Feed, PH, and sex ratios in litters

It is believed by some--that PH of the doe affects sperm motility , IE male sperm swim faster but don't live as long -and because of this "motility factor" adding things like Apple Cider Vinegar to rabbit water will tip the ratios of male vs female kits born -toward the female side--
I have further theorized that some natural diets "somehow" do the same thing-- When i fed root crops and kale as the primary feed, my records show I had about 65% female kits weaned-- as opposed to about 48% female when feeding pellets-
comments anyone????

Unfortunately, I didn't keep records, but my anecdotal experience agrees that there was a larger percentage of female kits when I used ACV regularly in the water. I always supplemented with weeds, even when I was feeding pellets, but I don't know if that may also have been a factor.

I really don't know either-- the genetics of my rabbits also changed quite a bit between those times-- and as is commonly known- different bucks have different ratios of male to female kits.. The natural feeding days still had some of the old Checkered Giant breed stock in the herd..... and those just might have been genetically prone to having litters of mostly female kits... after i moved into a "real commercial rabbitry" and changed to pellets, and imported NZ and Calli-- things changed a lot...

My understanding is that it's really hard to meaningfully change the internal ph of a living body, as it naturally readjusts the levels to maintain the proper balance for it's electrical systems to work, among other things. https://en.wikipedia.org/wiki/Acid%E2%8 ... omeostasis

It's possible nutrition could have some minor difference but it's unlikely to be a ph change. For one it's a totally unproven theory and for two as the wikipedia article states you are very unlikely to change the ph of blood and all the fluids it moves around the body. You can change urinary ph only because it's isolated as a way to maintain body ph. The balance of bacteria also helps maintain ph on surface tissue after fluids leave the blood or where they are stored in tissue and organs. Sweat and saliva are minor ways to change the ph of skin or mucus membranes but that's usually a result of health disorders and will show rashes, swelling, infection, fatigue, and overall unthriftiness as microbe levels become harmful. Vaginal ph can be altered by direct use of things as some misguided attempts at improved hygiene have shown some women but generally only is modified by foods when unhealthy items damage beneficial bacteria leading to infections. While vaginal ph does shift on it's own during estrous cycles if it consistently stays anywhere near the alkaline levels that make much difference for sperm it becomes a health issue. You are usually talking about a difference in ph between the female reproductive tract and sperm of around 4 or possibly greater. I would bet any change you can make for a long enough period of time to plan a breeding is going to cause health issues for the doe.

Because of the body's ability to keep a balanced ph and it's need to do so to avoid health problems if I actually thought it made a difference in resulting gender I'd suggest trying to change the ph of semen instead of a doe's reproductive tract. Infertility studies in human and animal have found the ph can vary quite a bit without a health problem present and at a low enough ph it will eventually cause complete infertility. Without a good enough buffer the sperm will not survive the huge ph difference before they fertilize eggs in the female reproductive tract. What has caused such a low ph in studies of otherwise healthy animals is not known though. Another thing to consider is that I found while the theory of killing some to get mostly females works in bird eggs using heat you do so at the sacrifice of how many hatch. Hatching at the extreme range of temps will give you more pullets and cut your hatch rate 20-50% due to all the roosters just staying dead in their eggs. If you have no good way to dispose of roosters that might be worth any lost pullets in the practice but if reducing semen in rabbits results in smaller litters it could have too many negatives for survival of the whole litter and what sales or meat you do get raising the males to be worth it. Lowered sperm survival is considered a fertility issue for a reason.

Times of Famine Linked to Disproportionate Number of Female Births
Cultural factors like selective abortions do not explain the trend, rather it seems evolutionary biology does

https://www.smithsonianmag.com/smart-ne ... s-1110208/

maybe feeding greens, and root crops stimulates a "famine type" response

My research is skewed toward what specifically impacts female hormones but it is quite easy to find ways the type of nutrients you take in could alter things with the reproductive tract of both genders. Various foods do have an impact on reproductive hormones and other little things in humans. Plants contain many compounds similar to our own hormones and that can be harmful or helpful. CBD oil from hemp or thc removed cannabis is useful for several disorders partially due to the fact the cannabidiol oil mimics the compounds in the endocannabinoid system the body already has receptors and it's own compounds for. That includes triggering the thyroid and reproductive hormones. Phytoestrogens are plant hormones which trigger human estrogen receptors and have long been implicated in health issues including breast cancer and reproductive problems but have also been refined for useful purposes. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3074428/
While humans cannot accomplish it and I'm not sure if herbivores can "natural" progesterone supplements that are supposed to be identical to human progesterone are modified versions of compounds from usually yams. The PS supplement I take is easier to find the whole compound already in animal brains but with mad cow disease they now alter a version from plants, which the human body can do but this skips a step to get a concentrated amount, for lowering cortisol. Stress hormones are created from the some base as some reproductive hormones so one results in less of another.

Those are extremes but even the general diet being made of grains or fresh leafy greens will impact reproductive hormones a tiny bit. Sometimes enough to eliminate negative symptoms in those prone to high or low of one thing and you can find various suggested foods to eat or avoid for both disorders and general increase in fertility. It also links to digestive health and the spread of beneficial bacteria throughout the body. Things like live ACV or some have claimed how great their animals do on fermented food will improve nutrient absorption and use overall, reduce harmful bacteria or yeast, and more directly impact what compounds the body makes out of the base ones it takes in from food.


My husband did mention last night that the male contraceptive pill they have been doing trials with and started using in some countries works by altering the ph of semen. They've gone ahead and and put it to use in some countries earlier than it's approved by government organizations like our FDA because of the added benefit that it turns out HIV can no longer survive in the ph altered semen either.