Quality Beef Breeding: Where Passion Meets Science

By Ross Fitzgerald, B&T Adviser, Teagasc Galway/Clare

Many suckler farms nationwide are currently in the midst of or approaching the conclusion of their respective calving seasons. The recent stretch of dry weather has resulted in many animals being moved from sheds to pastures in the last few days, and more are expected to start grazing with the upcoming expected weather. Enhancing the fertility and making more informed breeding decisions in your herd is a crucial strategy for boosting cow margins and, consequently, increasing business profitability. Throughout this article, I will cover some of the components of a successful breeding season, as well as several tips farmers might consider before they begin breeding.

Understanding the Oestrous Cycle

For every farmer the key to a successful breeding season to get a grasp of the oestrous cycle. Cows experience a recovery phase after giving birth before their fertility returns to a normal state or they start ‘cycling’ again. The uterus requires approximately 40 days to heal post calving, as it is stretched by the calf during delivery. This, however, may require significantly more time if the cow experienced a difficult calving due to malpresentation/a large calf, or the presence of any uterine infections.

A stumbling block in returning to normal cyclicity are primarily caused by inadequate body condition scores and challenges during calving. There is no solution for poor nutrition pre and post calving. It can be quite challenging to restore a cow’s body condition to an appropriate level for breeding while she is also nursing a calf. A target for all farms should be that every cow is seen bulling between 35 and 55 days post calving. An option some farmers use to help cows return to heat is the restricted suckling of calves.

Bull - Soundness and fertility

Fertility testing your bull before mating is crucial. Pre-breeding examinations every year will guarantee that any issues with your bull are detected sooner rather than later. Bulls need to have a healthy libido and be able to maintain their body condition during the breeding season. They must also have good locomotion coupled with good legs and feet. If purchasing a new stock bull both physical characteristics and Euro star index-related aspects must be considered. It's crucial to make sure a bull you're purchasing isn't overweight since overweight young bulls that have been on a high concentrate diet may develop back and rear leg arthritis in later life.

Bull examination tips;

1. Ensure bulls are physically sound and any feet that may require trimming is done 2 months before mating.
2. A bull soundness examination must be carried out by your vet at least 1 month before mating.
3. Bulls should be observed mounting to ensure they are mating properly during the 1^st week of breeding

Heat detection

Effective heat detection is essential to the success or failure of AI. Approximately 10% of the causes for failing to identify heats are linked to 'cow' issues, while 90% are due to 'management' issues. Management issues consist of: insufficient daily observations; inadequate time allocated for observing the cows; or observing them at inappropriate times or locations, like during feeding. Certain tools for heat detection consist of

• Vasectomised bulls with a chin-ball marking harness, active vasectomised teaser or detector bulls are very useful in identifying cows coming into or on heat.
• Scratch card type patches are affixed to the cow’s tail head. Friction from mounting rubs off the silver coating to reveal a bright coloured patch underneath.
• Electronic indicators have also come onto the market that either fit on a teaser bull or on the cow/heifer. These devices monitor behaviour and will indicate on your phone if an animal is showing signs of heat.

Is Synchronisation an option?

One of the main benefits of AI is increased genetic improvement, by allowing farmers to use a broader range of both high index replacement and terminal index bulls. Synchronisation is gaining traction and can benefit the farmer looking to utilise AI by:

• Permitting the utilisation of genetically enhanced AI bulls, both conventional and sexed.
• Minimising the effort required for heat detection or at least concentrating it during a crucial time when labour is more available.
• Enabling the adoption of AI on dispersed farms where consistent heat detection might be more challenging.
• Minimising the calving interval or advancing cows that have fallen behind in the calving schedule, resulting in a uniform group of calves that can be more readily managed when labour is more available.

Recommended synchronisation regimen for beef cows ≥35 days calved at time of treatment

Day 0, AM (Monday) - PRID or CIDR insertion + GnRH at insertion

Day 7, AM (Monday) - PRID or CIDR removal + prostaglandin + 400 iu eCG (also known as PMSG) i.m. at time of removal (Ideally tail paint cows or affix heat detection patches to cows)

Day 8 (Wednesday) - Cows will start to show standing heats late pm and through the night. Record cows in heat and active

Day 9 (Thursday) - Most heats expected. Inseminate all cows observed in heat in the evening of Day 9 and on Day10. Heat check cows and record all cows active or in heat (if required). Alternatively, inseminate all cows at 72 hours following progesterone insert removal and administer GnRH to cows not yet observed in heat.

Day 10 (Friday) - Continue heat detection and inseminate cows observed in heat. Alternatively, inseminate all cows not observed in heat at 72 hours post CIDR or PRID removal and administer GnRH to these cows at time of insemination

What should I look for in the ICBF Euro star indexes?

As breeders it is important to pay more attention to the sub-indexes. One sub-indices which should be looked at is the expected progeny performance, this takes into account traits like carcass weight weaning weight, age at finish, gestation and carcass confirmation. This Sub-Index will estimate how good a bull is at producing progeny with high value carcases. Bulls that are producing cattle that have a high carcase weight for age, good conformation at kill out and good lifetime feed efficiency will score highly.

The breeding decisions that will be made in the upcoming months will help meet SCEP's 2027 female replacement strategy requirement. These heifers will be entering the system at the desired age if born next spring. Sub-indexes such as daughter calving difficulty, daughter milk and calving interval should be studied in detail. Farmers should pick a bull based on both physical appearance and index related traits to suit their cows accordingly. Daughter Milk is the expected level of milk that daughters of a bull will have. It is expressed in terms of the kg’s weight gain from the progeny of those daughters. Calving Interval is a key measurement of fertility in a bull’s daughters. It is measured in terms of ‘Calving Interval’.

Upcoming Event

‘Optimising Beef Breeding Teagasc Ballinasloe Weds 23/04/2025 19:30-21-00. Guest speaker John Lynch Dovea to advise on calving ease and quality. Suckler and Dairy Scheme update with interactive stands discussing heat detection on a 100 cow suckler herd and stock bull management for breeding’.