With milk prices under pressure, farmers want all suggestions on how to cut production costs. A 10% increase in the proportion of grazed grass in a dairy cow’s diet reduces costs of production by 2.5c/litre.

The main ways to increase the proportion of grass in the animal’s diet are:

1 Extend the grazing season into early spring and late autumn. This can be achieved by implementing grazing management practices such as timely closing of paddocks in autumn for early spring grazing, where weather allows.

2 Where possible, match the herd calving pattern to the grass growing season. Begin calving when grass starts growing. This leads to most cows calving between 10 February and 1 March. Target an opening farm cover of 600kg to 700kg DM/ha.

3 Match stocking rate to the grass growth potential of the farm. For example, a cow consumes 5t grass DM. If the farm is growing 14t DM/ha, it can be stocked at 2.8 cows/ha (14 ÷ 5 = 2.8).

4Ensure soil fertility is optimised (see soil fertility section, page 5).

5 Implement a timely re-seeding programme to maximise sward productivity.

6Carry out regular farm grass cover measurement and grass budgeting.

7Ensure that farm infrastructure is sufficient to fully utilise grass grown, especially during periods of wet weather.

8Supplement with concentrate or high-quality baled silage when grass is in short supply.

9 Use on-off grazing during periods of wet weather to keep grass in the cows’ diet, provided soil conditions allow.

Maximise grass production and profitability throughout the year

SPRING

The simple rules are:

Turnout in mid-February.

30% of farm grazed by 1 March.

60% of farm grazed by 17 March.

100% of farm grazed by first week in April.

Graze paddocks to 3.5cm during the first rotation.

Each extra day at grass in spring is worth €2.70/cow/day.

MID-SEASON

During mid-season, the farm should be walked at least once per week and the farm cover (amount of grass on the farm) assessed. Target pre-grazing yield is 1,300kg to 1,600kg DM/ha. The target post-grazing height during the main grazing season is 4cm to 4.5cm. If there is a surplus of grass on the farm, remove the paddock from the grazing system and cut for winter fodder. If there is not enough grass on the farm, the animals may need supplementation with silage or concentrate. Rotation length should be 18 to 21 days. Keep topping to a minimum, as it delays re-growth of pasture. One round of topping to less than 4.5cm should be enough and should be completed from mid-May to late June. Maintaining the correct pre-grazing yield and post-grazing height during the main grazing season generates an extra €150/ha in milk receipts.

AUTUMN

A 60:40 autumn rotation plan helps to extend the grazing season into late autumn. Autumn closing management has the biggest effect on spring grass supply. Start increasing rotation length by one day per week from 1 August. Rotation length should be less than 35 days from mid-September. Start closing on 10 October. 60% of the farm should be closed by the first week of November. The remaining 40% should be closed by 1 December. These dates should be a week or two earlier on heavier soil types or slow grass growing farms. Once a paddock is closed, it should not be re-grazed as this will reduce spring grass supply. Each day’s delay in closing from 1 October to 11 December can reduce spring grass availability by up to 15kg DM/ha/day. Close some drier paddocks earlier to facilitate early spring grazing. Graze paddocks to 3.5cm to 4cm during the final grazing rotation to encourage winter tillering. The closing cover target is 550kg DM/ha for farms stocked at 2.5 cows/ha in late November.

DURING WET WEATHER

Where soil conditions allow, use on-off grazing. Allow cows two three-hour grazing periods after each milking. After each three-hour period, move cows from the paddock to a stand-off area (e.g. a shed). Silage supplementation is not necessary. Ensure full allowance of grass is offered during these periods as cows adjust their grazing behaviour to achieve full intake. Be flexible — graze lower grass covers (shorter grass) in wet weather. Ensure a good network of roadways to maximise pasture access and minimise poaching damage. Back fence areas that have been grazed to avoid poaching damage. Poaching paddocks can reduce grass growth throughout the year, particularly on heavy farms.

RESEEDING

Achieving high levels of grass production and animal performance from swards which do not have a high proportion of perennial ryegrass is difficult. High perennial ryegrass swards can produce 3t DM/ha more than swards with low levels of perennial ryegrass. Swards with low levels of perennial ryegrass are not as responsive to nitrogen. Greater spring growth is achieved with high perennial ryegrass swards. Pastures with less than 65% perennial ryegrass should be reseeded. Spring is the best time to reseed. A spring reseed produces as much grass in its year of establishment as an old permanent pasture. It is easier to establish clover in spring reseeds as soil temperatures are more stable then. Thre is a greater chance of more suitable weather and soil conditions.