A breakthrough has been made indicating just how significant the impact of supplying shelter in hot, humid northern cattle regions can be on calf survival rates.
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00:00Hello, I'm Kieran McCosker with QAFI at the University of Queensland.
00:24I'm here to talk about the Reducing Calf Loss from Exposure study,
00:29which we did at Avondale Station in the Northern Territory with Australian Agricultural Company.
00:37This project was about investigating the effectiveness of providing artificial shade
00:43or augmenting paddocks that had relatively few trees in them with additional shade structures
00:50and investigating and quantifying the impact of building those structures in these paddocks to see
00:57how it reduced calf loss or successful pregnancy to weaning outcomes.
01:03On average, losses between confirmed pregnancy to weaning are about 12% across all females.
01:10That's the figure that we determined in the Cash Cow project, which was reported in about 2016.
01:16Now, the rates are higher in heifers, so they can increase to around 30%,
01:23and rates higher than that are not uncommon either.
01:27What we did find is that in some years, cows do using these current measurements or threshold
01:33values for those heat stress measurements. In some years, cows do experience a lot of
01:39stress from heat. And so that probably warrants further investigation.
01:45One of the things that we don't know is how appropriate some of the current thresholds are,
01:51which have mostly been developed in intensive industries like dairy and feedlot,
01:55how applicable they are when we take them out to the grazing situation.
02:00What we did find is that if we take the measurements that we took under the shade
02:05shelter using those indicators, application of putting shade shelters did take those
02:12thresholds way down. It did mitigate a lot of the heat. So it was whether or not the cows
02:17utilized that access to that shade. Over the three years that this work was done,
02:22we measured about a 5.5% difference in confirmed pregnancy to weaning loss.
02:29That in scientific terms wasn't statistically significant, and we would like to investigate
02:34that further and are working with industry to see how we can do that, because industry is telling
02:40us that that's an important finding and if it holds up, a significant production benefit.
02:48We would do further work to obtain increased confidence about the results we saw. And so
02:55ideally we would like to engage multiple properties doing similar things and seeing whether or not
03:01that intervention held up there. And the other question, of course, is there's an element of
03:07cost here. Even though we might see production benefits and there are possible and likely
03:13welfare benefits, we also need to quantify the cost benefit of making these interventions.
03:20So in this study, we also used remote sensors, so GPS collars tracking their positions every 10
03:27minutes. What we were able to do was use that information to rank animals within the paddock
03:34that had access to shade. So the cow that used the shade heavily compared that cow to one that
03:39didn't use it so frequently. And what we did find is that there was association there, but again,
03:46that wasn't statistically significant. But for the number of animals we had it on,
03:51again, we would like to obtain increased confidence about seeing whether or not
03:54that association holds up as well.