Influence of Using Various Levels of Protein Concentrate in Rations of Ayrshire Dairy Cows on Rumen Microbiome, Reproductive Traits and Economic Efficiency

SIMPLE SUMMARY: Numerous studies in animal nutrition science have demonstrated a close connection between the chemical composition and nutritional value of cow diets, the number of rumen bacterial communities and animal productive and reproductive performance. Thus, the microorganisms of cow rumen play a primary role in the processes of digestion; meanwhile, it is necessary to highlight that their functional significance is much wider. The aim of this study was to investigate the outcomes of the inclusion of different levels of protein concentrate in rations of Ayrshire dairy cows in relation to the rumen microbiome, reproductive traits and economic value. Our manuscript presents molecular biological studies to establish the quantitative and specific composition of the microorganisms of the rumen. T-RFLP analysis was performed to determine the percentage of the components of the bacterial community. The results showed that the supplementation of “Agro-Matic” caused no deviations from the normal standards of cellulolytic, amylolytic, transit and pathogenic bacteria, no impact on reproductive traits and significantly improved the profitability of the milk production process. These findings provide a scientific addition for a greater understanding of the rumen microbiome of dairy cows when supplemented by different levels of protein concentrate in their rations. ABSTRACT: Animal feeding research has revealed a close relationship between the chemical composition and nutritional value of cow rations, the number of rumen bacterial communities and animal productivity. Our present research aimed to investigate the outcome of inclusion of different levels of protein concentrate in rations of Ayrshire dairy cows in relation to the rumen microbiome, reproductive traits and economic value. Forty-five Ayrshire cows were divided into three groups (15 in each). The first control group 0 AM was fed the basal ration, while the second 1 AM and third 2 AM groups were fed the basic ration with the sunflower cake replaced by different levels of protein concentrate Agro-Matic (1 and 1.5 kg/head/day, respectively). Ruminal fluid samples, reproductive parameters and economic value were studied. During the early lactation period, 120 days in milk (DIM), the number of pathogenic microorganisms decreased in both the 1 AM and 2 AM groups when compared with the control group 0 AM; moreover, a significant decrease in Peptococcus bacteria was recorded in the 1 AM group, while Fusobacterium decreased in the 2 AM group. At the end of lactation, the total number of cellulolytic bacteria increased with the use of protein concentrate in animals of the 1 AM group when compared with the control group. Regarding undesirable bacteria, the 2 AM group recorded the highest value for Lactobacilli and Actinobacteria when compared with the 0 AM group (0.18 and 8.90 vs. 0.04 and 4.24), and the differences were significant (p < 0.05). The insemination index and the duration of the days open period decreased in the 2 AM group, while the differences were p > 0.05. The profitability of milk production increased by 2.76% and 6.28% in both supplemented groups, and the differences compared to the 0 AM group were significant. We conclude that the supplementation of Agro-Matic caused no deviations from the normal standards of cellulolytic, amylolytic, transit and pathogenic bacteria, no impact on reproductive functions and significantly improved the profitability of the milk production process of Ayrshire dairy cows.