نوع مقاله : مقاله پژوهشی
عنوان مقاله English
نویسندگان English
Evaluation of a commercial probiotic (Parsilact®) on performance, egg quality, ileal microbial population, intestinal morphology, and blood biochemical parameters in high- and low-producing laying hens
Introduction:
An important issue that must be considered regarding laying hens is that maintaining high production is desirable to be continuous so that economic profitability is ensured. As laying hens age, they experience a greater decline in production, which leads to reduced economic returns. One of the strategies that can be mentioned to address this issue is the use of compounds that enhance gastrointestinal health, such as antibiotics, probiotics, prebiotics, synbiotics, and postbiotics. Therefore, the aim of this study was to investigate the effect of probiotics in high-producing hens (production rate above 90%) and low-producing hens (production rate below 70%), and to determine whether probiotics can increase the production percentage or production indices in low-producing hens. At the same time, the response of high-producing hens to probiotic consumption was also studied.
Material and Methods:
To separate low-producing and high-producing laying hens in terms of production percentage before the start of the experimental research, a total of 870 Shaver laying hens (495 days old) were placed under daily supervision and monitored for egg production for 30 days. At the end of this period, laying hens with production above 95% at 525 days of age were identified as high-producing hens, while those with production below 70% were identified as low-producing hens. Then, they were randomly divided into two groups (high-producing and low-producing), and each of these two groups was further divided into two other subgroups until Parsilact probiotic was added to their feed and used in the study. Low-producing hens were assessed for health and reproductive system disorders to ensure they did not have physiological problems in their egg-producing organs. Finally, a total of 48 Shaver laying hens (525 days old) were randomly allocated to 4 treatments, 6 replicates, with 2 observations per replicate. The experimental treatments were as follows: T1 - High-producing control (high-producing control), T2 - High-producing with Parsilact probiotic, T3 - Low-producing control (low-producing control), T4 - Low-producing with Parsilact probiotic. Finally, performance indices, egg quality indices, gut microbiota population, intestinal morphology, and blood indices were measured and evaluated.
Result and Discussion:
The effect of experimental treatments on performance indices showed a statistically significant difference between the high-producing and low-producing groups, such that the production percentage and egg mass were significantly higher in high-producing hens compared to low-producing hens. A significant interaction effect of treatments on egg weight was also observed, such that the high-producing control group had a higher mean egg weight compared to other treatments. Additionally, egg mass in the high-producing Parsilact group was significantly higher than in the low-producing Parsilact group. Regarding the effect of experimental treatments on egg quality indices, the high-producing treatment showed a higher relative albumen (white) weight. Similarly, the high-producing Parsilact treatment demonstrated significantly better shell thickness compared to the low-producing Parsilact treatment. Regarding the effect of experimental treatments on gut microbiota population, the results showed that the amount of Lactobacillus in the control group was significantly higher than in the groups consuming the Parsilact probiotic. The effect of experimental treatments on blood indices indicated that between the high-producing and low-producing treatments, the high-producing group had lower HDL, higher triglycerides, and lower glucose compared to the low-producing group. Additionally, the interaction effects of treatments showed that the low-producing Parsilact treatment demonstrated significantly higher cholesterol compared to the high-producing Parsilact treatment. The high-producing control group showed higher triglyceride levels compared to the other three treatments. Furthermore, the high-producing Parsilact treatment showed significantly higher thiol levels compared to the high-producing control and low-producing Parsilact treatments. Various studies have reported different effects when using probiotics on the performance indices of laying hens. This increase in performance is mainly due to improved physiological conditions of the digestive tract, ultimately leading to better nutrient digestion and improved gut microbiota balance. However, in this study, no significant effect on performance indices using Parsilact probiotic was observed, which may be attributed to the advanced age of the hens, the probiotic concentration, and the production level. Regarding the effect of probiotics on microbiota population, it has been shown to be highly dependent on the probiotic strain and concentration, which can sometimes lead to a decrease in these populations compared to the control group. Regarding the effect of probiotics on serum glucose concentration, it has been stated that the use of this probiotic can cause a significant reduction in glucose in high-producing hens. In relation to the cause of this phenomenon, the authors discussed several physiological and microbiological mechanisms.
Conclusion:
This study showed that the use of the probiotic Parsilact was not able to produce a statistically significant difference in the performance indices of low-producing 75-week-old laying hens, which may be due to the advanced age of the treated birds. In addition, the Parsilact probiotic caused a significant reduction in Lactobacillus bacteria. The results of this study also indicated that low-producing hens usually exhibit higher glucose levels compared to high-producing hens, which suggests a higher glucose metabolism in high-producing birds.
Keywords: Laying hens, probiotics, high production, low production
کلیدواژهها English
