In Vitro Screening Of Drinking Acidifier And Its Effects On Growth Performance,Tibia Quality And Gut Health Of Broilers

In this test,the effect of adding acidifiers(2-hydroxy-4-methylthiobutyric acid,lactic acid and phosphoric acid,of which 2-hydroxy-4-methylthiobutyric acid ≥ 44%)on the hardness and acidity of drinking water and In vitro antibacterial effect,screening of drinking water acidifier,and then,to study the effect of drinking water acidifier on broiler production performance,intestinal health and tibia quality,to provide scientific reference for the improvement of broiler production performance;Experiment 1 In vitro antibacterial test of compound acidifierIn order to study the effect of compound acidifier on the hardness and acidity of drinking water,Ca CO3 was used to adjust the water hardness to 100,200,and 400 mg/L,and then different concentrations of compound acidifier(0.02%,0.04%,0.06%,0.08%,0.10%,0.15% and 0.20%)were added to water with different hardness,and the effect of acidifier on the acidity and hardness of water with different hardness was determined.The results showed that the addition of 0.02-0.20% acidifier in drinking water had no significant effect on the hardness of drinking water,while the addition of compound acidifier in drinking water significantly decreased the p H value of drinking water(P <0.01).The effect of concentration compound acidifier(0.05%,0.10%,0.15% and 0.20%)on the bacteriostatic effect of Salmonococcus and Escherichia coli,the test found that compared with 0.05% group,the addition of 0.10 – 0.20 % compound acidifier in drinking water significantly increased the inhibitory diameters of Salmonella and Staphylococcus(P < 0.05).adding 0.10-0.20% acidifier to drinking water significantly increased the inhibitory diameter of Salmonella and Staphylococcus(P < 0.05).The results showed that adding 0.10-0.20% compound acidifier to drinking water can significantly reduce the acidity of drinking water and exhibit significant bacteriostatic effect.Experiment 2 Effects of compound acidifier on performance of broilersSubsequently,the purpose of this experiment was to explore the effect of compound acidifier on the performance and tibia quality of broilers.600 1-day-old AA broilers with similar body weight were randomly divided into 5 treatments,namely adding 0.05%,0.10%,0.15 % and 0.20% compound acidifier,6 replicates for each treatment,half male and female for each replicate,and the rearing period was 42 days.All chickens are fed the same basal diet.The results showed that the addition of compound acidifier in drinking water significantly increased the water consumption of broilers from 1-42 days(P < 0.05).The addition of 0.05-0.20% compound acidifier in drinking water linearly and quadratically increased broiler body weight at 42 d and 1-42d(P < 0.05),but had no significant effect on broiler feed intake and feed-to-weight ratio;compared with In the 0.05% and 0.01% groups,adding 0.15% or 0.20%compound acidifier in drinking water can significantly increase the body weight of broilers on 42 days and 1-42 days;the results of Broken-line weight analysis showed that the optimal addition amount of composite acidifier in drinking water was 0.128 %.In addition,the results of the test of adding 0.00 %,0.05 %,0.10 %,0.15 % and 0.20 %composite acidifiers to drinking water(five replicates for each treatment,10 chickens for each replicate)showed that there was no significant effect on the length and weight of the broiler tibia,but compared with the 0.00% group,the addition of 0.20%compound acidifier to the drinking water significantly increased the calcium content of the broiler 21 d and 42 d tibia,and had a trend of increasing the serum phosphorus in the broiler 42d(P = 0.068);and compared with the control group,the addition of 0.20 %compound acidifier in drinking water significantly reduced the contents of C-terminal cross-linked telopeptide of type I collagen(CTx)and Tartrate-resistant acid phosphatase(TRAP)in serum,which were related to bone resorption(P < 0.05).but it did not significantly change the serum bone formation-related alkaline phosphatase(Alkaline phosphatase,ALP)content(P > 0.05).The results showed that adding0.15%-0.20% compound acidifier in drinking water could significantly increase the 42-day production performance of broilers and increase tibial bone mass by inhibiting bone resorption.Experiment 3 Effects of complex acidifier on tibial mass and gut healthThe results of test 2 showed that adding 0.15%-0.20% compound acidifier to drinking water could increase the 42-day production performance of broilers and increase the calcium content of the tibia,which may be related to promoting intestinal development,increasing intestinal barrier and reducing body inflammation.The experiment was conducted to explore the effects of different levels of compound acidifiers in drinking water on the intestinal health and immune performance of broilers;250 1-day-old male broilers were randomly divided into 5 treatments,namely 0.00%,0.05%,0.10%,0.15% added in drinking water and 0.20% compound acidifier.5replicates per treatment with 10 birds per replicate.The results showed that adding 0.00-0.20% compound acidifier in drinking water could linearly and quadratic decrease the p H of glandular stomach,duodenum,jejunum,ileum and cecum of 42-day broiler chickens(P < 0.05).Adding 0.15%-0.20% compound acidifier to drinking water significantly increased the weight of duodenum and ileum in 42 d broiler chickens(P <0.05).Adding 0.15%-0.20% compound acidifier in drinking water linearly and quadratically increases the duodenal villus height and villus height/crypt depth in 21 d broilers,and adding 0.10%-0.20% compound acidifier in drinking water linearly and quadratically increases in ileal villus height and villus height/crypt depth in 42 d broilers(P < 0.05).The addition of 0.20% compound acidifier in drinking water significantly increased the m RNA levels of Occludin and Mucin-2 in the ileum of 42 d broilers(P <0.05);16S r RNA sequencing of cecal contents showed that the addition of 0.20%compound acidifier in drinking water compared with the 0.00% group The agent increased the relative abundance of Firmicutes and Bacteroidete,and decreased the relative abundance of Proteobacteria.In addition,the addition of 0.20% compound acidifier in drinking water significantly decreased the m RNA levels of proinflammatory cytokines TNF-α(P < 0.05)and IL-1β(P = 0.081)in the ileum of broilers on 42 days,and significantly decreased the IL-6 in serum(P = 0.072)and TNF-α levels of broilers on 42 days(P < 0.05);meanwhile,adding 0.20% acidifier to drinking water significantly increased the levels of Ig A,Ig G and Ig M in broiler serum(P < 0.05).The results showed that adding 0.20% compound acidifier to drinking water could promote intestinal development,increase intestinal barrier and reduce body inflammation.To sum up,adding 0.15%-0.20% compound acidifier to drinking water can increase the 42-day production performance of broilers,and its mechanism of action is related to promoting intestinal development and promoting intestinal absorption of nutrients;at the same time,promoting intestinal development and increasing the intestinal barrier can inhibit the body’s inflammation-mediated bone resorption,thereby increasing the quality of broiler tibia.