Effects of soft acid on production performance, egg quality, and serum biochemical indexes of laying hens in late stage of laying peak.

The purpose of this experiment was to investigate the effects of different proportions of soft acid in drinking water on the production performance, egg quality, and serum biochemical indexes of Jingfen No.2 laying hens at the late of laying peak. A total of 270 Jingfen No.2 laying hens with normal body condition and similar weight at 556 days old were randomly divided into three groups with six replicates in each group and 15 laying hens in each replicate. The control group (CON group) drank tap water. 500 mg/kg and 800 mg/kg of soft acid were added to tap water in the soft acid 500 group and 800 group, respectively. The pre-test period was seven days, and the formal test period was 42 days. The results showed that compared with the control group, the unqualified egg rate of the soft acid 500 group and the soft acid 800 group decreased significantly (P<0.05), the average egg weight increased significantly (P<0.05), and the feed to egg ratio of the soft acid 800 group decreased significantly (P<0.05). Compared with the control group, the eggshell scores of soft acid 500 group and soft acid 800 group increased significantly (P<0.05), and the egg weight, yolk weight, eggshell strength, yolk ratio and yolk score all showed an increasing trend (P>0.05). Compared with the control group, the total protein content in serum of the soft acid 800 group increased significantly (P<0.05). Compared with the control group, the levels of serum IgA and IgG in the soft acid 500 group and 800 group increased significantly (P<0.05). The study indicates that adding 500 mg/kg and 800 mg/kg soft acid in drinking water has positive effects on improving production performance, egg quality, serum biochemical indexes, and immune function of Jingfen No.2 laying hens, and the effect of adding 800 mg/kg soft acid is better than that of 500 mg/kg soft acid. [ABSTRACT FROM AUTHOR]