is it the dog or bitch that determins the litter size, we have found a great stud dog to use in the future who is proven but has only had small litters in the past for the breed and would like to know in your experience does this mean he will always have small litters.
                                                Many thanks for all your help.

the bitch normally

Litter size is more reliant on the timing of the mating than anything else. The more eggs that are ready to be fertilised when the mating takes place the bigger the litter. If you mate early or late you will get smaller litters. Thats the theory anyway :)

I suppose the sire has been fertiltiy checked?

There are a number of factors that can affect litter size. The number of eggs released by the bitch, the mating taking place at the optimum time, the active  sperm count of the dog all play a part.

The Bitch - Depends on amount of eggs and the sperm reaching them in the right time

Agree with Lois.  Litter size is up to the bitch.  Sex of pups is up to the sire.

Litter size is up to the bitch.  Sex of pups is up to the sire

I would question that to be honest as it is all down to genetics and the amount of times you get them to tie ? :-)

I have always thought it to be the bitch and timing of the mating. Obviously you need to mate when the eggs are ready and use a fertile stud!!

Litter size is entirely dependent on the female.
Firstly, how many eggs she has released...
And secondly how many of those eggs once fertilised, she can accommodate. If she has too many embryos for her body size then some will be reabsorbed... and that is not sex-selective, just according to what she can comfortably incubate to full birth development... it's random.

The male doesn't really influence the sex of babies to any degree - it is pot luck which, on average, pans out to be 50/50.

He contributes XY, and female contributes XX.
The male makes equal amounts of X and Y sperm. Once released, and they go to find the female's eggs, it's down to chance which of his Y sperm find an X making a male, and which of his X sperm find an X making a female.

> I would question that to be honest as it is all down to genetics and the amount of times you get them to tie ? :-)

I have had my largest litter from a slip mating which was 12 (average for my breed is 6!)

My largest littter of 9 was from a single mating.  I have had 4 pups several times from multiple matings.

>The male doesn't really influence the sex of babies to any degree - it is pot luck which, on average, pans out to be 50/50.

The sex of the individual sperm that fertilises the egg is what determines the sex of the puppy; gender is entirely down to the male.

One mating and tie and a litter of 8 comprising 4 of each. Now the last time I used this dog to the bitches mother there was only 5 pups and 4 were dogs and 1 bitch so I really believe it to be pot luck on gender but size IMO depends on the time being right.

i agree AlisonGold.

Of course it is pot luck on gender because it depends which sperm actually fertilise the eggs - but it is still the SPERM that determines the sex of the pups and not the EGGS so obviously it is the dog that is responsible ! It depends on the number of eggs available to be fertilised so the BITCH determines litter size. It is the same principle for humans on both counts.
It really annoys me when I see stud dogs advertised with the comment that they consistently sire big litters - as if litter size is down to them when it isn't. Although, it could be argued that they sire big litters since they are good stud dogs and so know when is the optimum time to mate a bitch ?

Spot on cavlover!  :-)

but it is still the SPERM that determines the sex of the pups and not the EGGS so obviously it is the dog that is responsible 
But as the dog will have sperm carrying male as well as female it will all depend on which sperm is the first into the egg.
I agree about people advertising their stud dogs like that. I know of someone that tells people that their dog is a prolific stud dog. Well as he mostly is used on their own bitches only I am sure multiple mating will be taking place.

> It really annoys me when I see stud dogs advertised with the comment that they consistently sire big litters

I totally agree!! I had an enquiry by email the other week and all it said was 'how many pups does he produce in a litter'

I sent an email explaining and that I thought they should research breeding before they mated their bitch!!

People that advertise their studs like that clearly have no understanding about breeding dogs and use this to just try to get more stud work for their dog equalling more money!

Definately the bitch for litter size, there can be millions of sperm but they can only fertilize what eggs are there and then as has already been said not all of those may go on to implant either so all determined by the bitch.

I had one bitch mated several times...had a miss and then 2 pups, her last litter was 1 mating and produced 12!  All about timing

I'm probably talking rubbish here but does it not work a bit like humans....ie.  male sperm swim faster but die quicker and female swim slower but live longer therefore a mating being a bit on the early side may produce a higher (although not only) number of females and a mating done just before the bitch goes over will produce more males?
Is there also not something to do with the acidity in the vagina, that male and female sperm survive longer or shorter depending apon the acid/akaline?  I know there is a lot of evidance in humans with about this and about people wanting certain sex babies altering their diet.

I suppose there is a multitude of factors and when mixed all together comes down to luck :-)

Litter one - one mating on day 13 - 14 puppies - 9 bitches & 5 dogs.
Litter two (Bitch from litter one) - one mating - day 13 - 14 puppies - 6 bitches & 8 dogs.
Litter three (Repeat of 2nd litter) - one  mating - day 13 - 14 puppies - 9 bitches & 5 dogs.

> I'm probably talking rubbish here but does it not work a bit like humans

No, not rubbish.  Your post makes perfect sense.  :-)

think you have a very fertile bitch there with perfect timings - Blimey :)

Thank God mine rarely have more than half that number, phew.

Actually I poorly worded that.  Litters 2 & 3 were from a bitch born in litter 1, does that make sense?  Litter 1 was my 'M' litter and Miranda from that litter, was dam of litters 2 & 3.    

A different Munster bitch gave birth to 15 (or was it 16?) last year - all survived!

> Actually I poorly worded that.  Litters 2 & 3 were from a bitch born in litter 1, does that make sense?  Litter 1 was my 'M' litter and Miranda from that litter, was dam of litters 2 & 3. 

That makes sense to me. I have always found litter size gets passed down the female line - if you have a dam who has large litters, chances are her female offspring will follow suit. That's how it has worked for me in other species; I've never bred dogs (and probably never will).

Needless to say the bitch I kept from litter 2 never had a litter, I don't think I could face that anymore!  She has been a good 'career' girl!