Week 4

Roughages

Cultivated Pasture and Rangeland Forages

Text Transcript

Follow along with the audio...

• Cultivated or seeded pastures
• Forage species
• In general, grass-legume mixtures
• Provision of adequate moisture
• Management of irrigation
• Factors to consider
• Method and frequency of irrigation
• Amount of moisture per application
• Removal of excess moisture (i.e. drainage)
• Fertilization
• Higher fertility required for maximum yield and nutritional value
• Type and amount
• Dependent upon plant species and production objectives
• Three main nutrients: N, P, and K
• Grass-legume
• N promotes grass growth
• P promotes legume growth
• Minerals deficient in soils
• Grazing animals
• Maximize profitability of pasture with high yield and nutritional value
• Graze high-producing animals
• Lactating and growing cattle and sheep
• Supplementation
• May be required to improve animal production
• Pastures in vegetative state high in CP
• Energy content low relative to CP
• Supplement with energy source to improve MCP synthesis and animal production
• Rangelands
• Large, naturally vegetated land areas
• Figure 8.14 – Sheep on rangeland; rotation grazing system



• Figure 8.15 – Cattle on rangeland



• In general, relatively low densities of grasses, legumes, forbes, and browse
• Native and introduced species
• Majority west of Mississippi River
• In west, majority owned and administered by U.S. government
• In general, compared to cultivated pastures
• Less productive – yield and nutritional value
• In part, due to properties of vegetation and rangeland system
  • Forage species
  • Topography
  • Soil and environmental conditions
  • Previous use of land
• More difficult to manage
• Multiple purpose
• Antinutritional factors more of a concern
• Specific factor varies
• Plant species
• Concentration of factor varies
• Soil and environmental conditions
• Forage manager
• Know: species, species’ antinutritional factors, and factors influencing concentration
• Manage to reduce opportunity for toxicity
• Economic loss greater for loss in productivity versus death
• Management
• Forage, animal, and rangeland
• Factors include forage species, yield, nutritional value, and season, stocking rate, distribution, supplementation, resource improvement, etc.
• Animal selection
• Factors include economics, vegetation, water, topography, and predators
• Common or dual use
• More than one species in grazing system
• Different preferences for forage species, portions of forage, terrain, temperature, and distance from water
• Forage preferences vary with season and maturity
• Maximum forage utilization
• Cattle
• Prefer grasses and forage legumes
• Sheep and goats
• Consume more forbes and browse
• Extent of defoliation
• 50-50 rule
• Graze 50% of weight of forage and leave 50%
• Promotes future forage production
• Also applied to cultivated pastures
• Season of use
• Animal and future forage production
• Factors include vegetation, topography, and climate
• Classifications of season
• Improvement
• Indicators of degradation include decrease in favorable forage species, an increase in unfavorable forage species, and an increase in erosion
• Animal management practices
• Conservative stocking rates
• Appropriate seasonal use
• Proper animal distribution
• Methods to improve
• Rotation system
• Fencing
• Herding
• Additional water
• Location of supplements
• Controlling pests
• Trail building
• Additional practices include reseeding and brush and weed control
• Grazing systems
• Principles similar to cultivated pastures
• Continuous
• Most common
• Management via stocking rate and animal distribution
• Advantages
• More efficient on less productive ranges
• More practical for seasonal ranges
• Disadvantages
• Lower stocking rate
• Lower animal production per unit area
• Poorer animal distribution
• Less opportunity for range improvement
• Rotation
• In general, maximize forage and animal productivity
• Preservation of wildlife habitat and water resources
• Primary types
• Deferred rotation
• Season of grazing and resting periods for each pasture vary year to year
• Figure 8.16 – Deferred rotation grazing system

• Short duration
• Frequent movement between small pastures
• Frequency dependent on forage availability
• More forage, more frequent movement
• Examples include rectangular and cell grazing
• Supplementation
• In general, required to fulfill nutrient requirements
• Type and level
• Depends on animal requirements and forage nutritional value
• Varies by season and year
• In general, include energy, protein, minerals (especially P), and vitamins (especially A)
• Energy
• Low forage availability
• Low forage digestibility
• Risk for nitrate toxicity high
• Low energy to protein ratio
• Daily
• Protein
• Provides protein and improves utilization of other nutrients
• Every other day or twice per week
• Macrominerals, microminerals, and vitamins with use of carrier