Genetic parameters for birth weight and litter size in Danish organic pigs

TY - ABST

T1 - Genetic parameters for birth weight and litter size in Danish organic pigs

AU - Zaalberg, Roos Marina

AU - Chu, Thinh Tuan

AU - Villumsen, Trine Michelle

AU - Jensen, Just

PY - 2021/8

Y1 - 2021/8

N2 - Denmark is the leading European country in organic pig production. Currently, 3.7% of all living pigs in Denmark is kept under organic conditions, whereas the European average is 1%. Compared to conventional pigs, organic pigs have more allocated space, they have access to different feed types, and they have a higher infection pressure due to outdoor conditions. Hence, organic pig farmers prefer smaller litters with stronger piglets to large litters with smaller piglets. The current organic pig breeding program is highly dependent on germ plasm from conventional pig breeding programs. Conventional breeding programs aim at increasing litter size. Consequently, the organic pig population follows this genetic trend. The strong differences between the conventional and organic production system demand for a reevaluation of the breeding strategy. Yet, little is known about the genetic parameters for traits under outdoor or organic conditions, such as litter size or birth weight. This study aimed at estimating genetic parameters for litter size and birth weight in organic pigs. Data were collected from March 2018 through October 2020 from a Danish organic multiplier pig farm. For birth weight, 18,971 records were available. For litter size, 2,985 litter records from 963 sows were available, with information on total litter size, number of live‐born, and number of stillborn. Statistical analyses were performed with DMU software, using a maternal effects model for birth weight (piglet records), and a repeatability model for litter size (sow records). For birth weight, the heritability estimate of the direct effects of the piglet estimate waslow (0.02), whereas maternal heritability was higher (0.19). Heritability for total litter size was 0.13, for live born 0.10, and for stillborn 0.06. In conclusion, heritability for litter size traits under outdoor conditions varied from low to moderate. Direct heritability for birth weight was negligible compared to the high maternal heritability. Moreover, these results show that birth weight in organic pigs is a maternal trait, rather than a piglet trait. This is the first time that genetic parameters were estimated for litter size and birth weight in pigs under organic or outdoor conditions.

AB - Denmark is the leading European country in organic pig production. Currently, 3.7% of all living pigs in Denmark is kept under organic conditions, whereas the European average is 1%. Compared to conventional pigs, organic pigs have more allocated space, they have access to different feed types, and they have a higher infection pressure due to outdoor conditions. Hence, organic pig farmers prefer smaller litters with stronger piglets to large litters with smaller piglets. The current organic pig breeding program is highly dependent on germ plasm from conventional pig breeding programs. Conventional breeding programs aim at increasing litter size. Consequently, the organic pig population follows this genetic trend. The strong differences between the conventional and organic production system demand for a reevaluation of the breeding strategy. Yet, little is known about the genetic parameters for traits under outdoor or organic conditions, such as litter size or birth weight. This study aimed at estimating genetic parameters for litter size and birth weight in organic pigs. Data were collected from March 2018 through October 2020 from a Danish organic multiplier pig farm. For birth weight, 18,971 records were available. For litter size, 2,985 litter records from 963 sows were available, with information on total litter size, number of live‐born, and number of stillborn. Statistical analyses were performed with DMU software, using a maternal effects model for birth weight (piglet records), and a repeatability model for litter size (sow records). For birth weight, the heritability estimate of the direct effects of the piglet estimate waslow (0.02), whereas maternal heritability was higher (0.19). Heritability for total litter size was 0.13, for live born 0.10, and for stillborn 0.06. In conclusion, heritability for litter size traits under outdoor conditions varied from low to moderate. Direct heritability for birth weight was negligible compared to the high maternal heritability. Moreover, these results show that birth weight in organic pigs is a maternal trait, rather than a piglet trait. This is the first time that genetic parameters were estimated for litter size and birth weight in pigs under organic or outdoor conditions.

U2 - 10.3920/978-90-8686-918-3

DO - 10.3920/978-90-8686-918-3

M3 - Konferenceabstrakt i proceedings

SN - 978-90-8686-366-2

VL - 27

T3 - EAAP Book of Abstracts

BT - Book of Abstracts of the 72nd Annual Meeting of the European Federation of Animal Science

PB - Wageningen Academic Publicers

T2 - 72nd Annual Meeting of the European Federation of Animal Science

Y2 - 29 August 2021 through 3 September 2021

ER -