Managing Crop Grazing Producer Demonstration Site

Summary

This producer demonstration site project aimed to demonstrate advantages of crop grazing on profitability and enhance producer understanding of how to best apply the tool in different seasons and situations. The objectives were to do so by demonstrating the impact on four properties in Western Australia's Great Southern, over three years. It was expected that this would show an increase in feed by deferring pastures during crop grazing, and a condition score advantage in ewes grazing crops compared to those grazing pasture. In addition, harvest yield was expected to be impacted by less than 10%. An economic analysis was conducted to show impacts on lambing performance and overall profitability.

Using paired-paddock methodology, performance of sheep grazing crops was compared to sheep grazing available pastures. Crops were grazed for 10 to 44 days during June, July and August, which coincided with three years of late season breaks. Stocking rates varied between 0.5 to 7.2 DSE/ha, using ewes lambing in June-July, or dry hoggets. Pasture tests were conducted at the start and end of grazing, and lambing results collected or modelled using the Lifetime Ewe Condition Score Comparison Calculator.

At the start of grazing, when crops passed the 'pinch and twist' test, crops had on average 27% higher metabolisable energy, 2.56 times more Feed On Offer (FOO) and were 18% more digestible compared to pastures. Crop was also more accessible, being erect and easier to eat compared to prostrate pastures. Grazing these crops allowed paddocks to be spelled, with deferred pasture having 69% more FOO compared to pastures grazed during the crop grazing period.

Crop grazing sheep were measured to be in better condition compared to those grazing normal pastures. Ewes had a 0.28CS advantage over ewes grazing pastures, while hoggets had a 0.35CS advantage. This led to a modelled additional 5.2% lamb survival in twins, partly due to increased birthweight of 120grams which contributed to 10.7% increase weaning survival. Ewe survival increased by 0.47%. Reduced costs of feeding were calculated at 12c/h/day and combined with reproductive impacts resulted in sheep net benefits at $11.42/ewe and $4.75/hogget grazed on crops.

Crop yield impacts ranged from a loss of 400kg/ha to an increase of 1360kg/ha. This converted to a financial impact of -$100/ha to +$408/ha.

Excluding 2017's abnormal increases in yield due to the impact of disease, average impact of grazing on crop was a 4.1% yield loss. This resulted in an average financial impact of -$21.56/ha, or when including 2017's abnormal year, +$81.13/ha.

To give the impact on whole business gross margin, yield impact was combined with sheep benefits. It is important to remember that this data is calculated using the extremely variable stocking rates producers used to graze crops, often with understocking paddocks. There was an average benefit of $15.67/ha for reproducing ewes. With the abnormal 2017 data included, the average benefit increased to $131.80/ha. It was also profitable to graze hoggets, which only used the feed and labour-saving costs to offset yield impact. Hoggets averaged a $10.19/ha profit.

Knowledge, Skills, Confidence & Adoption Results

• 93% of producers inreased their confidence in crop grazing to an average level of 7.4/10
• producers’ involved in the project increased knowledge, skills and confidence in pasture manipulation and selecting its timing
• 85% of producers found the project to be valuable and would recommend the PDS program to others
• Satisfaction and value of the project involvement was rated as an average of 7/10
• 24% of producers adopted crop grazing
• 22% indicated an intent to adopt in the future
• 78% of producers indicated that the likelihood of them adopting crop grazing had increased.

Impact

• The impact on crop profitability averaged a $81.13/ha profit over the three years (range - $100/ha to +$408/ha)
• Reduced costs of feeding (calculated at 12c/h/day) combined with reproductive impacts resulted in sheep net benefits of $11.42/ewe and $4.75/hogget grazed on crops
• Impact on whole of business gross margin was an average benefit of $15.67/ha for reproducing ewes
• Hoggets averaged a $10.19/ha profit which only used the feed and labour-saving costs to offset yield impact.