Large litters result in more competition for teat space. Piglet viability, survival and growth is dependent on birth weight, colostrum access and milk intake.A sow’s capacity to produce milk varies during lactation. Milk production is a complex process; however it is a heritable trait. Hermitage farms in Ireland have weighed in excess of 6,000 litters and have demonstrated the high potential in milk output by measuring litter weight at weaning.Top weights recorded are 140Kgs litter weight at 27 days of age.

As a greater number of piglets are born alive, there is larger variation in birth weights.Variation in piglet weaning weight results in increased variation throughout the pig’s life. Recent work at Hermitage has shown a 1kg difference at weaning can result in a 5kg difference at slaughter giving an economic advantage of £2.50 per finished pig.

The results from this work have demonstrated that there is a significant variation in the weaning weight output of Maternal Line sows. Sows producing heavier litters at weaning are profitable for two reasons:

1. A heavier piglet at weaning is better prepared to deal with various challenges at weaning.These heavier weaned pigs achieve slaughter weight more efficiently and economically, producing the ‘Full Value’ pig.

2.Sows producing heavier pigs at weaning have an increased feed intake and better feed conversion ratio of feed intake to piglet gain, which creates a more economical and profitable lactating sow.