Effects of a probiotic complex on liver morphology in broiler chickens

In industrial livestock farming, probiotic complexes of bifidobacteria and lactobacilli are used to improve the morphofunctional state of the domestic animals of the class Mammalia. In poultry farming, they are almost not used. That is why the study of the morphofunctional state of the broiler chicken organism, namely, the macro- and histoarchitectural morphology of their liver with the use of a probiotic complex of bifidobacteria and lactobacilli is an urgent issue. The absolute liver weight of the experimental broiler chickens, one-, 14-, and 42-day-old, when fed with complete feed and drinking water with the addition of a probiotic agent, did not essentially change in comparison with the indicators of the control broiler chickens. Still, a trend in its increase became visible. During ontogenetic development, the value of the absolute liver weight directly depends on the weight increase of the poultry organism during the experimental period. In pre-weaned chickens of 28 days of age, compared with the control group of birds of the same age, the absolute weight of the liver (32.3±1.07 g) was significantly (p<0.05) 1.15 times greater. With regard to the above-mentioned, the relative liver weight of the broiler chickens is the highest at the early stages of ontogenetic development, one-day-old (4.39±0.53%) and 14-day-old (4.25±0.27%) age. In comparison with the previous age groups of the chickens, the relative liver weight of the broiler chickens at 28 and 42 days of age is significantly reduced, equal to 2.27±0.12% and 1.72±0.08%, respectively, which indicates a progressive increase in their organ weight relative to the absolute liver weight. The relative liver weight in the experimental broiler chickens is similar in all age groups compared to the control ones. This confirms the positive effect of the probiotic complex of bifidobacteria and lactobacilli on the chicken organism of the experimental groups. The linear indicators and absolute weight of the liver, in the process of ontogenetic development in both control and experimental groups, are increased due to an expansion of the organ width relative to its length, as evidenced by a decrease in the liver development index in the age aspect: in the control group of one-day-old chicks, the IRP is 134.03±5.6%, in the 14-day-old chicks - 121.83±5.09%, in the 28-day-old chicks - 112.09±4.69%, in the 42-day-old chicks - 101.63±4.25%; in the broiler chicks of the experimental group, such indicators are lower - 138.96±5.81%, 116.78±4.88%, 107.44±4.49% and 98.95±4.14%, respectively.