| Cow's comfort is a new concept proposed recent years,it covers all aspects of the living environment of dairy cows,and it includes feeding,drinking,resting,walking,milking and other links.The health,reproductive performance,milk yield,milk quality,longevity of the cows and income for the farm were improved when cow's comfort was enhanced.The comfort of feeding,drinking,walking,milking were supported by hardware of dairy farm.the comfort has been greatly improved because of new ideas and new technology were applied.Dairy cows used maximum of daily time for rest,so the rest of the environment is good or bad impact on the overall comfort of the cows.The resting environment includes the air and the bed.In our country,the improvement of the resting environment mainly focuses on the size of the bed and the hygiene of the air,but not for the bedding,the air temperature and humidity(especially the high temperature and humidity environment).The traditional facilities for regulating air temperature and humidity include fans,spray,mister,wet curtains and chillers,the advantages and disadvantages of which have been familiar to us.High pressure spray and large chillers are new technology,the advantages and disadvantages of them are not clear.Due to the increase of bedding cost and the increase of environmental protection pressure,the requirements for manure treatment are getting higher and higher.Conventional bedding types include straw,sand,sawdust,rubber mats and so on.The deep litter system has been used at home and abroad for many years,but mainly for pig,poultry and beef cattle breeding industry,some scholars have suggested to use it in the dairy farm,but it is not yet possible.In foreign countries,Recycled Manure Solid(RMS)was used widely,but less in our country,so the data of use effect was lack.The contains a large number of micro-organisms,some of them are harmful to the health of udder,there is no dry and disinfectant disinfection powder for bedding.A dry,disinfection,deodorant and other multi-functional disinfection powder was developed by our laboratory,but we have no data about the application effect.The purpose of this test is to enhance the cow's comfort,the status of lactating cows' comfort were surveyed first,then the application of high pressure spray,large chillers,deep litter system,RMS and multi-functional disinfection powder were researched,to establish basic research data for promote the technologies.Experiment 1.Investigation on the Comfort of Lactating Cows in Shanghai.Two free-stall farm(Farm A and Farm B)and two tie-stall farm(Farm A and Farm B)in shanghai were chose for this research.Hardware were assessed by light,drinking,feeding,ventilation,milking,bed and other aspects.The comprehensive comfort was evaluation by light intensity,harmful gas content,teat condition,hock injury,stall usage after milking,cattle cleanliness and culling.The results showed that:In the study,only farm B meet the standard with all day light intensity in four farms,the differences between each farm were significant(P<0.01);the comfort of drinking and feeding was relatively inadequate in tie stall farm,but free stall farm were good;the ventilation in winter was lack in tie stall farm and the ammonia level was higher in winter,free stall farm were better than tie stall farm significantly(P<0.01),and ammonia content of four farms did not exceed the national standard in the study;teat condition and hock injury were exist in all tie-stall farm and free-stall farm;the hygiene of the cows in free-stall farm was better than tie-stall farm;Limb,lactation,and reproductive disorders are still the three major diseases that cause cattle culling;postpartum 90 days was concentration culling phase,especially within 30 days after calving delivery;heat stress and calving peak was also concentration culling period;the first to third parity are also the concentrated culling stage,the second parity with the highest proportion.Experiment 2.Research on Application of New Technology of Heat Stress Control.Four dairy farms with different summer cooling mode were selected in Shanghai.Experimental group A with the mode of "high pressure mister + fans",Experimental group B with the mode of "large chillers ",Experimental group C with the mode of "spray + fans",Experimental group D with the mode of "wet curtains +fans”.Temperature,humidity and wind speed and other heat stress-related indicators were detected in and outside the barn all day,THI and ETI in and outside the barn were compared,production data also be collected.The objective was to assess the advantages of high pressure spray technology and large chillers technology compared with the traditional summer cooling mode.The results showed that:"wet curtains +fans" and "large chillers" were the best mode for cooling,then "high pressure mister +fans";"high pressure mister + fans" and "spray + fans" were the best mode for wet control;"wet curtains + fans" was the best mode for THI control,then "high pressure mister + fans" and "large chillers";"large chillers" was the best mode for ETI control,then "spray + fans";"large chillers" was the best data with milk yield,incidence of the disease and so on.Experiment 3.Study on the Application of deep litter system in Lactating cows.Deep litter system was mixed by the special bacteria and sawdust.The temperature and moisture were continuous detected to understand the state of the bed,harmful gas content,milk production,disease record,the number of SCC and the cleanliness of cattle were detected to know the effect of deep litter system,staff working time,fecal clean record and cost record were collected to evaluate the feasibility of the application of the deep litter system.The results showed that:During the test period,the water content of the deep litter system gradually increased from about 55%of the start to about 70%at the end,the temperature gradually increased to 45? at the begin,then decreased gradually,and remained stable at about 35? after 40 days.Compared with control barn,the ammonia content of deep litter system barn was slightly lower during the experiment,Cattle cleanliness significantly improved,foot disease was improved,udder health turn better first then worse,but the average daily milk production of dairy no significant impact.Staff working efficiency was similar in different barn,25%of the manure(milking area)can not be processed through the deep litter system.In this experiment,the use of the initial cost of deep litter system was 3727 RMB per cow,follow-up operating costs of 2681.45 RMB per cow per year except for the cost of alteration of the barn and labor costs.Experiment 4.Study on the Application of Recycled Manure Solid in Lactating cows.Recycled Manure Solid(RMS)was produced by Bedding Recovery Unit(BRU)system.The safety of RMS was evaluated by measuring the fermentation time,the temperature of the fermentation process,the RMS moisture,the bacterial number and the bacterial type.The clinical application test was carried out in comparison with the sawdust,and the effect of the application was evaluated by detect the harmful gas content,the laying rate of cattle,the cleanliness of cattle,and the incidence of herd diseases.The results of the safety assessment showed that:The total time of the fermentation of the RMS was 16 h,and the temperature increased from 68.5 ? to the fermentation tank,the fermentation temperature was above 60 ? for 12 h.Fresh RMS moisture was 57.5%-60%,the bacterial type in fresh RMS was Thermophilic Bacillus,the average content was 600,000 cfu/g.The results of the application evaluation showed that:There was no significant difference in the level of harmful gas,the cleanliness,and the incidence of disease,but the lying rate of cattle in the RMS group was higher than that in the sawdust group significantly(P<0.05).The moisture of RMS group was higher than the sawdust,the speed of bacteria multiplication was faster than sawdust significantly(P<0.01).Experiment 5.Study on the Effect of New Type of Bedding Disinfectant on Dairy Cattle Yield and Udder Health.Three districts of A barn in free-stalled farm in Shanghai were selected as three experimental groups,which were divided to three groups:test group I(lime powder group),test group II(disinfection powder group)and the control group(untreated group),the base litter are sawdust.The effects of new disinfectant powder on dairy cows' production and udder health were evaluated by detecting changes of moisture,bacterial count,total milk yield,mastitis and SCC of each test group.The results showed that:During the test period,the moisture between the test group and the control group was significantly(P<0.01),the test group I and the test group II was about 30%,while the control group was about 35%,this indicated that both of the new disinfection powder and lime powder have drying function,and the performance was similar;the number of bacteria in each group was significant different(P<0.01),the test group II was the lowest,followed by the test group I,this indicated that both of the new disinfection powder and lime powder have bacteriostatic function,and the new disinfection powder antibacterial performance is better than lime powder;the milk yield of the tested group II was stable,while test group I and the control group decreased slightly;the incidence of mastitis in group II was stable,while group I and control was slightly increased;the average milk SCC of the test group II was stable,the test group I increased slightly,while the control group increased substantially,the difference between the test group II and the control group was significantly 30 days after begin(P<0.05),this indicated that the new disinfectant powder has a positive effect to maintain udder health. |
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