This week, we outline some of the main management tasks that will be carried out on the programme farms within the coming weeks. The focus will be on maintaining high levels of weight gain in weanlings prior to housing, as well as getting spring-calving cows scanned and ensuring there is sufficient fodder in store for the winter period.

Fodder budgets and silage analysis

August is a good time to complete a fodder budget to calculate how much silage is required to feed livestock this winter.

Completing a budget now gives the programme farmers time to take action to ensure they have adequate fodder reserves in place.

For some farms, this will include closing off fields to make more silage, some of which may be a third cut. This will certainly be a goal for those farms where second-cut volumes were reduced due to drought.

A third cut of pit silage, or bales taken from surplus grazing during August, will most likely be a more cost-effective option than purchasing additional concentrates or silage of variable quality.

The programme farmers are currently getting first-cut silage analysed. Knowing the feed value of first-cut silage means a more accurate feed budget can be carried out.

Higher-quality silage can be restricted to dry cows in adequate body condition, allowing for fodder savings, and vice-versa.

As high-quality silage will primarily be targeted to finishing and growing cattle, knowing the quantity of this forage on-farm allows the programme farmers to plan out how much concentrate feed is required to supplement silage.

Table 1 provides an example of how to complete a fodder budget on farm.

Calculating the volume of silage in store is simple. Measure the length (A), width (B) and average height (C) of the pit in metres and divide by 1.4 to calculate the tonnage (25% DM). If measuring in feet, divide the cubic volume by 45 to calculate tonnage.

A typical 4x4 silage bale weighs around 800kg, so assuming that dry cows are eating 25kg to 30kg per day, then one bale will feed approximately 30 cows every day.

Use this as a guide to work out how many bales you have in store and how long they are likely to last this winter.

Animal health

Bringing the animal health programme up to date is another key aspect of herd management during August and early September.

Ensuring that spring-born calves and store cattle are treated for both lung and stomach worms will help to maintain high levels of performance during autumn.

After a dry summer, the challenge from worm burdens has been relatively low. However, with rainfall becoming more frequent, there will be an increase in worm populations on pasture, with younger cattle particularly susceptible to lungworm infection.

Having an effective worming programme in place will provide adequate cover during the high-risk periods at weaning and housing.

The programme farmers will also be planning to vaccinate weanlings against viral pneumonia and IBR in late August to early September.

Again, this is carried out in advance of weaning, allowing sufficient time for a two-shot vaccine programme to be completed before the period of high risk.

Splitting heifer and bull calves and target concentrate feed

The majority of the programme farms have moved to finishing spring-born male calves as young bulls.

A key factor in getting spring-born bulls finished at carcase weights of 380kg to 400kg by next June is to maximise housing weight.

To help achieve this, the programme farmers separate calves based on the sex of the animal around late August to early September, depending on when the breeding period is finishing.

Separating calves is normally combined with other tasks, such as worming and vaccinations, or scanning cows.

Once bull calves have been separated, the programme farmers will offer higher levels of concentrate feed to these animals to maintain high levels of liveweight gain during autumn.

By offering higher levels of creep feed, this will also smooth the transition from pre-weaning to post-weaning management, as well as the housing period.

Allowing calves to creep-graze ahead of cows also gives calves access to better-quality grass, which also helps to improve weight gains in young stock.

Scanning cows

Spring-calving cows will be scanned in early to mid-September on the programme farms. Scanning results will be used to determine accurate calving dates for 2019 and also identify culls.

Cows can be scanned from 35 days after the date you want the last cow served. The last service date should be based on the planned finishing date for spring calving.

For example, if you start calving on 1 March and want to finish by 1 May, then all cows should be served by 1 August. Cows can then be scanned in early September to indicate how many animals will calve within the target calving period next spring.

If there has been a high level of breeding activity in late summer, or a high empty rate, cows can be re-scanned in late September instead.

Scanning will also identify which cows are empty so that they can be weaned early, while they are in good body condition, and finished before the start of the winter housing period, thereby reducing winter feed requirements.

Once scanned, steps can also be taken to wean the main cow herd. Weaning cows in ideal body condition allows the farmers to restrict silage feeding during mid-pregnancy.

This has proven to be a considerable cost saving in previous years.

Late-season fertiliser

The focus for grazing management will now be on building grass covers to carry livestock into late autumn.

Fertiliser applied in August and early September will give a cost-effective growth response when applied under the correct conditions.

Applying 25 to 30 units per acre of nitrogen by early autumn will boost late-season grass growth.

As silage ground rejoins the grazing platform, the increased land base will also allow grazing rotations to be extended and help build grass covers for autumn grazing.

Grazing rotations should be around 20 days in early August, increasing to 25 to 30 days by early September.