Exam 3 Study Guide - Forage Crop Ecology | CSES 4544, Study notes of Environmental Science

Download Exam 3 Study Guide - Forage Crop Ecology | CSES 4544 and more Study notes Environmental Science in PDF only on Docsity! Forage Crop Ecology Exam 3 Study Guide Weeds in Forage Crops 1. What is a weed? - Plant considered undesirable, unattractive or troublesome – especially when it grows where it is unwanted 2. Where have most of the invasive plants/weeds come from? What industry? - Horticulture Industry 3. Fill in the blanks: - Milkweed o Scientific Name – Calotropis procera o Family - Ascetepiadaceae o Positive uses – Medicinal - Cassia o Family – Fabaceae o Annual & Leguminous but DOESN’T fix N o Positive uses – Silage, grows in poor soil climates and can grab iron- bound P - Kudzu o Scientific name – Puerana lobata o Brought to the U.S. by USDA because they wanted to conserve soil o Positives – Baskets, hangover cure o Does it have enemies in U.S.? No – that’s why it’s so invasive o Importance of goats and Kudzu  Graze kudzu  Leaves have 23.7% proteins, stems 11.9%, so it’s high in nutritional value 4. What is the difference between wild onion and garlic? - Garlic has a hollow stem - Onion has a solid stem 5. Why should we even control weeds (4)? - They compete for: o Nutrients o Water o Light o Space 6. 3-5 lbs of grass increase for every 1lb of weed control. 7. What are the 7 impacts of weeds? - Toxic/poisonous to livestock - Unpalatable and limit consumption - Undesirable flavor in milk & meat - Cause irritations - Compete with forage - Slows hay drying - Aesthetics 8. What are 7 weeds that affect milk and meat products: - Bitter sneezeweed - Chickory - Dock - Buttercup - Horsetail - Ragweed - Wild Garlic 9. Many weeds have higher or lower water requirements than forages? - Higher 10. Weeds typically are more or less competitive on infertile and acidic soils. - More 11. Weeds are heavy users of the nutrients P & K . 12. If you manage your pastures, weeds aren’t really a problem. What are 4 aspects of good management? - Proper choice of forage species and variety - Adequate fertility and soil pH - Proper grazing management - Control of other pests (insects, disease, nematodes) 13. Weeds are opportunistic invaders; if they see an opening, they go for it. 14. Weeds can be transported by? (4) - Wind - Animals - Manure - Walking - Soil test for lime and fertilizer - Plant weed-free seed adapted to region - Rotate crops - Use high stock densities to eat/trample weeds 31. Discuss the mechanical method of controlling weeds: - Physical removal of all part of weed and brush - Hand digging - Burial - Mowing o Slower o Successful with good fertilizer and grazing o More effective with broadleaf weeds o Less successful in deep-rooted perennial weeds and brush 32. Discuss the biological method of controlling weeds: - Predatory insects and infectious disease being used to manage weeds and brush - Goats, musk thistle weevil 33. What are the following: - Crop competition o Long-term solution o Most economical o Requires compatible and usable crops o Maintenance of proper soil fertility levels required - Crop rotation o Replacement of one crop with another o Works best with annual o Not economical in perennial forage crops, but may be feasible with alfalfa - Fire o Earliest recorded form of forage management o Many benefits o Effective on young, annual weeds, not on perennial weeds o Timing is VIP o Very risky, high liability if not managed correctly 34. If you ever decided to use crabgrass as forage, what seed that has been developed by an OK seed company is good to use? - Red River Crabgrass 35. Where did crabgrass come from? How was it brought to the United States? Currently, where can it be found in the U.S.? - Evolved in S. Africa - Brought to Europe and then to U.S. - Prolific growth in the U.S. - Found in all 50 states – mainly SE U.S. 36. What is the ideal rainfall for crabgrass? Ideal soil? Temperature? pH? - >24” rainfall - Ideal soil – well-drained, sandy loams that don’t crust - pH – slightly acidic - Temp 80-100oF 37. What are the 4 growth characteristics of crabgrass - Moderately high yields if used as forage crop o Responds well to N - High forage quality and palatability - Drought tolerant 38. Discuss the crabgrass-winter annual forage system (6 steps) - Establish late summer - Light tillage in September, winter annual planted - Harvest winter annual in spring - Re-seed Crabgrass in late summer Grazing Management Southern Forages pgs 206-225 1. What is morphology? Physiology? - Morphology – outward appearance of a plant - Physiology – function of plant 2. Stocking rate gives us max performance per head vs. maximum performance per acre. 3. What are some fundamental aspects of grazing management? (4) - Implies degree of control over both animal and land - Consider: o Time of grazing and rest period o Residue (post grazing plant mass) o Animal needs o Animal density 4. Post grazing mass does what? (4) - Regenerate growth - Ground cover - Increase tiller density - Increase leaf area 5. The priority for energy is growth, then storage. 6. A defoliated plant will rely less on photosynthesis and more on CHO reserves for energy. 7. Where are 2 places energy comes from for a plant? - Leaf area - Stored CHO 8. Warm season grasses and all legumes store CHO as starch. Cool season grasses store CHO as fructosan. 9. The location of CHO reserves on a plant is very important for grazing management, why? - Depending on its location, the grazing animal could potentially eat it 10. Where is the CHO storage for the following plants? - Alfalfa - taproot - White Clover – stolons, taproot - Tall Fescue – stem base - KY Bluegrass – stem base, rhizome - Bermudagrass – stolons, rhizome - Millet/Sorghum/Sudangrass – stem base - Switchgrass/Gammagrass – stem base, short rhizome 2. List the following species in order from close grazers to higher grazers: - Horse, cattle, goat, sheep o Horse>sheep>cattle>goat 3. Animals learn many of their food preferences through social interactions. 4. What do the following animals prefer? - Cattle – grasses>legumes - Sheep – legumes>forbs=grasses - Goat – forbs>grasses>legumes - Horse - grasses - Deer – forbs>grasses 5. Define the following: - Preference – what an animal chooses to eat when physical constraints are minimum - Selection – function of preference modified by opportunity for selection - Adjacent monoculture – no need for animal to select, no constraint - Mixed swards – animal must search for preferred forage 6. Why do animals eat a mixed diet? (3) - Maintain rumen function - C:N ratio - Microbes are fully functioning 7. Why is it good to have both grasses and legumes in a ruminant’s diet? - Microflora in gut are more adaptive - Cope with changes in food supply 8. Discuss diurnal eating patterns: - Anti-predation theory – eat a lot during the daytime and then hide from predators during the night (deer) - Afternoon cut hay preferred - Non-structural CHO increase during the day - Grasses sweeter in afternoon vs. legumes Emerging Forage Systems: Extending Grazing in the Transition Zone (Guest Lecture – Chris Teutsch) 1. Sustainable forage systems do what? (3) - Protect and enhance natural resources - Profitable or meet lifestyle goals - Increase profit 2. What is the #1 cost in livestock? What is the most expensive season? - Feed, winter feeding most expensive 3. Grazing cattle on hay is very efficient; what does it decrease and benefit? - Animals may last longer than machinery - Natural fertilizers - No fuel costs 4. When you are starting with a controlled grazing system, what are 5 things you need to begin with? - Good attitude - Water - Controlled grazing - Soil fertility - Stocking rate 5. When picking forages, what should you take into consideration? (7) - Regionally adapted - Adapted to your soil - High yielding - High nutritive value - Drought and heat tolerant - Tolerant to close, frequent grazing - Persistent 6. 2-3 acres/cow-calf is needed in Virginia. 7. Warm season grasses are 1.6-2 x more productive in the summer compared to cool season grasses. 8. Tall fescue is the best adapted cool season grass. 9. When stockpiling cool season grasses, what should you take into consideration? - Allow forage growth to accumulate - Protect pastures that are stockpiled - Seasonal distribution 10. When putting N on stockpiled Tall Fescue, what is the best source to use? - Ammonium nitrate or Ammonium sulfate 11. When you have stockpiled fescue (pure stand) and stockpiled fescue-legume mix, what stand should you use first? - Fescue/legume mix – legumes aren’t as winter hardy as fescue so won’t hold up for very long during winter 12. Relatively little Bermudagrass has been planted, why? - Spreads by stolons 13. What is BMR? Describe it: - Brown Mid Rib – genetic trait in sorghum/millet o Lowers lignin content, increases digestibility Grazing Methods & Systems for Cow/Calf Southern Forages Chapter 26 1. What is Grazier’s Goal? - To grow as fast as possible so pasture can be grazed…then managed to grow more so it can be grazed again 2. What are 4 fundamentals of grazing management: - Meets animal’s needs - Optimize yield, quality, persistence - Maintain environmental quality - Make profit 3. The goal for grazing is year-round. 4. Soils should be tested for fertilization every 3-5 years. 5. Grass responds quickly to N. 6. Cool season grasses should not be fertilized during the summer, why? - Already dormant and under stress, so it’s not good to add N to increase the amount of stress on them 7. Discuss continuous stocking: - Most common grazing method - Requires least amount of management and investment - Animals could be selective o Overgrazed areas - Biochemical deterrent to overgrazing, from animals, insects and disease 23. Endophyte is only transmitted through seed. 24. When grazing stocker animals, they should be grazed on high quality pasture from weaning to 700-800 lbs. 25. Discuss the following pasture species: - Warm season annual grasses o Pearl Millet o Sorghum-sudan hybrids - Small grains o Mixtures of rye, ryegrass and arrowleaf clover can provide high gain o Winter annual pastures very expensive - Orchardgrass (pure) or with white clover o Short stand life under close grazing - Tall Fescue o Endophyte free vs. infected vs. novel o Endophyte free incorporated with alfalfa, BFT or clover further increases gain Forage & Grazing Management for Sheep & Goats Sheep 1. Forages account for 70-90 % of their total diet. 2. The last few weeks of gestation and the beginning few weeks of lactation are most important (nutrition-wise) for sheep. **When selecting forages for sheep, it’s important to match breeding season to feed supply** 3. When lambs are on pasture, they gain .60 lb/d in the spring and .30 lb/d in July/August. 4. Grazing cattle and sheep on the same pastures is a good idea, why? - Sheep are highly selective, consume short, fine forages compared to cattle - Sheep like broadleaf weeds - Parasite pressure is reduced - Graze sheep 3 weeks ahead of cattle 5. What are the implications of stockpiled fescue for sheep? - Reduce feed costs - 1 acre stockpiled fescue will meet nutritional requirements of 5 gestating ewes for 120 days - Need to supplement with protein and energy - Gain .1 lb/day on fescue alone 6. Discuss stockpiling: - AKA – deferred grazing - Allow grass to accumulate through fall, then begin grazing in late November - Apply 40-50lbs N - Strip graze and feed out pastures with legumes in it first 7. What are the benefits of stockpiling? - Cost effective way of wintering cattle - Less subject to heat stress and endophyte toxicity in winter - Leafy forage that is high in protein 8. What are the disadvantages of stockpiling? - Producer must have land - More management – don’t overgraze - Can be risky if late summer is dry - Winter precipitation can reduce digestibility and CP Goats 9. 80 % of the world’s population eats goat. 10. Goats are opportunistic grazers; they eat everything they have the opportunity to. 11. When feeding meat goats, you need a high quality forage. 12. Generally, with an increase in stocking rate you… - Increase parasites - Increase amount of fecal material on paddock - Reduced feed availability per individual and reduced selectivity 13. When talking about goats being “top-down” grazers, what does this mean? - Eat seedheads then work their way down - Behavior results in uniform grazing - Goats don’t close graze 14. What is tannin? - Chemical found in plant that can help decrease the parasite load Feeding Horses on Pasture 1. What type of grazers are horses? How long do they tend to graze for and why is it more than cattle/sheep? - Selective grazers/browsers - Take more time to graze because they aren’t ruminants 2. What are 3 main factors that affect grazing? - Time of year - Species of plant - Moisture of forage 3. Since horses are not ruminants, how can they digest their feed (what organ after the stomach)? - Cecum - Hind gut fermenters - Not as efficient as ruminant 4. Because of this they have a greater requirement for higher or lower quality feed? - Higher 5. How a horse is fed will greatly influence it’s growth, reproduction, speed/strength and appearance 6. A horses’ diet should consist of: (4) - Pasture - Hay - Concentrate - High quality silage - 1-2 ac/mature animal **Horses, when grazing close to the ground, could take the plant’s growth point, CHO storage point and they could also consume sand (cause sand colic)** 7. Horses need to receive ~ 1-2 lbs of high quality hay per 100lb body weight. 8. What are requirements of the quality of the hay for horses? (6) - No mold - No dust - No weed 4. Protein content of forages depends on what 2 things: - Species and stage of maturity 5. To maximize palatability and quality, legumes are harvested at boot to early bloom stage and grasses are harvested (1st cut) at boot and leafy for 2nd cut. Forage Quality & Forage-Related Animal Disorders 1. Describe the following: - Direct method to determine forage quality: o In vivo – directly see how animals use and respond to nutrients/forages o Costly and time consuming because they are feed trials - Indirect way to determine nutritive value: o In vitro – use rumen fluid  Determines the digestibility of the organic matter o Chemical methods  NIR, wet chemistry, ADF, NDF, lignin, protein, minerals 2. As a plant matures the amount of lignin increases. This makes it hard for an animal to digest because they can’t break it down. 3. Cool-season grasses have mesophyll cells 4. Warm-season grasses have bundle sheath cells. 5. Of the two answers above, which cells are much less digestible? - Bundle sheath cells 6. What does NDF predict? What 3 components does it contain? - Intake - Hemicellulose, cellulose, lignin 7. What does ADF predict? What 2 components does it contain? - Digestibility - Cellulose & lignin 8. How can you visually appraise forage quality? (6) - Plant maturity - Leafiness - Species o Legumes vs. grasses o Temperature vs. tropical - Green vs. brown tissue - Aroma - Foreign material/toxins **Stage of growth at harvest or grazing has more to do with nutritive value than most anything else** 9. The rate of change with maturity of a forage differs with (5): - Species (C3 vs. C4) - Grasses vs. legumes - Grain type vs. hay type - Temperature - Reproductive stage 10. Legumes are typically better than grasses (nutrition-wise) because (4): - Higher leaf: stem ratio - More digestible - More protein - Higher concentrations of Ca, Mg 11. The rate of nutritive value declines more in grasses vs. legumes. 12. Rank the following groups based on nutritive value (highest to lowest): - Alfalfa, Red Clover, White Clover o White Clover>Alfalfa>Red Clover - Small grains, Kentucky Bluegrass, Ryegrass, Orchardgrass, Fescue o Ryegrass>Small grains>KY Bluegrass>Rescuegrass=Orchardgrass>Fescue - Dallisgrass, Sorghum-Sudan hybrid, Pearl Millet, Bermudagrass o Dallisgrass>Sorghum-Sudan>Pearl Millet>Bermudagrass 13. What are 5 environmental factors that have an effect on nutritive value: - Fertilization/nutrient availability - Temperature - Water/rainfall - Solar radiation - Pest damage 14. When you fertilize a forage, what are its effects on nutritive value? (3) What can N impact? (3) - Influences yield over quality - N increases protein - Very little effect on digestion - N can impact: o CHO o Leaf: stem ratio o Brown: green ratio 15. Digestible DM declines with an increase of temperature due to: (3) - Lignification of cell wall - Photosynthetic production – converted to structural components - Increased reproductive growth (more dramatic with C4 vs. C3) 16. Cool temperatures and frost do what to grasses? (2) - Increase CHO in cool season grass - Frost freeze effects on prussic acid 17. Intake is higher in cool temperatures vs. hot temperatures. 18. What are 4 effects moisture has on yield? - Growth/yield influenced over quality - Can change stem: leaf ratio related to flowering vs. vegetative - Affects tissue death ration – dead vs. green tissue - Stress can affect toxic aspects – HCN, nitrate accumulation 19. What are 2 effects of light on nutritive value? - Total light – cloud cover decreases quality - Day length – affects reproductive tissue 20. Describe Bloat: - Foam build-up in stomach and esophagus, blocks animal’s ability to belch - Pressure builds up in rumen (left side of animal) - Treat with mineral oil or use a trocar to pop a hole in side of animal to release gases - Caused by increased consumption of legumes and lush forage - Bloat potential is the greatest during rapid growth