Soil fertility is spoken about only too often but it is only when you see first-hand what improvements in soil fertility can do to farm output that you really appreciate it. Last week, Teagasc’s BETTER Farm sheep walk took place on the farm of Michael and John Prendergast, near Hollymount, Co Mayo.

Host John Prendergast told the crowd that the farm was purchased by his grandfather back in 1964 and extends to 45ha (111 acres), all of which is laid out in one block. Of the 45ha, about 3ha are used for a pony enterprise with the remainder for sheep.

Since joining the programme, John said that they focused on changing the breed type on the farm, fertility and grassland management. The farm currently carries a flock of 400 mid-season ewes, lambing from mid-March onwards.

Local Teagasc adviser Eamonn Patten told the crowd that there have been three main areas of change on the farm: the flock structure and stocking rate; the breeding policy; and grassland management. He said that when the Prendergast farm joined the programme, they had 280 ewes but that has grown now to around 400. Despite this increase in numbers over a short period, they have managed it while retaining a closed flock to avoid buying in trouble. The focus on improved grassland management has resulted in a much reduced concentrate bill and better grass utilisation.

“Before joining the programme the concentrate bill was running at €30/ewe, now it is back to €7-€8/ewe, although there was an additional €6-€7/head fed to finish lambs last year.’’

Focus on soil fertility allows higher stocking rate

On the grassland stand, Philip Creighton said that while reseeding is one way to increase grass growth on a farm, you also need to get fertility right. Soil fertility was quite good on the farm originally, which is a credit to the Prendergasts. Applying lime and increasing the number of grazing divisions were the main areas of focus on the farm.

There were about 15 grazing divisions originally, but through the use of temporary electric fences to split these larger areas, they have now about 40 grazing divisions. With lambs weaned on the farm, they are operating a leader-follower system where lambs graze paddocks and dry ewes follow them to graze the paddocks out. As more lambs are drafted as we move into the autumn, the grass demand of the lambs reduces, freeing up more grass for the ewes, which will allow them to put on condition. The aim is to have ewes in a BCS of 3.5 going to the ram.

John said it takes about an hour and a half once or twice a week to complete a grass walk and 10 minutes to input it into the computer, but it has led to a huge decrease in meal usage and has allowed him to take out more, better quality 75-80 DMD silage as surplus during the year and better quality grass before grazing. With better silage quality, concentrate supplementation to the ewes during the winter is decreased also.

Teagasc’s Eamonn Patten warned farmers who are highly stocked and taking out surplus bales to watch the soil fertility. He said that there are one or two fields which have seen a drop in P and K on the farm in the last year or two as more surpluses have been taken off.

Frank Campion and Ciaran Lynch ran through the current performance of lambs on the farm

The heavy and persistent rain was such a delight to see by the farmers attending the walk that it didn’t dampen the mood or take from the walk in any way.

On arrival at the farm, several farmers commented not only on the abundance of grass present, but on the colour of the fields considering the drought conditions in the area.

Frank said that while weight at birth was good, from there to seven weeks lambs got a hard doing on account of the poor weather in the spring, and this affected weight gains. He added that currently lambs are lighter than target. Those under 30kg at this stage will present a challenge in getting them to slaughter.

The target is to finish as many lambs as possible off grass only. Going by current weights, there will only be 30-35% drafted for slaughter by 1 October. Ciaran Lynch advised farmers to weigh lambs and plan what to do with those that are below target. For the Prendergasts, he said that any lambs above 37kg to 38kg are going to be started at meal to finish them as quickly as possible. He said that these lambs for finishing should be offered 0.5 to .75kg/ day of concentrates.

By doing this, Ciaran said that it should increase the percentage of lambs finished off the farm by 1 October to about 50%. He added that because heavier lambs respond better to meal feeding, the cost-per-kilo of liveweight gain will be lower. The target will still be to grow the lighter lambs as much as possible before meal feeding and target at least 80% of lamb weight from grass.

John Prendergast said that with poor weather conditions last autumn, they did have to house the lightest lambs and finish them in order to maintain enough grass supplies for the ewes. In total, the concentrates fed per lamb last year were about 16-17kg/lamb.

Breeding for higher prolificacy

Traditionally the ewes on the farm were Suffolk and Texel crosses, but in recent years they have started using Belclare and Charollais rams in order to increase the number of lambs weaned per ewe.

Sheep specialist Michael Gotstein said that there are two basic ewe types on the farm. Ewes from Belclare rams have mostly white faces, and those with brown faces are from the Suffolk ram. Michael said that the white-faced ewes go to the Suffolk ram while the blacker-faced ewes are mated to the Belclare ram. The remaining group of ewes, that will not be used to breed replacements, are bred to a Texel ram in order to maximise output.

While Belclare rams could be used, their progeny are a little slower to finish. The breeding changes that have been implemented are only starting to kick in at this stage with the first crop of Belclare cross ewes mated in 2017.

Table 3 details the productivity of the flock in 2015 and in 2018. Ewe numbers are up by about 100, which has helped lift the stocking rate to 9.2 ewes per hectare. In addition, the influence of the Belclare breeding has started to be evident with the litter size increasing from 1.78 in 2015 to 1.88 in 2018. However, Michael said that the number of lambs reared dropped slightly from 1.59/ewe in 2015 to 1.46/ewe in 2018. Mortality was up by 6-7% on account of the poor weather conditions through the spring which had a negative effect. All in all, the number of lambs reared in 2018 is up by 108 on 2015 levels, which will add to farm output.

Colour coded tags to select replacements

On the breeding stand, John said that in order to correctly identify ewe lambs suitable for replacements, they are using coloured tags to identify ewe lambs that were single, double and triplets. Those that were singles get a blue tag in the right ear, while doubles get a red tag and triplets get a green tag. Ewe lambs born to the top 80 to 100 ewes get a purple tag in the left ear. Michael Gottstein said that selecting ewe lambs that were born in doubles or triplets have higher ovulation rates, so selecting these as replacements should help further to increase litter size.

When questioned on losing tags, John said that on occasion they find the coloured disc tags lost in the field, so as a precaution, they keep accurate electronic records at lambing. Those without a coloured disc are not considered for breeding. In terms of replacement rate, the target is to run it at 20-25%.

“Because we are still increasing the flock, we lambed 50% hoggets last year and about one third this year.’’

John said that they cull firstly on mastitis and teeth and if the ewes don’t recover weight quick enough when dry, they will also be culled. “We have 70 gone already this year in the first cull,’’said John.