Effect of Hydroponic Barley Seedlings Substituting for Different Ratios of Basal Diets on Serum Biochemical Indexes and Rumen Fluid Microbial Diversity in Lactating Ewes

The purpose of this study was to investigate the effects of hydroponic barley seedlings on serum biochemical indices and rumen microbial diversity of lactating ewes instead of different proportion of basal diet. It provides theoretical basis for the health and scientific feeding and management of hydroponic barley seedlings in ruminants. Forty-eight lactation sheep with 2-3 years old, second and third parity, 45 ±5 kg weight, 6 ±2 lambing days and two lambing number, respectively were randomly divided into 6 groups of 8 repeats in each group and the experimental period was 36 days, including the pre-feeding period of 6 days and the formal period of 30 days. (1) Growth performance, the average daily gain of ewes was increased as the proportion of hydroponic barley seedlings increased and reached the highest in group C. The average daily gain of ewes in group B was the lowest, which may be caused by the low dry matter intake of large-sized sheep. (2) Regarding blood biochemical indexes, the content of total superoxide dismutase (T-SOD) in groups A and B was significantly higher than in groups CK1, CK2, A, B, C and D (P 0.05). The content of malondialdehyde (MDA) in group A, C was significantly lower than in groups CK1 and CK2 (P 0.05). The content of triglyceride (TG) in group D was significantly higher than in groups CK1 and CK2 (P 0.05). The content of total protein (TP) in groups A, B, C and D was significantly higher than in group CK1 (P 0.05), and groups C and D was significantly higher than in groups CK2 (P 0.05). The content of glucose (GLU) in group D was significantly higher thanin groups CK1 and CK2 (P 0.05). The content of interleukin-1β (IL-1β) in groups C and D was significantly higher than in groups CK1 and CK2 (P 0.05). The content of interleukin-2β (IL-2β) in groups A and D was significantly higher than in groups CK1 and CK2 (P 0.05). The content of interferon gamma (IFN-γ) in groups A and D was significantly higher than in groups CK1 and CK2 (P 0.05). The content of CD4 in groups A, B and C was significantly higher than in group CK2 (P 0.05), and group D was significantly higher thanin group CK1 (P 0.05). (3) Microbial diversity in rumen fluid: there was no significant effect of different barley seedling ratios on in rumen fluid of ewes, and the coverage of each group was more than 0.99. The results showed that the microbial diversity data of each group acted accurately on the composition of rumen fluid microflora in lactating ewes. Different ratios of hydroponic barley seedlings could increase the relative abundance of Firmicutes, Actinobacteriota, Prevotella, Selenomonas, unclassified_ Prevotella and unclassified_ Selenomonas in the rumen fluid of ewes. Hydroponic barley seedlings can be used as supplementary green feed and can not only replace part of the basic diet. Mostly it can also improve the immune performance of female animals and alleviate oxidative stress. It can be concluded that in the ewes’ diet 10%-15% inclusion of Hydroponic barley seedlings is helpful to improve the overall performances of the animal.