Friday, March 29, 2024

Challenges but chances to improve

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It’s been a tough season so far for Owl Farm at Cambridge, the joint venture between St Peter’s School and Lincoln University.
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“There’s been a lot of uncertainty,” demonstration farm manager Doug Dibley told about 400 farmers attending its third field day in mid-September.

“It’s been a challenging couple of months but a good opportunity to pool resources and mould our systems to look for the profitable and sustainable results we’re all after. We are hurting as all farmers are with the payout.”

The 160ha effective property is made up of 137ha of land owned by the school and 32ha of leased land. Last season it milked 453 cows producing 201,000kg milksolids (MS), rearing 150 calves and grazing 104 heifers. A total of 471 cows were wintered on the farm set-up against the Lincoln University Dairy Farm model with the aim of applying proven research in a commercially viable way.

Calving date was brought back this year from July 7 to July 1 after good pasture growth rates were identified in winter. The aim was to capture that feed quality at an early stage while increasing the herd’s days in milk. 

But the weather this year meant milk production was lower than anticipated. There was an initial boost of more than 85% on last year’s July figures, because of the earlier calving but that came to a sudden halt in August when cold and wet weather meant slow growth rates, dropping milk production to 13.4% down on last season’s total for that month. 

By mid-September that month’s milk production was 14.4% down on the same time in 2014, meaning a 3% drop for the season to date. 

Owl Farm hoped to recapture lost production in the coming months by maintaining the current pasture grazing management. The season started with a 90-day round but covers dropped through the unusually cold and wet July and August. The stock had been kept tight as the farm kept to its spring rotation planner, with the future plan to identify pasture surpluses early and shut-up paddocks for silage.

Dibley said it had been a reasonably challenging calving with 90% of the herd calved in the first week. One cow had died from milk fever and there was one vet-assisted calving but generally few calving-related complications. The herd had averaged a body condition score (BCS) of 4.8 for cows at calving and 5.1 for heifers. This gradually dropped to BCS 4.6 and 4.5 respectively, which had been consistently maintained for the past six weeks. Both groups were starting to cycle well after a slow start.

After milk production got away to “a hiss and a roar” the farm was still waiting for balance date to come on September 16. Cows had hit 2kg MS/day and it was hoped they could maintain this level for a couple of weeks. 

Pasture growth rates that were 42kg drymatter (DM)/ha/day at the end of August had dropped to 37kg DM/day/ha in early August and 34kg in mid-September. Cows were being fed from 16-17kg DM/day of pasture supplemented by up to 6.5kg DM/cow/day of palm kernel earlier in the season, reduced to 1.5kg DM/head and due to cease altogether in late September.

Ballance had done pasture sampling that showed some deficiencies so was followed up by liver biopsies. Low selenium levels in the cows saw the entire herd receive a selenium pour-on. Low copper levels in the heifers had now been treated with long-acting copper boluses.

Applications of 150kg nitrogen/ha were planned for the season with one complete round of 33kg already applied.

“We’re ready to go,” Dibley said.

“We just need a week of good weather and we’ll be away laughing.”

The next field day at Owl Farm will be held on November 25 but in the meantime farmers can check its website, www.owlfarm.nz, or the Facebook page where the latest data is loaded up at the start of every week.

 Cull or cure?

Computer modelling work has shown the best option for Owl Farm to manage this season’s low milk payout would be to dry off about 100 of its heifers and light cows at the start of February.

Working on the basis that these animals were eating about 7kg DM/day during February and March they would start to regain a small amount of condition after drying off. This would allow the whole herd to reach BCS 5.0 by May 31.

Another benefit would be that supplements would be more efficiently used by the remaining milking cows, which would also be receiving slightly more pasture.

AgFirst consultant Dave Miller told a mid-September field day at the farm that it was already performing well, with its cows producing more than 400kg MS/cow, and is predicted to come close to 450kg MS/head this season. Farm working expenses (FWE) stood at $3.89/kg MS.

“But we are looking at some refining,” he said.

The farm was committed to buy in 300 tonnes of palm kernel so it was decided with the four scenarios looked at not to reduce that. This has been fed through July, August and September at levels from 4kg DM/cow/day up to 5.3kg. It will be fed again in February, March, April and May at 2-3kg DM/cow/day.  

The farm is forecasting 125 tonnes DM of maize silage to be bought in from leased land that will be fed at 2kg DM/cow/day in February and March and 1kg DM/cow/day in April. Owl Farm expects to make about 18ha of pasture silage on the farm which it will feed out in January and February at rates from 1.7 to 2kg DM/cow/day. Chicory from 14ha grown on the farm will be fed in December, January, February and March at rates starting at 3kg DM/cow/day and dropping to 2.4kg DM.

All four scenarios were run through Farmax on pre-graze pasture levels of 2140kg DM/ha at June 1 and 2250kg DM/ha at May 31 next year, with cow condition expected to be similar at the end of the season.

The first scenario compared with the base file was early culling, which would see 27 cows culled at the end of November and another 40 on February 10 after pregnancy testing. The final 17 would be culled in April at the last stage of this strategy to reduce total feed going into maintenance and to preserve cow condition on the rest of the herd.

This option showed milk income lifting from just short of 206,000kg MS to 207,294kg MS, a 1368kg increase. Total revenue increased by just over $8000 and FWE dropped by $8657 giving an economic farm surplus (EFS) boost of $16,743 and a farm profit before tax lift of $105/ha from $541 to $646.

The second and most profitable option would dry off 100 heifers and light cows at February 1. While they would remain on the farm cow condition would be preserved, so less feed would be required for rebuilding condition at the end of the season. With the farm’s lighter soils drying out in summer this option meant milking cows could be looked after more and provided with extra feed throughout autumn.

Milk income lifted by a little more than 2600kg MS, with total revenue increasing by $15,414 to $915,521. FWE dropped by $10,429 giving an increase in EFS of $25,843. At a farm profit before tax increase of $162/ha this was the strongest result of the four scenarios tested.

The third aimed to preserve cow condition by putting the whole herd on once-a-day milking from September 30. It was estimated they would be on average 0.4 BCS higher under this strategy. A benefit was that 60t of maize silage could be carried through to the next season and staff numbers were maintained as with other scenarios.

“There was a reasonably high hit on production,” Miller said.

This dropped by 11,695kg MS to 194,231kg. Total revenue was down by $25,826 to $874,281, FWE dropped by $1065 to $812,421 and farm profit before tax by $155/ha to $387/ha.

The fourth and last scenario looked at calves being kept at home. Instead of going off to grazing in December, 92 of them were kept at home, saving $9/calf/week or a total of $20,493.

This option saw milk production drop by 5765kg MS to 200,161kg because calves were fed on pasture that would have gone to the milking herd. Total revenue dropped by $25,211 to $874,897. FWE dropped by $21,049 to $745,877 and farm profit/ha before tax came back by $26/ha to $515.

Miller said the challenge was the increased calf demand for feed as any summer dry began to bite and making sure they were fed well compared with the cows. The scenario assumed the calves’ growth rate wouldn’t be compromised but there was a temptation to favour cows over calves if both were onfarm.

Farmers at the field day questioned why the most profitable scenarios, the first two, weren’t run together. Miller said that could be looked at as part of follow-up work. 

Consultant Jim Findlay asked whether milk production from heifers dried off early could be affected in subsequent seasons. DairyNZ researcher Chris Glassey said its research had shown no evidence of any impact and Miller said the risk of taking thin heifers into the next season was probably greater. 

He said farmers should look to take control of something they could control, but emphasised that figures produced from the modelling exercise would change on other farms depending on their feed costs and contracts, expected cow performance and onfarm conditions. Farmers should work with advisers to determine the best way forward.

Owl Farm demonstration manager Doug Dibley said it was still a month or two early to make a call on which of the strategies it might use.

“Management is sticking to its guns with what we are doing,” he said.

“There will be no knee-jerk reactions. We want to see what will happen with grass growth and GlobalDairyTrade prices.” 

Making money by managing residuals

New Zealand dairy farmers are only getting their pasture residuals right half of the time, DairyNZ researcher Chris Glassey says.

That meant that in Waikato they could be missing out on $199-$333/ha of operating profit at a milk price of $3.65/kg milksolids by not assessing pasture covers and the resulting poor feed management.

“There’s plenty of good ways of filling the vat but that doesn’t necessarily tell you what’s going in the bank balance,” he told farmers at the Owl Farm field day.

Julia Lee – target the second and third leaf stages of growth.

Many decisions farmers needed to make would be about compromise, he said.

“Don’t get on to a fast rotation too early. The farm has still got to feed the cows if you have a limited amount of supplement so you could be jeopardising that.”

There was also the risk of going too slow at this time of year, which meant pasture quality declined. A good rule of thumb was farmers should be able to find golf balls in a paddock with residuals that hit the target of 1500kg DM/ha.

It would pay farmers to be on a rotation of more than 25 days in mid-September so they didn’t shade daughter tillers out and affect future production.

Owl Farm demonstration manager Doug Dibley said a tow-behind pasturemeter was used every Tuesday. He admitted with some residuals hitting 1400kg MS/ha the farm could be guilty of overgrazing. Because there was usually strong grass growth at this time of year the preferred option was to feed palm kernel rather than apply nitrogen. 

“But we are on a journey here as to how to manage pasture quality,” he said. 

“We’re about to start topping in front of the cows.”

Glassey said topping had to be low enough to take off the reproductive stem of the plant, which was often not the case.

Another option was deferred grazing but this had to be managed well to get the benefits. Despite pasture quality declining as surplus feed was rolled forward it was better than doing nothing.

DairyNZ has produced a paddock guide for perennial ryegrass grazing management in spring, detailing the optimum time to graze, target pre-grazing yields and target residuals. Researcher Julia Lee told farmers they should ideally be grazing when their pastures were between the two and three-leaf stages. 

This was because the first contributed only 15-25% of the total amount grown to the three-leaf stage while the second and third leaves contributed 30-40% and 40-50%. If plants were grazed before the two-leaf stage energy could run down, which affected their persistence.

“When the fourth leaf is growing the first leaf is beginning to die,” she said.

An average tiller lasted a year but grazing below 1500kg DM put it at risk.

“You can do it once without any negative effect but if it happens multiple times the effect builds up.”

There was no difference when it came to diploids and tetraploids but tetraploids could be readily overgrazed by cows with yields and persistence reduced. And if pastures were at or near canopy closure stage they needed to be grazed or conserved regardless of the leaf stage, since this reduced the pasture density and clover content and increased stem production.

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