Studies On Maternal Behaviour Of Sows And Its Relationship With Prolactin Receptor Gene

Maternal behaviour is a kind of instinctive behaviour related to offspring survival. There is large individual difference in maternal behaviour and this difference is a result of interaction between genetic and environmental effects. Minpig, well-known on good maternal ability was used in this research in order to find the advantage of Minpig in maternal ability and this advantage can be applied into modern swine production.At present, many researches have been focused on the environmental effects on maternal behaviour, but genetic background has been rarely known. Prolactin has a very important effect in the development of chicken broodiness behaviour. So prolactin receptor gene was used to be the candidate gene for maternal behaviour of sow in this research. Through investigating different maternal behaviour in Minpig and Landrace, and combined with molecular genetics and quantitative genetics method, a study was carried out preliminarily to investigate the effect of prolactin receptor gene on sow maternal behaviour. The main results are as followed:1. There was significant difference in two pig breeds in nest-building behaviour before parturition, and Minpig sows showed highly stronger than Landrace sows.2. Minpig sows were in predominance on maternal behaviours including lateral lying, ventral lying and sitting.3. There were significant differences on performance of behaviour related to crushing between these two breed. Especially Minpig had the higher carefulness score of standing-to-lying and responsiveness value of sow to a piglet distress call calculated by weight least square analysis, and this can indicated the advantage of Minpig in maternal ability.4. In this experiment, seven SNPs were identified in Exon10 of PRLR gene. The results of population genetic analysis indicated that frequencies of genotypes and genes distribution among the two populations were very significantly different. There were two points mutation belonged to silent mutation, locating respectively at 1217bp (T→C) and 1620bp (T→C) in the sequence of PRLR gene cDNA. A missense mutation of A→C was detected at the position of 1283 which could cause the substitution of Ala for Asp at this position in PRLR molecule. A missense mutation of A→G was detected at the position of 1439 which could cause the substitution of Try for Arg at this position in PRLR molecule. A missense mutation T→A was detected at the position of 1528 which could cause the substitution of Met for Leu at this position in PRLR molecule and it caused...