The leptin receptor gene affects piglet behavior and growth

Area of Science:

• Animal Genetics and Genomics
• Reproductive and Developmental Biology
• Livestock Production and Management

Background:

• Low birth weight in piglets is linked to reduced vitality and impaired growth during lactation.
• A specific recessive variant (C>T) in the porcine leptin receptor gene (rs709596309) is associated with increased appetite and fatness, but its early-life effects are unknown.
• Understanding early-life impacts of genetic variants is crucial for improving piglet performance and survival.

Purpose of the Study:

• To investigate the effect of the porcine leptin receptor gene variant on birth weight and vitality of newborn piglets.
• To determine the influence of this genetic variant on piglet growth capacity during lactation and weight at weaning.
• To assess the implications of appetite-influencing genes on early developmental stages in pigs.

Main Methods:

• Experiment involved 668 purebred Duroc piglets and 74 sows, genotyped for the leptin receptor variant (CC, CT, TT).
• Piglets were weighed at birth and assessed for vitality (scale 1-3) based on behavioral observations.
• Bayesian 2-trait bivariate models and liability threshold (probit) models were used to analyze genotype effects on birth weight, vitality, and weaning traits.

Main Results:

• TT newborn piglets were significantly heavier at birth (+28g) compared to other genotypes.
• TT piglets exhibited higher vitality (6.5% higher probability of high vitality score) and suckling behavior before testing.
• TT piglets showed increased growth during lactation (+153g) and were heavier at weaning (+169g), partly compensating for maternal effects.

Conclusions:

• The studied leptin receptor gene variant influences piglet birth weight, vitality, and growth from birth through weaning.
• The TT genotype confers advantages in early-life development, enhancing piglet performance despite potential negative maternal influences.
• Appetite-regulating genes, like the leptin receptor gene, have significant developmental implications from the earliest life stages in pigs.