Supplements
Owl Farm is considered a DairyNZ System 2 which imports approximately 10-14% of its total feed annually.
Total purchased feed of 368 t DM in 2020-21 was made up of 170 t DM silage and hay, 8.3 t DM molasses, and 190 t DM PKE (palm kernel extract). This is equivalent to 2.5 t DM/ha or 900 kg DM/cow.
At Owl Farm all supplements are fed in the paddock or on the races. We have no feedpad but have three PKE trailers, a silage wagon and two small molasses lick ball troughs.
Hay is used in the winter for springer cows. Winter stored grass silage is used to support early calved cows in August and PKE is used from start of calving until balance date to cover shortfalls due to wet weather or early removal of paddocks for cropping. Cows in the colostrum mob are offered calcium-enriched molasses along with PKE with magnesium oxide and limeflour. Cows in the hospital mob throughout the year are often supplemented with PKE to help increase intake (and support reduced walking distances by grazing paddocks close to the shed).
During summer cows are fed 4 kg DM of brassica crop, and then the diet is topped up to 16 kg DM/cow/day using up to 2.5 kg PKE/cow/day. Once empty cows have left the farm in late February, grass silage is used to top up the diet for the cows remaining in milk that meet BCS criteria. A small amount of hay is fed as the cows are dried off at the end of lactation.
Total supplements imported has reduced from 655 t DM in 2015-16 (producing 176,197 kg MS) to 368 t DM in 2020-21 (producing 178,125 kg MS). See graph below. Changes include the removal of maize silage and reduction in PKE, along with an increase in pasture silage purchased.
Our aim is to use supplements strategically to increase Pasture & Crop Harvested to 15 t DM/ha and achieve animal well-being outcomes.
While total feed supply has declined each year we have been able to produce more milk from less feed by focusing on the quality and strategic use of the feed, i.e. less used for maintenance and more for milk production. This contributes to lower methane emissions.
Imported supplements enable us to grow and harvest more pasture and crops on farm (as seen in the graph below). In winter and spring they are a tool to prevent overgrazing and pasture damage, and in summer they are used to maintain BCS and keep some cows in milk to utilise the autumn regrowth. We have produced more milk from homegrown feed by focusing on quality of pasture, crops and feed allocation management.
The cows’ diet is also supplemented with minerals and additives throughout the season.
- Cows are supplemented with magnesium from June to November. All cows receive magnesium chloride through the Dosatron; paddocks for springers are sprayed with magnesium sulphate, and magnesium oxide dusting is used for the milkers.
- Cows are supplemented with calcium while in the colostrum mob.
- Cows receive zinc, iodine, selenium, copper and cobalt throughout the year via the Dosatron.
- Bloat oil is administered from October until December, and zinc is used for Facial Eczema prevention from February until May (depending on spore counts).
