An MLA-funded trial, led by Dr Angela Lees from UNE, is investigating the impact of shade and shelter on animal performance and carcase characteristics.
The project team set out to quantify the benefits of providing three different shade/shelter treatments – waterproof, shade cloth and unshaded – to southern feedlot cattle during summer and winter production cycles. The waterproof treatment kept the feed dry and covered approximately a quarter of the open pen (4 square metres per head).
“We now have the Cohort 1 and 2 results from the summer experiment, and the winter cohort results will be finalised early next year,” Angela said.
Here are the key findings from the trial so far.
As researchers expected, cattle in the ‘waterproof treatment’ group were heavier than the cattle in the ‘unshaded treatment’ group (12.2 ± 4.2 kg; p = 0.03) on exit. They also tended to be heavier than the cattle in the ‘shade cloth’ group upon exit from the feedlot (10.3 ± 4.2 kg; p = 0.06).
There was no difference in feed intake between treatments, resulting in an improvement in adjusted feed efficiency for the ‘waterproof treatment’.
“We anticipated results along those lines. What we didn’t anticipate was the mild, wet summer,” Angela said.
“The results we saw in the summer cohorts are probably the lowest magnitude increase we’re likely to see, if you were to compare it to a more ‘typical’ southern summer.”
Due to the unexpected and more challenging pen conditions, Angela believes cattle used up more energy walking through wet pens and keeping their bodies warm, meaning the weight difference for conventional shade could potentially have been larger under normal summer conditions.
Cattle in the waterproof treatment had hot standard carcase weights (HSCW) that were 7.20 ± 2.31 kg and 6.69 ± 2.31 kg heavier when compared with carcases from the unshaded (p = 0.02) and shade cloth (p = 0.03) treatments, respectively.
“Assuming a price of $9.00/kg HSCW, our data showed lot feeders would gross over $63/head more for the cattle under the waterproof shelter compared to the no shade or shade cloth treatments,” Angela said.
“Results to-date show that there are production benefits of providing shade to feedlot cattle in temperate climates,” Angela said.
“However, given that the summer was mild and wet, these production benefits are likely more associated with the reduced impact of wet and muddy pens rather than heat stress.”
Although all of the cattle have now been fed for this project, researchers are yet to finalise the behaviour and body temperarture analysis for the summer cattle and data from the winter cohort (slaughtered 4 November 2021).
The performance and carcase characteristics for the winter portion of the trial will be analysed early next year – keep an eye out for upcoming editions of The Quarterly Feed e-newsletter for an update.