Genetics of sow reproduction, including puberty, oestrus, pregnancy, farrowing and lactation

The possibility to improve different sow reproduction traits, such as age a t puberty, oestrous symptoms, ability to become pregnant, litter size, pigl et survival and weight, milk production, maternal behaviour and ability to show oestrus after weaning, are discussed in this review. Relations between different reproduction traits as well as between reproduction and producti on traits are also described. The current genetic progress in litter size a t birth increases the need for a broader breeding program which includes pi glet survival and growth. (C) 2000 Elsevier Science B.V. All rights reserve d.