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The 2018 grazing season is best described as a tale of two halves. The difficult spring resulted in an extended housing period for cows and calves.
Once summer arrived, it brought a period of drought and poor grass growth for many farms in the east of the province.
With this in mind, the programme farms still managed to achieve good levels of cattle performance throughout 2018.
Spring born calves were weighed at weaning and 200 day weaning weights averaged 268.5kg, marginally ahead of the 2017 average which was 267.1kg.
Identifying the most efficient cow
To identify the most efficient cows in the herd, farmers in the programme routinely weigh both the cow and the calf at weaning time. The target is to produce a calf that weighs 50% of mature cow weight at 200 days of age.
On average, calves were 44.06% of mature cow weight at weaning.
Average mature cow weight across the farms was 623.51kg and daily liveweight gain of calves averaged 1.14kg/day.
Averages within a herd can be improved by identifying trends from one year to another and targeting breeding replacements from those cows performing best.
For example, on Fionbharr Hamill’s farm the top 5% of cows (based on weaning %) produced calves that were 56% of cow weight at 200 days, while the bottom 5% were only 34% of cow weight at 200 days.
Often it’s quoted that regardless of weaning percentage, a bigger cow produces a bigger calf. The analysis of weaning to date in Fionbharr’s herd suggests otherwise.
The top 5% of cows were, on average, 163kg lighter than those in the bottom 5%. The calves weaned from the top 5% of cows were 72kg heavier at 200 days than those weaned from the bottom 5% cows.
This trend is similar across all of the programme farms.
By identifying the poorest performing cows, it is easy to avoid breeding replacements from these animals.
Feed cost savings with smaller cows
The most obvious and easily measured benefit from reducing cow weight is the saving in winter feed costs.
A dry suckler cow weighing 600kg requires slightly over 3.7t of average-quality silage (67 D-Value) to meet maintenance requirements for a 20-week period pre-calving.
A 700kg cow requires 4.1t of average-quality silage to meet the same maintenance requirement in the 20 weeks pre-calving.
When spread across 50 cows, and valuing silage at £20/t, the direct fodder savings works into slightly over £350.
While it is not necessarily a significant amount of money, it is worth bearing in mind that a larger land area will be required to produce extra silage for heavier cows.
This reduces the size of the grazing area. Producing more silage also means higher fertiliser and contractor costs are incurred, all of which are additional costs on top of the direct fodder savings.
Maintenance
Smaller and lighter cow has a lower maintenance requirement throughout the year, not just the outlined winter feeding period.
This means the smaller cow is easier managed during period of poor grass growth.
Lighter cows inflict less sward damage when ground conditions are poor and smaller cows can also be stocked at a higher density at grass and when housed.
During the course of the programme, smaller cows have tended to perform better within tight bulling and calving periods, meaning cows are retained on farm for longer.
Balance
Generally the most profitable cows in any suckler herd are the cows that produce a calf every 365 days, year after year.
It is the fundamental starting point for any suckler system.
However kilograms of carcase beef sold annually is the end goal and there is a balance to mature cow size, so that it does not compromise on the carcase weight of progeny produced.
For the programme farms, the aim has been to breed cows with a mature liveweight ranging from 600kg to 700kg as these animals had the best balance in terms of stocking rates, longevity, winter feed savings and calf performance.
In Table 1, the farms are ranked from highest to lowest in terms of weaning percentage, but there are points to note.
The 200 day weaning percentage does not take account of a number of aspects on farm, such as when creep was introduced to calves and rate of supplementation.
Higher rates of creep feeding would increase actual calf weaning weights and therefore corrected 200 day weights.
The percentage of younger breeding animals within a herd will also have a big effect.
This is especially the case with 24 month-old calving, as heifers are unlikely to be at mature weight by weaning time.
Body condition score of cows is also not accounted for. A cow housed in condition 3.5 with a lower weaning percentage, will have a lower winter feed cost than a cow in condition two achieving a higher weaning percentage.
However, any feed saving on the cow is likely to be outweighed by increased feed costs for the lighter calf. Therefore, a balance must be sought by avoiding the extremes.
Ryan McDowell finishes at the top of the league table for the second successive year. Weaning percentage has fallen from 59.08% in 2017 to 50.25% in 2018.
The reason for this is primarily that mature cow weights have increased by 56kg, due to a growing percentage of the herd maturing in weight.
Calves were also slightly lighter than in 2017, as prolonged housing of young calves during spring 2018 created health issues, which impacted on calf performance at grass.
At the opposite end of the table is Paul Jamison were cows are predominantly purebred Limousin.
While calf performance improved in 2018, steps have been taken to address the lack of milk in cows by introducing more maternal genetics into the herd through herd sires and buying some in-calf heifers. In Jonathan Blair’s herd, weaning percentage jumped by nearly 7% from 37.89% in 2017 to 44.29% in 2018.
Daily liveweight gain in calves was significantly higher in 2018 with bull calves in particular weighing almost 40kg heavier at 200 days old in 2018 compared to the previous year.
Calf performance was improved by addressing a recurring problem with coccidiosis in early spring, along with other measures such as improved grassland management, forward grazing calves and targeted creep feeding of bulls from autumn onwards.
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