Breeding has begun in autumn-calving herds in the programme, with cows and maiden heifers being artificially inseminated (AI) from this week onwards.

The focus on both spring- and autumn-calving project farms is to get as many eligible cows and heifers served and in-calf within a six-week period as possible.

Once the flag is raised for the start of breeding season, the race begins to get cows and heifers served in a compact time frame.

The main benefit of tightening the calving profile is the snowball effect in improving herd fertility.

Cows that are slow to get in calf fall outside of the calving window and leave the herd or are served with a stock bull, while cows that get in calf quickly stay and breed replacements.

There can be a stronger focus on heat detection in block calving herds, as more cows are eligible for breeding than in a spread-calving system. This has a knock-on effect in improving fertility too.

Heat detection can be labour intensive and there has been a move away from visually observing standing heats on some project farms to using tail paint, kamar heatmount detectors or teaser bulls with a raddle.

Some Dairylink farmers have also invested in pedometer heat detection systems recently.

A tight calving profile also means that heifer calves are a uniform group and easier to manage during heifer rearing.

This means more will be at target weights and eligible for AI at the start of breeding the following year.

Weigh scales on programme farms have proved useful for tracking heifer growth and managing diets accordingly to hit the 60% mature body weight target for breeding.

Some programme farmers inject any heifers that have not been served in the first six days of breeding with prostaglandin to bring them on heat. This is less labour intensive than observing heats for three weeks and is useful if heifers are on an out farm or are being moved away from the main yard after breeding is over.

Farmer focus: Bill Brown, Millisle, Co Down

Maiden heifers were weighed this week, with 44 averaging 419kg. This represents a 1.03kg daily liveweight gain since their last weighing in mid-September. The group is uniform, with only two younger heifers weighing under 350kg at present.

All heifers have been on a total mixed ration of third-cut silage and 2kg of blend since housing. Most of the heifers are well above the target breeding weight of 370kg to 380kg and so the blend will be reduced to 1kg/day. It could be cut out altogether, with just silage fed, but I do not want to change too much in the diet with breeding starting on Friday.

Sensors for the existing heat detection system for the milking cows have been extended from out-of-parlour feeders to the water trough in the maiden heifer house and all heifers were fitted with pedometers last week.

Heifers have also been freeze-branded to make it easy to identify which heifers are due to be served. There are headlock feeding barriers at one side of the shed and these will be used to hold heifers for AI. Jersey bulls Prop Joe and Hilario and the Kiwi Cross bull Sierra are being used on heifers for two cycles, then beef sires will be used after the six weeks.

Breeding in the milking herd began on Tuesday. I need around 50 heifers on the ground next year, so around 250 straws will need to be used to breed replacements. The pedometers have allowed pre-breeding heats to be easily noted since the start of November and the vet was out last week to check 15 cows that have not cycled so far. There were no major issues identified by the vet and no treatments have been given to these cows yet.

Farmer focus: Nigel Corbett, Banbridge, Co Down

There are 35 maiden heifers to be served on the farm this winter. Eight of these are below my target breeding weight of 360kg. The eight below-target heifers are from late-calving cows and have an average liveweight of 288kg at present.

We are focused on tightening the calving profile, but the younger heifers will fall outside our autumn-calving profile if they are left to grow on and served two months from now. An option is to put them in-calf in the new year and sell them either as springers or freshly calved heifers.

This will bring in more money than selling them as maiden heifers and cows calving at the right time for this system could be purchased to take their place if needed.

The other 27 maiden heifers are on target, with an average weight of 356kg. There is a three-month age range in this group with an average age of 14 months. A heat detection system has been installed in the heifer house and pedometers have been fitted.

Breeding in the milking herd began on Monday and there has been a good bit of activity in recent weeks. This is the first year a heat detection system and pedometers have been used and it has allowed more checks to be carried out on non-cycling cows before breeding.

Sires such as Nextgen Action and Diamond Anton, with EBIs over €110 for fertility and close to 15kg for protein and butterfat, have been selected for cows. Preh Oman is also being used and has similar traits on the £PLI system. Easy calving sires such as Ardragold Parker and Black Lightning are being used on heifers.

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All reports from the Dairylink programme