Ruminant nutrition Flashcards
Why does NZ use an extensive pasture production system?
- We have suitable/fertile soil.
- Enough sunlight and rainfall.
- Temperate climate Animals can stay outside 365 days of the year.
- Low input system less production costs/cheap.
What are the main types of pastures used in NZ?
NZ uses a mix of forages • Mainly perennial ryegrass & white clover. Supplement forages • Forage herbs – chicory & plantain. • Legumes – Lucerne & red clover. • Summer – turnips. Winter – Swedes & kale.
How does seasonality affect pasture growth?
Highest pasture growth is in SPRING , when there is the most rainfall and adequate sunlight.
Lowest pasture growth is in SUMMER and WINTER –
• Winter – too little sunlight + can be dry.
• Summer – too much sunlight, not enough rain.
• Spring – highest pasture growth – adequate rainfall and sunlight.
• Autumn – Waning pasture growth.
How does land topography and location determine land use?
Flatter areas tend to have more moisture – so yield highly, and enables easier movement of dairy cattle to and from milking.
Hillier/drier areas – Less interaction with Beef and sheep. Don’t have high daily productivity issues – so can survive on less volume of grass.
Alpine/tussock – Merino sheep – prefer dry colder climates.
What the challenges with the seasonality of pasture?
Pastures yields change month – month, and year – year but generally -
• Deficit in summer
• Surplus in spring
The upper limit of annual pasture growth in NZ is a limiting factor for production yields (meat/wool or milk).
How does the annual herbage production vary between production systems?
Dairy farms – require the highest level of supplementation + intensively graze the pasture >12 T DM/ha/yr
Lowland/finishing sheep + beef –
• Don’t use as many crops – removed during dry, and graze and use surplus spring growth during lambing/calving - ~9 T DM/ha/yr
• If using farm for finishing – grazing intensively and using more crops - ~14 T DM/ha/yr
Extensive sheep and beef hill country – Grazing is restricted during dry periods – may SR – less crops grown – 6-10 T DM/ha/yr
Why is it important to match feed supply and feed demand?
To match high pasture growth with periods of increased animal feed demand so production is not reduced
• Lactation during spring – high ME demand.
• Growth of offspring through spring + summer
• Adequate energy for cycling (dairy cows).
How can we ensure optimum feeding levels are maintained despite pasture variation?
- Grazing management (rotations etc)
- Conserving pasture in silage/balage/hay
- Fertiliser application
- Crops (maize, cereals, lucerne, brassicas etc)
- Concentrates
- Change stocking rate.
How do we ensure efficient utilisation of pasture year-round?
In periods of surplus – High SR so no wastage
Timing events with pasture variation
1. Calving, lambing when high PGR (helps pasture quality for summer).
2. Weaning when still high PHR for GR – so can sell for summer.
3. Ensuring LW targets are met for sale dates.
4. Drying off or 1xday milking when feed .
5. SR
What are some key performance indicators that we can use to assess feeding levels?
Lactation - Total MS yield/cow, daily yield, peak yields, Milk composition & Somatic cell count
Reproduction – Submission rate (% of cows that are inseminated once after a specific period of time e.g. 3 weeks/6 weeks), Conception rate (% of no. of cows/number of services) Empty rate, 6 week in calf rate (% of cows in calf within 1st 6 weeks of mating),% of young born/weaned/docked
Offspring growth – Average daily gain (g/day), no. of days to weaning, weaning %
Meat yield – Carcass weight, Killing out % (carcass weight/LV).
How can the quality of pasture be maintained?
Sward must be maintained in its young vegetative state in order to regrow
• Rotational grazing – to prevent overgrazing , and ensure pasture eaten is young and leafy.
• Monitoring pre + post grazing residuals dictates SR and rotation lengths.
• Meet residual targets (3-5 cm from ground)
• Conserving surplus pasture in silage – prevents dead matter.
• Topping
• Fertiliser
Why is the quality of pasture important?
Good quality pasture i.e. leafy and young DE% and protein.
Old, dead and stem pasture fibre and DE.
ENERGY IS 1ST LIMITING INGREDIENT.
Why is quality of pasture important for animal performance?
The higher the quality, the higher the energy content.
Optimum energy levels needed for maintenance and good performance in different physiological states.
If quality of pasture declines DE, and animal cannot consume enough to meet demands.
Why do extensive dairy systems not yield as much as intensive?
Milk + meat yield pasture growth + composition.
15-20% DM, fibre and have to consume a lot to meet higher yields.
Why should supplementing feed be carefully considered?
Supplements - DE, but cost. The profit from feeding crops must exceed the costs of planting Supplement choice is dependent on Cost per unit of ME Production risk Availability of paddocks and equipment Time/labour/experience.
