Suckler cows in Ireland are frequently cross-breeds - Leaving Cert Agricultural Science - Question a - 2019

Using cross-breed cows can provide several advantages:

• Improved hybrid vigor: Cross-breeding often results in offspring that are more robust and have better survivability.
• Enhanced traits: Cross-breeding can combine desirable characteristics from different breeds, such as milk yield and growth rate, leading to better overall performance.

Reproductive efficiency refers to the effectiveness of the suckler herd to produce calves. It can be quantified by:

• The number of calves weaned per hundred cows mated per year.
• The pregnancy rate of the herd, indicating how many cows conceive during a breeding season. High reproductive efficiency is crucial for economic viability in beef production.

The growth rate comparison reveals that:

• Suckled calf typically has a higher growth rate (average LWG: 1.2 kg per day) as it receives natural nutrients from the mother’s milk, which is nutrient-rich.
• Artificially-reared calf has a lower growth rate (average LWG: 0.8 kg per day) as it is dependent on milk replacers or feeds, which may not always match the quality of mother’s milk.

Grazing management for the suckler herd is crucial for maintaining herd health and optimizing growth. Common systems include:

• Paddock grazing: Utilizing equal-sized paddocks grazed for short periods, allowing for recovery.
• Block grazing: Keeping livestock in a designated area until grazed out, then moving to the next.
• Set stocking: Animals have continuous access to larger pastures but might not optimally graze all areas.

In comparing bull-beef production with heifer-beef production, the following points can be observed:

• Bull-beef: Generally grows faster (LWG: 1.6 kg per day) and has leaner carcasses with higher killing-out percentages.
• Heifer-beef: May have lower growth rates (LWG: 0.8 - 1.0 kg per day) and can yield fatter carcasses with lower killing-out percentages, making it more energy intensive.