage DMY by 31% ( P < 0.001), grazin g days by 32% ( P = 0.001), and calf weight gain per acre by 42% ( P < 0.001; Table 1 ). Average number of calves per acre was not affected by pasture forage species or mono crop vs. blend ( P > 0.0.05). With one possible exception, no species by mono crop vs. blend interactions were noted ( P > 0.05). The possible exception was pasture DMY in that the increase in yield was greater ( P = 0.06 ) for triticale/ryegrass vs. triticale only than the increase for rye/ryegrass vs. rye only (Figure 1). A forage species by yr interaction, however, was obtained for pasture forage DMY ( P = 0.04). Additionally, a yr by species interaction was close to significance for total calf weight gain per acre ( P = 0.06). The triticale treatments did better than the rye treatments du ring Yr 1 and the opposite occurred during Yr 2 thus explaining the year effect. The reason triticale outperformed rye in one yr but not the next is unknown, but differences in climatic conditions did occur between the two years. Year 1 tended to have near normal temperatures with periodic dry periods lasting up to 21 d whereas Yr 2 can be characterized as cold and wet. The results of the two yr were combined as yr was considered a random effect and no three way interactions were noted. Overall pasture fo rage DMY estimated every 3 wks during the two yr study is shown in Figure 2 for the four individual treatments. The main effect of blend treatments vs. the mono crop treatments is illustrated in Figure 3. Figure 4 shows the main effect of the rye treatment s vs. the triticale treatments. Overall pasture forage yields were lowest early and late during the grazing periods with peak production occurring in late March/early April. The increase in overall pasture forage yield of the blend treatments vs. the mono crop treatments was mainly due to the increased yield of the blend treatments late in the grazing seasons ( P < 0.01 for the last two dates). This increase late in the grazing periods also explains the increases in grazing season length, animal grazing days and weight gain per acre mentioned above for the blend treatments. While overall there was no difference in pasture DMY between the triticale and rye containing pastures, the triticale pastures were noticeable more even in forage availability during the c ool season whereas rye tended to have a large The triticale pastures produced more forage early ( P = 0.006 for the first date) and less during mid season ( P < 0.001 for the fourth date) than rye. Overall f orage quality as measured by CP concentration and IVOMD is presented in Table 1. Forage quality of samples taken every 3 wks during the grazing periods is summarized in Figures 5 and 6. Overall, average CP concentration was slightly lower ( P < 0 .01) for t he triticale treatments than the rye treatments; however, CP concentrations in the pasture forage were more than adequate for growing calves (requirement of 11 to 14%). As expected, both CP and IVOMD were very high at the start and then decreased (li near; P < 0.001 for CP and IVOMD) as the grazing seasons progressed. The blend treatments overall had a slightly greater ( P < 0.001) IVOMD than the mono crop treatments. This higher value was mainly due to higher IVOMD values of the blend treatments obtaine d late in the grazing periods (Figure 6). The results suggest that forage triticale is suitable for cool season pastures for grazing by growing beef cattle. Triticale tended to perform better than rye in a blend with annual ryegrass; however, more testing is required. The rather even distribution of forage growth for triticale over the grazing season would allow easier grazing management compare to rye. The results
also reinforce the advantages of planting a blend of forages as opposed to a mono crop of a single species during the cool season. Acknowledgments Part of project Qun 03854; partial support provided by Resource Seeds Inc., Gilroy, CA (presently part of Sygenta). The assistance of Harvey Standland, Jeff Jones, Don Jones, John Crawford, Richard Fethiere, Bill Smith, George Fohner, Brad Stevens, David T homas, Olivia Hill Helms and Tina Gwin is gratefully acknowledged. References Myer, R. O. and A. R. Blount. 2007. 2007 Florida Beef Report, pp 19 24. Myer, R. O. and A. J. Lozano. 2004. Triticale as Animal Feed. In Triticale Improvement and Production (M. Mergoum, ed). FAO, Rome, Italy. pp 49 58.
Table 1 Effect of pasture forage treatment and its main effects (means) on grazing season length and animal grazing days, on growth performance of growing beef cattle, and on pasture forage yield and quality. Item a Pasture forage treatment b Main means c P value Rye Trit. RRG TRG SE d RS TS MT BT SE e S f T g SxT h Grazing season, d 77 80 101 112 1.8 89 96 79 107 1.2 0.007 0.001 0.09 Cattle performance ADG, lb 2.24 2.46 2.42 2.64 0.09 2.33 2.55 2.35 2.51 0.07 0.04 0.11 >0.30 Avg. head/ac 2.0 1.7 1.8 1.7 0.1 1.9 1.7 1.8 1.7 0.1 0.12 >0.30 >0.30 Gr azing days/ac 152 135 195 186 9.0 173 160 143 190 6.4 0.20 0.002 >0.30 Gain/ac, lb 364 325 490 497 24 427 409 344 491 17 >0.30 0.001 >0.30 Pasture forage DM yield, l b/a c 4578 4307 5721 5913 105 5162 5112 4453 5819 75 >0.30 0.001 0.06 CP, % 22.5 19.2 21.8 19.7 0.5 22.2 19.4 20.9 20.7 0.4 0.002 >0.30 >0.30 IVOMD, % 73.2 72.5 75.7 76.0 0.5 74.4 74.2 72.8 75.8 0.3 >0.30 0.001 >0.30 a Gr. season = grazing season length in days. ADG = average daily weight gain, Avg. head/ac = average stocking density in number of head per acre, Gr. days/ac = average number of animal grazing days per acre, Gain/ac = average total weight gain per acre, DM yield = average pasture dry matter yield per acre, CP = crude protein as % of pasture forage dry matter, and IVOMD = in vitro organic matter digestibility as % of pasture forage dry b Trit. = triticale, RRG = rye and ryegrass blend, and TRG = triti cale and ryegrass blend. c RS = rye species mean of rye and RRG treatments, TS = triticale species mean of triticale and TRG treatments, MT = mono crop treatments mean of rye and triticale treatments, and BT = blend treatments mean of RRG and TRG t reatments. d SE= standard error, n = 4; e n = 8. f S = species effect of species (rye treatments of rye and RRG vs. trit treatments of trit and TRG). g T = treatment effect of treatment (mono crop treatments of rye and trit vs. blend treatments of RRG and TRG). h SxT = species by treatment interaction.
Figure 1. Overall average pasture forage dry matter yield of the four pasture treatments during the cool seasons (RG ryegrass; SE = 105, n = 4; rye vs. trit, P >0.30; mono crop vs. blend, P < 0.001; species x mono vs. blend P = 0.06, and yr x species, P = 0.04). F igure 2. Average pasture forage dry matter yield measured every three wk of the four pasture treatments during the grazing seasons (RG ryegrass; SE = 50, 52, 59, 75, 137, and 77 for the six sampling dates, respectively; n = 4). 0 1000 2000 3000 4000 5000 6000 7000 Rye Triticale Rye-RG Triticale-RG lb/acre 0 500 1000 1500 2000 2500 Jan Feb Mar Apr Apr May lb/acre Rye Trit. Rye/RG Trit/RG
Figure 3. Effect of mono crop (rye or triticale) vs. blend (rye or triticale with ryegrass) on estimated pasture forage amount every three weeks during the grazing season, lb dry matter/ac (SE = 35, 36, 42, 53, 96 and 55, and P = 0.08, 0.19, 0.16, 0.15, <0.001 and 0.002 for the 6 sampling dates, respectively). 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Jan Feb Mar Apr Apr May dry matter lb/acre Mono Blend 0 500 1000 1500 2000 2500 Jan Feb Mar Apr Apr M dry matter lb/acre Rye Trit. Figure 4. Effect of species (rye and rye + ryegrass vs. triticale and triticale + ryegrass) on estimated pasture forage amount every three weeks during the grazing season, lb dry matter/ac (SE = 35, 36, 42, 53, 96 and 55, P = 0.006, >0.30, 0.03, <0.001, 0.14 and 0. 12 for the six sampling dates, respectively).
Figure 5. Average pasture forage crude protein concentrations measured every three weeks during the grazing seasons, % dry matter basis (RG ryegrass; SE = 0.8, 0.6, 0.2, 0.4, 0.5 and 0.8 for the six sa mpling dates, respectively; n = 4). 0 5 10 15 20 25 30 35 Jan Feb Mar Apr Apr May percent Rye Trit. Rye/RG Trit/RG 0 10 20 30 40 50 60 70 80 90 Jan Feb Mar Apr Apr May percent Rye Trit. Rye/RG Trit/RG Figure 6. Average in vitro organic matter digestibility (IVOMD) of pasture forage measured every three weeks during the grazing seasons, % dry matter basis (RG ryegrass; SE = 0.3, 0.7, 0.8, 1.1, 1.9 and 1.0 for the six sampling dates, respectively; n = 4).