Week 2

High-Energy Feedstuffs

Corn

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• Most important feed grain
• U.S. estimated production - 9,506 million bushels
• Regions of production – Midwest and Great Plains
• Figure 4.2 – Field of corn



• Most productive of grains
• Largest yield
• Estimated average yield – 138.2 bu/acre
• Greatest amount of digestible energy per unit of land
• Produces grain and stover
• Stover – all nongrain portions of plant
• Nutritional value of corn
• Table 4.2 – Average nutrient composition of corn
• Energy source
• High in starch
• High in oil
• Low in fiber
• Protein source

Table 4.2 - Average Nutrient Composition of Corn

Nutrient	Average Composition, %
Crude protein	10.4
Ether extract	4.6
Crude fiber	2.5
Ash	1.4
NFE	81.3
Starch	72.2

• Low CP content
• Quality
• Poor quality
• Low solubility
• Deficient in lysine, methionine, and tryptophan
• Lipid source
• High lipid content
• Increase energy and palatability
• Provide essential fatty acids
• Minerals
• Very deficient in Ca
• Moderate in P
• Bound as phytate complex
• Requires microbial phytase
• Vitamins
• Yellow grain
• Vitamin A precursors
• Fair source of E
• Poor source of D and B-complex
• Classified based on kernel
• Kernel – germ and endosperm
• Dent - major commercial variety
• Yellow or white
• U.S., yellow preferred
• Presence of carotenoids
• Carotenoids - group characterized by yellow to red pigments
• Figure 4.3 – Yellow dent corn grain on the cob



• Figure 4.4 – Yellow dent corn grain



• Many hybrids
• Hybrids – offspring of genetically dissimilar parents
• Facilitate growth in range of climatic conditions
• Genetic engineered
• Bt corn
• Control pest
• Round-Up Ready Corn
• Resist herbicide
• Nutritional value-added
• High oil
• Low phytate
• High lysine
• C3 and C4
• Based on intermediates of photosynthesis
• Three- versus four-carbon compound
• Characteristics of C4 compared to C3
• Heat tolerance
• Drought tolerance
• Efficiency of nutrient use
• Carbohydrate production
• Summer annual
• Plant in spring or summer
• Harvest in summer or fall
• Figure 4.5– Mechanical harvester harvesting grain



• Figure 4.6 - Mechanical harvester transferring grain



• Processing prior to feeding
• Increases nutritional value
• Processing
• Breaks kernel shell
• Increasing availability
• Break apart or gelatinizes starch granules
• Increasing digestibility
• No significant intrinsic toxins
• Susceptible to deleterious factors – molds, smuts, blights
• Fungi
• Characterized by mold
• Produce toxins called mycotoxins
• Examples of grain mycotoxins include aflatoxin, zearalenone, vomitoxin, and fumonisin
• Figure 4.7 – Aspergillus flavis on corn



• Feeding livestock
  • General characteristics
• Digestible
• Palatable
• Cost-effective energy source
• Rarely, nutritional problems
• Swine and poultry
• Corn-soybean meal based are industry standard
• Adequate energy and protein
• Finishing beef cattle
• Increased weight gain, increased feed efficiency, and improved meat quality
• Lactating dairy cattle
• Support milk production
• Sheep
• Late gestation ewes and fattening lambs
• Generally, not fed to horses