Definitions
Monocotyledons
Dicotyledons
Grasses
Forbs or Herbs
Value of Australian Agriculture
Live Cattle Trade
Location of Beef, Sheep and Beef/sheep areas in Australia
Livestock Resources
Sheep distribution:
Cattle distribution
Constraints on Cattle Production
Importance of Grazed Pastures
14 major Native pasture communities of QL
use of supplements to manage dry season feed deficiencies
- Pastures: These are grasslands which can occur naturally or be sown. Pastures are used as grazing for livestock animals. They usually consist of herbaceous plant species that livestock eat to sustain themselves, to grow, to reproduce and to produce milk.
- forage: forage is the edible parts of plants (other than separated grain) that can provide feed for grazing animals or that can be harvested for feeding to livestock. The term is increasingly used to refer to the species planted, for example: forage sorghum, forage oats
- browse species/top feed: these are shrubs or trees that livestock feed on, often during dry times or in drought.
- native species: indigenous species
- introduced: exotic, from outside the country
- naturalised: introduced plants that have been thoroughly established in the area
Monocotyledons
- Grasses
- flower parts are in three parts or multiples of three
- the veins of the leaves are parallel
- plants lack secondary growth
- vascular bundles are distributed in the ground tissue in the stem
- roots are fibrous
- seeds contain one cotyledon
Dicotyledons
- Forbs or herbs (including legumes)
- flower parts in 4 or 5 parts or multiples of 4 or 5
- leaves have perpendiculare/reticulated/netted veins (run out towards edge of the leaf from the middle)
- Secondary growth is common and arises from vascular cambium
- vascular bundles are distributed as a ring in the stem
- consists, usually, of a taproot system
- seeds have two cotyledons
Grasses
- member of the Poaceae family
- lack a taproot system and so are most effective with shallow moisture
Forbs or Herbs
- non woody plant
- often valuable component of a pasture
- can make a substantial and important part of the diet of razing animals as during southern winter rainfall areas of QLD many grasses are dormant and have poor quality
Value of Australian Agriculture
- much of Australia's agricultural production comes from pasture-based livestock production
- much of the grains production regarding Australian Agriculture is directly related to pasture use particularly egumes as they have an important role in crop rotations to build up soil fertility, reak crop disease cycles and for maintaining grain yields.
- in the tropics butterfly pea i a valuable pasture legume for grazing and also for building soil fertility for crop production. CLovers and medic species play a similar role in more temperate climates.
- Australia is the world's second largest exporter of beef and the largest exporter of wool.
- Agriculture industries generate about 30% of our total export avenue and provides for about 12% of the Nation's workforce
- Beef cattle production in QLD is the largest agricultural indusctry contributing 41% of the State's Gros Value of Agrictulrual Production
Live Cattle Trade
- youn and lean quality cattle which are usually grass or apsture ed are exported live for fattening and slaughter voersease
- many animls are sold to live cattle exprot trade during our dry season, which reduces overstocking, pasture degradation and land degradation
- Why live exports? many asian countries ad market places lack refrigeration and animals are slaughtered daily and the meat is sold fresh. In Asia, agricultural and industrial fod by-products are feed or utilized in the feedlots such as cassava, rice bran and brewery by-products
Location of Beef, Sheep and Beef/sheep areas in Australia
- pastoral enterprises (grazing) are especially suited to Australia's mainly arid climate and infertile soils (as there is not enough rain or irrigation for crops)
- grazing livestock (ruminants) can utilize the available grass/plant cellulose and turn it in to valuable food and fibre (meat, milk, wool/fibres and leather)
Livestock Resources
- Beef: 26 million head, QLD has 44% of the national herd
- Dairy cattle: 2.6 million, QLD has 12% of Australia's dairy herd
- sheep: 80 million head, QLD has 10% of Australia's shep
Sheep distribution:
- 10 million sheep(most merino, producing medium/strong fibre wol of about 24 microns) are located in the mid west and far west of QLD. MOstly in the 250-550 mm rainfall zone.
- This distribution is due to pasture type: particularly the presence of spear grass which penetrates the wool and meat, as well as wild dogs/dingos
Cattle distribution
- production is constrained by variable rainfall and heat
- the variability of rainfall correlates with fluctuations in pasture production in addition to the regular nutritional deficits that occur in the dry season due to pastures haynig off (becoming dormant, dry, dead, nutrients lost from leaves)
Constraints on Cattle Production
- infertile soils, low in phosphorous and nitrogen
- tropical grasses have low digestibilities and low feed value once mature, tropical grasses mean digestibility is about 58%
- the total rain fall and its variability (which, aforementioned leads to variations in cattle production)
- some properties are less than 50% bos indicus (tropically adapted cattle)
- large property sizes can be difficult to manage
- woody weeds such as rubbervine or prickly acacia. These shade out pasture, lower pasture and animal production and cost money.
- sometimes the cattle are so poor by october that they cannot be mustered.
- shortage of experienced and reliable labour
- owner managers lack the financial skills
- remoteness and cost of inputs, marking and information
- infertile soils that are particulraly low in phosphorous and nitrogen resulting in limited pasture and livestock production: most soils lie in the following ranges- pH: 6-7.5, carbon is low at 1-2%, Nitrogen is 0.06-0.2 (0.1 is low, 0.25 his high), Phosphorous is 1-30ppm (1 is low, 30 ppm is good)
Importance of Grazed Pastures
- the economic importance of grazed pastures is matched by the critical role they play in maintian landscape stability and especially ground cover, protecting the soil from erosion.
- native and sown grasslands cover about 63% of the Australian landscape: in QLD, native pastures are a major feed resource for livestock and account for about 96% of the total area involved in primary production
14 major Native pasture communities of QL
- native pastures sparse or basent (4.4 million ha)
- blady grass (imperata cyindrica) 2.7 million ha
- black spear grass (heteropogon contortus) 25 m ha
- QLD blue grass (dicanthium sericeum) 2.4 m ha
- brigalow (acacia harpophylla) 8.7 m ha
- aristid/brothriochloa 33.5m ha
- gidgee (acacia cambagei) 4.8 m ha
- mulga (A. anurea) 19.1m ha
- Mitchell (astrebla spp) 29.5 ha
- Spinifex (triodia sp) pastures 21.2 m ha
- Channel pastures (millets, Mitchell, Native couch, panics) 5.4 m ha
- blue grass-brown top (dicanthium spp and elalia fulva) 5.6 m ha
- fire grass (schizachyrium spp) 9.4 m ha
- native sorghums (sorghum spp) 1m ha.
- Most of the native pastures and cattle are in savanna and rangeland areas
- savannas are defined as a continuous stratum of rasses, sedges and herbs that may contain shrub or tree species at varying densities but sufficiently dispersed so as not to influence grass growth to a major extent. Other definitions in the past described a savanna as being a land without trees but a lot of grass.
- Savannas are among the areas of the world with the greatest physical potential for increasing agriculture and animal production
- the term rangelands can be defined as a semi-natural ecosystem in which man seeks to obtain a productive output by simply adding domestic stock to a natural landscape. He/shee does not plough or fertilize; the natural plan communities form the bases of their enterprise. So the two terms do overlap.
- savannas/rangelands may contain more than 100 species of grasses and forbs but usually fewer than 10 specie provide most of the standing biomass and productivity.
- Forbs, especially legumes, may supply very hgih quality fodder but are usually not present in sufficient abundance to become an important component of the animal diet
- at the beginning o the rainy season, the new expanding leaves provide the ebst fodder. As the wet seasons porgress, the quantity (Dry matter, DM) of the grass increases but its quality decreases. With an increase in the amount of silica and hardened tissuesin the fodder.
- with the onset of the dry season, aerial biomass starts to dry out and dcompose and both the quality and quantity of fodder decreases dramatically, leading to low carrying capacity, livestock losing weight and low animal turn of.
- in the savannas, the quality and quantity of pasture changes dramatically throughout the year, producing a see-saw growth patern in cattle grazin on native pasture.
- on native pasture, cattle grow at about 0.2 kg/day, taking a long time to get big enoug to sell to very limited market, sown pastures can alleviate this problem
use of supplements to manage dry season feed deficiencies
- supplementary feeding for maintenance is a regular occurence in QLD
- as season starts to deteriorate, there is general an adequate availability of dry standing pasture or roughage
- pastures are initially deficient in phosphorou and sulphu, with a subsequnt decline in protein and digestibility as the season goes on
- molasses may be used as a carrier in a mix or to entice animals to lick it products include molasses plus 8% urea (M8U) and Molasses plus 10% vegetable protein meal plus 2% urea
- urea is not vera palatable and can be toxic, molasses enhances palatability and the aim is for cows to consume about 60g of urea per head per day.