Good crop despite bad weather

The 2020 GB harvest started in the south of the country in mid-July and was complete by the end of September. Although harvest progress was disrupted on many occasions due to periods of unsettled weather, notably Storm Francis in mid-August bringing heavy rain and strong winds to most of GB, the end of harvest was in line with recent years.

With the harvest now over for another year, our analysis of late harvest samples is complete and we are able to provide our report on the 2020 GB wheat and barley harvest with regard to feeding value for poultry. 

Wheat

Average wheat yields are estimated between 7.1-7.3 t/ha which is below the 5 year average of 8.4 t/ha (AHDB Report 6). Crops drilled earlier in the season (mainly Eastern regions) seemed to have fared better than those in the North that were drilled later, as they were able to establish before the wet weather last Autumn, making them more resistant to the extremes of the wet winter and dry spring. Just under a quarter of winter wheat crops were sown in January and February and most of these went into poor water logged seed beds, which rapidly dried out. As these plants had not fully established a sufficient root system, many became water stressed and as a result yields were negatively impacted. 

It is accepted there is a negative correlation between yield and protein concentration and therefore with wheat yields below average this year, it is unsurprising that protein has increased. Results from our survey indicate a protein increase of +0.58% on an as fed basis, and +0.55% when corrected to a standard moisture of 13.5% (excluding Scotland). The trend in protein content can be seen in Figure 1.

Figure 1. The trend in average crude protein content in wheat based on wet chemistry (excl. Scotland and corrected to a standard moisture content of 13.5%) - Premier Nutrition survey results
Figure 1. The trend in average crude protein content in wheat based on wet chemistry (excl. Scotland and corrected to a standard moisture content of 13.5%) - Premier Nutrition survey results

Although results show an overall average increase in protein, there is significant regional variation as shown in Table 1. with the lowest protein result of 9% seen in the South, and the highest protein result of 14.6% seen in the West/NW region. Wider industry data is in line with our results, although this suggests proteins have slightly decreased in the south. This variation emphasizes the need to carry out on-going local analysis.

Table 1. Regional changes in protein (%) content of wheat (moisture as is) based on wet chemistry – Premier Nutrition survey results
Table 1. Regional changes in protein (%) content of wheat (moisture as is) based on wet chemistry – Premier Nutrition survey results

Moisture content of this year’s crop has been variable and very much dependent on when harvested. At the start of harvest little grain required drying with some requiring cooling prior to storage. As harvest progressed, more grain required drying, as farmers opted to harvest at slightly higher moisture levels than ideal due to continued forecasted wet weather. On average, results from our survey indicate average moisture content is 0.21% lower than last year at 13.31%, although significant variation seen with results ranging from 10.7 – 19%. However, it must be noted that some samples may have been submitted for analysis post-drying.

Based on the WPSA equation, energy values have slightly increased (+0.02 MJ/kg) on an as fed basis, although when corrected to 13.5% moisture, results are in line with 2019. A summary is shown in Table 2.

Table 2. Average energy content of UK wheat (excl. Scotland) – Premier Nutrition survey results
Table 2. Average energy content of UK wheat (excl. Scotland) – Premier Nutrition survey results

Good specific weights have been reported throughout harvest, with samples submitted for our survey averaging 75.5 kg/hl, with AHDB Report 6 reporting specific weights typically between 72-76 kg/hl. 

Barley

Average winter barley yields have been reported between 6.5-6.7 t/ha which is below the five year average of 7.1 t/ha. However, spring barley yields have been estimated at 5.8-6.0 t/ha which is just above the five year average of 5.8 t/ha (AHDB Report 6). Similarly to wheat, high variation in yields was seen both between regions, but even within fields as bare patches where crops didn’t establish well brought down field averages. Unsurprisingly better yields were seen on heavier soils, where higher moisture retention limited water stress during the drier periods of the growing season.

Results of barley samples submitted for our survey indicate average protein is higher (+0.31%) compared to last year at 10.36%. However significant variation is seen, with samples reported above 12% in both Central and N/NE regions. Conversely, results below 8% have been reported in both Western and Eastern regions. A summary table showing regional variation and year on year change in barley protein is shown in Table 3.

Table 3. Regional changes in protein (%) content of barley (moisture as is) based on wet chemistry – Premier Nutrition survey results
Table 3. Regional changes in protein (%) content of barley (moisture as is) based on wet chemistry – Premier Nutrition survey results

On average, moisture is also slightly higher (+0.38%) at 13.84% compared to last year, although many later harvested crops required drying as weather conditions deteriorated. As with wheat, later harvested grain was of lower quality due to the wet weather in late August delaying harvest. Energy is slightly lower compared to last year (-0.02 MJ/kg) at 11.71 MJ/kg, although when corrected to 13.5% moisture, results from our survey indicate a slight  increase in energy (+0.03 MJ/kg).

Results from our survey indicate good specific weights averaging 66.6 kg/hl. 

Mycotoxins

Compared to 2019, there has been an increase in the levels of some mycotoxins in both wheat and barley samples, particularly from spring grown crops. Fortunately, levels reported are below the safe limits for feedstuffs for poultry but the variability we are seeing in all cereals suggests higher levels may be found. 

NIR Data Comparison

This year we have continued to analyse split samples using NIR and wet chemistry. Table 4. shows the year on year trend of energy values and demonstrates that NIR supports our wet chemistry data and can reliably predict trends in energy content

Table 4. Year on year changes in energy values (moisture as is) of wheat – Premier Nutrition survey results *Values based on AUSCAN
Table 4. Year on year changes in energy values (moisture as is) of wheat – Premier Nutrition survey results
*Values based on AUSCAN

The considerable variability of results observed within our sample set highlights the need for on-going local analysis to ensure that the most reliable information is used when updating matrix values. 

Summary tables of proximate analysis and expected amino acid profiles of wheat and barley split by geographical region can be requested by emailing poultry@premiernutrition.co.uk

Finally, we would like to acknowledge the support of our customers for providing the samples that form the basis of this survey.