Small Grains, Sorghum/Sudan, Alfalfa

Transcription

1 Simple Comparisons of Forage Quality vs. Stage of Growth Small Grains, Sorghum/Sudan, Alfalfa Calvin Trostle, Ph.D. Mark Marsalis, Ph.D. Extension Agronomy State Forage Specialist Texas A&M AgriLife Lubbock New Mexico State Univ. Las Lunas , , Southern High Plains

2 Lubbock Co. Oat Trial One-time Hay Harvest, var. Troy Growth Stage Harvest Date Dry Hay Lbs./A % Crude Protein Lbs. CP per acre Early Boot May 17 3, Init. Heading May 24 4, Fully Headed May 31 5, Milk June 7 6, Mealy Ripe June 14 6, Firm Dough June 21 6, Troy oat was harvested for six Fridays in a row among extra plots. Yield was Taken for three plots at each date, individual each sample analyzed for crude protein. When you consider your tonnage and forage quality goals, and your use or your market, which scenario is best for you?

3 Lubbock Co. Oat Trial One-Time Hay Harvest, var. Troy (cut every Friday)

4 Wheat Hay Castro Co. Growth Stage Dry lbs./a %CP Boot 2, Mid-heading 4, Soft Dough 6, Rick Auckerman, Texas A&M AgriLife Extension (currently Deaf Smith Co.)

5 Wheat Hay Castro Co.

6 The Trap of Beardless Wheat (1) When I (Trostle) came to West Texas in 1999, I had never heard of beardless wheat (I am from the Kansas, The Wheat State, and a Kansas State Univ. agronomy graduate) West Texas farmers and cattleman talked as if beardless wheat was superior small grains forage

7 The Trap of Beardless Wheat (2) My data for small grains forage clipping trials indicated beardless wheats had no more forage production (as a group) than did regular bearded wheats But you can graze or bale these beardless wheats longer than bearded wheat: little worry about the awns ( beards ) causing a problem with animal health (getting stuck in their throat, etc.) Hence the Trap of beardless wheat: What is it?

8 The Trap of Beardless Wheat (3) Beardless wheat if being beardless matters and is what you are shooting for means lower quality forage By extending the grazing or haying season you have perhaps unwittingly accepted lower quality forage Is this what you wanted? Were you aware of the issue? Yes, you get more tons of hay, but this might be counterproductive.

9 Sorghum/Sudan Hay Forage Stage of Maturity vs. Forage Quality Stage of Maturity % TDN % Crude Protein Early Veg Late Veg Boot Heading Bloom Dough

10 Sorghum/Sudangrass Growth Stage & Forage Quality

11 Sorghum/Sudan for Forage Hay Swisher Co., 2-week intervals Stage of Maturity Wet tons per Acre % Crude Protein Begin: August 13th Mid-boot Full head Post-flower Dough

12 Sorghum/Sudan for Forage Hay Swisher Co. (2-week intervals beginning Aug. 13)

13 General Grass & Legume Changes in Forage Constituents with Maturity

14 Legume/grass Digestibility with Growth Stage & Yield

15 Digestible DM, % Forage Digestibility vs. Livestock Requirement Dairy cow, 50 lb milk/day 450 lb steer, ADG 1.5 lb First calf heifer Beef cow/calf to wean 500 lb calf Dry pregnant cow, gaining condition 40 Warm season perennial grasses Cool season perennial grasses Cool season annual grasses Legumes Adapted from: H. Lippke and M.E. Riewe. TX Agric. Exp. Stn. Res. Mono. RM6C:

16 Effect of Maturity on Forage Quality Forage CP 1 ADF 1 % % NDF 1 % NE L 1 Mcal/kg Alfalfa NE M 1 Mcal/kg NE G 1 Mcal/kg Bud Full Bloom Sorghum/Sudan Vegetative Headed Corn Silage Few Ears Well Eared TDN 1 % 1 CP = crude protein, ADF = acid detergent fiber, NDF = neutral detergent fiber, NE L = net energy of lactation, NE M = net energy of maintenance, NE G = net energy of gain, TDN = total digestible nutrients. Source: Nutrient Requirements of Dairy Cattle, 1989.

17 Effect of Maturity on Alfalfa Quality Maturity CP % TDN % ADF % Pre-bud Bud /10 Bloom /2 Bloom Full Bloom Mature Source: Nutrient Requirements of Dairy Cattle National Academy of Science, Pub CP = crude protein, ADF = acid detergent fiber, TDN = total digestible nutrients.

18 Seasonal Changes in Alfalfa Nutritive Value Adapted from: C.S. Hoveland et al. J. Prod. Agric. 1: IVDMD = Invitro Dry Matter Digestibility.