Effects of flaxseed hull meal on rumen fermentation,plasma parameters,nutrient apparent digestibility,and milk quality in lactating dairy cows

YAO Tiansen; CHEN Yizhuo; XU Huixiang; ZHAO Boyuan; ZHANG Yanli

doi:10.13557/j.cnki.issn1002-2813.2025.10.001

Abstract：This experiment aimed to investigate the effects of different inclusion levels of flaxseed hull meal on the rumen fermentation,plasma parameters,nutrient apparent digestibility,milk performance,and milk quality in lactating dairy cows.Forty healthy Holstein cows with similar parity,lactation days,and milk yield were randomly divided into four groups,with 10 replicates per group,one cow per replicate.The cows were fed isoenergetic and isonitrogenous diets containing 0(control group),5%,10%,and 15%flaxseed hull meal,respectively.The pre-test period was 7 days and the formal test period was 56 days.The results showed that flaxseed hull meal had no significant effect on rumen fluid pH,ammonia nitrogen,or total volatile fatty acid concentrations(P>0.05).Compared with the control group,acetate content significantly decreased in all flaxseed hull meal groups(P<0.05),propionate content significantly increased in 15%group(P<0.05),and the acetate-to-propionate ratio significantly decreased in 10%and 15%groups(P<0.05).Plasma total antioxidant capacity(T-AOC)significantly increased in all flaxseed hull meal groups(P<0.05),plasma superoxide dismutase(SOD)activity significantly increased in 10%and 15%groups(P<0.05).Dry matter(DM)apparent digestibility significantly improved in the 10%and 15%groups(P<0.05),and crude fat(EE)apparent digestibility significantly increased in all flaxseed hull meal groups(P<0.05).Compared with the control group,the average daily dry matter intake and average daily milk yield significantly increased in the 5%and 10%groups(P<0.05),and milk enterolactone content significantly increased in all flaxseed hull meal groups(P<0.05).The study indicates that dietary supplementation with flaxseed hull meal enhances milk performance and improves milk quality of dairy cows,and the appropriate addition level is 10%of flaxseed hull meal.