Livestock producers have been urged not to stop their supplementary feeding programs, despite widespread - yet variable - rainfall over the past week.
Department of Primary Industries and Regional Development veterinary officer Danny Roberts said while the rainfall will greatly assist pastures, growth would be limited.
Dr Roberts said it would be at least four to eight weeks before pastures would be sufficient to provide adequate nutrition for stock.
"Pastures need to have at least 800 kilograms of food on offer (FOO) per hectare, at which point the sheep become disinterested in supplementary feed," he said.
"This means producers in the northern and central grainbelt will need to maintain supplementary feeding for an estimated 40 days, while those in the southern agricultural region, where solar radiation is lower, will need to wait about 80 days."
With more than 60 per cent of the State's sheep flock already lambing, Dr Roberts encouraged livestock producers to prioritise ewe and lamb nutrition.
"With reduced market opportunities over the next three months, due to the pause in live exports to the Middle East, the majority of producers will have little flexibility other than to feed sheep during that period," he said.
"The department's Live Export Sheep webpage lists a number of options, considerations and feed requirements to assist producers and consultants to make informed decisions about how best to manage their flock."
Landholders across the agricultural region have been encouraged to continue to review their livestock and cropping programs as the 2019 growing season progresses.
Forecasting models consistently predict a drier than average season, with the department's latest Statistical Seasonal Forecast suggesting a 40 per cent chance of exceeding median rainfall for the majority of the grainbelt for June to October.
The most probably decile range is 2-3 for the Central Grainbelt, Great Southern, South Coast and South West and decile 4-7 for the Central West and south east coastal districts, based on a predictive skill of 45-75 per cent.
Department senior development officer Jeremy Lemon said grain growers' cropping programs were well advanced, after extensive dry seeding across the grainbelt.
Mr Lemon said growers had modified their programs in response to low subsoil moisture and the late break and would continue to make adjustments as the season unfolded.
"Many growers in the medium and low rainfall zones have reduced crops and varieties, such as canola and longer season lines, to optimise margins this year," he said.
"With forecasts for a tight finish to the season, it is important for growers to proceed with caution and monitor their situation and strategies, such as in season fertiliser applications, in line with the constraints of the season and expected yields.
"The good news is that the risk of disease and associated control costs are likely to be lower this year, due to the dry seasonal conditions."