Quiz 3 Flashcards
What is aquaculture?
The farming of aquatic organisms, including fish, molluscs, crustaceans, and aquatic plants
In 2010, what percentage of the world’s fish food production for human consumption did aquaculture make up?
47%
Who are the world’s leaders in aquaculture?
Asia (China)
What are the top 3 world aquaculture fresh water fishes in 2010?
Silver & bighead carps, Indian major carps, and grass carps (other than carp (cyprinids) lower on the list catfishes, bass and perch, snakeheads, characins)
What are the top 3 world aquaculture diodromous fishes in 2010?
Atlantic salmon, milkfish, rainbow trout
What are the top 3 world aquaculture marine fishes in 2010?
Jacks, pompanos & mackerels/ Drums and croakers/ Gilthead seabeam
Describe extensive aquatic systems
Low cost, natural containment, simple structures, low control, seed stock from nature, no monitoring of water quality
Describe intensive aquatic systems
High cost, fabricated, concrete, cages, etc, domesticated seed stock, regular monitoring of water quality, feed source is commercial pelletised
Major aquaculture in Australia
Pearl oysters & Barramundi & Prawns, silver perch, murray cod, mussels, Abalone, SB tuna, yellowtail kingfish, scallops, rock lobster
In the salmon production cycle, where do salmon lay their eggs?
Freshwater
What are static pond systems in aquaculture?
Earthen impoundments, enclosed waterway in a valley or stream bed, natural light, soil important, lined with impermeable sheeting
What species are grown in static ponds in Australia?
Barramundi, murray cod, silver perch, golden perch, prawns
What are tank systems in aquaculture?
Second to ponds as the most commonly used for aquaculture, generally above ground on solid base indoors and outdoors, allow the use of land normally unsuitable for aquaculture, no contact to the surrounding soils, range of sizes
What species are grown in Australia in tanks?
Barramundi, Southern bluefin tuna, yellowtail kingfish, murray cod silver perch, golden perch, rainbow trout, atlantic salmon, abalone, prawns, oysters
What is a recirculation aquaculture systems (RAS)?
Intensive, rely on very little water exchange daily, significant risks, highly controlled environment, “closed” systems, generally high capital investments, usually run high stocking densities (>50 kg/m^3), dissolved oxygen first limiting factor, ammonia usually 2nd limiting factor, must strictly maintain water quality including temperature, fish housed in tanks
What are some critical equipment for a RAS?
Back up generator, biological filters (with sufficient capacity), oxygen supply (often liquid oxygen), protein skimmers, pumps, alarms
Open sea cages
Generally good water flow but where cages sited (moored) very important, must find site with adequate exchange of high quality water but also protected, stocking densities up to 10-15 kg/m^3, species grown in sea cages in Aus: atlantic salmon, rainbow (“ocean”) trout, yellowtail kingfish, southern bluefin tuna, barramundi, abalone
What is the most commonly farmed deer in Aus?
Red deer (Reindeer second most commonly farmed) (mostly in NSW and VIC)
What country has the world’s largest number of farmed deer?
NZ (1.2 million approx 2009)
What do Fallow Deer look like?
Bambi
What do red deer look like?
Red with large antlers
What do Wapiti look like?
aka Elk (think of WA state)
What comes out of a deer production system?
Venison, velvet, skin tails, pizzles, sinews, prices
What are the temperate deer species?
Fallow, red, elk (wapiti)
What are the tropical deer species?
Rusa, chital/sambar/ hog/ white-tail/blackbuck
What are some facts about temperate deer species?
Tight photoperiod for antler growth and reproduction, calve nov/dec, wean before rut (autumn), winter weight loss, double coat/ open coat, strong dominance hierarchy, seasonal venison
What are some facts about tropical species?
Much less photoperiod compared with temperate spp, calve in late autumn/winter, weaning variable, no winter coat, venison not seasonal, less aggression between stock
Stocking rates of fallow doe, red hind, rusa hind (females)
2 DSE (fallow dow), 3.5 DSE (red hind), 3 DSE (rusa hind)
When does velveting occur in red/elk, fallow, and rusa?
Nov/dec (red/elk), fallow (dec/jan), and rusa (dec/ june)
When does calving occur in red, fallow, rusa?
Late nov/ dec (red), fallow (dec/jan), and rus (self/3 months)
Male reproduction with deer
Neck hypertrophy, roar, antler calcification, aggression/ territory marking, 30% body weight loss, march- july
Male reproduction deer species differences
Less photoperiod influence, reds move with and protect harem, fallow occupty stationary territory with harem
Female reproduction deer species
Seasonally polyoestrus with very distinct photoperiod effects in temperate species, puberty reached at 15 months (second autumn), fertility peak at 5 yrs, 2nd and subsequent offspring heavier, twins rare, calf “stashed” for first few days
Seasonal advancement in female deer
hormonal manipulation by P4 implants with PMSG, oral melatonin, daily yarding to dark pens
Pregancy diagnosis in deer
Trans-rectal ultra-sound, 30 days onwards +/- 10 days foetal age, double progesterone
Velvet harvesting
Amputation of live antler prior to calcification from male deer, must be carried out under vet supervision with appropriate analgesia or by a farmer accredited through the National Velvet Accreditation Scheme
Antlerogenesis
Annual casting of buttons (or antlers) and regrowth and calcification, increased daylight–> decreased testosterone–> cast and new growth, decreased daylight–> increased testosterone–> shedding of velvet and calcification
Velvet casting and regrowth when?
July/ August (regrowth sept/ january 3-4 months)
Primary harvesting of velvet?
October/ November
Velvet maturation?
January/ February (3-4 months)
Velvet names from bottom to top of antler (on its side)
Brow tynes, bez tynes, trez tynes (all on the main beam) then the royal tynes (if present- splits of the trez tynes as a continuation of main beam)
In what areas can a vet advise a farmer about drought?
Nutritional assessment and feeding of stock, feed budgeting, disease management, animal welfare and humane destruction, and farm economics
What is a “drought?”
A period of acute water shortage, due to serious or severe rainfall deficiency over several months. (“serious” and “severe”- rainfall over the last 3 months have been in the lowest 10% and 5% of longterm recorded rainfall figures)
Green drought
Pasture is growing because of recent rain (i.e. is green, not senescent and dry) but does not meet the needs of livestock at a time when it normally should
Australian Govt. Exceptional Circumstances (EC) classification to ID rare and severe events (defined?)
Rare is 1 in 20 year event and severe is more than 12 months or at least 3 consecutive dry seasons
In a drought animal consequences?
Reduced weight gain or faster weight loss–> effects on lactation, wool growth, muscle/ fat growth; prolonged absence of green feed can lead to vitamin deficiences; prolonged grain supplementation can lead to digestive (rumen) upsets or mineral imbalances
In drought environmental consequences?
Overgrazing of pastures: excessive grazing damages/ reduces plants–> reduced seed and vegetative mass available to regrow and recolonize bare areas after the drought breaks; loss of vegetative ground cover can lead to soil erosion (loss of fertility); water quality may be degraded (dams contaminated with eroded topsoil, waterway erosion/ degradation by stock, etc.)
In drought farm business consequences?
Increased cost: supplementary feed, replacement stock are expensive when the drought breaks (demand increase); decreased income: lower liveweight and price/kg for sale stock, reduced wool growth and milk production, fewer animals left to restore future production & earning potential following animal sales or decreased reproduction during drought
Drought management options (4)
- Total or partial destocking
- Feed all stock for survival
- Agistment (take cattle to graze elsewhere if less than supp feed cost)
- Production Feeding
What is typically the cheapest energy supply on a cent per megajoule basis in AUS?
Cereal grain