Leastcost formulation and feed production Computer Formulation of

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Least-cost formulation and feed production

Least-cost formulation and feed production

Computer Formulation of Feeds • Least-cost feed formulation: a feed formula that is both

Computer Formulation of Feeds • Least-cost feed formulation: a feed formula that is both nutritionally-complete (within limits) and with a minimum ingredient cost (within limits) • now-a-days is developed and completed through the use of computers using linear-programming software • typical packages: Brill, Mix-it • used by most feed mills/manufacturers

Least-cost Formulation • Least-cost feed formulations require that the following information be provided: cost

Least-cost Formulation • Least-cost feed formulations require that the following information be provided: cost of feed ingredients nutrient content of feed ingredients nutritient requirement of the animal availability of the nutrient to the animal minimum-maximum restrictions on levels

Least-cost Formulations • Costs of feed ingredients and nutrient content are fairly available for

Least-cost Formulations • Costs of feed ingredients and nutrient content are fairly available for most commercial feedstuffs • costs can be evaluated on a daily basis • nutrient requirements are fairly well known • the most critical piece of information regards digestibility/availability of nutrients within the feed ingredient • various indices: DE, ME, APD, etc. • these can be set in formula w/restrictions

Least-cost Formulation • these are nutrient and ingredient restrictions that have been used for

Least-cost Formulation • these are nutrient and ingredient restrictions that have been used for least cost formulation of catfish feeds • theoretically, protein level does not have to be restricted if essential amino acid requirements are well-known • for catfish, if the minimum requirements for lysine and the sulfur-containing AA’s are met, other EAA requirements are also met

Least-cost Formulations • Other restrictions: minimum available phosphorus and digestible energy • only maximum

Least-cost Formulations • Other restrictions: minimum available phosphorus and digestible energy • only maximum calcium is typically considered due to availability in water • whole fish or other animal protein sources have been shown beneficial for catfish feeds • cottonseed meal is restricted to 10% due to gossypol (protein) content (toxic) • xanthophyll content often restricted due to it causing yellow discoloration of fish at high concentrations

Least-cost Restrictions for Shrimp Feeds

Least-cost Restrictions for Shrimp Feeds

Least-cost Formulations: other restrictions • Limitations to computer formulations exist and should be recognized

Least-cost Formulations: other restrictions • Limitations to computer formulations exist and should be recognized • where the computer says its ok, the experienced formulator knows differently • example: too high fat content for pelleting • example: sorghum might be as good as corn in an extruder, but not a pelletizer • this is why advantages are maximized when a number of options are available

Computer Formulation of Feeds • Originally, the development of feed formulations was a real

Computer Formulation of Feeds • Originally, the development of feed formulations was a real task • mathematical models formulating nutritionallyadequate diets at lowest cost were available • however, everything had to be hand calculated • feed formulation: the preparation of nutritionallycomplete diets for feeding animals

Least-cost Formulations: other restrictions • In many cases, logistics of obtaining ingredients and their

Least-cost Formulations: other restrictions • In many cases, logistics of obtaining ingredients and their storage limit the number of ingredients • availability of feedstuffs is not as important as having the option to substitute • must also take into consideration the physical, palatability, and toxicological properties of the feed • nutrient availability also varies

Least-cost Formulations: restrictions • As mentioned, most least-cost formulae are derived by linear programming

Least-cost Formulations: restrictions • As mentioned, most least-cost formulae are derived by linear programming • it has its disadvantage in that it uses data out of the NRC handbook for fixed, maximum growth rates • it does not take into consideration optimum return on growth for various feed nutrient concentrations • this requires regression analysis • regression analysis is now being integrated into poultry formulae, probably not yet available for fish

Part 2: Feed Production Largely provided by Wenger, Inc. and Akiyama

Part 2: Feed Production Largely provided by Wenger, Inc. and Akiyama

Feed Production • Two major methods: pelletizing and extrusion • steam pelleting produces a

Feed Production • Two major methods: pelletizing and extrusion • steam pelleting produces a dense pellet that sinks rapidly in water • extrusion produces a low density feed particle that has a tendency to float • steam pelleting uses moisture, heat and pressure to agglomerate ingredients into larger, homogenous particles • steam added to the ground feed mash (mix) partially gelatinizes starch, binding ingredients

Pelletizing Feeds • Generally, steam is also added prior to passing the mash through

Pelletizing Feeds • Generally, steam is also added prior to passing the mash through the pellet die • this increases its moisture content to 15 -18% • temperature goes up to about 85 o. C • steam pelleted feeds must be firmly bonded for satisfactory stability in water • starch is important for adequate binding • fat and fiber are antagonistic to process • supplemental fat not added if pelleting

Pelletizing Feeds • All conventional pellet mills include the following equipment: • variable speed

Pelletizing Feeds • All conventional pellet mills include the following equipment: • variable speed feeder • conditioning chamber • die and roller assembly • speed reduction device • prime mover • base • the variable speed feeder provides a continuous, controlled flow of feed mix

Pelletizing Feeds: conditioning • The conditioning chamber is actually a mixer with either fixed

Pelletizing Feeds: conditioning • The conditioning chamber is actually a mixer with either fixed or movable paddles • conditioning is accomplished by the addition of controlled amounts of steam • steam liberates natural oils, partially gelatinizes starches, increases temp, increases moisture • starch gelatinization: loss of birefringence or the irreversible rupture of the native secondary bonds in the crystalline region of the starch granule • the speed reduction device is added to reduce motor speeds to that of the die head • this is absolutely critical for the production of consistent-sized particles

Pre-conditioning gelatinization process machine

Pre-conditioning gelatinization process machine

Sinking vs. Floating Feeds

Sinking vs. Floating Feeds

Typical Pellet Mill

Typical Pellet Mill

Typical Pellet Mill Process Flow

Typical Pellet Mill Process Flow

Typical Pellet Mill

Typical Pellet Mill

Die Assembly

Die Assembly

Comparison: extrusion vs. pelleting Process flow diagrams

Comparison: extrusion vs. pelleting Process flow diagrams

Typical Extruder (side view)

Typical Extruder (side view)

Comparison: pelletized vs. extruded feeds

Comparison: pelletized vs. extruded feeds

Pellet Comparison: continued

Pellet Comparison: continued

Price Comparison

Price Comparison

Feed Appearance • Feeding behavior of aquatic animals is usually associated with some quality

Feed Appearance • Feeding behavior of aquatic animals is usually associated with some quality of the feed: • odor, palatability, texture, appearance, size • bottom line: a nutritionally-balanced feed is of little value if not consumed • often, the animal must be “attracted” to the particle • example: shrimp feeds w/attractants • leached attractants are detected through chemoreceptors located throughout their body

Attractability/Pallatability • Shrimp, unlike fish, feed by olfaction, not by sight • fish cue

Attractability/Pallatability • Shrimp, unlike fish, feed by olfaction, not by sight • fish cue on color, appearance, movement, all visionrelated • attractants: fish meal, fish oils, krill meal, shrimp head meal, Artemia meal • feeds with added attractability should bring the target animal immediately to the pellet • without binders, attractants leach out in 2 hr • if not consumed by then, forget it

Attractability/Palatability • Common misconception: if farmer can smell attractant, the feed is good •

Attractability/Palatability • Common misconception: if farmer can smell attractant, the feed is good • again, we don’t smell what they smell • palatability: is particle picked-up and then consumed/ingested? • Regards texture and handling ability of pellet • shrimp need this more than fish because they are sloppy eaters!!

Pellet Stability • In the past, farmers thought the longer the pellet stability, the

Pellet Stability • In the past, farmers thought the longer the pellet stability, the better the feed. . • We now recognize that if a pellet has lost its attractability, it will not likely be eaten • the key is to provide the right combination of attraction and stability • accomplished via binders, but expensive • normal stability: around 4 -6 hrs • determined by: dry matter, immersion, fractures, etc.

More on Appearance • Because some aquatics feed by smell, color is often irrelevant

More on Appearance • Because some aquatics feed by smell, color is often irrelevant (REM? ? ) • however, color can give you an idea of the nutrient composition and manufacturing quality of the pellet • pellet color should be uniform, few large ingredient particles • shrimp, unlike fish, can remove tiny ingredient particles and discard them

Pellet Appearance • Feed pellets should contain no fractures • fractures are indicative of

Pellet Appearance • Feed pellets should contain no fractures • fractures are indicative of poor processing and conducive to poor water stability • fractures allow water to seep into pellet more rapidly, pellet hydrates, breaks • feed pellets should not clump together (indivative of poor drying, results in poor nutritional quality, stability) • “fines” from bags should total less than 2% • result: you lose money, get poor water quality

Feed Pellet Size • What feed pellet size you feed is determined by age

Feed Pellet Size • What feed pellet size you feed is determined by age of animal • size of particle must be the one most efficient for location and consumption by animal • proper nutrient package, right size, welldistributed • smaller pellets usually imply easier distribution • feed particles range in size from less than 50 µM to over 1/8 in. diameter

Feed Pellet Size • Larvae: <50, 50 -125, 250, 500 µM, according to larval

Feed Pellet Size • Larvae: <50, 50 -125, 250, 500 µM, according to larval substage • postlarvae: flakes, fine crumbles (500 µM) • juveniles to 2 -3 g: medium crumble (1 mm) to coarse crumble (2 mm) • 3 -6 g: short pellet (3/32 x 2 -4 mm) • 6 -10 g: medium pellet (3/32 x 6 mm) • 10 -16 g: long pellet (3/32 x 10 mm) • over 16 g: 1/8 in. diam, various lengths • point: one pellet per shrimp per feeding

Feed Pellet Size • For a 2 mm x 6 mm pellet, you have

Feed Pellet Size • For a 2 mm x 6 mm pellet, you have approximately 1 million pellets per 100 lb bag • if your 10 ha pond has 2 million shrimp in it (20 per sqm), feeding two 100 lb bags gives each shrimp 1 pellet/feeding • 20 pellets per sqm pellet density