Effect Of Fermented Tea Pomace On The Performance And Nutrient Digestion Of Dairy Cows

In recent years,as grain and forage prices have risen significantly,the cost of farming has continued to increase.As a result,the need to use unconventional feed resources in the dairy farming process has further increased.Solid state fermented tea pomace not only improves the palatability of the feed,but also reduces the anti-nutritional factors in the pomace by sealing it for fermentation and improves the nutritional level of the pomace.This trial focused on the effect of fermented tea pomace on the productive performance and nutrient digestion of dairy cows,and thus to determine the optimum replacement ratio of fermented tea pomace in the concentrate supplement of dairy cattle diets.Prior to the start of the animal trials,the dried tea pomace was fermented in a solid state by mixing lactic acid bacteria and Bacillus licheniformis and then evenly spraying the dried tea pomace,which contained 40% water and was mixed with 10% wheat bran,into vacuum sealed bags for fermentation.Trial 1: Study of the effect of fermented tea pomace on the feeding of lactating cows.Forty healthy Holstein cows of similar litter size,lactation days,milk yield and body condition were selected and randomly divided into four groups of 10 cows each,with one replicate each.The fermented tea pomace was used to replace different proportions of concentrate in the diets of lactating cows.The groups were set up as: control,5%,10% and20% groups for a total of 9 weeks,with a pre-test period of 1 week and a formal period of8 weeks.The effect of fermented tea pomace on the performance,rumen fermentation and apparent nutrient digestibility of lactating cows was investigated.The results of the trial showed that:(1)Compared to the control group,the milk protein rate was significantly higher(P<0.05)in the groups with 5% concentrate,10% concentrate and 20% concentrate replaced by fermented tea pomace in the diet.There was no significant effect(P>0.05)on dry matter intake,milk yield,milk fat percentage,lactose percentage,total milk solids,somatic cell count and urea nitrogen in dairy cows.(2)The apparent digestibility of crude fat(EE)was significantly(P<0.05)lower in the groups with 10% concentrate and 20% concentrate replaced with fermented tea pomace in the diets compared to the control group.The apparent digestibility of other nutrients such as dry matter(DM),crude protein(CP),organic matter(OM),neutral detergent fibre(NDF)and acid detergent fibre(ADF)were not significantly affected(P>0.05).(3)There were no significant differences(P>0.05)in p H,acetic and butyric acid concentrations,acetic acid/propionic acid,total volatile fatty acids,ammoniacal nitrogen and microbial protein in the rumen fluid of the groups with 5% concentrate,10%concentrate and 20% concentrate replaced with fermented tea pomace in the diet compared to the control group.However,the rumen fluid propionic acid concentration was significantly higher in the 10% substitution group and 20% substitution group compared to the control group(P<0.05).(4)The 20% replacement of fermented tea pomace with concentrate supplement for lactating cows reduced feed costs and milk production costs per kg compared to the control group,with optimal economic benefits.Trial 2: Study on the effect of fermented tea pomace on the feeding of breeding dairy cows.Fermented tea pomace was used to replace different proportions of concentrate in the diets of mature dairy cows.Forty Holstein breeding cows of comparable weight,similar body condition and health were randomly divided into four groups of 10 cows each,with one replicate for each head,and set up as control,10%,20% and 30% groups respectively.The trial period was 9 weeks,including 1 week for the pre-test and 8 weeks for the main trial.The effect of fermented tea pomace on the performance,rumen fermentation and apparent digestibility of nutrients of breeding Holstein cows was observed,and finally the optimum replacement amount of fermented tea pomace in the feeding of breeding cows was screened.The trial results showed that:(1)As the proportion of concentrate in the diet replaced by fermented tea pomace increased,the differences in daily weight gain,dry matter intake and feed-to-weight ratio were not significant(P>0.05)in all experimental groups compared to the control group.(2)As the proportion of fermented tea pomace replaced concentrate in the diets of breeding cows increased,the apparent digestibility of dry matter(DM),crude protein(CP),crude fat(EE),organic matter(OM),neutral detergent fibre(NDF)and acid detergent fibre(ADF)were not significantly(P>0.05)affected in each test group compared to the control group.(3)There were no significant differences(P>0.05)in p H,total volatile fatty acids,acetic acid,butyric acid,acetic acid/propionic acid,ammoniacal nitrogen and microbial protein in the rumen fluid of the groups with 5% concentrate,10% concentrate and 20% concentrate replaced with fermented tea pomace in the diets of breeding cows compared to the control.However,the concentration of propionic acid in rumen fluid was significantly higher in each test group compared to the control group(P<0.05).(4)Fermented tea pomace replaced 30% of the concentrate supplement for breeding dairy cows in the group,which reduced feed cost and cost per kg of weight gain compared to the control group,with optimal economic benefits.In summary,this study used a mixture of Bacillus licheniformis and Lactobacillus solid-state fermented tea pomace feed to replace part of the concentrate in the dairy cows’ diets did not affect the growth performance and nutrient digestion of lactating and breeding cows,and could reduce feed costs in breeding.It is recommended that the appropriate proportion of fermented tea pomace to replace concentrate supplement for lactating dairy cows is 20% and 30% for finishing cows.