Extreme heat this season has dented Lincoln University Dairy Farm’s peak milk flows, cutting production by 15 per cent.
Budgeted to produce 295,000 kilograms of milksolids, LUDF now expects to finish the season at 250,000kg. Milk production per cow will be 448kg, back from the expected 527kg.
A combination of weather extremes, irrigation breakdowns and a spread calving caused the production shortfall, said South Island Dairying Development Centre executive director Ron Pellow. This generated challenges with maintaining pasture quality and milk production on the 160 hectare fully irrigated milking platform near the university campus.
“Clearly cows did not peak as they have in past seasons. Production dropped significantly at two points in November and December – coinciding with the hot weather and then again from early March until now.”
Milk prices had risen to a forecast $6.55 a kilogram of milk solids, compared with a budgeted $6/kg, to cushion the financial result, which was 7 per cent below budget.
A new management system was introduced at LUDF from the 2014-15 season to reduce the farm’s nitrogen loss to the environment while still remaining profitable. It did this by reducing its herd size and concentrating on higher per-cow production.
Despite reducing its imported feed and nitrogen fertiliser use, LUDF had until now maintained profitability through better matching of its stocking rate to feed supply. Nitrogen use was 178kg/ha this season compared with about 300kg/ha between 2011 and 2014.
LUDF’s forecast nitrogen-leaching losses for the 2017-18 season were 28 per cent lower than the farm’s 2009-2013 baseline loss figure of 60kg/N/ha. This puts it close to the 30 per cent cut in baseline figure required by 2022 for Environment Canterbury’s Selwyn-Waihora water management red zone.
In a trial, sexed semen was used in the first week of mating, which was brought forward one week earlier than normal. “Sexed semen historically has lower conception rates than fresh semen options, but it gives a higher probability of producing heifer calves. When we can use sexed semen reliably and get higher conception rates, it gives us more choice about the sires we use over the remainder of the herd,” said Pellow.
“We are keen on the technology, but the first priority is to get cows in-calf in a timely basis.” By starting mating a week early and the choice of sires, LUDF expected to condense its calving pattern, with an extra 150 cows likely to calve by the end of August than those in milk this season. “So we have turned that around very quickly.”
Of the 143 cows mated in the first week, 70 were mated to sexed semen and 73 to conventional semen. Of the sexed semen cows 44 per cent conceived (31 animals) compared with 58 per cent (42 animals) from the conventional product that week. “We expect that 28 heifers will be born from the sexed semen matings against 20 from the conventional semen. However, had the farm not used sexed semen, it’s possible a further nine cows may have been in-calf at the end of the first week.”
Calving and mating issues this season meant that LUDF will only milk 545 cows in 2018-19, compared with 560 for the last four years. “It will be interesting to see if LUDF can maintain its level of production with a lower number of cows,” said Pellow.
By: HEATHER CHALMERS