The results are in for the six-year Elmore Field Days' Ewes for the Future trial, and Merinos have performed well at the northern Victoria site compared to the first-cross and composite types.
At the presentation of the results last Friday, Kieran Ransom, formerly of DPI Bendigo, said in this Elmore trial all 210 ewes - including 42 of each Border Leicester Merino (BLM) cross, Loddon Valley Merino, Centre Plus Merino, Dohne and Prime South African Meat Merino (SAMM) - were joined to White Suffolk rams and were run together for six lambings.
The sheep committee chairman Ged McCormick said these types were chosen because they were all used in commercial operations within 20 kilometres of the Elmore trial site.
Ewes representing each breed were sourced from three properties to reduce the impact of genetic variability between flocks within a breed on the trial.
Mr Ransom said comparing the profitability of terminal sires joined to alternative ewe breeds was complex, and was made all the more difficult by climate and price (including for wool, sheepmeat and supplementary grain) variability experienced in the last decade or more.
Mr Ransom said a strength of this trial was that the average returns - from both lamb and wool - were adjusted for lambing percentage.
"Lambing percentage is the biggest driver of profit in a sheep enterprise," he said.
The BLM (the most common prime lamb mother in northern Victoria) and SAMM ewes both had 132 per cent lambs markets on average over five adult lambings, compared to the Centre Plus Merino with 116pc and Loddon Valley Merino and Dohne both at 96pc.
As expected, these two meat-focused types were also heavier at joining and had heavier lambs before sale, with SAMM lambs recording an average weight of 48.5kg and BLM 47.7kg, compared to Centre Plus Merino at 46.1kg, Dohne 46.3kg and Loddon Valley Merino 44.3kg.
However, these ewe-lamb units also had significantly higher feed needs, which Mr Ransom said exposed them to more risk in poor climatic conditions.
"When looking at profitability, you have to look at fluctuations in costs and incomes, not just averages," Mr Ransom said.
"I looked at 28 years of data, and in last 14 years, prime lamb enterprises had poorer return per hectare because of climate variability, and when droughts hit, you have to buy in supplementary feed and grain price skyrockets with increased demand, and drought-affected young lambs are sold at low weights and drought prices."
Sheep types that have been bred for wool quantity and quality can provide a more consistent income stream even through climate peaks and troughs.
In the trial, Loddon Valley Merinos' wool clip made an average of $52.96 during the five years as adult ewes, and Centre Plus Merinos made $49.67, which gave them a buffer in poor weather conditions compared to Dohnes making $38.70, SAMMs $23.17 and BLMs $19.94.
"You've got to look at what breed combinations can get you through a drought," Mr Ransom said.
"In a good season, not much difference between Merinos and first-crosses, but in poorer seasons when supplementary feed is needed, there could be a huge difference, maybe up to $100 a hectare because Merinos require less feed and have wool incomes."
Other interesting findings include post mortems on dead lambs found the different breed groups had similar results, of about 35 per cent due to a difficult birth, 30pc due to being born too small, 30pc due to mismothering, and only about 2pc were killed by foxes.
Mr Ransom also told the about 60 farmers at the result announcement that well-run sheep farming systems could in many cases be more profitable than cropping, and for cropping to beat these northern Victorian sheep operations that had animals grazing on annual lucerne pastures and residues over summer, cropping needed "super soils" and to achieve 80pc water-use efficiency.
The trial is run by the Elmore Field Days in co-operation with the Campaspe Lamb Producers Group, data was collected by Mr Ransom and statistical analysis was conducted at the University of Adelaide with financial support from Australian Wool Innovation.