Choosing the right dams to breed replacements makes a huge difference, writes George Ramsbottom
As thoughts turn to the breeding season once more, our decisions are largely unaffected by the huge rise in input costs.
There is perhaps an increased focus on breeding quality replacements, achieving compact calving and a look again at adding value to beef calves by using quality beef AI, particularly on the second tier of mature cows that aren’t up to the mark as dams of replacement heifers.
Compact calving patterns are there for a reason: to maximise the proportion of grazed grass in the diet of the milking cow.
While fertiliser is expensive and the grass it produces has increased in price, purchased meal costs three times as much per kg DM, so minimising meal input when cows are in milk is still advisable.
What then is the ideal calving pattern? Broadly speaking the 70:20:10 rule applies here: 70pc calved in February, 20pc in March and 10pc in April (preferably early April).
But a start date in late January to minimise or eliminate the April calvers is fine by me.
The optimum median calving date varies a little as we go from the south of the country to the north, and between wetter and heavier farms. It’s somewhere between February 15-25.
To hit a mean calving date of February 15, you’ll need to calve 50pc of your herd in the first 14-21 days. For most herds it means starting to calve at the end of January or in the first few days of February.
The results we’d like to see are as follows in the early part of the breeding season:
The threshold and average team targets that Teagasc recommends when selecting teams of AI dairy sires are presented in Table 1.
With the range and quality of the dairy AI sires available, greater values for EBI and the sub-indices are easily achievable in 2022.
On the beef AI side, we recommend that the Dairy Beef Index is used to select bulls for the herd. Over the past couple of years, improvements to the methodology underlying the calving difficulty figures means that a far more accurate estimation of the calving difficulty of beef AI sires on dairy cattle is possible.
Speak to your AI technician or breeding advisor to identify sires that are suitable for use on mature dairy cows and on younger animals.
An opportunity to add value to the crop of beef calves from your farm should not be missed.
There are three steps to selecting cows for dairy AI.
Step 1: Select early-calving cows
Cows calving after St Patrick’s Day aren’t the ones you want to breed your dairy replacements from. We’re looking for high conception rates to first service, and those of later calvers in the first three weeks of the breeding season is typically lower than average.
We want all our replacement heifers born early next year and as uniform in age as possible to make managing them easier during the rearing process.
Step 2: Select on EBI
There can be an enormous range in the EBI of a dairy herd.
I have a rule of thumb of setting a cut-off of €150 EBI for cows and heifers that you breed your dairy replacements from.
I have looked at a test case of a 250-cow herd in Wicklow with an average EBI of €157, ranging from €50 to €242.
90 of the cows have an EBI of less than €150, and should be bred to beef AI.
Nationally, around 45pc of dairy cows and 65pc of maiden heifers have an EBI of greater than €150.
Using the €150 EBI as the cut-off, the average EBI of the pool of cows selected as potential heifer mothers increases by €25, from €157 to €182.
Step 3: Select the most profitable cows
As the size of a herd stabilises, farmers can be more choosy about which cows to breed their replacements from and which to breed to beef AI.
It’s noticeable how much the market for dairy heifer calves has tightened this year. Average-quality heifer calves are harder to sell.
For farmers reliant on moving calves off farm quickly after birth, a switch to beef AI on the lower end of the herd seem a prudent move this spring.
Many of the cows you’d breed to beef are obvious, but a lot lie in the grey area between beef and dairy.
I’ve had a look at the lifetime profit figures for a number of herds recently. The difference between the bottom and top 20pc of cows in the herds is running at around €2 per day from first calving.
Over a lifetime of 1,500 days from first calving, that’s a difference of €3,000 between the top and bottom cows in the herd. Many of the cows in the top 20pc and upper average will be ones that are earlier-calving and higher EBI.
In my second test case, of a spring-calving herd in Tipperary, the difference in margin between the top 20pc and bottom 20pc of cows in the herd is €2.16 per day for the 2+ lactation cows since they first calved in the herd.
The higher-profit cows produce more milk solids and spend fewer days dry than the bottom 20pc of cows in the herd.
George Ramsbottom is a Teagasc dairy specialist based at Oak Park, Co Carlow