Investigation Of Risk Factors Associated With Lameness Of Dairy Cows And Correlation Between Different Degree Lameness And Biochemical Indexes In The Plasma Of Dairy Cows

Lameness is the main problem of affecting the health of dairy cows as a stressor. In this study,Locomotion score of milking cows in a large-scale farm from Heilongjiang province wasconducted using a five-point scale, parity, average daily milk production, dry matter intake, bodycondition score, and hoof trimming or not were recorded.147plasma samples of dairy cows withdifferent degree lameness were collected, energy metabolism indexes, inflammatory indexes,Immunoglobulin G, and mineral elements were measured; at the same time,49plasma samplesof milking cows with different degree lameness were collected to measure reproductivehormones within50days postpartum. That risk factors of lameness and correlation betweendifferent degree lameness and biochemical indexes were expounded clearly.Results of analysis associated with lameness revealed that risk factors of score2were averagedaily milk production, dry matter intake, and hoof trimming or not; risk factors of score3~5were average daily milk production, dry matter intake, parity, and hoof trimming or not. Hooftrimming is the biggest factor affecting incidence of lameness among them. Further analysis wasmade to find that milk production was reducing gradually following with degree of lameness wasseriously increasing, average daily milk production of health cows was higher5kg than milkyield of score5, average daily milk production of score4~5was significantly lower than averagemilk production of the whole herds.Results of correlation analysis between different degree lameness and biochemical indexes inthe plasma revealed that13variables were related to the degree of lameness among energymetabolism indexes, inflammatory indexes, IgG, and mineral elements, of which Mo, Fe, NEFA,BUN, BHBA, IgG, Ca, and Se had a significant effect on the degree of lameness(score1~5);plasma indexes of score1were regarded as the benchmark, NEFA was the significant factor ofscore2, score3, score5, Fe and Ca were the significant factors of score4. Results of hormoneindexes revealed that GnRH, FSH, E2, PGF2α showed a decreasing trend with different degree aslocomotion score increased.In this study, risk factors of dairy cows with different degree lameness and relevance betweenthe degree of lameness and biochemical indexes in the plasma were made it clear to investigate the situation of lameness in milking cows from a large-scale farm and to analyze variation ofmetabolism indexes, inflammatory indexes, IgG, reproductive hormones, and mineral elementsin the plasma of dairy cows with different degree lameness, a theoretical basis for preventing andcontrolling lameness of dairy cows, and exploring the mechanism of effects on the health ofdairy cows.