Reminders for Breeding Season 2022
George Ramsbottom, Teagasc Dairy Specialist summarises advice on breeding. Select a team of high EBI sires using the threshold and average values detailed here. As herds stabilise, there is an opportunity to more carefully select the cows that we breed our dairy replacements from in the years ahead
From a breeding viewpoint there is 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 in the herd that aren’t up to the mark as the dams of replacement heifers.
Calving date
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 the economically optimal thing to do. What then is the ideal calving pattern? Broadly speaking the 70:20:10 rule applies here. In other words, 70% calved in February, 20% in March and 10% in April (preferably early April). To be absolutely honest, 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 South to North of the country and between wetter and heavier farms. It’s somewhere between 15th and 25th February so it really isn’t that different in reality. To hit a mean calving date of 15th February you’ll need to calve 50% 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 in the early part of the breeding season are as follows:
Bull selection
The threshold and average team targets that Teagasc recommends when selecting teams of AI dairy sires are presented in Table 1.
Table 1: Threshold and team targets for EBI for dairy sires for the 2022 breeding season.
With the range and quality of the dairy AI sires available in 2022, 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.
Cow selection
There are three steps to selecting cows for dairy AI for this breeding season.
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 that of later calvers in the first three weeks of the breeding season is typically lower than average. We want all of 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. Figure 2 presents the range in EBI of the cows in a herd with an average EBI of €157. I’ve a rule of thumb of setting a cut off of €150 EBI for cows and heifers that you breed your dairy replacements from.
In the herd presented in Figure 1, individual cows range in EBI from €50 to €242. In using the €150 EBI as a cut off threshold for selecting the cows selected for dairy AI, the average EBI of the pool of cows selected as potential heifer mothers increases from €157 to €182, an increase of €25. In doing so, 90 of the 250 cows have an EBI of less than €150. These should be bred to beef AI. Nationally approximately 45% of dairy cows and 65% of maiden heifers have an EBI of greater than €150.
Step 3: Select the most profitable cows
As the size of individual dairy herds stabilises, farmers can become 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 would seem a prudent move this spring. Many of the cows you’d breed to beef are obvious but a lot of cows 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 20% of cows in the herds is running at around €2 per day from first calving. Over a lifetime of e.g. 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 20% and upper average will be ones that are earlier calving and higher EBI.
In Figure 2, the difference in margin between the top 20% and bottom 20% of cows in the example dairy 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 less days dry than the bottom 20% of cows in the herd.
The Teagasc Dairy Specialists issue an article on a topic of interest to dairy farmers every Monday here on Teagasc Daily. Find more on Teagasc Dairy here Read more on Breeding & Genetics
Read about ensuring a good supply of winter feed at Food and Fodder Security