Pasture-Based Dairy: Lower Cost And More Lactations

In an area where feeding total mixed rations is the norm for dairy production, Jurie and John Hartley milk 1 200 cows off pasture with impressive results. Gerhard Uys reports.

- Gerhard Uys

Jurie Hartley milks 1 200 cows near Meyerton, Gauteng. Until 2005, he and his father, John, fed the animals total mixed rations (TMR). They then decided to convert to pasture instead. With its lower input costs, the economics of this move made sense.

Cows on pasture yield less milk: an average of 20 twice a day in summer compared with up to 40 twice a day for TMR-fed cows. But a pasture feeding system lengthens a cow’s longevity and extends its lactations, as the animal is not ‘pushed’ as hard, says Hartley Jnr.

He points out that the average lactation in a South African dairy herd is about 2,8, whereas the cows in his herd average 6,5 lactations.

In order to be sustainable, however, milking on pasture requires strict grazing management and full-time involvement by the farmer.

Hartley plants a mix of rye grass, clover and chicory as pasture. Centre pivots and draglines provide irrigation for the 200ha farm.

Rainfall is about 800mm/year. Although this is a fair amount, the area suffers from excessive heat at times, making irrigation crucial for pasture health.

The farm is divided into 6ha camps. In summer, cattle are rotated, returning to each camp every 21 days, when regrowth can carry the group again. In summer, a group of about 100 cows are on 1ha for 24 hours.

To determine a camp’s carrying capacity, Hartley conducts a grazing assessment using a plate meter placed on the grass. He takes about 50 readings per camp. These are entered into the Fourth Quadrant phone app, which enables him to calculate how many kilograms of grass are growing on each hectare. The app also calculates how much growth took place in each camp, the total growth on the farm, and how much dry material is available per hectare per day.

Using this data, Hartley works out how many cows a camp can carry over a specific period.