Achieving a 12-week calving season is a realistic target for most suckler farms, with 80% cows calved within 8 weeks, writes Niamh Lynch - Teagasc Walsh Fellowship Masters Student - Teagasc Castlerea.
To achieve these targets, it is important to pay close attention to those late-calving cows.
Cows may fail to show signs of heat 60-70 days after calving which may be due to a number of reasons including low body condition score at calving, young cows, and/or twin producing cows.
Here are some tips on what to do to bring forward calving date in late-calving cows.
Remove the calf from the cow:
The bond between a suckler cow and calf is a major factor which can delay the onset of cyclicity after calving.
For late-calving cows, cow-calf separation should begin when cows are 30 days calved and should continue for 2-3 weeks with calves allowed to suckle morning and evening. This is a cheap option but demands time and appropriate facilities (very good fencing, etc.).
Calf removal/separation can equally be applied to cows that are longer calved and are not cyclic. 85% of these cows will show heat within 2-3 weeks of the first separation.
If heat is not induced within three weeks of calf separation, it is likely that the cows are not cyclic for nutritional reasons and a more aggressive treatment such as the use of a PRID or CIDR is needed. These animals will also require a longer period of high-plane feeding to overcome the nutritional effects on the reproductive system and resume cycling.
The insertion of an intravaginal progestagen device such as a Delta- PRID or CIDR for 8 days is capable of inducing heat in about 80-90% of anoestrous cows.
There are various Synchronisation programmes that can be undertaken and it is recommended that cows are at least 35 days calved when she starts a programme.
Ensure that cows calve down in good BCS (3.0+). Have replacement heifers well grown at the time of first breeding and are bred to calve at the start of the calving season.
Adopt a higher replacement rate for a number of years with heifers calving at the start of the season and cull late-calving cows.
Limit the breeding period to 12 weeks and have a definite finish date for breeding.
If you are using AI, use short gestation bulls for the later calving cows. If using natural service, monitor bull fertility and never assume that a bull is fertile.
If you have an extended caving season, say 16-20 weeks, give yourself up to three years to achieve your targets.
When you achieve compact calving, you will have reduced labour, have less disease e.g. scour, better fertility due to more cows coming in heat at the one time and more marketing options with calves of similar age.
Article written by Niamh Lynch - Teagasc Walsh Fellowship Masters Student - Teagasc Castlerea.