Effect Of "L&F" Peptide On The Performance Of Dairy Cows In The Middle And Late Lactation Period

"L&F "Peptide is a new feed additive mainly composed of small peptides and other small molecular substances.This experiment was conducted to investigate the effects of adding " L&F" Peptide on the milk production,lactation performance,blood biochemical parameters and body health of lactating cows in the middle and late stages of lactation period.A total 30 healthy Holstein cows?the middle and late stage of lactation?were selected on the basis of similar body weight,age,body condition,parity,milk yield and post-matching days.Then these 30 cow were randomly divided into two groups,1st served as a control group and 2nd served as an experimental group,having 15 cow in each group.Among them,the control group was fed a regular TMR diet and the experimental group was supplemented with 100 g/d/animal·"L&F" peptide,The diet was evenly mixed and then fed to the animals.The first 7 days were adaptation period?pre-test period,?and the trial period starts from day 8 and end at day 63?56 days?.The results of this experiment revealed that:1.The average daily milk yield of the experimental group was 28.39 kg·head^-1 during the period of feeding"L&F"Peptide,which was 0.72 kg/head^-1/d higher than that of the control group?P<0.05?.2.Feeding "L&F " Peptide can effectively reduce the number of somatic cells in milk?P<0.05?.The average number of somatic cells in the experimental group decreased from 248,900 to 231,400,a decrease of 17,500/mL and 7.03%compared with that before use.During the whole experiment,the lacto-protein rate and lactose rate of milk components increased by 1.74%and 0.62%respectively compared with the control group?P<0.05?.3.Dietary supplementation of "L&F" Peptide can improve plasma protein of dairy cows in the middle and late lactation stages.The contents of total serum protein and albumin in the experimental group were 3.31%and 4.91%higher than those in the control group?P>0.05?.4.The activities of glutamic-alanine aminotransferase,glutamic-oxaloacetic aminotransferase and alkaline phosphatase in the experimental group were higher than those in the control group,but the difference was not significant.?P>0.05?;However the total cholesterol and glucose contents were lower than those of the control group,all within the normal range.The levels of triglyceride decreased significantly;meanwhile,the contents of calcium and phosphorus increased.5.Dietary supplementation of" L&F " Peptide can effectively reduce the occurrence of diseases in mid-late lactation cows,improve the health of dairy cows and increase economic benefits.