Sheep and dairy support farmers Paula and Gareth Steel, of Greenfield, near Clydevale, expect to rear between 140 and 150 orphaned or abandoned lambs this season.
Mrs Steel said the decision to rear so many lambs was partly based on a business plan goal to improve their flock fertility.
That meant an increase in the number of triplets, which some ewes were not able to finish themselves.
It costs about $73 per lamb for inputs like power, meal, milk powder, teat replacements, and disinfectant (not including labour).
''We make about $30 to $35 profit on each lamb,'' Mr Steel said.
''A lot are sold as stores.''
Their lambing percentage is about 140% and for the past couple of years have weaned at 17kg, which Mr Steel said was slightly down on normal because of the recent dry summers.
They initially hand reared about 50 lambs on bucket feeders, which took a long time each day.
They invested in a $7800 DeLaval automatic lamb feeding system, which paid for itself in two seasons with the additional lamb survival.
The machine and pens are in an old, dry and sunny implement shed.
It automatically mixes whey milk powder, which contains vegetable fat as it is more easily digested, and warm water into a litre container when required, and the mix is pumped through hoses into four pens.
Each has two teats with some inset into the pen wall slightly so the more experienced drinkers cannot be knocked off their dinner by boisterous enthusiasts.
Other teats extend slightly from the wall, making it easier for new arrivals to find them.
The machine can feed 240 lambs, although their shed is too small for that number.
Mrs Steel said they have reared about 150 orphaned or abandoned lambs each season.
''We are in our third year [with the system] and we are learning every year.
''About 150 seems like a good number for us.''
The children - Caitlin (8), Hunter (6) and Oliver (3) - are also enthusiastic lamb rearers and the two older ones cannot wait to get off the school bus to head to the lambing shed.
''They are all a big help and all have wee jobs,'' Mrs Steel said.
The lambing shed system also saved Mr Steel a significant amount of time during his lambing beats as it means less time spent trying to find misplaced mothers, although he does mother on if he can.
He said if he saw an orphaned or lost lamb, he picked it up, applied navel iodine spray and took it to another shed beside the house, where it is fed on gold cow colostrum for two days.
''That is important so we can ensure they are drinking well before going on to be introduced to automated feeding, [in the lamb shed], which is available ad lib,'' Mrs Steel said.
''Initially they often over-indulge, but once the novelty wears off, they drink as they need to, and it works really well.
''We would end up losing some with bloat with the bucket system, but we don't get that with this system.''
The lambs are grouped in pens by size and age and also have access to a grassed area.
The lambs are also given ad lib meal and lucerne hay for rumen development, and are weaned at about seven weeks.
They continue to receive meal up to 10 weeks.
The Steels use woodchips as floor bedding, which is frequently topped up with fresh material.
At tailing and weaning time they receive Scabine vaccine, 5-in-1 and B12 shots.
While the reared lambs tend to be smaller than those reared by their mothers, many are sold as stores or go to the works later.
''They are always going to be that way,'' he said.
Once lambing is over, the workload reduces to about half an hour a day in the shed.
''It is very rewarding seeing them jumping and skipping and playing,'' Mrs Steel said.
