Data from the inbreeding studies in the United States were pooled to evaluate the magnitude of inbreeding depression in swine Bereskin et al. Results were adapted to construct Table 1.
Inbreeding of both the pigs and the dam have a substantial negative effect on litter size, pig weight and growth to days. The inbreeding of the boar had little effect on litter size or pig weight in these studies. Other research indicated that boars from highly inbred lines had more problems with lack of libido and delayed puberty than less inbred boars Hauser et al.
Inbreeding is nearly unavoidable in seedstock herds since it is frequently difficult to find new breeding stock that is not at least partially related to animals in an existing herd. Care should be taken to keep it at a fairly low level by avoiding mating of brothers with sisters or parents with their offspring. Mating of individuals with grandparents in common should also be avoided. Close breeding within small herds or familygroups not only produces rapid inbreeding buildup and, hence, depression, but can produce random losses of desirable genes.
If inbreeding builds up, the first economic effect will be that fewer boars and gilts will be available to sell. In addition, the pigs will have poorer performance so that they will not be as attractive to customers interested in performance.
Genetic improvement in swine should originate in seedstock herds. Inbreeding affects rate of genetic improvement in several ways.
There is a small increase in prepotency the degree to which a boar or gilt will pass his or her characteristics consistently. This is more than counteracted by the decline in selection intensity and loss of genetic variation.
Selection intensity is a function of the proportion of boar and gilt candidates that are actually selected. Selection will be less intense since more boars and gilts will be needed as replacements and there will be fewer to choose from. Furthermore, the variation will be less among the animals since inbreeding reduces intraline genetic variation.
Inbreeding should be avoided. This is an issue to both the seedstock producer and to breed organizations. It can be an obvious economic detriment to a seedstock producer but breed organizations also need to pay attention to inbreeding in the breed. They should be promoting breeding programs that maximize the quality of their product for commercial swine producers. There are several procedures that can be followed to avoid inbreeding.
The first, and most obvious, approach is to simply examine pedigrees before breeding commences so that closely related boars and sows do not mate. It is probably best to avoid mating individuals with parents or grandparents in common. Producers should also be encouraged to keep the ratio of females to males low. Mating large numbers of sows to each boar will tend to increase inbreeding.
This, obviously, is a consideration when artificial insemination is used. It is also helpful to keep replacement breeding stock from several parents instead of making one, or a few, boar or boars the focus of the breeding program. Inbreeding can have several benefits to a seedstock producer if the breeder understands how to monitor it and is willing to sacrifice some performance in the process. Inbreeding tends to subdivide a breed into families that can be identified and crossed with some small benefit.
Creation of families is unlikely to contribute to genetic improvement but may aid in merchandising if other members of the family have done well. If not, you are just getting another generation of piglets that will have a higher risk of problems yet a lower level of hardiness and vigor.
What this means is that breeding siblings together does not concentrate the genetics the same way as breeding parent to piglet, even though you are using closely related pigs in both cases. This also means that breeding siblings is not taking your breeding program in any specific direction, since this generation is genetically the same as the one before. Breeding littermates is a way to see what diversity you have in your genetics, since it kind of recombines or reshuffles the genes in the littermates to see what traits you have to work with.
For anyone with a small herd, using a half sibling breeding pair is less likely to cause problems than breeding a parent to his or her piglet. Using grandparents on grandpiglets or breeding pigs with a grandparent in common is not surprising, especially in breeds with small numbers of breeding stock or when a certain boar line remains popular for multiple years. And, once again, if you are new to pigs, you may not know what the parents of your breeding stock are, meaning you could be using relatives as breeding boars and not realizing that you are doing it.
If you are not seeing the growth rate and vitality you would expect in your piglets, consider using a different line of genetics to get better results. Small scale pig keeping: why inbreeding matters by Dr. Michaela Giles notes that the breed average of inbreeding in the U. She also has an extensive chart on percent relatedness of different breeding options. This is four generations of using non related breeding stock.
This is related to the probability that both copies of any given gene are derived from the same ancestor. A cousin-to-cousin mating actually gives a relatively low percentage 6. Is linebreeding or inbreeding safe? In his blog, David also states that in his opinion, this is neither good nor bad in itself.
Carriers can have normal builds, but statistically, if one carrier is mated to another carrier it is likely that one or more offspring could be born with Dwarfism. What not to feed pigs from the garden are unripened tomatoes, raw potatoes, raw sweet potatoes, parsnips, celery, celery root, parsley, onions, avocados, and rhubarb. Pigs can eat almost everything else you plant though. Begin typing your search term above and press enter to search. Press ESC to cancel.
Skip to content Home Essay Can you breed pigs that have same dad? Ben Davis January 26, Can you breed pigs that have same dad? Can you breed related pigs? What happens if you inbreed pigs? Is inbreeding bad for pigs? Can a brother and sister pig have babies? What are the disadvantages of inbreeding?
Can siblings from different litters mate? What do pregnant pigs need to eat?
0コメント