The probability a sow will have a big litter

[Mikethepigman]

So here's the thing..

Have a sow,twice I've gotten 7 pups. What's the chances she will have bigger litter numbers? Also is it one of those things where if the gilt didn't come from a big litter then she too will have a small litter? And how much of a roll in litter numbers does the boar play?

 

[NH homesteader]

Good question. I have no idea. @farmerjan and @misfitmorgan might. Seven isn't that many for a full size sow though for later litters. My husband thinks they usually have larger litters as they have more pregnancies. Not totally sure though

 

[Mikethepigman]

No. I'd like 12-15 per litter, 8 pups will cover feed bill and part cost of boar. I've got some gilts that came from a litter of 14, so guess I wondering if they will have big litters or if my boar could cause small litters? Idk never really got a straight answer from anyone I've asked.figured someone on here would have some good insight on this.

 

[NH homesteader]

If I run into our friend who's been breeding pigs forever I'll ask him. But I bet one of the people I tagged will know!

 

[Mikethepigman]

Ok thanks. I've asked a hand full oh folks, and checked Google but nothing to give me a good belief. I would like to better my breeding program, and litter number is something I'd like to improve on. I appreciate your help @NH homesteader

 

[frustratedearthmother]

I'm gonna chime in here - but in NO way am I a pig expert. However, I have always heard/thought/understood that the male of the species determines the sex of the offspring, and the female of the species determines the amount. The female releases eggs and eggs are what are fertilized so she has to have a big part in it. But, just to throw a wrench in it - if the male has a low sperm count then its possible that all eggs wouldn't be fertilized.

 

[NH homesteader]

See I should have tagged you! I didn't know that!

 

[frustratedearthmother]

There can be other variables, but that's a simplistic explanation. There are lots of things that can come into play. Timing of mating can influence things also...the female might have released a lot of eggs, but if the mating time is either too early or too late they may or may not all get fertilized. Female has to have a decent diet to release a good amount of eggs...uterus has to be healthy enough for implantation...etc...etc...etc.

 

[misfitmorgan]

So here's the thing..

Have a sow,twice I've gotten 7 pups. What's the chances she will have bigger litter numbers? Also is it one of those things where if the gilt didn't come from a big litter then she too will have a small litter? And how much of a roll in litter numbers does the boar play?

The problem of small litters is kind of a hard one when you only have one sow. Generally if you have a few sows and they all throw small litters the problem is your boar. With just 1 of each it is hard to know who is having the issue but i would guess it is the boar.

Typically unless you have landrace pigs you do not want more then 12 piglets in a litter as mom sow only has 12 teats. If all 12 teats do not work then you need to look at a smaller litter, our duroc sow has two non-functioning teats so we wounldnt want more then 10 piglets per litter with her. You can have more piglets then teats of course but more often then not the "extras" die and your entire litter will be more prone to being runty because of reduced calories. They may not appear runty at first but if compared to a smaller size litter of piglets they will be smaller at birth and at wean on average.

The number of piglets in the litter the gilt comes from does play a part which depends on the genetics the sow had. This can be completely mis-leading though as the sow's genetics may say she is capable of having 12-18 piglets per litter but if the boar doesnt do his job she may only produce 8 making the breeder think her genetics are only ment to produce smaller litters. So if you got a gilt from the 8 piglet litter her genetics would be for large litters but you wouldnt know that if you only went off the size of litter she came from.

Conversely the sow could have genetics for large litters and the boar could have genetics for small litters, so which the gilt would have is a roll of the dice even if she came from a small litter, she could end up being a large or small litter producer.

The boar plays a very large role in the litter size. Small litters could be due to a imature boar, an inexperienced boar, a boar with low mobility sperm, etc.

Most farmers have several gilts/sows and pu the boar to all of them and see the results that is how you figure out if the boar is good or not. We recently sent our new boar to freezer camp for not producing. The boar had 3 heats to breed 5 gilts and after 3 heats for each of them we ended up with one gilt pregnant with 4 piglets. That is a pretty good indication of the boar having an issue. Out of 15 heats total he only got one pregnant.

The other option is to AI the gilt with proven boar semen but unless you have practice doing AI on pigs a small litter or no litter could still be human error. Luckily AI'ing pigs is quite easy and if we AI twice in a row and both litters come out small we generally assume it is the gilt and replace her.

Out of curiosity...any reason your calling them pups?

 

[misfitmorgan]

There can be other variables, but that's a simplistic explanation. There are lots of things that can come into play. Timing of mating can influence things also...the female might have released a lot of eggs, but if the mating time is either too early or too late they may or may not all get fertilized. Female has to have a decent diet to release a good amount of eggs...uterus has to be healthy enough for implantation...etc...etc...etc.

Very much so, that is why keeping track of heat cycles is very important in pigs if the boar is not housed with them. When we use a boar we put him in 2 days before heat starts leave him in for 5 days of heat and pull him out the day after..so in total the boar is in with the gilt for 8 days so we dont miss the best breeding window.