Spring-born bull

With spring-calving systems predominating in the suckler herd, thoughts turn to preparation for weaning and the coming winter for cattle. It’s at this time decisions must be made as to what system of production should be selected for these animals.

One option is to leave male calves entire and slaughter them as young bulls either at under 16 months or at 18 to 19 months of age. Bull beef has seen a significant increase in popularity over the last 10 years.

In 2006, young bulls accounted for less than 10% of the total young male kill. At its highest point in 2012, bulls accounted for just over 30% of the young male kill. However, this had reduced to around 20% by last year.

From the outset, as with all systems of production, talking to your processor is a must to confirm there is a market for what you want to produce. Clarify carcase weight, fat score and age specifications.

For the purposes of this article, we will assume a 1 March-born calf, weaned and 340kg at housing in early November.

19-month spring bull

The first winter diet for these animals should consist of high-quality grass silage (>70 DMD) plus 1kg to 2kg of concentrate. Target an average daily gain (ADG) of 0.6kg to 0.7kg.

Recent research at Grange has shown that there is no benefit in increasing ADG above this level during the first winter when animals are destined to return to pasture the following spring.

This is due to compensatory growth, whereby animals that grow more slowly during the winter have a period of accelerated growth post-turnout to grass, thus reducing the benefit of expensive kilos gained indoors.

At the end of the winter, bulls are turned out to pasture for a three-month grazing period. Target a turnout of 1 April (earlier on drier farms). This gives a 140-day winter, so bulls should be going to pasture at around 430kg.

This is the key component of this system. Here, we can replace three months feeding indoors at relatively high cost with low-cost grazed grass. Bulls are out at pasture in April, May and June when grass growth and quality is at its highest.

Performance at pasture can be excellent, typically in excess of 1.2kg/day, provided bulls are grazed in a rotational system and offered fresh pasture ideally every two to three days.

Rehouse these animals in the first week of July. They will be 16 months of age and in the region of 550kg to 560kg liveweight. Over a three-week period, adapt these animals to an ad-lib high-energy (>0.92 UFL) concentrate diet.

This intensive feeding period is critical to ensure animals hit target carcase fat scores, typically 2+ for bulls. Therefore, depending on carcase weight limits (400kg to 420kg) bulls should receive an 80- to 100-day finishing period.

If the target carcase weight is 400kg, a kill-out of 57% gives a target slaughter weight of 700kg. Growing at around 1.8kg/day during the finishing phase gives an 80-day finish for this animal.

16-month spring bull

This has become the preferred option in the last couple of years due to the under-16-month bull being paid on the grid and being eligible for the 12c/kg Bord Bia quality assurance (QA) bonus payment.

Again, taking our 1 March-born calf, slaughter date must be before 1 July the following summer. Post-weaning bulls should remain at pasture for as long as weather and grass-growing conditions allow.

Once housed, place on a diet of high-quality grass silage (>70DMD) and 2kg to 3kg of a high-energy concentrate. At this stage, ADG should be in the region of 0.8kg to 0.9kg.

Bulls remain on this diet until the turn of the year, when concentrate feeding should be increased gradually until ad-lib, along with some fibre source.

Bull beef trials at Grange feed grass silage along with concentrates. This is due to the fact that grass silage is available on the vast majority of farms, whereas straw may have to be bought in.

Given free access to both concentrate and silage, animals will self-regulate the diet, with concentrate accounting for 85% to 90% of DM intake.

When feeding ad-lib, it is important that the animals never run out of concentrate, that there is always a fibre source available and animals have access to fresh clean water at all times.

Performance for these young bulls will be in the region of 1.6kg to 1.8kg/day over the finishing period. The genetics of the animal will determine the end-point of the system.

Well-bred continental type animals will continue to lay down lean meat for longer than animals with some earliermaturing breed types.

While performance is maintained, it pays to feed on these animals. However, once performance starts to decline and bulls are sufficiently fleshed to meet fat score specifications, bulls should be drafted and sent for slaughter.

Regular weighing of these animals is the only way to accurately measure performance. Remember that carcase weight limits are exactly that – limits. They shouldn’t be seen as a target for all animals.

Autumn-born bull

When getting grass into beef bulls, timing is everything. The role of late-season grass in any bull beef system is questionable – the plant’s feed value is dropping and mixed weather conditions will upset the bull quite easily.

Hence, if we’re getting grass into the bull, it should be early in the year. Chasing weight on grazing bulls in August will be a struggle and, at that point in the season, the animal will have framed up and is ready to begin its finish.

Grass role

Teagasc work has shown that, by and large, continental bulls will not fatten sufficiently at grass, even at high concentrate feeding levels (6kg).

While good rates of weight gain can be achieved at grass, more exercise and a higher maintenance energy requirement limit fat deposition on the animal. A continental bull typically needs an indoor intensive feeding period prior to finishing.

Ideally, we want to turn a beef bull out to grass early in the season and have him coming in around July for a short, sharp intensive finishing period.

When aiming for the lucrative under-16-month bull (U16) market, an autumn-born bull can be the perfect fit for getting grass into the system.

Although the calf is being marketed at a time of the year when beef price is usually lower than in spring or summer, over 130kg of cheap, grass-based weight gain and a reduced overall meal demand relative to the spring system make autumn-born U16 bulls attractive.

Sweet sixteen

The U16 bull beef system suits a July to August calving period, which works extremely well on heavier farms. Bulls will be old enough to wean at turnout and, in a wet spring, it allows cows to be left indoors.

Two management aspects are crucial to the success of any autumn-calving system: top-quality silage and a facility for calves to creep away from their mothers in the shed, be it to a separate pen or outdoors.

The silage quality should be maximised to keep the cow milking well and have her putting on condition ahead of breeding. Cows in the correct body condition score, eating silage in excess of 75% DMD, shouldn’t need any meal supplementation during the winter.

A creep area allows for calves to receive some concentrates, provides a healthier environment if outdoors and helps to break the cow-calf bond, improving fertility.

Aim to house a 1 August-born calf having achieved an ADG of 1.0kg from birth – that’s a 145kg calf in early November and 175kg in early December.

It should be offered 1kg of a 16% crude protein, high-energy (>0.92 UFL), palatable calf ration daily with top-quality silage and allowed to creep away from the mother, preferably outdoors, as it pleases. Target ADG during the housed period should be 1.15kg.

Spring time

On drier farms, turn out cows and calves in late February and wean in early April.

On wetter farms, let calves creep outdoors where possible early in the spring. A 1 August-born calf can be weaned without any issues from St Patrick’s Day onwards.

Wean indoors in one week by letting calves suck cows intermittently for seven to 10 days. Meal levels can be gradually increased to 2kg during the weaning process. Simply close the creep gate/door when restricting calves. There should be minimal stress as animals are alongside each other.

When you’re satisfied that calves are healthy and consuming meal and silage readily, and that the weather is settled and to remain so for two or three days, turn calves out to grass.

Some farmers keep supplementing grazing bull weanlings with meal, but, in reality, the weight gain response to meals at this point in the year is poor. However, it can facilitate easy herding and help identify health problems (calves not eating).

Pull meals back gradually over two weeks. From then on, it’s a case of getting as much weight gain from grass as is possible. Rotationally graze these bulls and ensure that grass under them is as leafy as possible. Target three- to five-day grazing intervals.

Home stretch

Target weight gain at grass for these bulls is 1.3kg daily. The aim is to house these bulls on their birthday at live weights of at least 475kg.

Introduce 1.5kg of meal outdoors four weeks prior to housing, building quickly to 3kg by the end of the first week.

Once housed, build bulls up to ad-lib concentrates over three weeks. To do so, offer 3kg initially, adding 1kg every three days.

At rates above 5kg, split feeds in two. Concentrates can be offered ad-lib once 10kg is being consumed. Ensure that fresh water and long fibre are available at all times.

These bulls should achieve an ADG of at least 1.6kg for three and a half months, leading to a slaughter weight of 645kg at 15.5 months. This translates to a carcase of around 380kg.