Effect Of Extremely Low Protein Diet To Meishan Gilt On Its Farrowing Performance And Characteristics And Immunity Of Its Offspring

Chinese landrace pig prefers to coarse diet, so it isn't in order to the alien pig diet. XiaoMeiShan pig was in extensive feeding and management conditions in the countryside tradition. The feed was mainly bran, aquatic feed, grass and leaves, its still has a high production performance.In this study, XiaoMeiShan gilts were as experimental animals, during pregnancy and lactation fed extremely low level protein diets to explore the reproductive performance of the gilts and their piglets on the growth and development and immune function. The aim of this study is to provided for the chinese landrace pig better diet.Experiment 1:Total of 24 healthy Meishan gilts similar in day of age and weight were selected and randomly divided into two groups:12 gilts in control group were fed with normal level protein diets; 12 gilts in treatment group were fed with extremely low level protein diets. All gilts were artificially inseminated at a same period with semen from a same Meishan boar. The results showed that:Extremely low protein diet to gilts during their gestation and lactation period, (1) did not cause changes to their delivery performance and fertility characteristics; (2) decreased body weight, liver weight, spleen weight and spleen index of their offspring at born (P<0.01); and decreased kidney weight at born(P< 0.05); (3) decreased body weight, liver weight, kidney weight, spleen weight, longissimus muscle weight and longissimus muscle ratio of their offspring at weaning (P<0.01); and decreased spleen index and psoas major weight at weaning(P<0.05); (4) did not cause significant changes to their offspring at the end of fattening when thinking of the item of terminal weight; the weight and index of spleen, heart, kidney or liver; weight and index of longissimus muscle or psoas. It is concluded that extremely low level protein diet significantly affected embryo development and offspring growth, while did not affect their prolificacy. The pigs born from those sows accepted extremely low level protein diet have supplemental growth effect after weaning.Experiment 2:The experimental animals were their piglets involved in experiment 1. Developmental changes of splenic TNF-a, IL-2 and IL-6 mRNA expression levels were detected by real-time PCR. The results showed that:Extremely low protein diet to gilts during their gestation and lactation period, (1) decreased body weight of their offspring on Od and 35d(P<0.01), decreased average daily gain of their offspring during 0-35d and 150-180d (P<0.01); (2) decreased spleen weight and spleen index of their offspring on Od (P<0.01), as well as spleen weight (P<0.01) and spleen index (P<0.05) on 35d; decreased spleen average daily gain (P<0.01) and increased spleen differentiation ratio (P <0.05) during 0-35d; (3) did not cause significant changes to splenic TNF-a mRNA and IL-2 mRNA expression levels of their offspring, but increased splenic IL-6 mRNA expression levels of their offspring at born. It is concluded that extremely low level protein diet significantly affected embryo development and suckling offspring growth, while did not keep an effect after weaning. The pigs born from those sows accepted extremely low level protein diet have supplemental growth effect after weaning.Experiment 3:The experimental animals were their piglets involved in experiment 1. The small intestine sections (including the duodenum, jejunum and ileum) of new-born and weaning piglets were for HE staining to compare the differences of morphology and development of small intestine between the control group and treatment group. The aim is to study the effect of intestine development and immunity function involved of their piglets with the maternal extremely low protein. The results showed that:Extremely low protein diet to gilts during their gestation and lactation period, (1) the newborn piglets and weaning piglet small intestine villus height, width had no significant effect (P>0.05), but it can significantly reduce the new-born piglet intestinal muscle thickness (P<0.01). (2) the average size of the offspring ileal lymphoid nodules had no significant effect (P>0.05), but lymphoid nodules arranged closer together in the control group. So we can conclude that maternal extremely low protein diets did't affect the piglets intestinal villi early development, only impact on their intestinal muscle development. And there was a certain influence on the distribution of the ileum lymphoid nodules, but it did not produce a significant effect on the intestinal immune function.