ANSC 318 1st Edition Lecture 16 Outline of Last Lecture I Forage Toxicity Problems in Texas Outline of Current Lecture II The Ensiling Process a Aerobic and Anaerobic Stages b Acids Produced During Anaerobic Stage c Losses During Ensiling Process d General Considerations with Silages e Corn Silage III Factors Affecting Forage Quality a Plant Species b Plant Maturity c Soil Fertility Current Lecture The Ensiling Process what happens during the first 3 weeks Aerobic 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 days Anaerobic Stage 2nd stage of ensiling process Temp spike from anaerobic stage causes O2 to drop and eventually kills all aerobic yeasts 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 pH doesn t drop too much the rumen is an open system cow is always consuming more forage and new feeds move in and out of the rumen silos are closed systems new forages do not come in once process is started Acids 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 produced Losses 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 below 25 DM Importance of Packing Silage into Bunker Silos limits spoilage by driving back and forth over silage all day it decreases the amount of air General Considerations with Silages General 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 critical Corn 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 milk line when using upright silo 1 0 milk line black line maturity Factors Affecting Forage Quality 1 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 small 2 Plant Maturity as plant maturity increases forage quality decreases as a plant matures leaf stem ratio decreases cell wall NDF content increases DM digestibility decreases protein content decreases as plant maturity increases forage quantity increases digestibility energy density as plant maturity increases protein concentration decreases Reasons for Producing Less Milk with More Mature Forage stage of maturity of alfalfa impacts quality impacts on quality decrease feed intake Term for Plants that Bloom Definition Comparable Terms Germinated Stage where the embryo in a Sprouted seed resumes growth after a dormant period Early Vegetative Stage where plant is Fresh new growth very vegetative and before stems immature young elongate Late Vegetative Stage where stems are Before bloom bud stage beginning to elongate to just budding plants prelim before blooming first bud to first flowers Mature Stage where plants are Dent in seed ripe seed normally harvested for seeds Item Tall Fescue Hay in May Tall Fescue Hay in June ADF 42 0 48 6 CP 11 6 6 9 DM digestibility 62 5 48 6 Forage Intake of BW 2 6 1 5 CP Intake 1000 lb cow 3 0 1 0 lb day 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 least 3 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 Grass hay yield tons per acre Crude protein of forage lb acre DM 0 2 67 7 9 100 4 38 9 1 200 5 93 10 5 400 8 59 11 7