Dairy Management: breeding, synchronising heifers and feeding cows

Breeding: There seems to be a lot of interest in synchronisation programmes for heifers this year.

Using hormones reduces the amount of heat detection required and front-loads the majority of heifers to calve at the start of the calving season.

There are lots of variations of synchrony programmes. The target should be to get 65% to 70% of heifers in calf to the first service.

The lowest-cost approach is to watch heifers for seven days and then inject with prostaglandin (PG) any heifers not served and wait for them to come into heat. Some farmers are using a double shot of PG.

The first shot is given 13 days before mating start date and the second is given 11 days later, two days before the planned start of mating. Using this method, all of the heifers should be served within a three-day window.

Progesterone-based protocols (using a CIDR or PRID) are more expensive, but do away with the need to watch for signs of heat. The Teagasc protocol is as follows:

Other protocols are available but the key thing is to stick to the days and times. Find the ideal time for AI and work backwards to find out the time to give each shot. Make sure you have enough manpower for AI so all the heifers can be done in the ideal time range. In terms of synchronisation, healthy, cycling cows should be left alone but late-calving or problem cows should be looked at for hormone treatment.

Calving date: The weather picked up over the last few days and it looks likely that grass growth rates will average in excess of 60kg/day for the coming week. Many farms were tight for grass over the last few weeks and had to put in extra feed. High stocking rates and early calving dates combined can put huge pressure on grass in late March and early April. Farmers tight for grass should take a look at calving date. Delaying calving date to early February may be more prudent, particularly when stocking rate is high.

Feed: With grass growth rates on the up, farmers who have been feeding higher levels of meal and/or silage should look at getting back to as near an all-grass diet as possible, save for one-or-two kilos of meal to cover tetany and minerals. Walk the farm regularly to assess growth and act fast to prevent pre-grazing yields getting too high. The first step is to increase demand by reducing supplement. The next step is to skip over paddocks for either silage or reseeding.

Many parts of the south and east have not got substantial rain for weeks and some farmers on the most free-draining land are concerned about growth prospects. There are no proper soil moisture deficits currently. What has been holding back growth has been cold temperatures and north/easterly winds. With kinder weather, growth rates will increase and should stay high for a few weeks, even in the absence of rain, for the rest of the month.