Feed Mixing and Storage October 10, 2012

Factors that Influence Stored Feed Moisture Heat Pests

Desired Moisture (when stored in aerobic conditions) Whole grains should contain less than 13% moisture. – Shelled corn can go up to 15.5% Ground and/or rolled grains should contain < 11%. Baled forages should be cured to contain 18-20% before being stored.

Facilitating Safe Moisture Storage Artificial drying – Disadvantage: can be expensive due to energy costs Field drying – crop remains in the field longer – Disadvantage: weather losses/damage, predators, harvest loss, time in field Proper ensiling

Too much moisture Bacteria growth Mold growth Fungi growth – Reduce palatability, alter nutrients, and produce toxins Fermentation and heat = browning Spoilage and nutrient destruction Issues with caking Spontaneous combustion risks

Pest Infestations More common issue for grains rather than forages. Insects or rodents Damage may be grain destruction or contamination. Feces and urine contamination 10 x more than grain destruction or consumption Reduce palatability Increase risk of disease

Reducing Pest Issues Store feed in rodent proof containers Don’t store against the wall. Leave space. Off floor. – USDA inspection issue Empty and clean bins when not used. Clean up spills. Keep feed rotated – first in first out. Get a rat terrier!!!

Mixing Feeds Most important thing is accurate formulations and proper weighing. Scales must be adequate and appropriate. Scales should be maintained and kept clean, calibrated on a regular schedule. Conversions are a must-have skill. – % to grams per ton, Lb to Kg, g to Lb, oz to grams 16 oz per Lb grams per Lb 1000 grams per Kg 1 mg/kg = 1 ppm

Types of Feed Mixers Two major types – Batch Feed Mixers – Continuous Flow Mixers

Batch Feed Mixers Types – Vertical – Horizontal – Auger wagon

Mixers Comparing horizontal with vertical mixers: Better for molasses and liquid ingredients. Handle silage and ground hays better. More expensive. Require less mixing time. Typically higher energy cost

Batch Mixers Stationary – Advantages: High accuracy, flexibility for mixing – Disadvantages: Feed needs transported to mixer, storage, labor and energy costs Portable – Advantages: Convenient to producer, ease of transport, uses existing tractors for power, fenceline feeding, freshly mixed – Disadvantages: Equipment tied up, labor and time, start up costs (renting or purchasing)

Continuous Flow Mixers Ingredients are simultaneously measured, ground and mixed. Advantages: automated, little space needed, accurate, may be more ideal for smaller situations and batch sizes. Disadvantages: No roughage, storage costs, energy costs, transporting costs associated with ingredients and finished mixes.

Mixing of Feeds Order of ingredients added is EXTREMELY important to the final mix. – Typical corn/SBM diets About 25% corn should be added first to “charge” the mixer. Followed by vitamin/mineral premix, additives, protein supplements. Followed by remaining grain. Liquids should not be added at the very end but after the critical additives (approximatley 60 – 70% of the mixing time)

Factors Affecting Mixing Efficiency Type of mixer chosen Sequence of ingredients Filling of mixer Length of mixing time Ingredient particle size Ingredient density Proper clean out – Flushing with ground grain after mixing a batch

Interpreting Mixer Tests Assay for salt in multiple locations within the mix to determine the mean & standard deviation. Determine coefficient of variation (CV): – %CV = SD/mean x 100 – < 10% CV is Excellent mixing – 10 – 15% CV = Good = increase mixing time by 25 – 30% – 15 – 20% CV = increase mixing time by 50% – > 20% CV = may need to re-evaluate other factors

Example LocationSalt (%) Mean = Standard Deviation = CV = (0.1156/0.523) x 100 = 22.10% What would you do with this mix?

References PDF Articles on Mixing – Testing Mixer Performance – K State Extension – Sequencing of Feed Ingredients for Mixing – South Dakota State University – Residue Avoidance Program – ISU Extension Book – Processing Feeds = pages – Mixing and Storage = pages 271 – 275 – Laws and labeling (including collective terms) = pages

GA Requirements for Labeling