Breeding
I started breeding my 40 spring calving cows and 11 heifers on 2nd May. I have set breeding season dates to help control the length of my calving season next year. The herd will be bred to AI for 8 weeks until 27th June and then my Charolais stock bull will be let out with them for two/three weeks to mop up. This will allow for a 10/11 week calving spread which will start around 14th February until mid/late April 2023.
A vasectomised bull is used for heat detection on the farm. The bull detects when cows/heifers are in heat and serves them without putting them in calf. They can then be brought in for AI approximately 12 hours later using the am/pm rule, i.e. if the cow is on standing heat this evening, she can be AI’d tomorrow morning. Along with this, I have dates recorded of observed heats before the breeding season starts so I know when to expect cows and heifers to cycle again at around 21 days later. I also observe the herd 3 times per day in the morning, afternoon and evening for around 10 minutes each time to monitor them for signs of heat.
This year I had some May calving cows which have been marked for culling to help tighten the calving spread. As I work off farm they drag out the calving period and I don’t have the same amount of time to spend monitoring them. It also spreads out routine tasks like disbudding and if I want to finish the bulls under 16 months of age there is too much of an age and weight range between the earlier and later born calves. Nine out of 49 cows have been marked for culling due late calving, age and/or a lack of milk this year.
The breeding heifers on the farm were selected on a number of criteria:
- Date of birth: Ideally 14-16 months of age to calve at 2 years
- Weight for age: Over 400kg at 14-16 months of age
- Genotyped
- Eurostar figure: 4/5 star on the replacement index
- Daughter milk: Positive figures
- Daughter calving interval: Negative figure so as not to extend the calving spread
- Visual assessment: Good feet, wide hips and not too muscly so as to avoid potential calving issues
The heifers will be AI’d to an easy calving Angus bull who is 3.2% heifer calving difficulty at 96% reliability. The heifer calves would have the potential to be kept as replacements.
The Charolais type cows (~9) will be AI’d to a high replacement Simmental bull who is 7.6% for cow calving difficulty, 9.7kg daughter milk, -4.71 days on daughter calving interval and is €196 on the replacement index. The Limousin type cows will be AI’d to a Charolais bull who has 6.5% calving difficulty, 35.7kg carcass weight, 2.44 on carcass conformation and is €164 on the terminal index. Further terminal Charolais and Belgian Blue bulls have also been selected which will be matched to the cows.
I am concerned about TB in the local area and as there is a genetic component to it which is available for the AI bulls, I also looked at the figures. One bull is in the top 10% for TB resistance, a further 2 bulls are in the top 30%, one bull has average resistance and another is in the bottom 30% which is interesting to note.
The breeding targets for the coming weeks are to submit over 90% of eligible females that are over 30 days calved to AI in the first 3 weeks of the breeding season, and to have 70% conception rates for these.