| Diarrhea,a common digestive disease,is most severe in early growth and development of calves.Diarrhea calves excrete thin feces,watery feces or bloody feces,resulting in reduced feed intake and average daily weight gain,prolonged mating time and reduced lactation performance of young cows in late stage.Severe diarrhea can lead to the death of calves,which greatly affects the economic benefits of the farm.The modern method of relieving calf diarrhea in farms is antibiotic therapy,which is responsible for bacterial resistance and destruction of the beneficial gut flora,but is still used by most farms.In addition,health supplements(probiotic products)are added to improve the beneficial flora of the calf gastrointestinal tract to relieve calf diarrhea.In this study,an epidemiological survey was conducted on cattle in a large farm to determine the effects of calf diarrhea on the performance of calves and the various factors affecting calf diarrhea.Based on the results of the epidemiological survey,this study investigated the effect of two colostrum infusions on calf diarrhea and the effect of feeding colostrum extract on calf diarrhea relief,aiming to provide some reference for reducing calf diarrhea rate and improving calf performance.In the current study,data recorded in the farm system were collected and on-site investigation of calf diarrhea was investigated from a large farm in Hebei Province.Various data were collected,such as calf identification,maternal identification,maternal age,calf birth date,calving process,onset date,colostrum instillation data,total serum protein values,weaning weight,weaning body height and onset date of other diseases,and information describing various risk factors of interest.The following results were obtained from data analysis and conclusions drawn from a combination of secondary colostrum instillation and feeding of colostrum extract trials:(1)The effect of diarrhea on the performance of calves.Significant effects of diarrhea were observed on mean daily weight gain of calves at weaning and weaning body height(P < 0.05)and no significant difference on first mating and days in lactation(P > 0.05).There was no significant effect on the total milk yield in the first lactation cycle(P > 0.05),but a highly significant effect of calf diarrhea was observed on late daily milk production(P < 0.01).(2)Factors influencing calf diarrhea.The effect of colostrum quality on calf diarrhea within 7 days of age was highly significant(P < 0.01);serum protein values of calves with diarrhea were mainly concentrated between 6.0 and 6.8g/d L.Calving method could also affect calf diarrhea,with assisted births having a 7% higher diarrhea rate than normal births.In addition,fecundity was also associated with calf diarrhea,as shown by diarrhea rate: first birth > second birth > multiple births.Maternal body condition could affect calf newborn weight.The calf diarrhea rate was low in calves with a higher birth weight and increased in calves with a birth weight greater than 45 kg.Temperature also affected calf diarrhea,with the lowest calf diarrhea rate in winter and the highest in summer,and calf serum protein values were significantly affected by heat and cold stress(P < 0.05).Moreover,both changing milk replacer and weaning contributes to a transient increase in diarrhea rate.(3)Effect of secondary colostrum infusion and colostrum extract feeding on calf diarrhea.Second dosing of colostrum reduced the rate of diarrhea in calves within 7 days and significantly increased serum protein levels(P < 0.01).Also,feeding colostrum extract evidently decreased the incidence of diarrhea in calves.There was a significant effect on weaning weight and mean daily gain(P < 0.05),and a highly significant difference in fecal scores between the two groups(P < 0.01).In summary,diarrhea causes a decrease in calf performance and affects calf weight and late lactation performance.Factors such as colostrum quality,serum protein value,temperature,newborn weight,maternal condition,milk replacer and weaning stress all affected the rate of calf diarrhea.Secondary administration of colostrum and feeding colostrum extract can significantly decrease the calf diarrhea rate,and feeding colostrum extract can increase calf weaning weight and daily weight gain and decrease fecal score to improve calf performance.Thus,modern farms can reduce the rate of calf diarrhea by giving high quality colostrum,increasing the frequency of colostrum feeding,maintaining good ambient temperature,managing the body condition of and the initial calf weight,reducing the number of assisted births,relieving the stress caused by milk replacer and weaning,and feeding colostrum extract. |
