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In The Paddock – Seasonal sheep flock management tips

‘In The Paddock’ is a monthly column that gives seasonal sheep flock management tips. It is emailed each month to growers who have provided their email address to Meat & Wool Innovation. Email us if you want to go on the emailing list.

May 2003 - Feed budgetting - An important item in the modern farm profitability toolkit

  • Feed budgets can be used to help improve anilmal performance and profitability
  • They enable farmers to plan for impending feed shortages and surpluses
  • Key parts of the budget are calculations of feed available and animal requirements
  • Feed budgets can be done on the whole farm and/or a paddock by paddock basis
  • An expert should be consulted for training when starting out
  • A computer makes the job a lot easier and quicker

April 2003 - Seasonal sheep and beef management tips
Supplementary feeds for sheep – Feed quality can be very important

  • ME levels are usually the best basis for assessing the quality of supplementary feeds
  • High quality feed is needed to assure ewe or lamb liveweight gains
  • Specialist forage crops have MEs of 12–13 MJ ME/kg DM if grazed at the correct growth stage
  • Grains have MEs of 12–13.5 ME/kg DM
  • Pasture silages and hay have MEs of 8.5–10.5. Most are suitable for maintenance feeding only
  • For supplementary feeding to be economic, feed planning or budgeting is essential

March 2003 - Management around mating - The key to optimising next year's lambing percentage

  • Put the rams out near the peak of the breeding season
  • Lambing date should coincide with the onset of the spring pasture growth flush
  • Ewes should have a condition score of 3 or better
  • Avoid taking weight off ewes between weaning and mating
  • Androvax can increase lambing percentages by about 20 per cent
  • Vaccinate against the abortion diseases toxoplasmosis and campylobacter
  • Rams must be fit and healthy

February 2003 - Beating endophytes – Grazing management and pasture renewal are the best solutions

  • Absorbent yeast and clay compounds may reduce ryegrass staggers and improve stock health.
  • Reducing intake of toxic ryegrass by grazing management or offering supplements, crops etc is beneficial.
  • Replace toxic ryegrass with AR1 ryegrass or a similar safe endophyte cultivar where possible.
  • Spraying/cropping or double spray/fallow reduces toxic ryegrass seed in the soil and ensures a safe pure sward is established. This could take two years.
  • Prevent the invasion of wild-type seed via hay/silage, dung, fleeces and machinery.
  • Selection for animal resistance to staggers may be a good long-term strategy.

January 2003 - Ryegrass endophytes – both friend and enemy

  • Endophytes are fungi that exist inside plants
  • They produce a wide range of compounds. The main ones are peramine, lolitrem B and ergovaline
  • Peramine helps protect plants from insect attack, especially Argentine stem weevil
  • Lolitrem B is a neurotoxin that causes ryegrass staggers in animals
  • Ergovaline lowers blood prolactin levels and causes heat stress
  • Some of these chemicals, in combination with other as yet unidentified compounds, depress intake and liveweight gain, and cause scouring and dags in sheep
  • Non-toxic strains of endophyte have been identified
  • The most promising, AR1, produces peramine and is commercially available. It protects the plant from insect attack and has no ill-effects on grazing animals

December - Thistles can be controlled – but there's no silver bullet

  • For control puroses there are two types of thistle - Californians and the rest
  • Annual and biennial thistles are best controlled by pasture management practices that encourage the maintenance of a tight sward
  • Topping, grubbing and herbicides also have a place in thistle control
  • Californian thistle can be controlled by regular rotational grazing, associated with the use of either topping or herbicides to deplete root reserves and weaken the plant

November 2002 - Ram buying tips – Rams have a definite purpose

  • Select rams which will produce profitable lambs
  • Performance recording is the only way to accurately identify genetic merit
  • Breeding values describe individual traits
  • Indexes describe the total genetic package
  • Genetic trend graphs indicate whether your ram breeder has adopted good selection practices
  • Select rams on index first, then on structure and appearance

October 2002 - Managing the spring pasture flush

  • 50–70 per cent of the year's pasture growth normally occurs during spring/early summer.
  • To maximise profit, as much of this pasture as possible should be converted into liveweight gain. To achieve this, the pasture should be of high quality.
  • Pasture surpluses need to be managed so the build up of low quality dead material is minimised. If pasture has a lot of dead material in it, lambs may not gain any weight.
  • The aim of grazing management should be to keep average cover from 1400–1800 kgDM/ha, or 4–6 cm, and to enhance clover growth.
  • Surplus late-spring pasture can be conserved as hay or silage, topped, controlled with low rates of herbicide, or grazed with cattle or weaned ewes.

Special edition (October 2002) - Orphan lambs: Artificial rearing can pay if the lambs would otherwise have died

  • In high fecundity flocks, about 25 per cent of triplets are either born dead or die before they are 12 weeks of age.
  • In severe storms, losses due to exposure and mis-mothering can be higher than this.
  • Orphan and triplet lambs, which otherwise would have died, can be successfully reared on fortified cow colostrum and meal.
  • The total cost is around $30/lamb (excluding labour). With prime lambs worth around $65/head, it is clearly economic to artificially rear such lambs.
  • It is not economic to remove small triplet lambs for rearing. If a ewe is capable of rearing its lambs it should be allowed to do so.
  • Artificial rearing requires good animal husbandry skills, and careful attention to hygiene and animal health.

September 2002 - Measurement of pasture cover

  • Monitoring pasture growth is a key to better livestock nutrition and greatly improved farm productivity
  • There are effective tools available for measuring pasture cover and these are now being calibrated for sheep pastures
  • By measuring how much pasture is present in a paddock, we can make accurate feed budgets, plan feed requirements and make better grazing management decisions
  • Pasture cover estimates need to be adjusted for seasonal differences in the amount of dead matter in the sward
  • Meat & Wool Innovation has set up PasturePlan, a nation-wide pasture measurement programme which will help farmers become familiar with pasture measurement

August 2002 - Principles of pasture growth and measurement

  • Ryegrass/white clover pastures are productive and tough
  • Optimum growing temperature ranges are 15–20 deg C for ryegrass and 20–25 deg C for white clover
  • Large regional differences in total pasture production are mainly due to climate
  • Seasonal growth patterns vary little between regions, with a peak in spring/summer
  • Optimum pasture growth occurs at pasture masses of 1000–2250 kg DM/ha

July 2002– Achieving target pasture covers in time for lambing

  • Careful planning is needed to get the correct pasture covers for lambing.
  • Too little cover at lambing will lead to underfeeding of ewes, low milk production and poor lamb growth rates.
  • Too much cover will result in an early decline in feed quality, and a drop-off in milk production and lamb growth.
  • To achieve target covers, you need to have adequate pre-winter cover and to adopt a slow (60–120 day) winter rotation. Strategic nitrogen use may also have a place.
  • Ideal target covers vary between regions, but in most cases pre-lambing covers of 1100–1400 kg DM/ha are appropriate. This equates to 2–3 cm pasture height.
  • Ewes with twins or triplets should be offered pasture at the high end of the range.
  • Ewes with singles can be offered pasture at the low end of the range. If pasture supplies are limited, feed for these ewes can be supplemented with grain.

June 2002 – Managing mid-pregnancy shearing

  • Mid-pregnancy shearing of crossbred ewes is becoming common as a means to increase lamb birth weight, improve lamb survival and wean heavier lambs.
  • Sheep should be shorn with winter combs. Lifters or blades may be necessary in some environments.
  • Shear ewes in mob sizes that can be adequately fed and sheltered.
  • Get shorn ewes onto sheltered pasture well before dark.
  • Covered yards and/or the woolshed should be available for emergency shelter.

May 2002 – Shearing crossbreds in mid-pregnancy

  • Thousands of lambs die soon after birth each year
  • By increasing the birth weights of twins and triplets, losses can be greatly reduced
  • Shearing crossbred ewes in mid-pregnancy (around day 70) can increase the birth weights of their lambs by around 0.4 kg and their weaning weights by around 1.0 kg
  • The birth weight response does not appear to occur in ewes which are very light (<50 kg) or very heavy (>70 kg). Nor does it occur in those with very low (<1–1.5) or very high (>4) condition scores.
  • Ewes produce about 0.2 kg more wool a year if they are mid-pregnancy shorn
  • To protect winter-shorn ewes from exposure, they should be shorn (depending on the region) with genuine winter combs, winter combs with lifters, or blades
  • They also must have good shelter and adequate feed after shearing

April 2002 – Big benefits from hogget mating

  • Hogget mating has high management requirements. It should be attempted only if these requirements can be met.
  • Ewes that lambed as hoggets have improved lambing performance as 2-tooths and for the rest of their lives.
  • Breed and/or strain of sheep has a significant impact.
  • Hoggets should be mated at around 40 kg at a condition score of 3 or better, using 2 rams per 100 hoggets.
  • Good growth rates after weaning are essential in order to achieve these targets
  • Vaccinate hoggets for toxoplasmosis and campylobacter before joining teasers or entire rams.
  • Aim for growth rates of 80–100 g/day from mating until mid-pregnancy and for a target weight of about 52 kg at lambing.

March 2002 – Facial eczema: an invisible drain on production

  • NZ pastures have a number of fungi that produce toxins that can markedly reduce productivity. Facial eczema (FE) is the most common.
  • While clinical FE is well-known and easily recognised, farmers are often unaware of major lifetime losses due to sub-clinical FE.
  • FE outbreaks can be predicted from weather patterns and FE levels can be easily monitored from pasture or dung samples.
  • In FE-prone areas, it is advisable to use rams that have been selected for FE-tolerance.
  • Zinc boluses, while expensive, are effective in reducing the risk of losses due to FE.

February 2002 – Condition scoring at flushing pays dividends at lambing

  • It is very hard to accurately judge the condition of woolly sheep visually
  • Condition scoring manually is a very useful way to judge the fatness of sheep
  • Ewes should not be losing body condition over the pre-mating and mating period
  • A condition score of 3 to 4 at this time of the year is recommended
  • Ewes should be given priority at this time to get good lambing percentages
  • They should be rapidly rotated into 5–6 cm pasture and not graze to lower than 3 cm.

January 2002 – Flushing ewes on silage: Protein is the key

  • Protein is the key to achieving a flushing/ovulation response in silage-fed ewes
  • A minimum of 12 per cent true protein is required
  • High DM wilted silage is better than low DM silage

December 2001 – Prepare lambs well and they'll thrive on forage crops

  • At current lamb prices the use of finishing crops is often profitable
  • Specialist forage crops, if grazed at the correct stage of growth, can provide a bulk of high quality feed when the quality or quantity of ryegrass pasture is low
  • Risks include possible crop failure, the lag time before the crop can be grazed and potential animal health problems
  • Animal health problems can occur with most fodder crops, especially brassicas
  • An acclimatisation period is essential when introducing sheep to brassicas.

November 2001 – Feeding weaned lambs for maximum growth rate

  • Wean lambs when pastures are grazed below 3 cm or at 10–12 weeks of age
  • Pasture quality is of paramount importance and should be mainly new green grass leaf and clover
  • Such pasture has an ME content of 11–12 MJ ME/kg DM and is more than 20 per cent protein
  • Don't try to utilise too much pasture in each grazing — aim for 25–30 per cent, and a post grazing level of 3–5 cm
  • In many areas a crop or special purpose pasture can provide high quality feed when pasture quality declines in summer

October 2001 – Managing pasture for maximum feed quality

  • Optimum quantity and quality of feed is needed for high levels of animal performance
  • Clover and green grass leaf are the quality components in the sward
  • Pasture quality declines in late spring
  • Grazing management at this time should aim to keep grazed pastures at 3–4 cm
  • Surplus late-spring pasture can be conserved as hay or silage, mechanically topped, or grazed with lower priority stock like cattle or weaned ewes

September 2001 – Ewes need priority feeding after lambing

  • Feeding levels at this time of the year will determine whether productivity targets are achieved
  • Single-suckling ewes should be fed twice maintenance
  • Twin-suckling should be fed three times maintenance
  • Feed quality is extremely important
  • Early weaning or creep grazing should be considered if feed is short

August 2001 – The late pregnancy countdown

  • Late pregnancy is a critical time for breeding ewes
  • Priority should be given to feed management so that ewe health is optimised and to ensure there is enough colostrum and early milk for lamb viability
  • Shearing and ultrasound scanning in mid-pregnancy are useful tools for improving lamb birth weights and survival. They also lead to other improvements in lamb production
  • After scanning, single- or multiple-carrying ewes can be run in separate mobs during late pregnancy for differential feeding
  • Shearing crossbred ewes with winter combs and lifters in mid-pregnancy can result in increased lamb birth weights and improved lamb survival.

July 2001 – Silage for the ewes

  • Pasture silage is generally cheaper than hay and is usually a higher quality feed
  • Breeding ewes readily eat ryegrass-white clover silage
  • Silage intake can be increased by wilting and/or chopping before ensiling
  • Baleage is a convenient form of silage
  • Good ewe liveweight gain can be achieved on pasture silage
  • Silage supplementation has a ‘pasture sparing’ effect, and helps with feed planning by reducing over-grazing of pastures
  • Improvements in wool growth can occur and if silage is used as a flushing feed, lambing percentages can be improved.

June 2001 – Ewe feeding in early- and mid-pregnancy

  • Start rationing feed by lengthening ewe grazing rotation. Feeding low quality supplements may help achieve this.
  • Feed well-conditioned ewes at maintenance — about 1.1–1.2 kg DM/day intake per head for a 60–65 kg ewe at condition score 3.
  • Preferentially feed light, poorly-conditioned ewes at about 1.3–1.5 kg DM/day intake per head.

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