What determines size of litter?

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Have had two litters from a New Zealand doe. The first litter was just three babies, and the died within a couple days. Now she has had a second litter (same young buck) and again, only three. They are fed a standard rabbit pellet, occasional alfalfa and carrots as treats. The doe is about a year old, the buck I used was 8 months old. She has been an excellent mother this time--probably heard me threatening her after the first litter's demise! Thanks for any input- Jan

-- Jan in CO (Janice12@aol.com), January 19, 2002

Answers

Hi Jan, I would guess it is genetics. Maybe try another buck? I have been told to cull all does that do not have atleast 8 kits if you are trying to do this for profit. Any replacement stock you should keep from your does that have the largest litters. That way hopefully the genitics will be there.

-- tracy (murfette@stargate.net), January 19, 2002.

Pat, First off thanks for taking the time to answer here. You are such a woderful source of information. So, what you are saying is that keeping the litters out of a good producing doe doesnt mean that you will get that size in replacement? What would be the standard for culling? How many should kits should you expect to get out of a litter before you cull?

-- tracy (murfette@stargate.net), January 19, 2002.

Surprisingly, litter size is only 5% inheritable, although it is always possible after many, many, MANY years worth of selectively breeding for litter sizes. Contributing factors are generally due to age of either the doe or buck, nutrition, too much internal fat, short & compact bodies with no room to carry larger litters, and/or not enough sperm reaching fertilization (which is why it is standard procedure to allow the buck to make contact twice with every doe). Using young, verile bucks usually takes care of the problem if it's not due to the doe or the feed.

Pat Lamar

-- Pat Lamar (fuzyfarm@3-cities.com), January 19, 2002.


First off, I haven't quite figured out how to reply to the posting that I wish to reply to, as it will most likely be a bit out of order, here.

Anyhoo.... if you have a doe that is producing 8 to 10 per litter and is able to raise them all, this means she is a good "milker." This should be a top priority! WHY she is throwing that size litter will also need to be determined. As I have said, it is quite possible for some lines to have been selected for litter sizes over the span of MANY years, and thus, selecting from a doe with this size litter CAN *possibly* count toward litter sizes. However, the chances are that her body is simply a bit longer in the midsection and with a wider rib cage spread for carrying the larger litters. This is what you need to look for. Keep that milking ability in mind, though. Afterall... what good are good sized litters if she can't produce enough milk to feed and raise them all? Some growers will weigh the litters weekly beginning at 2 weeks of age for determining the better milkers in their own herd. NOTE: These weights can NOT be compared to other herds due to different strains, different feed, different climates, different management programs, and so on. They would be applicable ONLY for comparison purposes within your own herd.

In order to be economically feasible, you will need to maintain 8 to 10 per litter as much as is possible. Culling for too many is just as important as culling for too few! More is NOT better, in this case! Over 10, the kits tend to be smaller at birth, and which means slower growth rates, and which, in turn, means more $$$$ for feeding them longer to reach marketable weights. Most growers will use the "strike 3, you're out" rule... give the doe 3 tries to produce and raise a decent litter. Once you have all your does producing decent litters, you can then begin culling on lack of receptiveness to breeding when needed to be bred. You don't need to be wasting your time with does that won't breed!

I hope this helps.

Pat Lamar

-- Pat Lamar (fuzyfarm@3-cities.com), January 19, 2002.


Thanks for the responses--gives me some more things to check out on the doe. I'm going to try some other does, and see if the results are the same with the younger buck. If so, I'll know it's him. Thanks again, Jan

-- Jan in Co (Janice12@aol.com), January 21, 2002.


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