| A variety of hormones(growth hormone,thyroid hormone,estrogen secretion and so on)had changed dramatically when the cows went into the perinatal period.The cows’appetite decreased,dry matter intake significantly reduced and recovery was very slowly.But because of the need of lactation,nutrients demand along with the increase of milk yield increased significantly,the cow appeared negative balance of nutrients(consumption was greater than intake),until the cow appetite completely restored(consumption is greater than or equal to the intake).In order to meet the nutritional requirement of lactation,cows need to use the body store.Therefore,in the early period,the body condition of cows was decreased obviously.While the body store was constantly consuming,it also produced some side effects of metabolites,like ketone bodies,so cows were prone to some metabolic related diseases,hypocalcemia and ketosis were the most common diseases.In addition,they increased the incidence rate of retained Placenta,displacement on the abomasums,endometritis and mastitis.In recent years,scholars at home and abroad attach great importance to the management of perinatal metabolic diseases,from prenatal nutrition regulation to postpartum health care,carried out a series of studies,and formed a lot of valuable theoretical and practical experience.In the study of prevention and control of hypocalcemia and subclinical ketosis in dairy cows,calcium supplements and energy substances have been reported most frequently,there were two main ways to supplement nutrients:intravenous injection and oral.Intravenous injection of calcium gluconate and glucose could increase blood calcium and glucose levels quickly,the cost is very low,but the effective time was too short,and frequent infusion was needed to maintain its,the operation also was very tedious,the effect in production is not satisfactory.Another way is oral nutrition mixture,nutrient mixture mainly including calcium and glucose precursors(calcium propionate,propylene glycol or glycerol),this nutrient mixture was generally concentrated liquid,need to be diluted by warm water,and drinking by themselves or was directly poured into the rumen by equipment.Many studies had shown that it was effective in the prevention of postpartum displacement on the abomasums and the reduction of Postpartum Metabolic diseases,but others were not.Because the same as infusion,its nutrients also play a quick role,rapid decline,it was difficult to maintain for a long time.Therefore,if the postpartum nutrient fluid can laintain the calcium level and alleviate the negative energy balance for a long time,it is of great significance for improving the incidence of Postpartum Metabolic diseases.So me studied traditional composition,combined the latest industry research results,made a viewpoint of slow release of calcium,combined with the use of raw sugar and fat metabolism regulators(Calcium chloride,niacin),in order to maintain the stability of calcium and stabilize the fat metabolism,and formed a new postpartum drenching supplement.In this study,the incidence of hypocalcemia and subclinical ketosis in daily cows in shanghai was investigated,the effect of the new postpartum drenching supplement on the prevention of postpartum serum calcium,BHBA,NEFA,liver function and production performance was researched,the objective was to verify the clinical effect of the new postpartum is ideal.Experiment 1.Incidence of hypocalcemia and subclinical ketosis in dairy co.vs in Shanghai area The incidence of hypocalcemia and subclinical ketosis in dairy cows from 9 farms in Shanghai was investigated.The results showed that the prevalence of hypocalcemia in cows within 12 h postpartum was very high,the average concentration was 86.1%,the average concentration of serum calcium was 1.82±0.02 mmol/L,and the average incidence of hypocalcemia was 35.2%3-7 d postpartum.The average concentration of serum calcium was 2.05±0.01 mmol/L,low blood magnesium average incidence was 8.6%within 12 h postpartum,the average serum magnesium concentration was 0.98±0.02 mmol/L,and low blood magnesium average incidence was 19.8%of 3-7d postpartum,the average serum magnesium concentration was 0.92±0.01 mmol/L.The subclinical ketosis average incidence was 5.5%12 h postpartum,and the average concentration of BHBA was 0.68±0.04 mmol/L,the average incidence was 16.3%3-7 d postpartum,and the average concentration of blood BHBA was 0.98±0.07 mmol/L.The average incidence of high NEFA was 49.4%12 h postpartum,and the average concentration of blood NEFA was 0.76±0.03 Meq/L,the average incidence was 41.3%3-7 d postpartum,and the average concentration of blood NEFA was 0.71±0.03 Meq/L.Correlation analysis showed that:There was a significant positive correlation between the concentration of calcium in blood and the concentration of phosphorus(P<0.001),which was positively related to the concentration of magnesium,but not significant(P=0.081),and negatively correlated with the concentration of NEFA(P<0.001);A significant positive correlation with the concentration of phosphate in the blood magnesium(P=0.003);the concentration of NEFA in blood and phosphorus has the tendency of negative correlation,but not significant(P=0.077),was positively correlated with the concentration of BHBA,but not significant(P＝0.062);was positively correlated with BHBA concentration the blood of the NEFA(P<0.001).Experiment 2.Study on the effect of different nutrient fluid on the prevention of hypocalcemia in dairy cows 30 cows with more than 2 parity and 15 cows with firstborn in one dairy farm in shanghai were chose,whose appeared health and body condition score were 3.0-3.5 points,which were randomly divided into three groups(new nutrient fluid group,normal nutrient fluid group and blank control group),tested to prevent hypocalcemia.The results showed that:For multiparous cows,the blood calcium level increased significantly when fed the two different nutrient fluid,but the blood calcium level of cows in the normal nutrient fluid group declined immediately after peak,then similar to the control group,and the new nutrient fluid group can maintain about 10 h,it showed that the new nutrient fluid had better effect on maintaining blood calcium level.Blood magnesium content had no significant effect in different groups.The average content of early multiparous cows postpartum blood calcium and magnesium was lower than that of firstborn cows.Milk production was improved numerically caompared with control and normal nutrient fluid.Milk fat and milk protein were not effected.Experiment 3.Study on the effect of different nutrient fluid on the prevention of subclinical ketosis in dairy cows 30 cows with more than 2 parity and 15 cows with firstborn in one dairy farm in shanghai were chose,whose appeared health and body condition score were 3.0-3.5 points,which were randomly divided into three groups(new nutrient fluid group,normal nutrient fluid group and blank control group),tested to prevent subclinical ketosis.The results showed that:The serum of the average BHBA and NEFA levels of the cows in two nutrient fluid groups were significantly lower than the blank control group within 12 h postpartum,serum average BHBA and NEFA level of new nutrient fluid group cows was slightly lower than that of normal nutrient fluid group cows but the difference was not obvious;Multiparous postpartum cows average serum BHBA,NEFA were higher than in first-calving cows.Milk production was improved numerically caompared with control and normal nutrient fluid.Milk fat and milk protein were not effected.Experiment 4.Research on new type of nutrient fluid on postpartum morbidity and performance of dairy cows 100 diry cows with similar parity,body condition,last parity yield were chosed in one farm which were randomly divided into two groups(new nutrient fluid group and normal nutrient fluid group),Serum calcium levels,blood BHBA concentration,incidence rate of hypocalcemia and subclinical ketosis,cull rate and production performance were evaluated in two groups.The results showed that:The blood calcium of dairy cows at 24 h postpartum could be significantly improved by the new nutrient fluid(P<0.05),and there was no significant effect at 48 h and 72 h,but the average calcium level of the cows in new nutrient fluid group was higher than the normal nutrient fluid group all of the time;The blood BHBA level of the cows 3 d postpartum was significantly reduced in new nutrient fluid group(P<0.05),7 d postpartum similarly(P=0.08),but 14 d postpartum had no significant effect;The incidence rate of hypocalcemia and subclinical ketosis of the cows were decreased greater in new nutrient fluid group,and abomasal displacement rate also be reduced;The average milk yield within 70 d postpartum could be improved by the new nutrient fluid(P=0.15),but no obvious effect of milk fat and milk protein content in milk.Experiment 5.Evaluation of clinical application of new type of nutrient fluid in different dairy farms 5 dairy farms in Shanghai,Shandong,Anhui,Henan province were selected to conduct this research,and 2234 cows were involeved total.The cows were divided controls and treatments and drenched with traditional nutrient fluid or new type nutrient fliud separately.The result showed that:the new trype of nutrient fliud can reduce postpartum disease and cull rate(postpartum 60 days),milk production(postpartum 100 days)was also be improved.It indicated that the new type nutrient fliud had a positive effect on improve the health status of dairy cows and improve production performance,it can be used in dairy farms. |
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