FowlWitch
Songster
So, I've been trying to do dry incubation, as many recommend, but most of the eggs have been failing for me. It turns out that my elevation (about 5770 feet), I should actually be using higher humidity.
I found this on Google: https://thepoultrysite.com/articles/incubating-eggs-at-high-altitudes
They include a chart that I'm finding slightly difficult to interpret.
I'll try to copy and paste (and hope the formatting transfers over okay):
The First Priority: Ensure That Egg Weight Losses Are Correct
The first priority when incubating eggs at high altitudes is to ensure that egg weight losses are correct (see Hatchery How To No.1 for recommendations on optimum egg weight loss). Based on the fact that water diffuses through the pores in the eggshell faster at altitude this would mean running a higher incubator humidity set-point.
Starting with two common incubator humidities at sea level, Table 2 gives the relative humidity set-points that would compensate for the increasing speed of movement of water molecules at higher altitudes.
Table 2. Relative humidity settings that will give the same egg weight losses at different altitudes
Altitude
metres (feet) If 50% RH used at sea level If 53% RH used at sea level
0 50 53
500 (1,640) 53 56
1,000 (3,281) 56 58
1,500 (4,921) 58 61
2,000 (6,562) 61 63
2,500 (8,202) 63 65
3,000 (9,842) 65 67
*Note this part is supposed to be columns, but they didn't copy/paste properly. My elevation is between the two rows I bolded.
However, there is evidence that chickens reduce their eggshell porosity with increasing altitude. This means the altitude of the breeder flock relative to the altitude of hatchery may influence the best choice of the humidity set-point (Figure 3). Therefore, always be guided by actual egg weight loss in your hatchery, and alter your humidity set-point to achieve the recommended optimum egg weight losses.
The eggs in question are from eBay. I don't know what elevation they were laid at - this may explain why eggs from my flock hatched so well, but my eBay eggs usually fail at lockdown or during the first 10 days. It could also be a result of shipping, but for the sake of this post, I'm going to assume the issue is something within my control so I can improve my incubation techniques.
So, to the matter at hand, if I'm reading the table correctly, should I be aiming for 50% humidity? I'm making the assumption that I want to increase the humidity based on what % I would keep my eggs at if I lived at sea level, which I think I would aim for 35% to 40%. What do you guys think?
I found this on Google: https://thepoultrysite.com/articles/incubating-eggs-at-high-altitudes
They include a chart that I'm finding slightly difficult to interpret.
I'll try to copy and paste (and hope the formatting transfers over okay):
The First Priority: Ensure That Egg Weight Losses Are Correct
The first priority when incubating eggs at high altitudes is to ensure that egg weight losses are correct (see Hatchery How To No.1 for recommendations on optimum egg weight loss). Based on the fact that water diffuses through the pores in the eggshell faster at altitude this would mean running a higher incubator humidity set-point.
Starting with two common incubator humidities at sea level, Table 2 gives the relative humidity set-points that would compensate for the increasing speed of movement of water molecules at higher altitudes.
Table 2. Relative humidity settings that will give the same egg weight losses at different altitudes
Altitude
metres (feet) If 50% RH used at sea level If 53% RH used at sea level
0 50 53
500 (1,640) 53 56
1,000 (3,281) 56 58
1,500 (4,921) 58 61
2,000 (6,562) 61 63
2,500 (8,202) 63 65
3,000 (9,842) 65 67
*Note this part is supposed to be columns, but they didn't copy/paste properly. My elevation is between the two rows I bolded.
However, there is evidence that chickens reduce their eggshell porosity with increasing altitude. This means the altitude of the breeder flock relative to the altitude of hatchery may influence the best choice of the humidity set-point (Figure 3). Therefore, always be guided by actual egg weight loss in your hatchery, and alter your humidity set-point to achieve the recommended optimum egg weight losses.
The eggs in question are from eBay. I don't know what elevation they were laid at - this may explain why eggs from my flock hatched so well, but my eBay eggs usually fail at lockdown or during the first 10 days. It could also be a result of shipping, but for the sake of this post, I'm going to assume the issue is something within my control so I can improve my incubation techniques.
So, to the matter at hand, if I'm reading the table correctly, should I be aiming for 50% humidity? I'm making the assumption that I want to increase the humidity based on what % I would keep my eggs at if I lived at sea level, which I think I would aim for 35% to 40%. What do you guys think?
