Practical Feedlot Nutrition Flashcards
Describe differnces between domestic and export market specifications and suitable diets to achieve these
Describe domestic trade specifications
- Hot Standard Carcass Weight (HSCW) = 160-250kg
- Fat depth = 6-9mm@P8
- Feeding period = 60d (heifers), = 70d (steers) up to 90d
- Entry LW = 220-300kg
- Entry age = 6-12 months
Describe differences between domestic and export market specifications and suitable diets to achieve these
Describe domestic trade DIET specifications
- High ME
- low cost high ME source (wheat, triticale, barley)
- **Low cost protein source
- but may need to consider UDP**
- In Australia, need cheap, high quality roughage
- E.g. maize silage (contains grain)
- avoid high carotene diets
- Green & yellow coloured plants needed for vitamin A synthesis but taints meat and discolours fat
- Better to add vitamin A to diet
Describe differences between domestic and export market specifications and suitable diets to achieve these
Describe export trade specifications
- HSCW = 280-390kg
- Fat depth = 16-20mm@P8
- Sex = steers
- Feeding period = 120-150d, over 200d
- Entry LW = 300-500kg
- Entry age = 16-20 months
Describe differences between domestic and export market specifications and suitable diets to achieve these
Describe export trade DIET specifications
- **In Japan, slow growth rate of 1 kg/d over 300-500d
- up to 75% concentrate
- cattle fed ad lib**
Describe differences between domestic and export market specifications and suitable diets to achieve these
Preparing for feedlot entry
- what diet should be fed?
- how much kg ADG is preferable?
- feeding high roughage (forage) diet
- common to start with 20% concentrate
- Build up to 40% concentrate
- typically obtain approximately 1kg ADG
Describe differences between domestic and export market specifications and suitable diets to achieve these
What do introductory feedlot diets aim to achieve?
What % concentrate and what % roughage should be fed?
- Aims to adjust rumen to high grain
- introduce to cereal grain over 3 weeks
- lupins can be used to improve daily gain in introductory phase
- expect low consumption in the first week
- Common to start with 20% concentrate
- can start with 50% for young cattle
Describe differences between domestic and export market specifications and suitable diets to achieve these
What do feedlot finishing diets consist of?
- feeding cattle to an endpoint suitable for slaughter
- feed a high concentrate ration to increase ration energy density
- increases rate of gain, decreases cost of gain
- promotes fattening to achieve desired quality grade
- *-typical finishing ration is
- 90-95% concentrate, 5-10% roughage**
List ways in which protein deposition can be altered
How can you control growth through nutrition?
- Repartitioning agents
- Sex hormones/analogues
- Growth hormones (GH)
- Growth promoting medications (Bacitracin (BMD))
- agonists (Ractopamine & ZH) Muscle promotants
- MGA - melengestrol acetate
- Progestogen-like compound that inhibits oestrus in heifers
- Promote muscle growth
- Quiet cattle gain more rapidly and efficiently
- For lean production, protein supply must be in balance with energy
- Compensatory growth effects
- Nutritional phasing
Nutrients
Energy?
maximised to provide as much as NEg as possible
-11 + MJME/kg DM
Nutrients
Protein?
typically fed at 12-14% of ration DM
Nutrients
Minerals?
- Ca is usually deficient in typical feedstuffs
- Added at 1% diet
- Grains are high in phosphorus but low in calcium (Ca:P ratio)
- Sulphur sometimes added (microbes)
- Trace minerals are usually mixed in ration
- Zinc & cobalt
- Salt is usually mixed in ration at 0.2% of diet (Sodium)
- Urea at 1% of diet (N source)
Nutrients
Vitamins?
- Only major concern is Vit. A, maybe D
- vit. E
- thiamin
Feedstuffs
Energy concentrates?
- Cereal grains
- Fat (no more than 7%)
• By products
-E.g. oilseed meal, cotton seed meal
Feedstuffs
Protein concentrates?
- Oilseed meals
- NPN
• By products
-E.g. Distillers and brewers grains
Roughages
?
- Corn or sorghum silage
- additional benefit: contains additional grain
- Lucerne hay
- additional benefit: contains protein
- Grass hay
- Straw
What roughage types should be fed on high grain (90%) diets?
- Coarse roughage preferred
- Often low quality
- Aims to maintain rumen function
- Keep rumen fill (avoid acidosis and ulcers)
What roughage types should be fed on low grain (<50%) diets?
• Quality critical (e.g. maize silage)
Describe common grain processing methods
Describe particle size reduction?
- grinding
- dry rolling
• Aim is to increase starch access
• Can be soaked prior (tempering)
Describe common grain processing methods
Describe heat processes?
roasting, popping, micronising
Describe common grain processing methods
Describe moisture processes?
High-moisture grain
- Harvested early and ensiled (silage)
- Steam rolling and flaking
- Extrusion
- Exploding
- Feed in high tensile containers subjected to high pressure steam
- Gelatinisation
- Breaks down starch structure
- dissolve in water
- increase digestion
Describe the major health issues related to nutrition in feedlots and how these can be minimised
What are the issues with feeding starch to a ruminant?
- pH drops as starch intake increases
- eat too much, pH falls quickly (<5.6)
- creates unstable intake pattern
- goal of nutritional management is to stabilise intake
- challenge is stable intake for individuals when managing pens
Describe the major health issues related to nutrition in feedlots and how these can be minimised
Feeding starch: Nutritional management
how can we adapt cattle to a high starch diet?
- Start at 50-55% grain
- Increase grain by 10% every 5 days
- Takes about 20 days to get to 90-95% grain
Describe the major health issues related to nutrition in feedlots and how these can be minimised
Feeding starch: Nutritional management
What are the goals of bunk management?
Goals:
- Consistent intake and pattern of intake
- Eliminate acidosis
- Manage gain and feed efficiency
Describe the major health issues related to nutrition in feedlots and how these can be minimised
Feeding starch: Nutritional management
What are the challenges of bunk management?
- How much are they willing to eat?
- How much remains from last delivery?
- How much do you change amount each day?
- What is their feeding behaviour?
Describe the major health issues related to nutrition in feedlots and how these can be minimised
Feeding starch: Nutritional management
What are the responsibilities of the employee managing a bunk?
- correctly mix ration
- deliver correct amount
- deliver at the same time each day
- distribute evenly in the bunk
What are the two systems of bunk management?
- continuous feed
- clean bunk
Describe continous feed bunk management
- Always feed in the bunk
- Theoretically no limit on performance
- Less control – harder to manage
- Feed waste needs to be managed
- Big responsibility on bunk reader
Describe clean bunk management
Empty bunk at same time each day
- Goal is to maintain or increase consumption
- Controls intake better
- Reduces feed waste
- Less responsibility for bunk reader
Describe the various additives that can be included in feedlot diets
What are ionophores?
- Selective antibiotics that alter rumen microbial populations and thus fermentation patterns
- Select against grampositive bacteria and protozoa
Describe the various additives that can be included in feedlot diets
What are ionophores used for?
- Increases energetic efficiency by changing VFA profile to greater propionate:acetate ratio and reducing methane
- More propionate for glucose production
- Improves feed efficiency by increasing ADG and/or decreasing feed intake
- Protein sparing effect
- Less protein degradation by microbes, more feed protein available to ruminant (bypass)
- Control nutritional disorders including coccidiosis, acidosis, and bloat
Describe the various additives that can be included in feedlot diets
Name some examples of ionophores?
Rumensin (sodium monensin)
Bovatec
Describe the various additives that can be included in feedlot diets
What are feed-grade antibiotics used for?
- reduce incidence of subclinical bacterial infections
- digestive and respiratory tracts
- stimulate appetite
- These 2 effects are particularly valuable in diets for newly received calves
- nutrient sparing effects
- control acidosis when feeding high levels of grain
Describe the various additives that can be included in feedlot diets
What are some examples of feed-grade antibiotics?
Virginiamycin (Eskalin)
- Highly regulated
- Only issued under tight veterinary directive
- Section 4 drug
- Used for set periods of time in set quantities
Describe the various additives that can be included in feedlot diets
- Ionophores
- Feed-grade antibiotics
- Buffers
- Probiotics or Direct Fed Microbials (DFM)
- Antifungals (eg propionic acid)
- Antioxidants (eg ethoxyquin)
- Pellet binders (eg bentonites)
- Feed flavours?
Describe the various additives that can be included in feedlot diets
What are buffers used for?
- control rumen pH to reduce acidosis on high grain rations
- very common in dairy rations, infrequently used in feedlot rations Eg. Sodium bicarbonate
