ANSC 318 1st Edition Lecture 16 Outline of Last Lecture I. Forage Toxicity Problems in Texas Outline of Current Lecture II. The Ensiling Processa. Aerobic and Anaerobic Stagesb. Acids Produced During Anaerobic Stagec. Losses During Ensiling Processd. General Considerations with Silagese. Corn SilageIII. Factors Affecting Forage Qualitya. Plant Speciesb. Plant Maturityc. Soil FertilityCurrent LectureThe Ensiling Process•what happens during the first 3 weeksAerobic Stage:•1st stage in the ensiling process•O2 consumed (oxygen level drops significantly)•Energy released and heat is produced  temp. rises to 80-100°F (happens quickly)•Aerobic yeasts and molds continue to grow•Lasts only a few daysAnaerobic Stage:•2nd stage of ensiling process•Temp. spike from anaerobic stage causes O2 to drop and eventually kills all aerobicyeasts and molds•Anaerobic bacteria begin to grow and multiply•Small amounts of protein are broken down in AA’s, NH3, and amides•CHO’s and sugars are broken down into acetic and lactic acids•Acetic and lactic acids cause pH to drop•pH of plant material decreases until anaerobic growth stops at a pH = 4 (kills microbes)Key Differences between Silo and Rumen****These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.-acids are removed from the rumen and do not have the chance to build up so the pHdoesn’t drop too much-the rumen is an open system  cow is always consuming more forage and new feedsmove in and out of the rumen-silos are closed systems  new forages do not come in once process is startedAcids Produced During Anaerobic Stage:•Acetic Acid: first acid produced during anaerobic phase; found in rumen and silo•Lactic Acid: most abundant acid formed; found in both but, higher levels in silo•Butyric Acid: low in both; higher levels found in bad silage•Propionic Acid: very little produced; higher in rumen, lower in silo•Formic Acid: very little producedLosses during the Ensiling Process:•Field Losses: minimal compared to hay making•Ensiling Losses: plant respiration and microbial fermentation•Spoilage Losses: higher with bad silage•Seepage Losses: happen when forage is put into silo too wet; especially when below25% DMImportance of Packing Silage into Bunker Silos:-limits spoilage-by driving back and forth over silage all day, it decreases the amount of airGeneral Considerations with SilagesGeneral Considerations:•for most crops  25-35% DM is ideal for making good silage•optimal pH = 4•well-made silage will last 10-15 years•stage of maturity of plant at harvesting is criticalCorn Silage:•most popular silage produced in the US•most energy dense feedstuff; high in NDF•low in protein, 7-9% CP on DM basis•corn silage DM distribution:-grain = 50.4%-stalk = 19.9%-cob = 11.5%-leaf = 9.4%-husk = 8.4%•as maturity increases, hardness of plant increases (.20 milk line – 20% hard, 80% soft)•harvest corn at 1/3 milk line when using bunker silo•harvest at ½ milk line when using upright silo•1.0 milk line = “black line” maturityFactors Affecting Forage Quality1. Plant Species:•Plant forage species differ in nutritional quality **-Legumes (highest)-Cool-season Grasses (intermediate)-Warm-season Grasses (lowest)-annual grasses > perennials-Fiber and protein concentrations differ; differences are very small2. Plant Maturity:•as plant maturity increases, forage quality decreases•as a plant matures  leaf:stem ratio decreases, cell wall (NDF) content increases, DMdigestibility decreases, protein content decreases•as plant maturity increases, forage quantity increases•digestibility = energy density•as plant maturity increases, protein concentration decreasesReasons for Producing Less Milk with More Mature Forage:-stage of maturity of alfalfa impacts quality-impacts on quality decrease feed intakeTerm for Plants that Bloom Definition Comparable TermsGerminated Stage where the embryo in a seed resumes growth after a dormant periodSproutedEarly Vegetative Stage where plant is vegetative and before stems elongateFresh new growth, very immature, youngLate Vegetative Stage where stems are beginning to elongate to just before blooming; first bud to first flowersBefore bloom, bud stage, budding plants prelimMature Stage where plants are normally harvested for seedsDent, in seed, ripe seedItem Tall Fescue Hay in May Tall Fescue Hay in JuneADF % 42.0 48.6CP % 11.6 6.9DM digestibility % 62.5 48.6Forage Intake (% of BW) 2.6 1.5CP Intake* (1000 lb cow) lb/day3.0 1.0*Protein requirements of 1000 lb lactating beef cow = 2.0-2.6 lb/day-waiting a month had huge effects on ADF %, CP %, and CP intake•some forages are impacted more than others by plant maturity-warm season grasses are affected the most-cool season grasses are in the middle-legumes are affected the least3. Soil Fertility:•level of fertilization affects both forage quality and quantity•effects of nitrogen fertilization on yield and crude protein content of grass hay:Nitrogen fertilizer applied, lb/acreGrass hay yield, tons per acre Crude protein of forage, % (DM)0 2.67 7.9100 4.38 9.1200 5.93 10.5400 8.59