Watch: flag raised for start of breeding season

Breeding season is likened to a race on Dairylink Ireland farms, with the aim being to get as many cows and heifers served and in-calf within as short a time period as possible.

Most programme farmers are trying to improve herd fertility by tightening calving profiles, as this means cows that are slow to get in-calf leave the herd and don’t breed replacement heifers.

As seen on phase one programme farms, a few years of this approach means more and more cows are calved down and eligible for serving by the start of breeding season. This has a snowball effect on herd fertility, so tightening and then maintaining a compact calving profile gets easier each year.

Phase two programme farms are predominantly autumn-calving, so having the herd calving down early and in a tight time frame reaps maximum benefit from winter milk bonuses paid to Lakeland suppliers in November and December.

Concentrates

Most Dairylink farms also have cows with genetic potential to respond well to concentrate feeding. Putting effort into getting more of the herd calving early in the autumn means cows can be fed silage and concentrates over the winter and then can make use of grazed grass in the spring when they are settled in-calf and further on in lactation.

Heat detection is usually easier and more labour-efficient if more cows are ready for service. Dairylink adviser Conail Keown points out that it is easier to get a big number of cows in-calf over a short period, compared with a smaller number over a longer period.

With breeding season beginning on some programme farms from next week, preparations are well advanced for the start of the race, with sires selected and pre-breeding heat detection ongoing. The flag is up. On your marks, get set ...

Weekly roundup

There are 45 freshly calved cows and 66 late-lactation cows milking on Stephen Wallace’s farm near Seaforde at present.

Breeding is due to begin in the first week of December, with the 45 fresh calvers, as well as 50 maiden heifers, eligible for service from the start.

Stephen artificially inseminates (AI) all stock himself and he has some straws left over in the flask from last year. He has also selected some new sires for the 2018/19 breeding season and will be using these straws first. The new sires include Commend, Praser and Agronaut.

Sexed semen is being used, as the aim is to get as many heifer calves from early cows and maiden heifers as possible.

This means replacements in two years’ time will be from fertile cows and will be calving at the right time for Stephen’s autumn-calving system.

Fertility and solids

The sires selected are Holstein bulls listed on the UK-based Profitable Lifetime Index (PLI) system.

Stephen mainly selected sires based on sub-indices for fertility and milk components. All bulls being used have a PLI over £700, predicted transmitting ability (PTA) for fertility over 10 and a production proof over 28kg for fat and over 20kg for protein.

All milking cows have Heatime collars for heat detection and heifers are observed visually, with tail paint used as an aid.

Stephen plans to get his vet to examine any eligible cows and heifers that have not recorded a heat before breeding begins.

The maiden heifers are being housed on an outfarm and will be on a prostaglandin-based synchronisation programme.

After six days of watching heats and AI, all heifers not served will get a shot of prostaglandin and will be inseminated after they show signs of heat. AI will be used on repeat heifers for a second natural cycle and a beef bull will be used after that to sweep up.

Tough decisions

The current calving profile on the Wallace farm is spread over eight months from mid-September into April. Stephen wants to tighten the calving profile to improve herd fertility, but also for labour efficiency reasons, particularly with heifer rearing.

Doing this is easier said than done and requires some tough decisions with letting late calvers go. It can be difficult for some to sell a cow that is calving at the wrong time of year, but is correct every other way.

Stephen doesn’t want to establish two distinct calving blocks on his farm (spring and autumn) and he isn’t keen on holding spring calvers over to have them calving in the autumn the following year.

Instead he wants to generate as many replacement heifers that will calve early in the autumn as possible. This will mean he won’t be breeding replacements from late calvers and he will have sufficient heifers to replace late calvers as they gradually leave the herd over time.

Stephen is also considering buying in some autumn-born Holstein heifer calves that can be reared with his homebred heifers to further increase the proportion of the herd calving down at the right time for his system.

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