Community Group day five summary

Hitting pre-winter targets

16th March 2011

Overall situation

The last year has been a difficult one with extreme dry, followed by extreme wet with associated stock deaths, returning to extreme dry.  Very little grass has grown and despite 100mm of rain over January and 50mm in February, the ground is still dry.

In the year to February 2011, annual pasture growth as determined from pasture cage cuts was 9.9T dry  matter. Given that the cage cuts are about a 20% overestimation of whole-farm pasture production,  about 7.3T were available to stock.

To minimise the impact of the dry, the Wishnowskys kept quitting stock as the rain stayed away. This allowed some prioritisation of ewes, hoggets and cows. Other ways this priority feeding has been achieved include: rotation planning, crop allocation and investigating off-farm grazing. With the decisions made so far, the feed budget looks better than it did.

Sheep

Ewes were set-stocked with lambs at foot in November and were weaned in early December. This was almost three weeks early but was a good decision as cull ewes were sold and the lambs could go onto crop to finish. 265 lambs were sold off mum, with 280 finished in January, half off grass and half off pasja. The pasja finished another 115 during February.

The ewes will be mated on the first of April. Their body condition was an average of 2.7, with 44% being BCS 3 or more. The lower half needs to do 200g/day to be in BCS 3 or more at mating. In adult ewes it is difficult to put on more than 150g/day. Getting ewes to BCS 3 at mating will have a 43c/kgDM return!

There is little benefit in feeding ewes well if they are BCS 3+. However, they should be maintained on a rising plane of nutrition, especially for the 10 days before mating and 10 days after the start of mating.  Having ewes at BCS 3 at mating not only improves conception rate but is also insurance that ewes will not lose too much weight over winter. Most ewes lose half a condition score over winter, a whole BCS in a bad one. It would be beneficial to draft the light ewes out, drench them and feed them well. All ewes should receive 5mg selenium pre-tup to ensure selenium is not limiting to conception.

180 two-tooths were bought in mid-February. They are ½ Perendale, ¼ Finn and ¼ Texel. They came from near the Whanganui River and were bred by Minda Hills rams. To preserve two-tooth ongoing performance, they should be weaned early, so are being bred to a terminal ram. Mating date will be the 10th of April. Both the two-tooths and hoggets were vaccinated for toxoplasmosis and campylobacter. 

Ewe hoggets

The ewe hoggets were shorn mid-March at which time they were an average of 34kg (range 26-46kg).  They look good and have been maintained largely on the plantain/clover crop. Only ewe hoggets over 40kg will be mated on the 1st of May (requires 115g/day live weight gain average). The hoggets will be mated for the first time this year as part of the self-replacing sheep flock on this farm. 

Cattle

The yearlings were sold in December to make room so other stock could be prioritised.

Cows were mated in four mobs - two Limousin mobs and two cross-bred mobs. The cross-bred cows were put to a Charolais bull. Weaning will occur in mid-April with the majority of the cross-bred calves sold, as well as the Limousin steer calves. The lighter weaners and Limousin heifer calves will be kept and fed on saved pasture.

After pregnancy testing, those cows that are calving late may go away for grazing in May to return in August. Empty and old cows will be culled at weaning. Cows were joined with the bull on the 1st of December for three cycles. This calving date may seem late but is well suited to the country

Off-farm grazing is being investigated for the late calving cows. Some of the cows are too light at the moment. Next year's performance will be determined by their condition going into winter. The number of calves weaned is more important than the weight of the calves in terms of farm profitability. Also, skinny cows going into the winter and being underfed are more likely to die.

Cropping/regrassing

The cropping programme was behind schedule due to the extreme wet in September. The ground then became too dry and many crops were not sown until November, with some going into the ground on Boxing Day. The crops have been very weedy this year and the yields lower than expected, except the pasja crops which have done well.

The rape crops are ready to graze. Some lambs will be purchased in the next few weeks to utilise these.  The Spitfire rape has the best growth, followed by Goliath and Titan.  The spitfire yield is estimated at 4.6T/ha; with 85% consumption, this is approximately 3.8T. The Spitfire and Goliath crops will be lightly grazed now then saved for winter crop. Brassica crops respond well to nitrogen e.g. a 30:1 response.

The spring grass paddock was a disaster grass-wise although the clover established well.. This will be oversown with Moata. The pasja paddocks will be sown in new grass at the end of the month. The plantain is growing well and the hoggets are performing well despite the failure of the clover. Clover and fertiliser may be added to this crop in the spring. It probably produces 9-11T each year but may need grass drilled in within the next few years.

Technical topics

Measuring pasture cover

Farmax have designed a pasture sward stick that has been calibrated by large amounts of data from AgResearch. These are simple to use and if used consistently, will give a pasture cover reading that can aid grazing management decisions.

Points to consider when doing pasture cover readings:

  • Farmax have shown that measuring the average cover in 40-50% of the paddocks on the farm, with 6 measures per paddock, consistently gives an average cover within 100kgDM/ha of the ‘true' average cover
  • Have a plan before you set out:
     - Measure hills and flats
     - If measuring only part of the farm, measure the average paddocks
     - Consider measuring blocks of the farm each time
     - If on rotation, measure pre-grazing and post-grazing covers, next time you go back to the pre-grazing paddocks and re-measure, you can then derive pasture growth rate for the period
  • Measure consistently e.g. use a clipboard with the farm map to measure off each time

Sward sticks can be used to calibrate your eye but keep revisiting the sward stick to check yourself. Pick a system that is quick and consistent and suits you.

Hogget mating

Once a hogget has ovulated, had a lamb and reared a lamb, its lifetime performance will be higher. Teasing hoggets is very important - put the teaser in precisely 17days prior to the ram date. Harnessing the teasers is a good way to see the spread of cycling and to choose replacements.

Sire choice is important. Remove the hybrid vigour factor to limit lamb size by using the same breed or the hogget's brothers. The hogget must be heavy - a minimum of 40kg is desirable.  Limit mating to two cycles. Parasite management should be implemented during summer-autumn and again pre-lambing.  Hogget lambing has a big impact on profitability but it must be well managed.

Toxoplasmosis and campylobacter - Roger Marchant, Intervet Schering-Plough

Over 40% of New Zealand farms have had a toxoplasmosis abortion outbreak. Cats are an integral part of the lifecycle of this parasite, as when they are infected they shed the infective oocyst in their faeces e. g. 10,000,000 oocysts in 10g of cat faeces, when it takes only 500 infective oocysts to cause abortion.

100% of farms and 80% of mixed-aged ewes had been exposed to this disease in a serological survey. However, at mating most hoggets are still naïve. Infected sheep that haven not been exposed to toxoplasmosis abort, resorb the pregnancy or give birth to non-viable lambs. 

The toxoplasmosis vaccine, Toxovax® is a very effective vaccine. Natural exposure occurs mostly between February and June. With natural exposure, the sheep must mount an immune response and will not be protected from abortion for approximately 40days. The vaccine gives a much faster response. Because of this, it is recommended to vaccinate well before mating. Only one vaccination is required for life.

Campylobacter also causes abortion in sheep in New Zealand. 80% of farms have been exposed. This disease is spread by aborted foetuses, discharge from aborting ewes and carrier ewes.  Campylobacter abortions can occur throughout pregnancy, including early pregnancy, so vaccination should be completed prior to tupping. This vaccine requires two doses four weeks apart.

The importance of nutrients - Alec Mackay, AgResearch

The bulk of hill country pasture growth is driven atmospheric nitrogen  fixed by clover, which is required to drive the bulk of pasture growth. To perform well, clover legumes require water P, K, S, trace elementsTE and lime. Legumes are less competitive for P than pasture so require high P levels. However P levels have a ceiling level of production.  On easy country, P levels of 20-25 are desired, and on steeper, harder country <20 is usually adequate.

Ballantrae High Fertility (HF) v. Low Fertility (LF) Long-term Farmlet StudyLong term fertiliser & sheep grazing study

  • Farmlet LF - 125kg super phosphate (SSP)/ha/yr since 1975
  • Farmlet HF - 625kg SSP/ha/yr 75-79, 1250kg lime 1975, 2500kg lime 1979. Since 1980, HF 375kg p/ha/yr
  • LF 6 - 9TDM/ha, HF 6 - 11TDM/ha
  • Stocking rate: LF 10su/ha, HF 16su/ha (set stocked year round)
  • Olsen P was initially 6-7. LF 11, HF 55 2004.
     - 125kg SSP to run 10su/ha annually
  • High fertility block:
     - Increased pasture growth, especially autumn
     - All slopes and aspects grazed more readily
     - White clover and ryegrass contents increased
     - Easier to control covers and quality
     - Less reversion of scrub

System will respond to nitrogen all year round but the biggest response is seen in spring and summer when there is plenty of light around and it is warm.  The nitrogen response is not impacted by P level but in low fertility soils there will be a response by browntop rather than high fertility where you will get a response in ryegrass and clover. Even with lots of legumes, systems are still responsive to N.  Nitrogen can be a planned tactical tool.