The Alleviative Effect Of Sodium Butyrate On Yellow Broilers Reared At High Stocking Density

The growth performance and welfare of broilers affected by stocking density, high stocking densities lead to broilers in stress, and resulting in an increase of nutrition metabolism of the body, growth stunting and produce a variety of welfare problems of broilers, bringing serious economic losses to poultry industry.Studies have shown that adding sodium butyrate to broiler diets can promote intestinal development and improve growth performance of broilers, but the mechanism is not yet understood well. In this research, the effect of dietary sodium butyrate on growth performance immune organ index, antioxidant and morphology and mucosal growth-related gene expression of intestine of yellow broilers, and the effect of stocking density on growth performance, immune organ indexes and welfare quality of yellow broilers, also, the effect of sodium butyrate on production performance, immune organ indexes and welfare quality of yellow broilers at high stocking density were studied.The research was designed to determine the alleviative effect of sodium butyrate (SB) on growth performance, immune function and intestinal morphology of yellow broilers reared at high stoking density. The aim of the research is to provide a scientific basis for the scientific use of sodium butyrate and exploring healthy breeding patterns of yellow broilers. The study includes the following three sections:1. The effect of sodium butyrate on growth performance, immune function, intestinal morphology of yellow broilersA total of 384 day-old male Suqin yellow broiler chicks were allocated at random into two groups with six replicates each. Two group were fed with basal diet (control) or diets supplemented with microencapsulated sodium butyrate at the level of 500 mg/kg. The experiment lasted for 21 days. The results of the experiment showed that the dietary supplementation of sodium butyrate significantly decreased F/G and mortality (P < 0.05), and increased the tendency of the index of thymus and serum SOD of broilers (P= 0.05). In addition, dietary supplementation of SB increased villus height of duodenum (P< 0.05), and V/C of jejunum and duodenum (P< 0.05), also decreased crypt depth of jejunum and duodenum (F< 0.05). Moreover, SB increased the expression of GHR gene of jejunum of broilers (P< 0.05). The results demonstrated that basal diet added microencapsulated SB decreased the mortality and increased the immune organ index of yellow broiler, dietary SB also can increased the antioxidant capacity, improved the intestinal morphology and development, increased the expression of GHR of jejunum of yellow broilers.2. The effect of stocking density on growth performance, immune organ indexes and welfare quality of yellow broilersA total of 25221-days-old male Suqin yellow broilers were allocated at random into two groups with six replicates each. The socking density of the two groups were 10,20 bird/m2 (HSD and LSD). The experiment lasted for 35 days. The results of the experiment showed that the ADF and ADFI of HSD group were decreased (P< 0.05), and mortality were increased significantly (P< 0.05) while F/G had a tendency of increase (P= 0.05). The indexes of spleen and fabricius were significantly decreased (P< 0.05). And the indexes of plumage pollution, plumage damage, foot pad dermatitis, hock swelling, breast skin crusting and breast blister of HSD were higher than LSD (P< 0.05). The results demonstrated that high stocking density decreased the growth performance and immune organ indexes, and damaged welfare situation of yellow broilers.3. The effects of sodium butyrate on production performance, immune organ indexes and welfare quality of yellow broilers at high stocking densityA total of 336 21-days-old Suqin yellow male broilers were randomly allocated 2 groups (Basal diet and Basal diet add 500 mg/kg microencapsulated sodium butyrate) with 6 replicates per group and 28 birds per replicate (20 birds/m2). The results showed that sodium butyrate had significant effects on mortality of yellow broilers at high stocking density (P< 0.05), and significantly affected the welfare quality indexes of plumage pollution and hock swelling (P< 0.05). The results demonstrated that dietary SB decreased the mortality rate and improve the welfare situation of yellow broilers.Through the above three experiments in this study can be concluded that sodium butyrate promoted early intestinal development and decreased the mortality rate of yellow broilers; the growth performance and welfare situation of broilers were adversely affected by high stocking density, and the adverse effects were alleviated by dietary sodium butyrate.