The discovery of bovine TB in Hawke’s Bay threw Owl Farm’s heifer grazing plans up in the air. Their grazier lost access to grazing for over 1000 heifers, including the 90 calves from Owl Farm. They then had to rethink this season’s heifer management strategy.
The simplest solution would have been to find alternative grazing off-farm, but this proved challenging, with fierce competition from other operations in the same situation.
All was not lost though, as analysis of their on-farm options led to the development of some viable alternatives.
“Making sure our milking herd was not impacted was fundamental to our strategy,” says Jo Sheridan, Owl Farm Demonstration Manager. “We didn’t want to reduce our herd numbers or their feed allocation. So, it was a matter of investigating how we could provide the extra 3 kg DM/ha/day the calves would add to our daily demand over the summer months.
“Aside from the extra feed demand, we also had to factor in the extra demands on labour and infrastructure, and in summer the calves will need feed that contains more energy and protein than our pasture can provide.”
“In our opinion, the benefits of having them at home outweighed any drawbacks,” says Tom Buckley, Owl Farm Manager. “We have a support block adjoining the milking platform that is not ideal for the milking herd – it is further away from the shed and we find we don’t get good pasture utilisation when the cows graze there; it will suit the heifers better. We were going to use it for silage, so we have bought silage in instead to free the land up. It will also give us the chance to use the heifers to graze our new grass in autumn, which went really well last season, and we can carry out an analysis of calf growth rates on a summer crop to share with the industry.
“I’m excited about tackling the challenge, and it means we will be able to keep a close eye on our heifers – weighing them regularly and checking they are on track to meet LIC’s MINDA targets, carrying out vet checks when we need to, and intervening with farm feed or bought-in feed if the summer is dry again.”
“It is a great chance to involve St Peter’s School students in a new learning opportunity too,” adds Sheridan. “Some of the students adopted a calf in spring, now they will be able to follow them through the whole season, and be involved in regular activities, like weighing.”
The alternatives they came up with included buying in feed – silage and PKE, and/or planting a specialist crop that would fill the summer gap – either chicory or a brassica crop, such as forage rape or the new forage brassica, Pallaton Raphno, developed by PGG Wrightson Seeds.
After pulling their options together with the help of a variety of tools, including DairyNZ’s Facts and Figures, they ran the different scenarios through Farmax to test them out. The end result was a decision to plant Puna II chicory.
Kyle Gardyne, from PGG Wrightson Seeds, helped with the decision-making process. “They could have gone with a grass system, but, although it would be low cost, they would take feed away from the milking herd.
“Owl Farm has a lease area next door where they have the opportunity to grow a crop that isn’t a part of the dairy platform; because there is such a large area to crop, around 4 ha, it lends itself to chicory. They can set the heifers up in a rotational grazing system on chicory, supplemented with 20-30% silage. This will create a complete diet for growing young animals, as chicory is such a high quality, high protein feed (11.5-13 MJ ME/kg DM, CP 20-26% DM). If there was less area available they could use a high yielding brassica crop and strip graze it. A benefit of brassicas would be a reduced cropping area – not so many hectares out, but because they have that amount of land available to them it makes sense to utilise the full area for chicory.
“Chicory will give an exceptionally good growth rate over the summer, whereas a grass-only diet may not deliver a desirable liveweight gain. Also, the heifers won’t be grazing pasture in the summer, so their exposure to facial eczema is greatly reduced. In terms of negatives, it is more of an intensive system, there is more to do, break fencing every day or two. There is the feed cost too, they do need adequate fresh water and silage every day.”
Although the switch to on-farm grazing will fit the bill this season, long term the intention is to continue grazing the heifers off the farm. However, successfully grazing heifers at home will broaden their options, and give them additional flexibility to shift with changing circumstances in future seasons.
Owl Farm holds regular field days, so there is always the opportunity for dairy industry people to visit and hear about how they are progressing this season, including with their new heifer policy. There are two more field days scheduled this year, on 16th and 17th December. Otherwise, people can learn more through the regular updates on Owl Farm’s Facebook page.
