Hi. I posted the link to the abstract, which as you point out, is merely an synopsis of a study. I personally don't feel the need to read the entire study. I interpret the study as: control group - received 0% calcium in their diet; group#2 received 2% calcium; group#3 received 3% calcium. The results of this particular study - as I read it - conclude that the control group and 2% group had the "best" sperm motility. The study names other findings, "
reduced blood cholesterol, elevated seminal calcium, and enhanced sperm (motility), thermo-tolerance and cryosurvivability" [
Anim Reprod Sci. 2010 Jul;120(1-4):158-65. Epub 2010 Apr 13.]. It is a little sketchy whether the control group received 0% Ca or? And also interesting that if the control group did indeed receive 0% Ca in their diet, that their fresh, non-frozen sperm motility was highest of the groups.
Whatever I am, I'm no poultry nutritionalist! I merely find it interesting that out of the 40 or so birds in my current flock, the three males visit the oyster shell hopper the most faithfully. I feed a "complete" processed pellet (Blue Seal Extra-Egg). It supposedly contains a min 3.3%-max 4.3% of calcium. Which, according to the study, might suggest the boys should be receiving enough calcium in the pellets alone. But then, my birds free range. Maybe they're not eating enough pellets?
I attended a day long seminar with
Michael Darre. Poultry nutrition was covered in about 1/2 hour at 95 mph. The one thing I remember him saying in regard to nutrition is that unless birds are penned and you feed them only "known" rations, you have no real way of knowing if their nutritional needs are being met. So, do I put all of my faith in a bag of processed feed? No. Feed producers are only human. It's good to keep track of lot numbers on feed so if you develop an issue such as widespread soft shells or whatever in your flock, you can contact the feed company.
But, returning to the topic of roosters and calcium...I dunno why my males eat more oyster shell than the hens. I have had good fertility. Who knows?
And, by the way, very nice looking Barred Rocks you have there, Fred's Hens!