پديد آورنده :
محرمي، يدالله
عنوان :
اثر نمره ي وضعيت بدني بر عملكرد توليدي، فراسنجه هاي توليد مثلي و ناهنجاري هاي متابوليك در گاوهاي شيري هلشتاين
مقطع تحصيلي :
كارشناسي ارشد
گرايش تحصيلي :
﴿ علوم دامي ﴾
محل تحصيل :
اصفهان: دانشگاه صنعتي اصفهان، دانشكده كشاورزي
صفحه شمار :
ده، 112، [II] ص.: جدول
يادداشت :
ص. ع. به فارسي و انگليسي
استاد راهنما :
غلامرضا قرباني، حميدرضا رحماني
استاد مشاور :
مسعود عليخاني، مهدي محمد عليپور
توصيفگر ها :
غلظت لپتين , رگرسيون خطي چندگانه
استاد داور :
محمد علي ادريس، عبدالمجيدرضايي
تاريخ ورود اطلاعات :
1396/02/31
چكيده فارسي :
به فارسي و انگليسي: قابل رويت در نسخه ديجيتال
چكيده انگليسي :
Abstract This study investigated the relationship between body condition score BCS and milkyield reproductive parameters and metabolic disorders in high yielding dairy cows Three hundred and twelve multiparous Holstein dairy cows in two commercial dairyfarms were scored for body condition beginning at one month before dry off Cowswere scored monthly before calving and bi weekly after calving until 120 DIM Bodycondition score were assigned by two independent individuals using the visualtechnique Glucose insulin leptin triglyceride NEFA and BHBA were determined inplasma one week before and one week after parturition Milk yield and milk fat percentwere recorded for all cows Reproductive parameters including conception at firstservice calving to first insemination open days services per conception and conceptionrate were recorded Also metabolic disorders including dystocia retained placenta LDA laminitis and mastitis were recorded in first 120 DIM Treatments were arrangedin a 2 2 factorial design that factors included farm 1 and 2 and BCS BCS 3 5 andBCS 3 5 Also multiple linear regression and principal component analysis were usedto characterize relationships Principal component analysis was used to reduce thecollinearity among independent variables calculate new parameter estimates anddetermine the relationship of each variable with milk yield The results indicated thatthere was no difference between the two scorers From close up until second month cows in farm 2 had a higher BCS Differences in milk yield between cows calving withhigh and low BCS was not significant but milk fat percent fat yield and 4 fatcorrected milk yield was significantly higher in cows calving with BCS 3 5 Resultsfrom principal component analysis and multiple linear regression indicated thatincreasing BCS in dry off and occurrence of metabolic disorders were associated withdecreased milk yield Increasing BCS from dry off to calving and decreasing BCS infirst and second month of lactation were associated with higher milk yield Bloodparameters were similar in cows calving with high and low BCS High BCS at calvingwas significantly associated with decreased calving to first insemination p 0 02 Similary cows calving with higher BCS had lower open days p 0 05 Conception atfirst service services per conception and conception rate were not different betweencows calved with high and low BCS Interesingly BCS of 3 5 or higher at calving wereassociated with increased risk for laminitis p 0 05 Inversely cows that calved withhigh BCS had lower mastitis p 0 02 Incidence of dystocia retained placenta andLDA were not different between two groups These results suggest that multiparousdairy cows should possibly be dried off at a lower BCS 2 75 3 and cover their BCSduring the dry period In the cold seasons cows at parturition should have at least aBCS of 3 5 to produce higher milk and milk fat percent It seems under this condition reproductive parameters improved and mastitis might be reduced Based on the resultsof this study the hypothesis that BCS or changes in BCS during the dry period or earlylactation are relatively associated with milk yield is acceptable
استاد راهنما :
غلامرضا قرباني، حميدرضا رحماني
استاد مشاور :
مسعود عليخاني، مهدي محمد عليپور
استاد داور :
محمد علي ادريس، عبدالمجيدرضايي
