As the laying cycle progresses, eggs get bigger while the hens’ calcium (Ca) metabolism becomes disrupted. The capacity to keep hens well beyond 90 weeks emphasizes the necessity to manage eggshell quality all along the cycle to avoid some end-of-lay disorders. All the Ca deposited on the eggshell comes from the feed. Therefore, its assimilation and mineralization also rely on the bird’s digestive health status. This is where BACTOCELL probiotic comes into action.
A demanding mineralization process
Ca requirements grow with the age but should be carefully managed from the pullet stage, a critical moment for the medullary bone Ca reservoir constitution. During egg production, this reserve is mobilized into the uterine gland for shell mineralization. When blood Ca levels become critical, a Ca resorption from bones process is initiated.
Ca metabolism in laying hens is a dynamic process highly regulated by environmental (light) and biochemical (minerals, vitamins, and hormones) stimuli. The Ca pathways are regulated by the calcitriol hormone and by the parathyroid hormone. Both act jointly to increase the circulating level of Ca by triggering the mobilization from the bone, kidney, and intestinal origin (from feed) when Ca is needed.
BACTOCELL benefits eggshell quality
A trial performed at Dankook University (South Korea) has investigated original parameters such as hormonal and mineral blood and bone markers in relatively mature hens (50-week old Hy-line). BACTOCELL and control hens were fed a standard diet with 10% suboptimal level of Ca and Phosphorus (P) levels.
Results confirm the previously observed positive incidence of the probiotic supplement on egg production (Figure 1) and egg weight (+1%; p<0.05).
Figure 1 – Effect of BACTOCELL on the rejected rate (p=0.072)
This higher production partially comes from a significant reduction of the rejected eggs criteria, and notably a positive incidence on the broken percentage.
Starting with similar retentions at week 1, both the Ca and P retentions were improved after the 14-week BACTOCELL supplementation as compared to control. This reflects a better utilization of the dietary mineral sources, which supports eggshell quality.
Hormonal activities related to Ca metabolism have been also analyzed. The calcitriol blood concentration was increased by 83% after the 14-week treatment duration when compared with the control group (Figure 2).
Figure 2 – Effect of BACTOCELL on blood markers of the Ca metabolism (p<0.05)
In this trial, probiotic supplementation showed stimulation of the calcitriol activity in the advanced hen laying cycle (>50 weeks; Figure 2). This resulted in a better Ca dietary absorption without affecting the bones, and mineral content.