SNPs for More Uniform and Bigger Litters Found

by 5m Editor
9 December 2011, at 11:01am

NETHERLANDS - TOPIGS researchers have found a series of SNPs that define the region of the genome that explains genetic variation for litter size and uniformity between litters.

Using these SNPs uniformity in litter size and increased litter size can be bred for faster, more accurately and at the same time.

The genes connected to the SNPs have the phenotypic effect of increasing uniformity between litters as fewer small litters are produced. Average litter size also increases.

The difference in average litter size between pigs with the genes or without the genes is 1.2 piglets. The lowest litter size more than doubles to 2.7 piglets. See the graph as well.

Explanation: Pigs with the genotype GG have the homozygote SNPs for uniformity and litter size. Pigs with the genotype AA do not have the SNPs. AG genotypes have only part of the SNPs.

The effect of these more uniform litters with heaver piglets also influences the finishing stage. Piglets that are heavier at birth develop better in later stages. The higher uniformity pays off in the finishing stage with more uniform groups of fatteners with a higher and more efficient level of production.

We expect to find more interesting SNPs during the next few months. The knowledge gathered with genomic selection will be used in the balanced breeding programme of TOPIGS to achieve faster and more accurate genetic progress in traits for various aspects like meat quality, feed efficiency, fertility and finisher traits.

Sows with the genotype AA produce an average of 15.2 piglets per litter. The highest production is 19.8 piglets and the lowest 9.8, which is a difference of 10.

Sows with genotype GG produce an average of 16.4 piglets per litter. The highest production is 20.9 piglets and the lowest 12.5, which is a difference of 8.4. This smaller difference indicates a higher uniformity. Sows with these SNPs produce more uniform and bigger litters. The effect of more uniform and heavier piglets also influences the finishing stage. The pigs perform better, need less feed and have a better carcass quality.