| Ketosis is one of the most common metabolic diseases in intensive cattle farms.The perinatal period is the critical period for the high incidence of ketosis in dairy cows.The improper health care measures during this period is an important reason for the high incidence of ketosis in postpartum dairy cows,and it will bring adverse effects on the performance,health and economic benefits of dairy cows.Although propylene glycol has been widely used in intensive cattle farms at home and abroad as a health care agent for dairy cows with perinatal ketosis,the application form,dosage,timing and duration of propylene glycol vary greatly,the control effect is different,and there is a lack of norms and standards.Therefore,this study through the two trials of “Investigation on the health effects of perinatal ketosis in lactating dairy cows in intensive dairy farms” and “Evaluation on effect of new measures of propylene glycol for control of ketosis in dairy cows” to evaluate the health effects of ketosis in intensive dairy farms and the new measures of propylene glycol prevention and control in order to lay the foundation for providing effective new health care technology for ketosis in intensive dairy farms in the future.Test 1.Investigation on the health effects of perinatal ketosis in lactating dairy cows in intensive dairy farms.In this experiment,120 dairy cows were randomly selected from four intensive cattle farms in Heilongjiang Province,and 20 dairy cows were randomly selected at 10 days before calving,on the day of calving,10 days,20 days,50-60 days and 80-100 days after calving,respectively.Blood samples were collected for biochemical analysis.At the same time,the information of ketosis health plan,body condition,production performance(lactation and reproduction),diseases and feed of experimental dairy cows were collected.One-way ANOVA and chi-square test were used to conduct inter-group analysis of different health plans.The results showed that:(1)Farm C and D had high postpartum body condition score,while Farm D had great postpartum body condition loss at 10-20 days,and high postpartum body condition score or loss had adverse effects on postpartum lactation,reproduction and disease of cows.(2)Farm A had the lowest incidence of disease,and Farm D had the highest incidence,especially ketosis.At the same time,the blood BHBA level was also the highest and the blood glucose was normal in Farm D,indicating that the highest level of propylene glycol supplementation relieved the blood glucose,but failed to reduce the incidence of ketosis.(3)Cows in Farm A had the best milk production and reproduction performance,followed by Farm B and C,and Farm D was the worst.Farm D was the worst,which was related to high postpartum body condition score or loss,and poor adaptive regulation of body energy metabolism.These results showed that the health effects of the four farms were not consistent,with Farm D having the worst effect,followed by program C and B,and program A having the best effect.Therefore,the dairy ketosis health care program needs to be improved in Farm D.Test 2.Evaluation on effect of new measures of propanediol for control of ketosis in dairy cows.In this experiment,dairy Farm D was selected for the experiment.On the day of parturation,90 experimental cows were randomly selected and divided into 3 groups,which were blank control group(Group C),original plan experimental group(Group O)and new plan experimental group(Group N),with 30 cows in each group.Among them,Group C was not given propylene glycol on the day of parturation,Group O was given 500 m L propylene glycol once on 1 day and 2 day postpartum,and 500 m L propanediol once on 7 day,8 day and 9 day postpartum.Group N was given 500 m L propylene glycol once on postpartum 7 day and 14 day,respectively.At the same time,the body condition scores were performed on prenatal 14 day,parturation day,postpartum 7 day,14 day,21 day,28 day,and 50 day,and blood samples were collected for biochemical analysis.The postpartum production performance(lactation and reproduction),diseases and feed information of the experimental cows were collected,and the inter-group analysis was conducted by one-way ANOVA and chi-square test,etc.The results showed that:(1)In body condition,milk yield and disease,the body condition of cows in the new health care scheme(Group N)was in the most reasonable range,and the milk yield was higher,which significantly reduced the risk of disease in dairy cows by 2.5 times,while the body condition of cows in Group O was higher and the incidence of ketosis was higher.(2)In energy metabolism and liver function,both Group C and Group O had serious negative energy balance(the increase of BHBA,NEFA and leptin,and the decrease of INS and GLU)and abnormal liver function(AST increased and ALB decreased)after postpartum.(3)In oxidative stress,the antioxidant capacity(T-AOC)of cows in Groups C and O was significantly decreased,and the oxidative stress(MDA)was increased.(4)In terms of economic benefit,the net profit of each cow in Group N and Group O increased by 98.76 yuan and 23.07 yuan respectively compared with that in Group C within 50 days postpartum.The new ketosis health care scheme in Group N was better.These results indicated that the new health care measures of Group N could more effectively reduce the occurrence of diseases(especially ketosis),improved energy metabolism and oxidative stress,and then improve milk yield,reproductived performance and economic benefits,but the body condition would affect the health care effects of propylene glycol.In summary,the four intensive dairy farms in Heilongjiang Province were not completely consistent in the ketosis health measures,and the effects were different.The good and bad order of comprehensive evaluation of health care effect was Farm A,Farm C and B,and Farm D.The new prevention and control measures of propylene glycol(Group N)for ketosis in dairy cows have better effects,save costs,reduce the incidence of the disease,improve the milk yield,reproductive performance and economic benefits,and are worthy of further promotion and application. |
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