Shepparton dairy farmer Duncan Crawford has been fuelling his 800 Holsteins on corn silage from varieties PAC 606 and PAC 606IT for six seasons and he doesn't plan on changing the program anytime soon.
Mr Crawford said that is because it produces high quality, high yielding silage and the maturity is ideal.
"We've been growing PAC 606 and its replacement PAC 606IT for six seasons now under the two centre pivots," he said.
"We can hit our target of 23 tonnes per hectare of dry matter most seasons and it's great for putting condition on the cows.
"Having a CRM of 114 also maximises the growing period.
"So it gives us a chance to grow a decent crop and then get early autumn growth after harvest.
"There are varieties with a shorter CRM available, but we find the 114 maximises yield.
"When it comes off, it's not so late we can't sow the winter crop."
Duncan runs Fenton Hall with his wife Emily and father Ross.
They milk the 800 cows on a 60-unit rotary with auto draft.
They also grow wheat for silage, lucerne, perennial ryegrass, Italian ryegrass, and buy in grain to supplement the diet.
Mr Crawford said they run three 1000t earth bunkers at the property with one for pasture, one for lucerne and one for corn.
"We aim to plant the corn in early November and harvest in March," Mr Crawford said.
"Then we have feed in the bunkers to supplement the herd over winter."
Last season, the farmers stuck to that window, seeding 47 hectares of PAC 606IT in November with chicken manure into a paddock out of Italian ryegrass that was strip tilled before sowing.
Mr Crawford said it was a hot, dry season, with tight water allocations to go with it.
"It was a terribly dry, awful, hot summer season and it was a pretty tight year for water too," he said.
"Luckily enough we filled our cobs."
Shepparton received 28mm in November, 37mm in December, 7mm in January, 7mm in February and 5mm in March - a growing season rainfall total almost half that of the annual median.
Each month's annual median temperature was also exceeded in that period, making it tough going for the corn.
Despite all this, the family harvested the corn at the end of March and averaged 22t/ha dry matter from the 47ha block.
"Getting close to our usual 23t/ha dry matter target was pretty remarkable given how harsh the season was," Mr Crawford said.
"In the best seasons we can get the 606IT to push 26t/ha dry matter.
"The 606IT, having the IT gene, also gives us the option to spray Lightning herbicide in-crop to tackle weeds."
The paddock has now been sown to wheat, which will produce silage, and the Crawford's will sow their seventh season of PAC corn in November.