Study on the Effects of Compound Probiotics on Improving Laying Performance and Egg Quality of Laying Hens

GOU Zhongyong; FAN Qiuli; DING Fayuan; CHENG Zhonggang; CHEN Limin; LIN Xiajing; WANG Yibing; ZHANG Sai; RUAN Dong; YE Jinling; MA Manting; JIANG Shouqun

doi:10.19978/j.cnki.xmsy.2025.04.01

Abstract：This study aimed to investigate the effects of dietary supplementation with different doses of compound probiotics on production performance,egg quality,reproduction-related traits and organ indices in old aged laying hens.A total of 288 Jingfen laying hens aged 68 weeks with normal egg production were selected and randomly divided into 4 groups based on similar laying rates.The basal diet was supplemented with 0,200,300,and 400 mg/kg of compound probiotics,respectively.The results showed that:dietary supplementation with compound probiotics exhibited certain trends in affecting the laying rate and daily egg mass(EM)(P<0.10).With the dietary supplementation level of probiotics increased,the laying rate demonstrated a significant linear increase(P=0.047),while daily EM showed a tendency toward linear increase(P=0.092).Meanwhile,the unqualified egg rate exhibited a tendency toward linear decrease(P=0.078).Eggs from the 300 mg/kg group had the highest eggshell strength,significantly exceeding the other 3 groups(P<0.05).With increasing dietary probiotic levels,Haugh unit displayed a significant quadratic effect characterized by an initial increase followed by a slight decrease(P=0.005).The number of dominant follicles also showed a trend of initial increase followed by decrease(P=0.078).Dietary probiotics significantly affected abdominal fat percentage(AF%)(P=0.037),with the lowest value observed in the 300 mg/kg group.Based on the significance(P values)and correlation coefficients(R2)of quadratic polynomial or broken-line models established for Haugh unit and AF%in response to probiotic dosage,and considering all experimental indicators comprehensively,the optimal dietary supplementation level of compound probiotics for aged laying hens was determined to be 300 mg/kg.